Physics in Canada La Physique au Canada

Transcription

Physics in Canada
La Physique au Canada
Congress Issue 1984
Numéro du Congrès 1984
Vol. 40 No. 3
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radionics scientific inc.
585 Canarctic Drive, Downsview, Ontario
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PRODUCT EXCELLENCE SINCE 1955 I
Physics in
Canada
La Physique
au Canada
The Bulletin of
The Canadian Association
of Physicists
Vol. 40 No. 3
Congress Issue 1984
Bulletin de
l'Association canadienne
des physiciens
Vol. 40 N° 3
Numéro du Congrès 1984
EDITORIAL B O A R D / C O M I T É D E RÉDACTION
TABLE OF
CONTENTS/SOMMAIRE
Editor/Réacteur en chef
J. Rolfe
Bank of Canada, 234 Wellington St., Ottawa, Ontario
(613) 563-8906
K1A 0G9
Associate Editor/Rédacteur Associé
M.L. Jento
Managing/Administration
Book Review Editor/Rédacteur à la critique des livres
J.P. Svenne
Dept. of Physics, University of Manitoba,
Winnipeg, Manitoba R3T 2N2
(204) 474-9856
Laurent G. Caron
Département de phvsique. Université de Sherbrooke,
Sherbrooke, Québec I1K 2RI
(819) 565-3583
R. Fraser Code
Physics Department, University of Toronto,
Erindale Coll R. 4039, Mississ'auga, Ontario L5L IC6
(416) 828-5353
G.A. Daigle
Officers of the Association
Corporate Members/Membres Corporatifs
1984 Congress, General Information
Congrès 19X4, Renseignements généraux
Maps/Plans
CAP Medallists 1984/Lauréats de l'ACP 1984
CAP Prize Lxam 1984/Examen de l'ACP 1984
Exhibitors/Exposants
Invited Speakers/Conférenciers invités
Instructions for Timed Papers
Program Sunimary/Résumé du programme
Congress Program/Programme du Congrès
Author index/Index des auteurs
2
2
3
3
8
9
9
9
10
11
12
14
74
Front Cover
Campus de l'Université de Sherbrooke
Vue de l'Agora
Illustration de Maurice Buist
Conseil national de recherches du Canada, Div. de physique,
Ottawa, Ont.
(613) 993-2840
Elmer H. Hara
Department of Communications,
Room 1648, Journal Tower North,
300 Slater Street, Ottawa K1A 0C8
(613) 593-6460
Notice to CAP Members
John A. Nilson
Lumonics Inc.
105 Schneider Rd. Kanata (Ottawa), Ont. K2K 1Y3
(613) 592-1460
Avis aux membres de l'ACP
Bring this free copy of the Congress Issue Veuillez apporter cet exemplaire gratuit du
lo the .tiiiiii.(I congress in Sherbrooke; otherprogramme au Congrès à Sherbrooke. Des
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Vancouver, B.C. V6T 1W5
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Published — Jan., March, May (Congress), July, Sept., Nov.
canadienne des physiciens 1984. AH rights reserved
Second Class Mail Registration Number: 5415
ISSN 0031-9147
Officers of the Association/Bureau de direction
Councillors/Conseillers
COUNCIL/CONSEIL1983-84
*President, B.P. Stoicheff, University of
Toronto
*Past President, A.R. C r a w f o r d , Anatek Electronics
British Columbia and Yukon
R.M. Clements, ( 1 ) University of Victoria
R. Frindt, (2) Simon Fraser University
Limited
•Vice-President, G . C . H a n n a , A . E . C . L .
•Vice-President Elect, A.I. Carswell, York
Alberta
C . D . Anger, ( 1 ) University of
University
•Honorary Secretary-Treasurer, B.C. G r e g o r y , Université du
Québec
Director — Members, D . W . L . S p r u n g , M c M a s t e r
Director — Affiliates, T.W. East, Raytheon
Saskatchewan and Manitoba
University
Canada
K.G. Standing, (1) University of Manitoba
M. A. Preston, (2) University of
Saskatchewan
Ontario — Southwest
M.M. Pintar, ( 1 ) University of Waterloo
D.S. Rosner, (2) University of Western Ontario
Limited
Director — Student Members, L. Z e r a f a , University of
Toronto
Director — Corporate Members, A.I. Carswell, York
Calgary
F.L. Weichman, (2) University of Alberta
University
Ontario — Central and North
M . H . H a w t o n , ( \)Lakehead
University
G . R . Hebert, (2) York University
Ontario — East
E.W. F e n t o n , ( 1) National Research Council of Canada
R.R. T u r k i n g t o n , (2)Royal Military College
Division Chairmen
Aeronomy & Space Physics, D. Venkatesan, University of Calgary
Atomic & Molecular Physics, J . W . M c C o n k e y , University of
Windsor
Canadian Geophysical Union, Z. H a j n a l , University
Saskatchewan
Québec — Nord et Ouest
M. Z u c k e r m a n n , ( I ) M c G i l l University
G . Beaudet, (2) Université de Montréal
of
Condensed Matter Physics, A.J. Berlinsky, University of British
Columbia
Québec — Sud et Est
L.G. C a r o n , ( 1 ) Université de
R. Roy, (2) Université Laval
Medical & Biological Physics, D . W . O . Rogers, National
Council
New Brunswick & Newfoundland
F. Weil, ( 1 ) Université de Moncton
Nuclear Physics, J . S . C . McKee, University of
Optical Physics, J - M . G a g n é , E c o l e
Research
S.P. Reddy, (2) Memorial
Manitoba
Particle Physics, G . Karl, University of Guelph
Physics Education, W. Brouwer, University of Alberta
Plasma Physics, H.A. Baldis, National Research
Industrial & Applied Physics, P. Kirby, Ontario
Council
Editor — Canadian Journal of Physics:
G . Rostoker, University of Alberta
Labs
Editor — Physics in Canada/La Physique au Canada :
J. Rolfe, Bank of Canada. Ottawa
Executive Secretary-Secrétaire Exécutif :
M.L. J e n t o
•Member of Executive Committee
( I ) Term ends June 1984; (2) Term ends June 1985
MEMBRES
Allan C r a w f o r d Associates Ltd.
A n a l y t e c h C o m p o n e n t s Inc.
Newfoundland
Toronto
Hydro
Surface Science, P.R. N o r t o n , Chalk River Nuclear
University of
Nova Scotia and Prince Edward Island
A. Weingartshofer, ( 1 ) St. Francis Xavier University
M.P. M a d a n , (2) University of Prince Edward Island
At Large,
J - L . L a c h a m b r e , Institut de recherche de
t'Hydro-Québec
Polytechnique
Theoretical Physics, P.J. O ' D o n n e l l , University of
Sherbrooke
CORPORATIFS
1984 C O R P O R A T E
Edwards High Vacuum
(Canada) Limited
MEMBERS
Ontario Hydro
Optech Incorporated
A n a t e k Electronics Inc.
Electrovert Ltd.
O p t o - E l e c t r o n i c s Inc.
A P T E C Engineering Limited
Gulf C a n a d a Limited
Polysar Limited
A t m o s p h e r i c E n v i r o n m e n t Service
Institut de recherche
R a d i o n i c s Scientific Inc.
d'Hydro-Québec
Spar Aerospace Limited
Bell-Northern Research Ltd.
C A E Electronics Ltd.
L i n e a r T e c h n o l o g y Inc.
S R P Control Systems Ltd.
C a n a d i a n G e n e r a l Electric
L u m o n i c s Inc.
S S T Scientific C o n s u l t a n t s Inc.
C o m p a n y Limited
M a d s o n Electronics
TRIUMF
C a n a d i a n Industrial
(Canada) Limited
Innovation Centre/Waterloo
X e r o x Research C e n t r e of C a n a d a
Mitel C o r p o r a t i o n
C T F Systems Inc.
Moli Energy Limited
Queen's University
Ealing Scientific Limited
M P B Technologies Inc.
University of W a t e r l o o
1984 Congress
General information
Congrès 1984
Renseignements généraux
T h e Université de S h e r b r o o k e is p r o u d t o be your host for the
39th a n n u a l C o n g r e s s of the C a n a d i a n Association of Physicists
f r o m J u n e 18 to 20, 1984.
L'Université de S h e r b r o o k e est heureuse d'être l'hôte du 39^ congrès
annuel de l'Association c a n a d i e n n e des physiciens du 18 au 20 juin
1984.
S h e r b r o o k e is in the heart of Estrie, within a rolling hill landscape
s o m e 145 km f r o m M o n t r e a l . T h e w e a t h e r in J u n e is variable.
Bring w a r m clothing especially for the o u t d o o r activities.
S h e r b r o o k e est sise au coeur d e l'Estrie, d a n s une région vallonnée
à q u e l q u e 145 km de M o n t r é a l . La t e m p é r a t u r e en juin est c h a n geante. Pensez d o n c aux vêtements c h a u d s , s u r t o u t p o u r les activités extérieures.
T h e region is f l o u r i s h i n g in c r a f t s w o r k of all kind, in fine r e s t a u rants and boutiques.
La région est riche en artisans, en restaurants de haute g a s t r o n o m i e
et en b o u t i q u e s .
A longer stay in Q u e b e c this year would be particularly interesting.
T h e tall ships that are g o i n g to t a k e part in the festivities c o m m e m o r a t i n g the 450th a n n i v e r s a r y of the Atlantic crossing by
J a c q u e s C a r t i e r will be open to visitors in Q u e b e c City h a r b o u r
f r o m J u n e 25 to 30th. D o not forget also that every m a j o r city in
Q u e b e c will hold o u t d o o r p o p u l a r festivities on the S t - J e a n
national holiday o n J u n e 24th. You should already have taken
care of y o u r hotel reservations.
V o u s p o u r r e z en p r o f i t e r p o u r rallonger votre séjour au Q u é b e c
afin de visiter les g r a n d s voiliers qui traverseront l ' A t l a n t i q u e en
1984 en l ' h o n n e u r du 450 e anniversaire de l'arrivée de J a c q u e s
Cartier. Ils seront d a n s le port d e Q u é b e c du 25 au 30 juin. Il y
a u r a également de g r a n d e s fêtes p o p u l a i r e s d a n s toutes les g r a n d e s
villes du Q u é b e c à la St-Jean le 24 juin. Il fallait réserver vos hôtels
longtemps d'avance.
Travel to S h e r b r o o k e
Transport à Sherbrooke
T h o s e w h o will be traveling by a u t o m o b i l e s h o u l d t a k e a u t o r o u t e
10 (a toll r o a d ) f r o m M o n t r e a l or a u t o r o u t e 55 f r o m D r u m m o n d ville. T h e S h e r b r o o k e exit is via highway 410 which brings you to
the d o o r s t e p of the c a m p u s on the b o u l e v a r d Université.
Ceux qui v i e n d r o n t en voiture p r e n d r o n t l ' a u t o r o u t e 10 à péage de
M o n t r é a l ou l ' a u t o r o u t e 55 de D r u m m o n d v i l l e . La sortie de
S h e r b r o o k e via la r o u t e 410 vous m è n e r a au b o u l e v a r d Université
à quelques minutes du campus.
T h o s e people c o m i n g by air will be landing at the D o r v a l a i r p o r t
in M o n t r e a l ( n o r t h - a m e r i c a n flights). We shall o r g a n i z e a special
bus service f r o m D o r v a l to the University on S u n d a y a f t e r n o o n
a n d evening, J u n e 17th. D e p a r t u r e s will be between 2:00 p . m . a n d
8:00 p.m. every t w o h o u r s (look for signs at the a i r p o r t ) . T h e fare
will be $20.00 per p e r s o n , o n e way. T h o s e w h o m a y arrive at
Mirabel a i r p o r t can take a bus to Dorval a i r p o r t . In o r d e r to ensure
a seat on the c h a r t e r buses, it is imperative that you fill in the lower
part of t h e a d v a n c e registration f o r m , indicating y o u r flight
n u m b e r a n d arrival time at D o r v a l a i r p o r t . W e shall also a r r a n g e
a return service to Dorval a i r p o r t on W e d n e s d a y evening ( a r o u n d
6:00 p.m.) a n d T h u r s d a y m o r n i n g ( a r o u n d 9:00 a.m.).
P o u r les gens v o y a g e a n t p a r a v i o n , vous devrez vous r e n d r e à
l ' a é r o p o r t de D o r v a l à M o n t r é a l (vols n o r d - a m é r i c a i n s ) . N o u s
vous o f f r i r o n s un service d ' a u t o c a r spécial D o r v a l - U n i v e r s i t é de
S h e r b r o o k e , l'après-midi et le soir du d i m a n c h e 17 juin. 11 y a u r a
des d é p a r t s de 14 h à 20 h à toutes les deux h e u r e s (surveillez les
affiches à l ' a é r o p o r t ) . Le forfait aller sera de $20.00 par p e r s o n n e
( p o u r ceux qui arriveraient à l ' a é r o p o r t de M i r a b e l , il y a un car
M i r a b e l - D o r v a l ) . Pour vous assurer une place, il est impératif de
n o u s r e t o u r n e r la partie du bas du f o r m u l a i r e de pré-inscription en
spécifiant l'heure de l'arrivée de votre vol à D o r v a l . N o u s prévoyons également un r e t o u r le mercredi soir (vers 18 h 00) et le jeudi
en d é b u t de matinée (vers 9 h 00).
W h o e v e r will not be using this special bus service will have no other
choice t h a n to take a limousine f r o m D o r v a l t o the d o w n t o w n
hotels ($5.00) plus the s u b w a y ($0.80) o r a taxi ($3.00) t o the
V o y a g e u r b u s terminal. T h e alternative is a taxi ($17.00). F r o m
the t e r m i n a l , t a k e the express b u s to S h e r b r o o k e ($14.00) a n d then
a taxi ($6.00) f r o m the S h e r b r o o k e terminal to the Université de
Sherbrooke.
P o u r ceux qui ne v o y a g e r o n t pas p a r ce service nolisé il faudra
vous résigner à p r e n d r e la limousine de D o r v a l vers le centre-ville
($5.00) puis le m é t r o ($0.80) ou le taxi ($3.00) vers le t e r m i n u s
d ' a u t o b u s V o y a g e u r . L ' a l t e r n a t i v e est un taxi ($17.00). Du term i n u s , vous devrez p r e n d r e l ' a u t o b u s - r a p i d e p o u r S h e r b r o o k e
($14.00) et d u t e r m i n u s à S h e r b r o o k e , un taxi ($6.00) p o u r
l'Université.
Registration
Inscription
T h e registration t o the C o n g r e s s a n d t o o n - c a m p u s a c c o m o d a t i o n s
will take place in the hall of the Faculty of E d u c a t i o n . On S a t u r d a y ,
the desk will be open f r o m 6:00 p.m. for the people a t t e n d i n g the
nuclear a n d particle physics w o r k s h o p . O n S u n d a y , the desk will
be o p e n f r o m 3:00 p . m . t o 10:30 p.m. O n week days, it will be
f r o m 8:30 a . m . to 4:00 p . m . Y o u r a d v a n c e p a y m e n t f o r registration
t o the Congress and the o n - c a m p u s residence will greatly accelerate
processing.
L'inscription au congrès ainsi q u ' a u x résidences d u c a m p u s se fera
d a n s le hall d ' e n t r é e de la F a c u l t é d ' é d u c a t i o n . Il y a u r a un accueil
le s a m e d i de 18 h (X) à 21 h 00 p o u r les gens de l'atelier sur la physiq u e nucléaire et des particules. Le d i m a n c h e , l'accueil se fera de
15 h 00 à 22 h 30. Sur semaine ce sera de 8 h 30 à 16 h 00. Votre
p a i e m e n t avec la pré-inscription au c o n g r è s et aux résidences
accélérera g r a n d e m e n t les choses.
Parking
Stationnement
T h e r e is a daily fee of $1.00 for an a u t o m o b i l e . T h e permit is
p u r c h a s e d at the c a m p u s e n t r a n c e b o o t h . T h o s e people staying on
c a m p u s will be able t o p u r c h a s e the p e r m i t s at the reception desk
in the hall of the F a c u l t y of E d u c a t i o n . These permits entitle the
bearer t o park his a u t o m o b i l e on the lots identified by a yellow
sign.
II en c o û t e $1.00 par j o u r p o u r une a u t o m o b i l e . Le permis q u o t i dien s ' a c h è t e à la guérite à l'entrée du c a m p u s . Ceux qui h a b i t e r o n t
aux résidences p o u r r o n t r e n o u v e l e r leur p e r m i s à l'accueil au hall
de la Faculté d ' é d u c a t i o n . Ces permis d o n n e n t droit aux aires
identifiées par des affiches j a u n e s .
rugi
Accommodation
Hébergement
O n campus
Sur le campus
T h e c a m p u s residences can a c c o m m o d a t e all delegates. T h e rate
for a single r o o m will be $25.00 per day a n d t h a t f o r a d o u b l e
r o o m will be $17.00 per d a y per p e r s o n , with central w a s h r o o m
facilities. These rates include breakfast.
Les résidences du c a m p u s peuvent accueillir t o u s les congressistes.
Le prix p o u r une c h a m b r e simple sera de $25.00 par j o u r et celui
d ' u n e c h a m b r e d o u b l e sera de $17.00 par p e r s o n n e par j o u r . Les
salles de bain sont centrales. Ces tarifs incluent le petit déjeuner.
T h o s e p e r s o n s wishing t o stay on c a m p u s s h o u l d a l r e a d y have
returned the o n - c a m p u s a c c o m m o d a t i o n form. In order to accelerate
the registration to the residences it had been suggested that you
send the full a m o u n t for your stay a l o n g with the f o r m . Registration t o o n - c a m p u s housing will be in the entrance hall of the Faculty
of E d u c a t i o n . W e shall provide t r a n s p o r t between the registration
area a n d the residences, d u r i n g registration h o u r s on S a t u r d a y
a n d S u n d a y (see Registration). People arriving a f t e r registration
hours should g o directly t o the residence reception at the i n f o r m a tion desk (see m a p of c a m p u s : residence, single o c c u p a n c y ,
information.)
Les p e r s o n n e s désireuses de loger aux résidences a u r a i e n t déjà dû
n o u s r e t o u r n e r le f o r m u l a i r e de logement d û m e n t rempli. Afin
d'accélérer l'inscription aux résidences il était r e c o m m a n d é d'y
inclure un c h è q u e p o u r c o u v r i r le m o n t a n t du séjour. Ce m o n t a n t
sera r e m b o u r s a b l e sauf p o u r le prix d ' u n e nuit.
Off-campus
Hors-campus
A r r a n g e m e n t s h a v e been m a d e with two hotels in S h e r b r o o k e .
These are on t h e city bus lines a n d are within 5 km of c a m p u s . The
Motel l ' E r m i t a g e is the closest o n e at $34.00 for a single a n d $40.00
f o r a d o u b l e r o o m . T h e y serve b r e a k f a s t only (at extra cost). T h e
A u b e r g e des G o u v e r n e u r s is very m o d e r n a n d luxurious. T h e rates
a r e $45.00 f o r single or d o u b l e o c c u p a n c y . T h e o f f - c a m p u s a c c o m m o d a t i o n reservation must be m a d e directly to the hotel of y o u r
choice.
Des a r r a n g e m e n t s ont été pris avec deux hôtels d e S h e r b r o o k e .
Ces hôtels sont desservis p a r les a u t o b u s de ville et sont en deçà
de 5 km du c a m p u s . Le motel l ' E r m i t a g e est le plus près à $34.(X)
p o u r une c h a m b r e simple et $40.(X) p o u r une d o u b l e . O n y sert le
petit d é j e u n e r seulement (avec s u p p l é m e n t ) . L ' A u b e r g e des G o u verneurs est très m o d e r n e et o f f r e t o u s les services. Le prix est de
$45.00 par j o u r p o u r une c h a m b r e simple ou d o u b l e . II faut réserver directement à l'hôtel d e votre choix.
Camping
Camping
M o u n t O r f o r d Provincial Park has c h a r m i n g c a m p i n g facilities on
the shores of a lake. It is s o m e 20 m i n u t e s away f r o m c a m p u s by
car. If you wish to rough it you may be interested by this alternative. T h e b a n q u e t will be held quite close by. T a k e the C h e r r y
River exit 118 on A u t o r o u t e 10. You can m a k e reservations by
calling (819-843-9855). T h e sites cost a r o u n d $10.00 per day.
Le parc du M o n t - O r f o r d a un c a m p i n g des plus p i t t o r e s q u e a u
Q u é b e c 11 est situé à 20 m i n u t e s en a u t o m o b i l e du c a m p u s . Si
vous êtes hardis, vous serez s a n s d o u t e séduits par cette perspective. Le b a n q u e t a u r a d'ailleurs lieu tout près de là. Prenez la sortie
118 direction C h e r r y River sur l ' a u t o r o u t e 10. Vous pouvez réserver en a p p e l a n t (819) 843-9855. Les e m p l a c e m e n t s coûtent a u t o u r
de $10.00 par j o u r .
S o c i a l events
Activités s o c i a l e s
W e c a n n o t g u a r a n t e e places to those that have not already reserved
their seats for the m é c h o u i , the concert a n d / o r the b a n q u e t .
N o u s ne p o u v o n s assurer de place à ceux qui n ' a u r o n t pas déjà
réservé leur place p o u r le méchoui, le concert et le b a n q u e t .
Welcome cocktail
Cocktail
T h e r e will be a m o o n l i g h t reception on S u n d a y evening f r o m
8:00 p . m . t o 11:00 p . m .
Il y a u r a une réception le d i m a n c h e soir de 20 h 00 à 23 h 00 sur
l'agora.
Méchoui
Méchoui
W e a r e o r g a n i z i n g a m é c h o u i (an i n f o r m a l d i n n e r of l a m b or beef
roasted over a fire) on M o n d a y J u n e 18th at 6:00 p . m . under the
tent on the c a m p u s lawn. T h e price will be $15.00.
N o u s o r g a n i s e r o n s un méchoui (dîner c h a m p ê t r e à l'agneau rôti à
la broche, et boeuf grillé) le lundi 18 juin à 18 h 00, sous la tente,
sur les pelouses du c a m p u s . Le prix sera d e $15.00 p a r personne.
Concert
Concert
T h e m é c h o u i will be followed by a concert at the Faculty of
E d u c a t i o n a u d i t o r i u m , "Si on c h a n t a i t e n s e m b l e " by the Heritage
choir. T h e a d m i s s i o n will be $4.00.
Le méchoui sera suivi d ' u n concert à l ' a m p h i t h é a t r e de la F a c u l t é
d ' é d u c a t i o n : le choeur Héritage et « si on c h a n t a i t e n s e m b l e ». Le
prix d ' e n t r é e sera de $4.00.
Banquet
Banquet
T h e b a n q u e t will be held on T u e s d a y at the O r f o r d Arts C e n t e r
looking u p to beautiful M o u n t O r f o r d . It is a very c h a r m i n g place
where you will be able t o u n w i n d in nature. T h e r e will be a cash
b a r between 6:00 p . m . a n d 8:30 p.m. T h e artistic e n v i r o n m e n t at
the O r f o r d C e n t e r invites music. T h e r e will be a concert between
7:00 p . m . a n d 8:00 p.m. for the music lovers. T h e b a n q u e t will
follow a n d will cost $25.00 per p e r s o n , the main dish is " t i m b a l e
de fruits de m e r " , including wine.
Le b a n q u e t a u r a lieu le mardi au C e n t r e d ' A r t d ' O r f o r d . à l ' o m b r e
du m o n t O r f o r d . C'est un endroit tout à fait c h a r m a n t où vous
p o u r r e z vous délasser en pleine nature. Il y a u r a un b a r p a y a n t sur
les pelouses de 18 h 00 à 20 h 30. L ' a m b i a n c e d u C e n t r e d ' A r t se
p r ê t a n t bien à un concert, les m é l o m a n e s seront bien servis d e
19 h 00 à 20 h (M). Le b a n q u e t suivra et c o û t e r a $25.00 du c o u v e r t ;
plat de résistance : timbale de fruits de mer, et vin inclus.
L'inscription aux résidences se fera à l'accueil, d a n s le hall d ' e n t r é e
de la Faculté d ' é d u c a t i o n . Il y a u r a une navette entre l'accueil et
les résidences p e n d a n t les heures de p e r m a n e n c e le s a m e d i et le
d i m a n c h e . Les personnes désirant p r e n d r e possession de leur
c h a m b r e en dehors des heures de permanence à l'inscription p o u r ront le faire directement aux résidences, aux renseignements (voir
plan d u c a m p u s ; résidence c h a m b r e simple, i n f o r m a t i o n ) . Les
cartes de crédit ne seront pas acceptées.
rug
Wednesday evening social
We shall organize a g r o u p activity on Wednesday evening for those
w h o are interested. You will be consulted in the registration area.
Mercredi soir
Meals
Repas
The c a m p u s cafeteria will be open for breakfast and lunch. T h e
S o m m e t restaurant and bar (adjacent to the cafeteria) will be open
for lunch and dinner. Those who do not wish to attend the méchoui
or the banquet can go to the Sommet or one of the o f f - c a m p u s
dining places.
La cafétéria du c a m p u s sera ouverte p o u r le petit déjeuner et le
déjeuner. Le restaurant le Sommet et son bar (adjacent à la cafétéria) sera ouvert p o u r le déjeuner et le dîner. Les personnes qui
n'iront pas au méchoui e t / o u au b a n q u e t , p o u r r o n t aller au
Sommet ou à un restaurant hors c a m p u s .
Companions'
P r o g r a m m e des c o n j o i n t s
program
Nous organiserons une activité le mercredi soir p o u r ceux qui le
souhaiteront. Vous serez consultés à l'accueil.
We are planning a n u m b e r of tours within Estrie for the companions. The participants will be asked to cover travel and entrance
fees.
N o u s prévoyons plusieurs visites dans l'Estric pour les conjoints.
Il en coûtera le transport et les forfaits d'entrée aux endroits
commerciaux.
Day I: National Historical park Louis-S. St-Laurent. Lunch at
the St-Laurent m a n o r . T h e Coaticook G o r g e (walking
shoes are a must) or the Beaulne Musuem (in case of rain
or for the less athletic).
J o u r 1: Parc historique national Louis S. St-Laurent. Déjeuner
au d o m a i n e St-Laurent. Les gorges de Coaticook (portez
des souliers de marche) ou le musée Beaulne (en cas de
pluie, ou p o u r les moins athlétiques).
Day 2: B o m b a r d i e r M u s e u m . Lunch in an auberge. A b b a v e
St-Benoît. The "le noir m o u t o n " farm owned by the
culinary expert J e h a n e Benoît.
J o u r 2 : Musée Bombardier. D é j e u n e r d a n s une auberge. A b b a y e
St-Benoît. Ferme <« le noir m o u t o n », a p p a r t e n a n t à
J e h a n e Benoît.
Day 3: Visit of N o r t h - H a t l e y (visit to local artists' workshops,
boutiques). Lunch in an auberge overlooking Lake
Massawippi.
J o u r 3 : Visite à N o r t h - H a t l e y , (ateliers d'artisans,
déjeuner sur le lac Massawippi.
The order of the visits d e p e n d s on the weather. The registration
for the c o m p a n i o n s ' p r o g r a m will be in the general registration
area, in the entrance hall of the Faculty of Education. The residence salon will be the gathering place. Coffee will be available
there.
L ' o r d r e des visites d é p e n d r a de la météo. L'inscription des
conjoints se fera sur les lieux, au hall de la Faculté d ' é d u c a t i o n . Le
point de rassemblement sera au salon des résidences où il y aura
un café en permanence.
Sports
Sports
Sailing and canoeing addicts will be able to rent equipment and
try out our lakes and rivers. There is also a nice golf course in
M o u n t O r f o r d Park.
Les a m a t e u r s de voile ou de canot p o u r r o n t louer le matériel et
s'en d o n n e r à c œ u r joie sur nos lacs et rivières. Il y a aussi du golf
au Parc du mont O r f o r d .
The University sports center will be open to all for a daily user's
fee of $3.00. It is possible to swim or play b a d m i n g t o n , squash. . .
E q u i p m e n t can be rented.
Le centre sportif de l'Université est disponible pour un forfait
quotidien de $3.00. Vous pourrez y faire de la natation ou du badminton, squash, etc. . . Les raquettes peuvent être louées.
There are a n u m b e r of nature trails on the m o u n t a i n behind the
campus.
Il y a de n o m b r e u x sentiers de nature d a n s la m o n t a g n e derrière
l'Université.
Varia
Divers
Poster sessions
Séances d'affichage
There will be a poster party this year. Indeed, two thirds of the
posters will be under a tent a n d the other third in the corridors
a r o u n d the exhibitors area. There will be a bar strategically located
between the two.
Les séances d'affichage seront empreintes de b o n n e h u m e u r cette
année. Les deux-tiers seront sous la tente et l'autre tiers d a n s les
couloirs a u t o u r des exposants. Et il y aura un bar stratégiquement
situé entre les deux !
Discussion area
Aire de détente
Il y a u r a un endroit réservé pour les discussions sérieuses à
l'extérieur et près du bar.
There will be an area outside and next to the bar at y o u r disposal
for relaxed discussions.
boutiques)
rugi
Divisional business meetings
Réunions d'affaires des divisions
T h e r e will be a cold plate service available t o those wishing t o
a t t e n d these n o o n t i m e business meetings.
Il y a u r a un service de plats f r o i d s p o u r ceux qui désirent assister
aux r é u n i o n s d ' a f f a i r e de leur division le midi.
Refreshments
Rafraîchissements
In a d d i t i o n to the beer service at the b a r , there will be coffee a n d
juice in the exhibitor area.
A part le b a r qui servira la bière, il y a u r a café et jus d a n s l'aire des
exposants.
F o r f u r t h e r i n f o r m a t i o n , please c o n t a c t :
P o u r tout renseignement, veuillez vous a d r e s s e r a u :
C o m i t é d ' o r g a n i s a t i o n locale, A C P '84
D é p a r t e m e n t de physique.
Université de S h e r b r o o k e ,
S h e r b r o o k e , Q u é b e c . J1K 2R1
Tel. 819-565-3593
(this will be the official Congress
phone number.)
(c'est le n u m é r o de téléphone
p o u r toute la durée du congrès).
LOCAL COMMITTEE/COMITE
Chairman
L.G. Caron
Social Events
D. C h e e k e
Exhibits
M. A u b i n
Registration/
A.M. Tremblay
Président
Activités sociales
Exposants
Inscriptions et
hébergement
Accommodation
Physical Arrangements
LOCAL
J. Lefaivre
with the cooperation of the
staff of the Physics Department.
Arrangements matériels
avec la collaboration du personnel du département de
physique.
Residence
(chambre double)
(doublevoccupancy)
- Cafeteria
- Restaurant
- Bar
Agora
- Education Inscription
Registration
Pavillon Albert-Leblanc
Conferences
Sport's Center
Centre sportif
Département
de physique
UNIVERSITE
DE SHERBROOKE
Campus de l'ouest
Pavillon A l b e r t - L e b l a n c
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Canadian Association of Physicists Medallists 1984
Lauréats de l'Association canadienne des physiciens 1984
C A P M e d a l for Achievement in Physics
M.P. Bachvnski
M P B Technologies I n c o r p o r a t e d
Herzberg Medal
N. Isgur
University of T o r o n t o
Canadian Association of Physicists Prize Exam 1984
Résultats de l'examen de l'Association canadienne des physiciens 1984
O n e h u n d r e d a n d eighteen s t u d e n t s f r o m t w e n t y - f o u r universities c o m p e t e d this year. T h e exam was a d m i n i s t e r e d by a C o m m i t t e e f r o m
S i m o n Fraser University. T h e n a m e s of the first, second a n d third prize-winner are s h o w n followed by the next six in a l p h a b e t i c a l o r d e r .
D.B. M u r r a y
C. Jui
D. Salopek
G. S t a r k m a n
S.E. Allen
D. A t w o o d
B. H a r r o l d
T. Hsu
FIRST
SECOND
PRIZE
PRIZE
THIRD
PRIZE
THIRD
PRIZE
A.P. Smith
T.R. Stevenson
Simon Fraser University
University of O t t a w a
University of Alberta
Q u e e n ' s University
Queen's University
Memorial University
University of British C o l u m b i a
LIST OF EXHIBITORS/LISTE DES EXPOSANTS
Congrès A C P 1984 C A P Congress
M a n u f a c t u r e r s and S u p p l i e r s /
M a n u f a c t u r i e r s et Représentants
MERLAN SCIENTIFIC
LTD.
OP I IKON CORPORATION
RADIONICS SCIENTIFIC
W.G. A L E X A N D E R
LTD.
SRP C O N T R O L SYSTEMS LTD.
ALLAN CRAWFORD ASSOCIATES
ANALYTECH
BOMEM
LTD.
INC.
INC.
DIGIDYNE
TASMAN SCIENTIFIC
INC.
TECHNICAL MARKETING ASSOCIATES LIMITED
VARIAN C A N A D A
CANADIAN SCIENTIFIC PRODUCTS
INC.
LTD.
PUBLISH ERS/ÉDITEURS
INC.
EDWARDS HIGH
LIMITED
INC.
VACUUM
EG & G I N S T R U M E N T S
DIVISION
ACADEMIC
PRESS
J O H N WILEY & SONS
Invited Speakers/Conférenciers invités
A R M S T R O N G , R.L., University
of Toronto: AA2: Magnetic
Excitations in O n e - D i m e n s i o n a l Ising-Like A n t i f e r r o m a g n e t s
B A C H Y N S K I , M . P . M PB Technologies
Inc.: E A 2 : Inertial
C o n f i n e m e n t and Opportunities for C a n a d a
BALD1S, H.A., National Research
Council of Canada; C D 1 :
Parametric Instabilities in Laser Produced Plasmas
BANDRAUK, A.D., Université de Sherbrooke:
BD1: Le concept
de la molécule habillée en spectroscopic, p h o t o p h y s i q u e et p h o t o chimie en c h a m p intense
B I R G E N E A U , R.J., Massachusetts
Institute of Technology: AA1:
Synchrotron X-ray Studies of Structures and Transitions in T w o
Dimensions
B I R N B A U M , G., National Bureau of Standards: CC2: CollisionInduced A b s o r p t i o n : Astrophysical Implications and ab initio
Calculations
B O U L A N G E R , J.-S., National
La Seconde du Cesium
Research
CF3: Physics Education,
AE2: Particle
B U H R M A N , R.A., Cornell University: AC3: S u b m i c r o n Device
Physics Research
B U R E S , J . et L A P I E R R E , J . , École Polytechnique:
F B I : Fibres
optiques m o n o m o d e s : Filtres coupleurs capteurs
C A M E R O N , J . M . , University of Alberta: F C 3 : Meson Exchange
and Isobar C u r r e n t s in N e u t r o n - P r o t o n Radiative C a p t u r e
C A M M , D.M., Vortek Industries Ltd: C D 3 : Developments of'
High Intensity Arc L a m p s
C E L O T T A , R.J., National Bureau of Standards;
Polarization Spectroscopy — Recent Advances
C E R N Y , J . , Lawrence
Nuclei
Berkeley
Laboratory;
Microscopic
AD1: Electron
AB1: Exotic Light
C R I N E , J - P . , Institut de recherche d'Hydro-Québec;
BC2: La
recherche sur les isolants électriques à I ' I R E Q
C U J E C , B., Université Laval; FC1: Heavy Ion Reactions at
Low Energies
D E L I S L E , C., Université
instruments versatiles
Laval;
FB2: Les systèmes bistables,
D E S L A U R I E R S , J . , Mitel Semiconductor
the Ever Shrinking Line
D T O R I O , M., National Research
Quantum Standard Ohm
Inc.; AC2: In Pursuit of
Council
of Canada;
CE2: A
D O M E Y , J . et R I O U X , M., Conseil national de recherches du
Canada; FB3: C a p t e u r de vision tridimensionnelle pour l ' a u t o m a tisation industrielle
EARLE, E.D., Chalk River Nuclear Laboratories;
FC2: Nuclear
Parity Violation: A Needle in a Haystack
E G E L S T A F F , P.A., University of Guelph; AA4: T h e Future of
N e u t r o n Scattering in C a n a d a
EVANS, W.F.J., Atmospheric Environment
Winter and the A t m o s p h e r e
Service;
CB4:
Random
Council of Canada: CE4: T h e
HARDY, J . C . , AECL. Chalk River Nuclear Laboratories;
DA3:
The Laboratory Synthesis of Nuclei: Exploration and Consolidation
H A R R I S O N , J.P., Queen s University; BAI : Heat Transfer between
Liquid Helium and Solids
B R O U W E R , W., University
2000 A.D.
DA4:
H A N E S , G.R., National Research
New Metre and Its Realization
Research;
AB2: Recent
Columbia:
C A R B O T T E , J . P . , McMaster
University;
Parameters in Superconductivity
G U Y E R , R.A., Schlumberger-Doll
Walking on a Fractal
CE3:
Council of Canada:
BRYANT, D.A., Rutherford
Appleton Lab, U.K.:
Acceleration in Space and L a b o r a t o r y Plasmas
G E R S O N , N.C., Laboratory for Physical Sciences. College Park.
MD; Auroral Associated Émissions below 5000 Hz
G R I F F I N , A., University of Toronto: FA2: P h o n o n s in BoseCondensed Systems — What are They?
HARDY, W.N., University of British Columbia; CE6: A Very Cold
Hydrogen Maser; DA2: Atomic Hydrogen: Its Behavior and Its
Uses below I Kelvin
B R E W E R , J . H . , University of British
Progress in p S R Techniques
of Alberta:
G A G N É , J - M . , Ecole polytechnique;
BD2: Effet opto-galvanique
(E.O.G.) dans un plasma luminescent: Mécanismes et applications
optiques
HASEGAWA, A A T & T Bell Laboratories;
Nonlinear Plasma Phenomena
H I R O S E , A., University
High-Beta T o k a m a k
of Saskatchewan;
AE3: Theory of
FD1: Approaches to
H O P P E R , M.A., Xerox Research Centre of Canada; BC1: Physics
Research at Xerox Research Centre of C a n a d a
I S G U R , N„ University of Toronto; BB2: A Flux Tube Model for
H a d r o n s ; EA1: Deriving Nuclear Physics f r o m the Quark Model
J A F F E , R.L., Massachusetts Institute of Technology;
ing the Q u a r k s in the Atomic Nucleus
J A M E S , H.G., Department
of Communications;
Research in Space Plasma Physics
BB4: WatchF D 1 : Current
J O H N S O N , B„ Cornell University: BA2: Experimental Observation of Nuclear Spin Waves in Spin Polarized Atomic Hydrogen
Gas
KIRKBY, P., Ontario
Physicists in C a n a d a
Hydro;
AC4: The Professional Status of
KR1MIGIS, S.M., The Johns Hopkins University; AE I: Plasma and
Energetic Particles in Planetary Magnetosphere
K U N S T A T T E R , G., University
of Toronto;
CBI: Magnetic
Monopoles and Unified Field Theories
L I B C H A B E R , J . A., University
Fluid Systems
of Chicago; FA I: Noise in Chaotic
L O C K E , J . L . , National Research Council
Birth of Collision-Induced Absorption
of Canada;
CC'I: The
L O U T F Y , R„ Xerox Research Centre; CA3: Organic Solar Cells
McKELLAR, R.W., National Research Council of Canada; D A I :
Molecular Ions in the Infrared
M O O D Y , R.V. and PATERA J., Université de Montréal; CB2:
General Charge C o n j u g a t i o n Operators in Simple Lie G r o u p s
NAGUIB, H., Northern Telecom Electronics;
tion for VLSI Circuits
AC1: Ion Implanta-
N I C K E L , B., University of Guelph: CB3: Developments in the
Theory of Dilute Polymer Solutions
O R A M , C.J., TRIUMF;
in M u o n Decay
FC4: Search for Right-Handed Currents
BF1: Nuclear
P A L M A D E S S O , P., U.S. Naval Research Laboratory;
AE4:
Interaction of Microphysical and Macrophysical Plasma Processes
F A U C H E R , G., École Polytechnique;
C F 2 : Qualitative Physics
and Conceptual C h a n g e : A New Trend in Physics Learning
S A N C H E , L. et M I C H A U D , M., Université de Sherbrooke; AD3:
Vibrational-Librational Excitation and Shape Resonances in
Electron Scattering f r o m Molecular Solids
F A W C E T T , E., University of Toronto: C F 1 : Teaching about
Physics and War: Nuclear A r m s and High-Tech Militarism
FRANK, A.J., Solar Energy Research Institute;
chemical/Electrolysis Solar Cells
C A 2 : Photoelectro-
SEKA, W., University of Rochester;
Experiments at 0.35 /L/m
FD2: Laser-Plasma Interaction
Il
STAIRS, D.G., McGill University; BB1 : Measurement of the High
Mass Dimicon Continuum in Anti-Proton Nucleus Collisions at
125 GeV
STANSFIELD, B.L., INRS-Énergie; CD2: Plasma Diagnostics
Using Laser-Induced-Fluorescence
STATT, B.W., University of British Columbia; BA3: Electron Spin
Resonance of Spin-Polarized Atomic Hydrogen
SULAK, L., University of Michigan; BB3: May be diamonds
Are forever: Results from the Latest Proton Decay Experiments
SUTTON, M., Massachusetts
Institute of Technology; AA3:
Layering and the Approach to Wetting in Ethylene on Graphite
TETU, M., Université Laval et VANIER J., Conseil National de
Recherches du Canada; CE5: Recherches sur les élalons atomiques
de fréquence à l'Université Laval
THOMAS, R., Carleton University: CA1: Semiconductor Solar
Cells
TRAJMAR, S., California Institute of Technology; AD2: ElectronAtom Collision Processes in Laser Fields
TREMBLAY, A-M., LEMIEUX, M.-A. et BRETON, P., Université de Sherbrooke; FA3: How to Get Your Money's Worth from
Your Favorite Model of Disorder
VAN KRANENDONK, J., University of Toronto; CC3: Theory of
Induced Absorption: How It Began and Where We Stand Today
WOOD, B.M., National Research Council of Canada: CEI: The
Josephson Volt
Listeners, Speakers, and Session Chairmen
Special Instructions for Timed Papers
T h e p a p e r s will be t i m e d in o r d e r t o m a k e it possible f o r listeners to t r a n s f e r f r o m o n e session to a n o t h e r .
LISTENERS
1) Please a r r i v e at a lecture r o o m p r o m p t l y before the next p a p e r is to begin.
2) Leave a session u n o b t r u s i v e l y , p r e f e r a b l y either d u r i n g o r at the end of the q u e s t i o n a n d a n s w e r p e r i o d .
SPEAKERS
1) M a k e y o u r slide p r o j e c t i o n a r r a n g e m e n t s before the start of y o u r session.
2) Be r e a d y t o start y o u r talk on time.
3) Pace y o u r talk to e n d well b e f o r e the next talk begins: a b o u t 3 m i n u t e s f o r a c o n t r i b u t e d p a p e r a n d a b o u t 10 m i n u t e s f o r
an invited p a p e r .
4) A n s w e r q u e s t i o n s a n d p e r h a p s c o m m e n t s as c o m p l e t e l y a n d briefly as m a d e necessary by the r e s p o n s e of the a u d i e n c e .
5) O b e y y o u r c h a i r m a n ' s i n s t r u c t i o n s .
6) M o s t i m p o r t a n t , p r a c t i c e giving y o u r talk before the m e e t i n g . R e m e m b e r , you a r e the a m b a s s a d o r of y o u r d e p a r t m e n t a n d i n s t i t u t i o n , a n d you will be judged by y o u r a u d i e n c e .
CHAIRMEN
1) G e t t o the session r o o m a b o u t half an h o u r b e f o r e y o u r session begins. C h e c k t h a t all n e e d e d p r o j e c t i o n a n d auxiliary
equipment are present and operational. Check that your speakers are present.
2) S t a r t e a c h p a p e r right on time.
3) M a k e s u r e each s p e a k e r s t o p s t a l k i n g well b e f o r e the next p a p e r begins.
4) K e e p the q u e s t i o n p e r i o d s interesting, lively a n d p r o d u c t i v e . Read over the p a p e r s in y o u r session b e f o r e h a n d . If
necessary, p r e p a r e c o m m e n t s a n d q u e s t i o n s .
5) D o not let a n y d i s c u s s i o n p e r i o d get out of h a n d , either on the s p e a k e r ' s o r the q u e s t i o n e r s ' side.
6) If n o o n e a p p e a r s to give a p a p e r , t h e n either close the session until the time of the next s c h e d u l e d s p e a k e r o r else use the
t i m e i m a g i n a t i v e l y , p e r h a p s begin a discussion of earlier p a p e r s .
7) U n d e r no circumstances m a y the o r d e r of giving the p a p e r s d i f f e r f r o m that given in the p r o g r a m , even t h o u g h y o u
m a y , in y o u r w i s d o m , see a b e t t e r a r r a n g e m e n t t h a n that d e t e r m i n e d by the P r o g r a m C o m m i t t e e .
rugi
PROGRAM SUMMARY/RESUME D U PROGRAMME
T h e letter c o d e of the session, the s t a r t i n g time, the location a n d the topics of each session a r e given in o r d e r . Session r o o m s a r c located in
Pavilion Albert - L e b l a n c except r o o m 154 which is in the Faculté d ' é d u c a t i o n a n d r o o m 1060 in the Sciences Building. T h e personal
n a m e s are those of invited s p e a k e r s .
S U N D A Y , J U N E 17, 1984
9:00 to
16:30
154
W o r k s h o p : T h e Nuclear a n d Particle
Physics of the F u t u r e
15:00
244
CAP Council
20:00
Agora
Opening Reception
M O N D A Y , J U N E 18, 1984
AA
9:00
AB
10:30
154
AC
9:00
328
Industrial and Applied Physics — Physics Aspects of VLSI: N A G U I B , D E S L A U R I E R S ,
B U H R M A N , KIRKBY
AD
9:00
228
Recent A d v a n c e s a n d A p p l i c a t i o n s in Electron Spectroscopv: C E L O T T A ,
SANCHE
AE
9:00
234
12:00
244
13:30
334
BA
334
BB
13:30
154
BC
13:30
328
BD
13:30
228
15:30
228
BE
13:30
234
BF
16:30
154
10:00-16:00
S y n c h r o t r o n and X - R a y Studies of Structures a n d T r a n s i t i o n s in T w o D i m e n s i o n s :
BIRGENEAU, ARMSTRONG, SUTTON, EGELSTAFF
Technical A d v a n c e s in Nuclear Physics: C E R N Y , B R E W E R
P l a s m a s in Space a n d L a b o r a t o r y : K R I M I G I S , B R Y A N T , H A S E G A W A . P A L M A D E S S O
A n n u a l Business Meeting of the Division of Particle Physics.
E x p e r i m e n t a l O b s e r v a t i o n of Spin Waves in Spin-Polarized A t o m i c H y d r o g e n :
HARRISON, JOHNSON, STATT
Particle Physics: S T A I R S , I S G U R . S U L A K . J A F F E
Industrial a n d Applied Physics — Research at X E R O X a n d I R E Q : H O P P E R , C R I N E
Interaction laser-matière: B A N D R A U K ,
GAGNÉ
Politique et O p t i q u e
A u r o r a a n d Winds
Physics a n d Society: Evans
POSTER PARTY — PART I
In T h e T e n t a n d T h e Foyer.
PA
Solar Cell Devices
1-8
PA
9-17
Semiconductors
PA
18-26
//SR a n d Magnetic Properties of Solids
O p t i c s a n d Lasers
PB
PC
Plasma Physics
PD
A t o m i c a n d Molecular Physics I
PE
Particle Physics, Theoretical Physics
18:00
The Tent
20:30
154
Méchoui ( I n f o r m a l dinner)
Concert
T U E S D A Y , J U N E 19, 1984
CA
9:00
334
CB
9:00
154
CC
9:00
228
TRAJMAR,
Solar Cell Devices: T H O M A S , F R A N K , L O U T F Y
Theoretical Physics, K U N S T A T T E R . P A T E R A , N I C K E L . G U Y E R .
Thirtv-five Years of Collision-Induced A b s o r p t i o n : L O C K E , B I R N B A U M ,
VANKRANENDONK
Plasma Physics I: B A L D I S , S T A N S F I E L D .
CAMM
T h e Q u a n t u m Electronics Basis f o r Precision M e a s u r e m e n t s : W O O D ,
BOULANGER, HANES. TÊTU,
HARDY
Physics E d u c a t i o n : F A W C E T T , F A U C H E R ,
BROUWER
A n n u a l Meeting of the Division of Physics E d u c a t i o n
C a n a d i a n C o n s o r t i u m f o r University Space Science
Meeting of the Board of D i r e c t o r s
ANNUAL MEETINGS OF CAP
DIVISIONS
Division of A e r o n o m y a n d Space Physics
Division of A t o m i c a n d Molecular Physics
Plenary Session in H o n o r of G e r h a r d H e r z b e r g : M C K E L L A R ,
H A R D Y (W), H A R D Y (J), C A R B O T T E
DIVISIONS
Division of Optical Physics
Division of Plasma Physics
Division of Theoretical Physics
Reception a n d B a n q u e t
O r f o r d Arts C e n t r e
P O S T E R PARTY — PART II
O n e a n d T w o D i m e n s i o n a l Systems
Phase T r a n s i t i o n s , S u p e r c o n d u c t o r s , Fermi G a s
Nuclear a n d Accelerator
Instrumentation
Project C e n t a u r
Laser — Plasma
Interactions
A t o m i c a n d Molecular Physics II
Industrial a n d Applied
Physics
Plenary Session — Medallists: I S G U R .
BACHYNSKI
Break
A n n u a l G e n e r a l Meeting of the C a n a d i a n Association of Physicists
D A S P Luncheon
DIVISIONS
Division of C o n d e n s e d M a t t e r Physics
Division of N u c l e a r Physics
N o n - S t a n d a r d Structures: I . I B C H A B E R . G R I F F I N .
Optique Moderne -
Nuclear Science: C U J E C . E A R I . E , C A M E R O N ,
P l a s m a Physics II: H I R O S E , S E R A . .1 A M E S
D A S P E x p e r i m e n t e r s ' Meeting
C A P Council
P O S T E R PARTY — PART 111
Vibrational Spectra, Local M o d e s , N M R
Metals, Electron Scattering
Optics a n d Lasers
Nuclear Fission a n d P h o t o n u c l e a r
Nuclear S t r u c t u r e
Nuclear Physics
TREMBLAY
N o u v e a u x systèmes: B U R E S , D E L I S L E ,
Reactions
ORAM
DOMEY
D'lORIO,
rugi
CAP Congress Program
1984
Programme du Congrès ACP
S U N D A Y , J U N E 17, 1984
ROOM
154
Chairmen: J.S.C. McKee
M. Waddington
W o r k s h o p : " T h e N u c l e a r a n d P a r t i c l e P h y s i c s of t h e
Morning/Matinée
Future.
Speaker/Orateur
Subject/Sujet
08:30-8:45
Perceptions of the W o r k s h o p / A p e r ç u de la session de travail
F.C. K h a n n a
08:45-09:10
T R I U M F — T h e Next Five Y e a r s / T R I U M F — Les cinq a n n é e s à venir
E.W. V o g t / P . Kitching
09:25-09:50
E R O S — T h e Next Five Y e a r s / E R O S — Les cinq a n n é e s à venir
H.S. C a p l a n / J . C . Bergstrom
10:05-10:20
COFFEE BREAK/PAUSE
CAFÉ
10:20-10:45
T A S C C — T h e Next Five Y e a r s / T A S C C — Les cinq a n n é e s à venir
J.C. Hardy
11:00-11:25
Particle Physics — T h e Next Five Y e a r s / P h y s i q u e des particules — Les cinq
D . G . Stairs
11:40-12:00
G e n e r a l D i s c u s s i o n / D i s c u s s i o n générale
12:00-13:30
LUNCH/DINER
a n n é e s à venir
Afternoon/Après-midi
13:30-13:55
Physics W i t h o u t Accelerators a D e c a d e F r o m N o w / L a Physique sans
accélérateurs d a n s une décennie
A.E. Litherland
14:10-14:30
Particle Physics With High Energy P r o t o n B e a m s a D e c a d e F r o m N o w /
La physique des particules avec faisceaux de p r o t o n s à g r a n d e s énergies
d a n s une décennie
A. A s t b u r y
14:30-14:50
Nuclear Physics With High Energy P r o t o n Beams a D e c a d e F r o m N o w /
La p h y s i q u e nucléaire avec faisceaux de p r o t o n s à g r a n d e s énergies
d a n s une décennie
E . W . Vogt
15:15-15:30
COFFEE BREAK/PAUSE
15:30-15:55
Electron Physics a D e c a d e F r o m N o w / L a physique des électrons d a n s une
décennie
E.L. T o m u s i a k
16:10-16:35
Physics With Relativistic Heavy Ions a D e c a d e F r o m N o w / L a physique des
ions l o u r d s relativistes d a n s une décennie
D. Boal
16:50-17:15
Particle Physics a D e c a d e F r o m N o w / L a p h y s i q u e des particules d a n s une
décennie
N. Isgur
17:30-18:00
G e n e r a l D i s c u s s i o n / D i s c u s s i o n générale
CAFÉ
S U N D A Y , J U N E 17, 1984
ROOM
244
15:00
Meeting of C A P C o u n c i l / R e u n i o n d u Conseil de
C h a i r m a n / P r e s i d e n t : B.P. S t o i c h e f f
S U N D A Y , J U N E 17, 1984
20:00
Reception
l'ACP
rug
MONDAY, JUNE 18, 1984
ROOM 334
SYNCHROTRON
AND
AND X-RAY STUDIES
OF
TRANSITIONS
IN TWO
C h a i r m a n : J . Berlinsky
9:00
AA1
Synchrotron X-ray Studies of Structures and Transitions in Two Dimensions
R.J. Birgeneau, kaSiachuietti
Institute
o(.
Technology
S y n c h r o t r o n sources p r o v i d e an i n c r e a s e i n x - r a y f l u x over c o n v e n t i o n a l x - r a y g e n e r a t o r s by 3 t o 4
o r d e r s o f magnitude.
This has opened up a new g e n e r a t i o n o f high r e s o l u t i o n d i f f r a c t i o n e x p e r i ments.
I n t h i s t a l k we w i l l d e s c r i b e r e s u l t s o f a s e r i e s o f experiments on the phases and
phase t r a n s i t i o n s o f monolayer k r y p t o n and xenon on g r a p h i t e .
The measurements were c a r r i e d
out on a w i a g l e r beam l i n e a t the S t a n f o r d S y n c h r o t r o n R a d i a t i o n L a b o r a t o r y ; they are p a r t o f a
c o n t i n u i n g c o l l a b o r a t i o n w i t h the groups o f P. M. Horn o f IBM and D. E. Moncton o f Brookhaven.
We have employed both high s u r f a c e area e n f o l i a t e d p y r o l y t i c g r a p h i t e and s i n g l e c r y s t a l
g r a p h i t e as s u b s t r a t e s .
The r e s o l u t i o n i s such t h a t one can m o n i t o r c o n t i n u o u s l y t h e d e v e l o p ment o f o r d e r from t h e Angstrom t o t h e micron l e v e l .
E x p l i c i t issues addressed i n c l u d e t h e
n a t u r e o f m e l t i n g i n two dimensions f o r d i s c r e t e and continuous symmetry systems and 2D commensurate-incommensurate t r a n s i t i o n s .
For k r y p t o n i n the monolayer t o b i l a y e r coverage r e g i o n
one f i n d s p a r t i c u l a r l y novel behaviour w i t h doubly r e - e n t r a n t f r e e z i n g .
We w i l l d i s c u s s the
o u t s t a n d i n g e x p e r i m e n t a l and t h e o r e t i c a l issues connected w i t h these model 2D systems.
9:45
AA2
Magnetic Excitations in One-Dimensional Ising-Like Antiferromagnets
R.L. Armstrong, UniveASiXy
Toronto
Spin-wave and soliton responses of the one-dimensional lsing-like antiferromagnet CsCoBr^ have been
studied by inelastic neutron scattering. The highly asymmetric spin-wave line shape arises from
local staggered fields which vary on a much slower time scale than the transverse spin motion and
whose effect decreases with increasing temperature in the manner expected for the decay of intrachain and interchain interactions. The soliton response arises from the propagation of domain
walls. The observed dispersion, intensity and polarization are reasonably described by the theory
using parameters determined from spin-wave measurements. Static and dynamic spin correlations in
CsCoq^ g3MgQ^ J -7CI3 , a randomly dilute ant i f erromagnet, have also been investigated by neitron
scattering. The one-dimensional correlation length tends to a geometric limit at low temperatures
in analogy with percolation in higher dimensional magnetic systems. The quasi-elastic scattering
is well described by exact calculations for a dilute chain. In addition to the usual spin-wave
band of the host crystal, the spectrum contains localized modes that arise from oscillations of
spins at the ends of magnetic chains. Their frequency is approximately half that of the host band.
Calculations of the dynamic response are compared with the experiments.
10:30
AA3
Layering and the Approach to Wetting in Ethylene on Graphite*
M. Sutton, Haaachuietts
Institute
0{
Technology
We have begun to study multilayer adsorbtion spanning coverages from a monolayer to many
layers. Ethylene has been chosen since at low temperatures, only a finite number of
layers of ethylene will adsorb onto the basal planes of graphite. Any excess forms bulk
crystalline ethylene. The maximum number of layers which adsorb changes abruptly at
discrete layering transitions. Thus at T a 75K the maximum number changes from one to two
and at T-98K from two to three. Above the triple point of bulk ethylene ( T » 103.8K) it
appears that any amount will adsorb. In this work we will present synchrotron x-ray
diffraction studies of ethylene on exfoliated graphite. In situ vapor pressure isotherms
allow us to measure the amount adsorbed and x-ray scattering enables us to separate thl3
Into film and bulk contributions. The diffraction profiles give us Information on the
structure of the film phases and the high resolution of the synchrotron allows us to put a
lower bound on the bulk crystallite sizes. This value is quite large, around 400A. We
have measured much of the phase diagram of ethylene on graphite. A fundamental change in
behavior occurs near the triple point temperature. There is evidence for prewetting and
wetting that suggests the wetting temperature is the triple point temperature.
* Work done in collaboration with S.G.J. Mochrie, R.J. Birgeneau (MIT), P.M. Horn (IBM)
and D.E. Moncton (Brookhaven National Labs.).
11:15
AAA
The Future of Neutron Scattering in Canada
p.A. Egelstaff, UnLvewity
of, Guelph
At present there are three neutron sources in Canada which are readily available to users from any
institution in the country. These are (in order of neutron Intensity) first the N.R.U. (and NRX)
reactors at Chalk River, secondly the McMaster reactor and thirdly the steady state neutron source
at Triumf. Comments on the way to use each source will be made and proposals for a wider University
program at Chalk River will be outlined. In addition to using these facilities, Canadian Scientists
have been invited to make experimental proposals for work on the two pulsed neutron sources in the
U.S.A. These sources will be compared to the above sources, and with a proposed pulsed neutron
source at Triumf.
STRUCTURES
DIMENSIONS
16
M O N D A Y , J U N E 18, 1984
ROOM
154
Chairman: F.C. Khanna
8:30 - 10:30
Meeting of nuclear science and particle physics community
with the Nuclear Science Grants Selection Committee of
NSERC, to discuss planning and planning policy.
ROOM 154
Chairman: F.C. Khanna
10:30
AB1
TECHNICAL
ADVANCES
IN NUCLEAR
Exotic Light Nuclei
J. cerny, Law*.e.nce BeAkeZey Labonjxtony
11:15
AB2
Recent Progress in ySR Techniques
J.H. Brewer, UvUveMiXy oj[ Blitlik
Columbia
The basic technique of muon spin rotation in transversely applied magnetic field (TF~uSR) was
established in 1957 by the same experiment that demonstrated parity nonconservation in the n—p —e decay
sequence. This simple method of precessing the muon's spin is still the mainstay of gSR. However,
such experiments are now done at dramatically higher rates, and the variety of applications discovered
in the last decade make uSR rival NMR and END0R in versatility. At the same time, novel new techniques have been invented that give pSR a decided advantage in certain applications. For Instance,
muon spin relaxation in zero applied magnetic field (ZF-ySR), which has no analog in NMR, has changed
our way of thinking about spin relaxation in general; this is coupled with longitudinal field (LF-uSR)
techniques to make uSR a powerful tool in the study of dynamical effects in magnetism and diffusion.
The direct analogy with NMR etc., muon spin resonance (also uSR), has also made a comeback in recent
years, and new pulsed resonance techniques promise to provide ySR with many of the advantages of NMR
in addition to its own unique capabilities. I will attempt to provide an overview of the many methods
of uSR and their applications in condensed matter physics, nuclear physics and chemistry. If time
permits, I will predict the future of pSR in Canada and the world.
PHYSICS
rug
ROOM 328
INDUSTRIAL
AND
— PHYSICS
APPLIED
ASPECTS
C h a i r m a n : A. Yelon
9:00
AC1
Ion Implantation for VLSI Circuits
H.M. Naguib, UonXheAn Telecom
Elec&iorUci
Ion implantation is a well established doping technique in the fabrication of integrated circuits.
However, as device dimensions shrink to 1 m™ in very large scale Integrated (VLSI) circuits, the
demands on ion implantation processes have increased significantly. In this paper, some basic
fundamental issues in ion beam interaction with solids will be described first. Current areas
of ion implantation research will then be reviewed for applications in VLSI devices. These
cover a wide range of possibilities involving new doping schemes, modification of materials
characteristics, and formation of device elements. Advantages and potential limitations of
these applications will be discussed.
9:45
AC2
In Pursuit of the Ever Shrinking Line
J. Deslauriers, Hotel Semic.ondu.ctoi
Inc.
With the c o n t i n u i n g increase in the degree of i n t e g r a t i o n a p p l i e d t o the
manufacture
of m i c r o c i r c u i t s ,
novel
techniques have t o be used f o r p a t t e r n d e f i n i t i o n
of
the
various t h i n f i l m s forming e l e c t r o n i c devices.
X-ray,
electron-beam,
and ion-beam
lithography
are being c o n s i d e r e d t o overcome the l i m i t a t i o n s of o p t i c a l l i t h o g r a p h y .
Dry e t c h i n g methods based on low p r e s s u r e gas discharges are now being used
instead
of c o n v e n t i o n a l wet chemical e t c h i n g f o r more a c c u r a t e p a t t t e r n t r a n s f e r ,
w h i l e new
materials
are being i n t r o d u c e d t o o p t i m i z e device performance and r e l i a b i l i t y .
The
m i l e s t o n e s and the t r e n d s marking t h i s r a p i d l y e v o l v i n g f i e l d w i l l be reviewed in an
a t t e m p t t o f o l l o w t h i s p u r s u i t of the ever s h r i n k i n g l i n e .
10:30
AC3
Submicron Device Physics Research
R.A. Buhrman, ColnM
UniveMlty
The r a p i d development o f submicrometer l i t h o g r a p h y and t h i n f i l m p r o c e s s i n g t e c h n o l o g y has opened
up new p o s s i b i l i t i e s f o r s o l i d s t a t e d e v i c e p h y s i c s and m a t e r i a l s science r e s e a r c h .
In t h i s t a l k
I w i l l b r i e f l y d i s c u s s some o f t h e fundamentals o f advanced submicron fabrication
t e c h n o l o g y and
d e s c r i b e i t s a p p l i c a t i o n t o s e v e r a l d i f f e r e n t submicron physics research problems.
Some r e c e n t
developments a t the N a t i o n a l Research and Resource F a c i l i t y f o r Submicron S t r u c t u r e s a t C o r n e l l
U n i v e r s i t y i n the areas o f submicron superconductor and submicron semiconductor d e v i c e research
w i l l be d i s c u s s e d .
11:15
AC4
The Professional Status of Physicists in Canada
P. Kirkby, Ra4eoAch Division,
Ontorvio HydAo
The CAP Committee on Professionalism is studying the professional status of physicists in Canada.
This talk will provide an outline of the professional levels legally defined in the country, a
description of the work carried out by CAP in protecting the practice of the natural scientist in
Ontario, and a description of the work in progress by the Committee on Professionalism.
PHYSICS
OF VLSI
rugi
ROOM 228
Chairman: J.W. McConkcy
9:00
AD1
RECENT
ADVANCES
AND APPLICATIONS
IN
ELECTRON
SPECTROSCOPY
Memorial
Session in Honour of J.D.
Carette
Electron Polarization Spectroscopy-Recent Advances
R.J. Celotta, National
BuAeau ol
StandaAdi
E l e c t r o n spectroscopy u s u a l l y connotes a measurement of the momentun change of an e l e c t r o n upon
impact or o f t h e momentum o f e l e c t r o n s e m i t t e d as t h e r e s u l t of a c o l l i s i o n process.
Recently,
owing t o d r a m a t i c improvements i n e l e c t r o n p o l a r i z a t i o n sources and d e t e c t o r s , s p e c t r o s c o p i e s based
on the e l e c t r o n s p i n p o l a r i z a t i o n have become p r a c t i c a l .
Examples t o be discussed i n c l u d e an
a p p l i c a t i o n o f t h i s powerful t e c h n i q u e t o an i n v e r s e photoemission 1 study o f s u r f a c e magnetism.
A l s o t o be d i s c u s s e d , i s a study o f t h e dynamics of e l e c t r o n impact i o n i z a t i o n , 2 which i s h e l p i n g t o
e l u c i d a t e the d i f f e r e n c e s between the Wannier and Coulomb-dipole t h e o r i e s o f t h r e s h o l d i o n i z a t i o n .
F i n a l l y , I s h a l l d e s c r i b e t h e enhancement 3 of our p o l a r i z e d e l e c t r o n source t o produce monochromatic
(31 meV), p o l a r i z e d e l e c t r o n beams o f an i n t e n s i t y (21 pA) which exceeds t h a t a v a i l a b l e from
c o n v e n t i o n a l e l e c t r o n monochromators.
X
J. U n g u r i s , A. S e i l e r , R . J . C e l o t t a , D.T. P i e r c e , P.O. Johnson, and N.V. Smith, Phys. Rev. L e t t .
9 , 1047 ( 1 9 8 2 ) .
2M.H. K e l l e y , W.T. Rogers, R . J . C e l o t t a , and S.R. M i e l c z a r e k , Phys. Rev. L e t t . 51, 2191 ( 1 9 8 3 ) .
3
C.S. F e i g e r l e , D.T. P i e r c e , A. S e i l e r , and R.J. C e l o t t a , A p p l . Phys. L e t t , ( i n p r e s s ) .
9:50
AD2
Electron-Atom Collision Processes in Laser Fields
S. Trajmar, Cali(,oiyu-a Institute
oi Technology,
Jet VnopuZilon
LabohatoKy
The general treatment of electron-atom collision processes in laser fields represents a difficult
question. Besides the complicated many body problem, one also has to consider the interaction of
the electromagnetic field with the target atom, the free electron and the electron-atom collision
complex. So far both in theory and in experiments only cases where one electromagnetic effect
dominates, have been dealt with. We will describe two types of electron scattering experiments:
1) weak tunable laser field which is resonant with an atomic energy level (electron scattering by
laser excited atoms and electron impact ionization of laser excited atoms) and 2) electron
scattering in high-intensity, non-resonant laser fields (free-free transitions or induced
bremsstrahlung and inverse bremsstrahlung). The theory necessary for the interpretation of these
experiments will be briefly discussed.
10:35
11:00
AD3
Break
Vibrational-Librational Excitation and Shape Resonances in Electron Scattering from Molecular Solids
L. Sanche et M. Michaud, Faculté de médecine, Université de Sherbrooke
Low-energy (1-30 eV) electron scattering from multilayer films of N 2 ,C0,0 2 , and NO, condensed on a
metal substrate near 20 K, has been investigated using hemispherical electron spectrometers and onedimensional multiple scattering theory. The essential features of the experiment are the following:
a highly monochromatic (~0.007 eV FWHM) electron beam emerging from an hemispherical monochromator is
incident on a molecular film deposited on a metal substrate; within a well-defined solid angle, a
small portion of the backscattered electrons are energy analyzed by another hemispherical deflector.
Comparisons of experimental electron energy loss spectra with those generated theoretically indicate
that the former are composed of peaks which result from single and multiple vibrational losses convoluted with multiple librational phonons having a mean energy of about 8 meV. Strong and broad peaks
in the energy loss functions of the v=l to 3 vibrational levels of ground state N a ,C0, and 0 2 are interpreted to arise from the formation of transient anions. In N2 and CO, all of the gas-phase shape
resonances are observed, whereas in 0 2 , only the 2I1U and
states seem to exist. The 2Itg state of
N~ exhibits vibrational structure and a relaxation shift of 0.7 eV in the solid. Nitric oxide dimerizes upon condensation and we observe two broad resonances at 11.6 and 14.2 eV in the \>i and Vs decay modes of the dimer. They appear to be associated with the splitting of a single NO" state via
«through space» orbital interaction.
rug
MONDAY, JUNE 18. 1984
ROOM 234
Chairman: D. Venkatesan
9:00
AE1
PLASMAS
IN SPACE
AND
Plasma and Energetic Particles in Planetary Magnetosphere
S.M. Krimigis, The Johm
Hopkini
UniveAA-ity,
LauAel,
MaAyland
The sources, losses and transport of energetic particles in the Terrestrial, Saturnian, and Jovian
magnetospheres will be reviewed. Comparisons among these trapped radiation systems will be made.
It will be shown that, in each case a torus of dense plasma surrounding the planets at varying
distances acts as both a source of plasma and a sink of energetic particles via wave-particle
interactions. The relationship of the tori to planetary aurorae and the relative power levels
from precipitating particles will be estimated for each planet. Finally, the effect of natural
satellite on energetic particles and plasma within the magnetospheres will be discussed.
9:45
AE2
Particle Acceleration in Space and Laboratory Plasmas
D.A. Bryant, RuXheAfioid Appleton
Lab, Abingdon,
U.K.
The general process of Particle Acceleration in Space and Laboratory Plasmas is illustrated by a
discussion of three particular types of acceleration. These types are stochastic acceleration,
collisionless shock acceleration and coherent acceleration. Fermi acceleration which occurs
naturally in space plasmas and electrostatic wave current driven Tokamaks are examples of
stochastic acceleration. Acceleration of particles in the bow shock of the earth is an example
of collisionless shock acceleration. Acceleration by large electric fields, produced in double
layers or In the best wave accelerator are examples of coherent acceleration. The physical
processes involved in each type are discussed. Emphasis will be put on the acceleration of auroral
particles.
10:30
10:45
AE3
Break
Theory of Nonlinear Plasma Phenomena
A. Hasegawa, AT ST B ell
laboKaXoulu,
UuMiay HM,
W.J.
Conceptual developments in nonlinear theories in plasma physics are reviewed, covering the weak
turbulence theory, nonlinear waves (such as solitons and shocks), strong turbulence (and selforganization) double layers and chaos.
11:30
AE4
Interaction of Microphysical and Macrophysical Plasma Processes
P. Palmadesso, Naval RueaJiC-h Labo lato MJ, Waikington,
P.C.
Complex dynamic phenomena in plasmas commonly involve an interplay between physical processes spanning
a broad range of scale sizes. In many cases the macroscopic evolution of the system is controlled or
profoundly influenced by processes operative on the smallest spatial scales. The earth's bow shock,
the physics of ionosphere-magnetosphere coupling in the auroral zones, and the merging or reconnection
of magnetic fields at the nose and in the magnetotail are all examples of this kind of interplay,
arising in the study of the earth's magnetosphere and its interaction with the solar wind and the
ionosphere. We discuss techniques employed, problems encountered, and progress made to date from the
point of view of a theorist trying to understand and model the interaction of large and small scale
phenomena in the magnetosphere. This work was supported by the National Aeronautics and Space
Administration and the Office of the Naval Research
TIME
ROOM
ANNUAL BUSINESS MEETINGS OF CAP DIVISIONS:
12:00
244
Division of Particle Physics
LABORATORY
rugi
ROOM 334
EXPERIMENTAL
OBSERVATION
SPIN-POLARIZED
OF SPIN
ATOMIC
C h a i r m a n : W.N. H a r d y
13:30
BA1
Heat Transfer between Liquid Helium and Solids
J.P. Harrison*, Queen'6
UniveAi-tfy
Heat transfer between liquid helium at one temperature and a solid at another has been particularly
interesting in the temperature extremes below 20 mK and above 1 K. The long-standing high temperature problem appears to be associated with surface impurities and defects, whereas the low temperature problem is not yet settled. Below 20 mK the heat transfer per unit area is very small because
of the small number of excitations so close to absolute zero. To compensate for this, low temperature physicists use sintered metal powder (metal "sponge") heat exchangers with interface areas ^
100 m 2 to cool "v 1 cm 3 of liquid helium to 1 mK and below. Studies have shown that heat transfer
is then relatively large ('v 10 pW/cm3 K at 1 mK) and varies linearly with temperature, a result
that has been variously explained by magnetic energy transfer across the interface or by modified
acoustic theory. This talk will describe the Rutherford, Harrison and Stott model for heat
transfer between a Fermi-Dirac gas confined to the pores of a sinter and the vibrational modes of
the sinter. Application of the model to liquid 3 He and 3He-'*He mixtures, together with experimental
support for and limitations of the model will be discussed.
Research supported by NSERC and School of Graduate Studies and Research.
*Killam Research Fellow.
14:15
BA2
Experimental Observation of Nuclear Spin Waves in Spin Polarized Atomic Hydrogen Gas
B. Johnson, LASSP, CoUnM
UniveAAity
The NMR spectrum of d i l u t e ( - 1 0 1 6 atoms/cm 3 ) s p i n p o l a r i z e d atomic hydrogen (H+) gas
has been observed by pulsed F o u r i e r t r a n s f o r m and CW t e c h n i q u e s .
The spectrum c o n t a i n s
many n a r r o w , d i s c r e t e resonances due t o s p i n wave modes w i t h i n t h e sample volume. The
s p i n waves a r i s e from i d e n t i c a l p a r t i c l e exchange e f f e c t s d u r i n g two body c o l l i s i o n s , even
though the i n t e r a c t i o n H a m i l t o n i a n i s e s s e n t i a l l y independent of n u c l e a r s p i n .
These e x change e f f e c t s g i v e r i s e t o a m o l e c u l a r f i e l d , j u s t as i n l i q u i d 3 He, d e s p i t e the low
d e n s i t y of the non-degenerate H+ g a s . The s p i n wave resonances become much n a r r o w e r , more
numerous, and more i n t e n s e as the n u c l e a r p o l a r i z a t i o n i n c r e a s e s due t o r e c o m b i n a t i o n .
The s p i n d i f f u s i o n c o e f f i c i e n t U 0 a n d t h e parameter p, which i s a measure o f t h e
importance o f exchange e f f e c t s i n s p i n t r a n s p o r t , have been measured.
Supported by N a t i o n a l
15:00
15:30
BA3
Science Foundation DMR-83-05284
Break
Electron Spin Resonance of Spin-Polarized Atomic Hydrogen
B.W. statt, Univvuity
o{ BAitiih
Columbia
Spin-polarized atomic hydrogen (H4-) gas at low temperatures (<0.5 K) has been studied using
Electron Spin Resonance (ESR) techniques which allow direct measurements of the densities of
H atoms in each of the two lower hyperfine states (a and b). It has been demonstrated that
ESR can be made to yield accurate and detailed information about the decay of H4- densities
in time. Crucial to the analysis of the data is the ability to confine the sample of H+
gas inside the liquid '•He coated microwave cavity where the magnetic field and temperature
are well known. Measurements of Kaa and Kab > the two surface recombination rate constants,
have been made and from these results the binding energy of H on liquid 4 He has been
extracted. Also reported are the results of the first detailed study of the one-body surface
relaxation rate which we find is due to microscopic magnetic impurities in the cell walls.
WAVES
IN
HYDROGEN
21
M O N D A Y , J U N E 18, 1984
ROOM
PARTICLE
PHYSICS
154
Chairman: Gabriel Karl
13:30
BB1
Measurement of the high mass dimuon continuum in anti-proton nucleus collisions at 125 GeV
D.G. Stairs, HcG-M UniveAA-Cty
14:15
BB2
A Flux Tube Model for Hadrons
N. Isgur, UniveAAitij
Toronto
Ideas from strong coupling Hamiltonian lattice Q.C.D. are incorporated into a model for hadrons.
The model reduces to the usual quark model in appropriate limits, but it also contains pure glue
and hybrid states.
15:00
BB3
May be diamonds are forever : results from the latest proton decay experiments
L. Sulak, UniveMiMj
15:45
BB4
oi Mic.lviga.ti
Watching the Quarks in the Atomic Nucleus
R.L. Jaffe, UaiiachuAitti
Institute
o£
Technology
Recent electron and neutrino scattering experiments have enabled us to measure the distribution of quarks
within the nucleus.
Contrary to expectations they differ strikingly from those in isolated nucléons and
show evidence for the breakdown of quark confinement high densities.
ROOM 328
Chairman: P. Kirkby
13:30
BC1
INDUSTRIAL
AND APPLIED
RESEARCH
AT XEROX
PRESENTATION
Physics Research at Xerox Research Centre of Canada
M.A. Hopper, KeAox ReAeaAch CentAe o6 Canada
Xerox Research Centre of Canada is primarily concerned with materials that would be
incorporated into future Xerox products. As a result most of the technical personnel
at the Centre are synthetic chemists, materials scientists and chemical engineers.
Research in Physics, ranging from fundamental studies of polymer dynamics to the
electrical and optical characterization of materials has been an ongoing part of the
research effort throughout the ten year life of the Centre. This presentation will
review the scope and background behind this Physics research and will concentrate on
a few selected topics. The projects to be discussed in detail include the methods used
to dteremine the electrical behavior of small (10 micron) particles that are used to
develop the latent electrostatic image in Xerography, the physics behind a new plain
paper printing process and the requirements of high density optical recording media.
14:10
BC2
La recherche sur les isolants électriques à l'IREQ
J-P. Crine, InitUut
de AeckeAchz
d'Hydfio-Québec
(IREQ.)
Les principales activités de recherche en physique appliquée effectuées à l'IREQ seront brièvement passées en revue. On présentera ensuite les principaux problèmes industriels et fondamentaux rencontrés dans la recherche de nouveaux isolants électriques solides et liquides, ainsi
que dans l'amélioration de ceux existants. Une rapide discussion de certains problèmes plus
susceptibles d'intéresser les physiciens (c'est-â-dire, d'être résolus par des physiciens) sera
aussi présentée. En particulier, on proposera une explication thermodynamique simple de la loi
de compensation, loi empirique qui stipule que dans l'équation d'Arrhénius le terme préexponentiel varie linéairement avec l'énergie d'activation. Comme la loi de compensation est observée
pour de nombreux matériaux (liquides, solides, gaz, isolants, semiconducteurs, polymères) et
différents phénomènes (conduction électrique, processus catalytiques, destruction d'organismes
unicellulaires, etc...), le modèle présenté dépasse de loin le cadre de l'industrie électrique.
14:50
Break
PHYSICS
—
AND
IREQ,
OF
PRIZES
rugi
ROOM 328
Chairman: P. Kirkby
INDUSTRIAL
XEROX
AND APPLIED
PHYSICS-RESEARCH
AND IREQ, PRESENTATION
OF
AT
PRIZES
15:00
1984 DIAP Prize for Innovative Young Physicists
BC3
C. Bouchard, Viviiion
ElecÙUcal
Engineering,
NRC
Secondary Electron Detectors
BC4
L. Whitehead, T . I . R . Sy&temi
Light Pipes
Ltd.,
B.C.
Each winner will receive a $200 prize and a certificate from the Division of
Industrial and Applied Physics.
15:40
Annual Business Meeting of the Division of Industrial and Applied Physics
ROOM 228
Chairman: S.L. Chin
13:30
BD1
INTERACTION
LASER-MATIÈRE
Le Concept de la molécule habillée en spectroscopie, photophysique et photochimie en champ Intense
A.D. Bandrauk*, Département de chimie, Université de Sherbrooke
Notre compréhension de l'interaction rayonnement molécule repose sur des théories de perturbation,
telles que la règle d'or de Fermi, réponse linéaire, etc. Or, aux intensités électromagnétiques accessibles aujourd'hui (jusqu'à 1 0 1 6 Watts/cm2), les effets multiphotoniques prédominent.
Dans ces
régions hautement nonlinêaires, les molécules ne se comportent plus comme des systèmes à deux niveaux.
Etant donné que l'énergie totale du système photon + molécule est toujours conservée, les états stationnaires de ce système total appelé molécule-habillée, seront calculés par des méthodes nonperturbatives.
Vu la propensité pour les molécules à se dissocier et s'ioniser en champ intense (â des
intensités au-delà de 10 1 2 Watt/cm 2 ), il faut tenir compte dans la description théorique des états
liés et des états continus (dlssoclatlfs) en même temps.
La méthode des équations couplées de la
théorie quantique des collisions s'apprêtent bien â traiter les états habillés moléculaires, car ceuxci apparaissent comme des résonances dans les matrices de diffusion. Nous présenterons des exemples
de photodissociation et de spectroscopie laoléculaire nonlinéalre pour illustrer des effets de renormalisation à champ très élevé.
Nous terminerons par un exposé du problème de la séparation de BornOppenheiner (adiabatique) de l'hamiltonien moléculaire en champ Intense.
* Boursier Killam, Conseil des Arts du Canada
14:30
BD2
Effet optogalvanique (E.O.G.) dans un plasma luminescent:
J-M. Gagné, Ecole
mécanismes et applications optiques
Polytechnique
Le pompage optique d'une espèce (atome-molécule) dans un plasma luminescent produit un changement d'impédance qu'on appelle effet optogalvanique. Cet effet a été principalement étudié dans les différentes
régions de la décharge luminescente et dans les flammes. Malgré plusieurs tentatives de modélisation de
l'E.O.G., les mécanismes responsables du changement de l'impédance ne sont pas encore bien compris. Les
résultats des derniers travaux sur l'E.O.G. seront présentés. Des applications de l'E.O.G. en spectroscopie laser et en technologie laser seront considérées.
ROOM 228
Chairman: J.M. Gagné
15:30
Rapport du comité d'étude de la division de Physique Optique de l'A.C.P. déposé au C.R.S.N.G. en 1981
J. Lit, Sit
15:45
POLITIQUE
WiZ^Hid Lawiiesi
UniveMAity
Politique et subventions du C.R.S.N.G
J.E. Halliwell, Conieil
de KecheAchti
pour la recherche en optique
en iciencu
natuAeZlei
et en génie,
Ottawa
ET
OPTIQUE
23
AURORA
M O N D A Y , J U N E 18, 1984
R O O M 234
AND
Chairman: D. Wallis
13:30
Simultaneous Observations of Cosmic Ray Intensity
in the Inner and Outer Hellosphere. D. VENKATESAN,
Univ. of Calgary, Calgary, Alberta, Canada, R.B. DECKER
and S.M. KRIMIGIS, Applied Physics Lab/Johns Hopkins
Univ. Laurel, MD, USA, and J.A. VAN ALIEN, Univ. of Iowa
Iowa City, USA - Cosmic ray intensity measurements by
detectors onboard the earth-orbiting satellite IMP-8
(E >35MeV), Voyagers 1 and 2 (E >70MeV/nucl.) and Pioneers 10 and 11 (E >80MeV/nucl.) are investigated over
the period 1977-mid-1982. Solar Flare events, Forbush
decreases and periods of encounter, with Jupiter and
Saturn are deleted before forming 27-day averages. The
changes in cosmic ray intensity registered on all the
five spacecraft over the period are compared. Appropriate corrections are made, to enable a comparison of the
data from all the Spacecraft to a radial distance of
1 AU using a value of 3%/AU for the radial gradient
and a propagation delay of 500 km/sec. The results are
discussed in terms of current ideas of cosmic ray
modulation.
13:45
BE2
Frequency dependence of electrostatic plasma
wave propagation in the auroral E-region.*
D. R. Moorcroft and G. w. Frank, Department of Physics,
University of Western Ontario - The propagation of
electrostatic plasma waves has been studied using
kinetic theory, in order to validate earlier fluid
theory results, and to extend them to the higher
frequencies applicable to many radio-auroral
observations. At all frequencies from 50 to 400 MHz,
the wave packet trajectories include the possibility
of reflection at some minimum height in the E-region.
As' the frequency is increased, the reflection occurs
more"rapidly and the ray path is more nearly parallel
to the magnetic field, with correspondingly larger
grôup velocities. Fluid theory results indicated that
waves could become trapped in a narrow height interval
by variations in magnetic field line direction. The
kinetic theory results show that as the frequency is
raised this becomes increasingly unlikely.
14:15
BE4
Auroral Current Modelling Based on Hagsat
Data T.J. HUGHES, J.R. BURROWS, and J.D. TRICKEY.
Herzberg Institute of Astrophysics, Ottawa - The altitude of the MAGSAT satellite was low enough to permit
the sensing of the magnetic field perturbations due to
ionospheric currents, as well as those from fieldaligned currents. Northern hemisphere data from along
orbits near the dawn-dusk meridian have been analyzed
using a semi-automated method to produce current models
whose associated calculated magnetic fields produce
very good fits to both the eastward and field-aligned
components of the measured field perturbations.
Reasons for the poorer fit to the northward component
will be given, and the ramifications of the current
models with respect to electric field components and
conductivity ratios, and crustal anomaly detection
will be discussed.
14:30
BE5
Radar A u r o r a l Echo Heights as Seen by a 398-MHz
Phased-Array Radar*. J.M. Ruohoniemi and D.R. M o o r c r o f t ,
Centre f o r Rad. S c i . U. o f Western O n t a r i o - Observations
o f t h e radar aurora were c a r r i e d out a t Homer, Alaska
d u r i n g the w i n t e r and s p r i n g o f 1973, 1976 and 1978.
The r a d a r recorded echo s t r e n g t h as a f u n c t i o n o f s l a n t
range over a g r i d spanning 40° i n azimuth and 12° i n
e l e v a t i o n angle.
The e l e c t r o n i c scan c o u l d be repeated
i n as l i t t l e as 20 seconds.
The f a d i n g i n these data i s
Rayleigh.
Echo h e i g h t s vary c o n t i n u o u s l y over d i s t a n c e s
o f tens o f k i l o m e t r e s .
The accuracy o f the h e i g h t
measurement averages 2 km. Maps show both p e r s i s t e n c e
and e v o l u t i o n o f the h e i g h t s t r u c t u r e .
U s u a l l y echoes
are r e c e i v e d from a wide range o f the a u r o r a l l y - a c t i v e
h e i g h t s (95 - 125 km), though o c c a s i o n a l l y s c a t t e r i n g
i s c o n f i n e d t o a l a y e r very l i m i t e d i n v e r t i c a l e x t e n t
(< 4 km).
Echoes a r i s e p r e f e r e n t i a l l y , but not
e x c l u s i v e l y , from volumes n e a r l y s a t i s f y i n g t h e z e r o aspect c o n d i t i o n (a _< . 3 ° ) .
These f e a t u r e s and the
v a r i a b i l i t i e s o f t h e echo h e i g h t s are d i s c u s s e d .
• S u p p o r t e d by NSERC
•Supported by a grant from NSERC.
14:00
BE3
Harmonic ELF waves from an a r t i f i c i a l l y
modulated a u r o r a l e l e c t r o j e t .
H.G. JAMES, Communications
Research C e n t r e , Department o f Communications, Ottawa
K2H 8S2 - H i g h - f r e q u e n c y i o n o s p h e r i c h e a t i n g has been
used s u c c e s s f u l l y t o a r t i f i c i a l l y modulate the a u r o r a l
electrojet.
A c o l l i s i o n a l t h e o r y f o r D/E r e g i o n c o o l i n g
and h e a t i n g has been a p p l i e d t o the case o f ELF-squarewave m o d u l a t i o n o f the HF c a r r i e r .
The e l e c t r o n temper a t u r e has been c a l c u l a t e d as a f u n c t i o n o f both h e i g h t
and t i m e f o r a s e r i e s o f ELF p u l s e s .
The c o r r e s p o n d i n g
waveform o f the c o n d u c t i v i t y p e r p e n d i c u l a r t o the
e a r t h ' s magnetic f i e l d has been computed and F o u r i e r
analyzed as a f u n c t i o n o f a l t i t u d e .
This e s t a b l i s h e s
the s p e c t r a l components o f t h e ELF harmonic c u r r e n t s .
These c u r r e n t s r a d i a t e w h i s t l e r - m o d e r a d i o waves which
can be observed by o v e r p a s s i n g s p a c e c r a f t .
The
c h a r a c t e r i s t i c s o f t h e r e c e i v e d s i g n a l s can be used
t o determine the h e i g h t o f the wave s o u r c e .
14:45
BE6 The EEV P8602 Charge Coupled Device as an Image
Sensor for Scientific Applications C.D. ANGER,
J.W. HASLETT, S.K. BABEY, B.M. LECKIE and G.A. KLASSEN,
Univ. of Calgary - The P8602 CCD image sensor array
made by English Electric Valve Co. (England) is being
used in two major instrument development projects in
Canada. For the past year the Space Sciences Group has
been carrying out tests to evaluate the suitability of
this array for certain scientific imaging applications,
with a particular emphasis on linearity, noise, dynamic
range, quantum efficiency, charge transfer efficiency,
and techniques for "on-chip charge summation" as a means
of trading off between resolution and sensitivity. A
summary of our own and others' test results on the EEV
array and a comparison with other arrays will be given.
15:00
Break
WINDS
rugi
15:15
BE7
Higher Resolution Auroral Spectroscopy.
R.L. GATTINGER and A. VALLANCE JONES, Herzberg Institute
of Astrophysics, National Research Council - A TV
echelle spectrograph has been constructed to obtain
higher resolution spectra of aurora. A 79 1/iran plane
echelle is crossed with a 1200 1/mm plane diffraction
grating to produce spectra in the 42 to 49th orders
of the echelle. Resolution is about 1-2A in the 5000A
region. An image intensifier relays the primary image
to an ISIT TV tube which is used in the pulse counting
mode. Data recorded on video tape are integrated to
produce a final digitized image from which plots of the
spectrum may be prepared. High resolution spectra of
proton and electron aurora are presented.
15:30
BE8 A Comparative Study of the Intensities of Optical
Emission (5577A) and of Bremsstrahlung X-rays of Oct. 14
1982. D. VENKATESAN, L. VARGA, J.S. MURPHREE,
L.L. COGGER and C.D. ANGER, Univ. of Calgary - A balloon
-borne payload consisting of an assembly of four Nal (Tl)
crystal cum photomultipliers was launched from Cold Lake
Alberta, yielding ^5 hours of auroral x-ray data at
altitudes above 109,800 ft. Intensities of x-rays were
measured by one integral channel (> 20keV) and 6 differential channels in the range 20-140keV, in steps of 20
keV. Simultaneously a ground-based CCD system at the
balloon launch sice measured optical data (at 5577A) in
the form of digital all-sky camera images (100x100 pixels) each covering a 170° field of view typically once
every 6 seconds.
The 5577 images allow the determination of whether
enhancements in the x-ray count rates are primarily spatial or temporal. A general large-scale agreement exists between the lower energy differential x-ray channels
and the 5577A intensity observed over the field of view
of the balloon. At specific times the optical data
show intense features over the field of view of the balloon which are also observed in the x-ray data. A quantitative comparison of the x-ray flux with the 5577A
emission rate will be presented.
15:45
BE9
PRESTO Observations of X7320 0 I I Emission in
Twilight. R.H. WIENS and G.G. SHEPHERD, Centre for
Research in Experimental Space Science, York University,
Toronto - The ^P state of 0+ is produced by the EUV
photoionization and photoelectron ionization of atomic
oxygen in the dayglow. Quenching of this state by
atmospheric neutrals is important below 300 km, so
the measurement of the spectral lines at 7320 Â resulting from the forbidden ( D- 2 P) transition gives an
estimate of the column density of atomic oxygen above
250 km. The ability of PRESTO 1 to separate the pair of
0 + lines near 7320 A from nearby OH emission lines, H^0
absorption lines, and scattered sunlight makes it a
useful instrument for the study of this emission during
twilight. Observations from White Sands, Toronto, and
Bird, Manitoba during the 1983/84 period are presented,
and F region oxygen densities are inferred.
X
W.A. Gault, R.H. Wiens, G.J. Gottschalks, R.A. Koehler
and G.G. Shepherd. PRESTO: A Programmable Etalon
Spectrometer for Twilight Observations, Applied Optics,
22, 2551 (1983).
16:00
BE10
Measurements of E-Region Neutral Winds during
Periods of Auroral Activity. L.L. COGGER, J.S. MURPHREE
Univ. of Calgary, and J.W. MERIWETHER, JR., Univ. of
Michigan - Neutral winds were measured from Calgary
during the summer of 1982 by means of a 15-cm aperture
Fabry-Perot interferometer. Line of sight velocities
were obtained from the Doppler shift of the 5577A emission of atomic oxygen that originates near 105 km in
aurora. Measurements from various directions were combined to produce a map of the wind field during the dark
hours. During periods of moderate auroral activity the
wind fields did not show a repeatable pattern from night
to night. For two extremely disturbed nights (Kp'vS),
however, the wind fields were consistent, with strong
westward winds before local midnight that turned towards
the south after midnight. Observed wind speeds were
typically 100 to 200 m/s.
16:15
BE11
Optical Dopplergrams of the Aurora Borealls.
G.G. SHEPHERD and WAMDII COINVESTIGATORS*, Centre for
Research in Experimental Space Science, York University,
Toronto - Optical Doppler images of the aurora were
obtained in February 1984 at Saskatoon, using the prototype instrument for the WAMDII (Wide Angle Michelson
Doppler Imaging Interferometer) developed under the
Canadian Space Program and scheduled for flight on the
Space Plasma Lab-1 mission in 1988. The important elements of the interferometer are achromaticity, fieldwideness and thermal stability in an all-glass system,
a stepping mirror with an accuracy of X/500 and a CCD
camera. The results show a large variation of wind
velocity across the field of view.
C.D. Anger, L.L. Cogger, R.L. Gattinger, J.W. Haslett
R.A. Koehler, E.J. Llewellyn, D.R. Moorcroft, J.C.
McConnell, K.V. Paulson.
16:30
Summary of Project Centaur
F. Creutzberg, HeAzbMx) InAtUbate. ofa
Aifwphyilci,NKC
rug
MONDAY, JUNE
ROOM
18, 1984
PHYSICS
154
Chairman: T.W. Johnston
16:30
BF1
Nuclear Winter and the Atmosphere
W.F.J. Evans, A t m o i p h & v L c EnvVwment
SeAv-ice, Voivniview,
Out.
In the last year "Nuclear Winter" has been widely reported 12 . This session aims at informing
CAP members as to what it might be and what consequences might ensue.
1.
Physics To-day pp. 17-20, October 1982 and pp. 17-20, February 1984
2.
Science Vol. 222, pp. 1283-1292 and 1293-1300, Dec. 23, 1983
MONDAY EVENING
18:00
Méchoui —
20:30
Concert
—
In T h e Tent
Room 154
Faculté d'Éducation
AND
SOCIETY
26
M O N D A Y , J U N E 18, 1984
10:00-16:00
Poster Party — Part I / F e s t i v a l de
de démonstration — Première partie
The posters will be located in THE TENT, except Series PA 1-27
which will be located in the Foyer adjacent to the Exhibit area.
SOLAR
CELL
DEVICES
PAl
Improved efficiency of CdZnS Thin Film Solar
Cells'*'.
S.
CHANDRASEKHAR,
S.
MARTINUZZI*
and
F.Z. NATAREN**, Phys. Dept., Collège militaire royal
de Saint-Jean - Substituting cadmium sulphide by
cadmium-zinc
sulphide
increases
the
open-circuit
voltage.
This is due to the decreased electron
affinity mismatch between CdZnS and CU2S.
However,
this is accompanied by a decrease in the short-circuit
current.
In utilizing a composite collector viz. CdS
with an overlayer of CdZnS, the short-circuit current
is
increased
and
consequently
the
conversion
efficiency.
A quantitative model is given for the
above system.
*Lab. de Photoelectricite, Univ. D'Aix-Marseille-III,
Marseille, France.
**Universidad de Sonora, Mexico.
+ This work was carried out in Lab. de Photoelectricitê, Univ. D'Aix-Marseille-III, France.
PA2
Effect of Varying Fabrication Parameters on
Amorphous Silicon Fims.* T.E.W. STURTEVANT and D.E.
BRODIE, (GWP) 2 ** ~ Waterloo Campus - Much interest
has been shown in amorphous silicon recently, largely
due to Its potential usefulness as a solar cell
material. In most current research, hydrogen is
added to the silicon to obtain desirable electrical
and optical properties in the films produced. It has
been shown that many of these hydrogenated amorphous
silicon films degrade in use. We have suggested that
the electroraigration of protons may be responsible
for the deterioration. To test this assumption,
attempts have been made to produce good quality films
without intentionally adding hydrogen. Some effects
of varying the fabrication parameters were investigated, including substrate temperature, deposition
rate, and irradiating the substrate with electrons,
ultraviolet radiation and argon ions during deposition. Results of these experiments will be presented.
*Supported by NSERC.
**Guelph-Waterloo Program for Graduate Work in
Physics.
A TEM Study of Vacuum Deposited Polycrystalline Zn 3 P 2 .* U. VON SACKEN and D.E. BRODIE, (GWP) 2 **
- Waterloo Campus - Technologically, it would be useful
to fabricate large grained polycrystalline semiconductor
films for large area device applicacations. Zn3P 2 is of
particular interest because it is a promising material
for the active layer in a thin-film solar cell.
Transmission electron microscopy has been used to investigate the morphology of 1-2 micron thick Zn3P 2 films
deposited on a variety of substrates. Electron transparent samples are produced by ion-milling Zn3P 2 films
which have been stripped from the substrate. The unique
feature of this technique is that it allows one to
observe the size and orientation of Zn 3 P 2 crystallites
at any depth in the film, particularly at both the front
and back surfaces. This allows one to observe unambiguously any significant influence the deposition
parameters might have on the nucleation and growth of
the film. Typically, Zn3P 2 films consist of conical
crystallites having their apex at the substrate and the
[22Q]or[004] axis preferentially oriented perpendicular
to the substrate.
PA4
Effect of Varying Fabrication Parameters on
Amorphous Silicon films.* T.E.W. STURTEVANT** and
D.E. BRODIE, (GWP)*** - Waterloo Campus - Much
interest has been shown in amorphous silicon recently,
largely due to its potential usefulness as a solar
cell material. In most current research, hydrogen is
added to the silicon to obtain desirable electrical
and optical properties in the films produced. It has
been shown that many of these hydrogenated amorphous
silicon films degrade in use. We have suggested that
the electroraigration of protons may be responsible for
the deterioration. To test this assumption, attempts
have been made to produce good quality films without
intentionally adding hydrogen. Some effects of
varying the fabrication parameters were investigated, including substrate temperature, and deposition
rate. Also the effect of irradiating the substrate
with electrons, UV and argon atoms, during deposition
will be reported.
*Supported by the NRC under DSS contract
#01SX-3155-2-2718
**Supported by NSERC
***Guelph-Waterloo Program for Graduate Work in
Physics.
PA5
Some Properties of Electron Beam Irradiated
a-Si:Ç Films.* R.D. AUDAS, C.J.L. MOORE, D.E. BRODIE,
(CWP^t, Waterloo Campus - Thin films of amorphous
silicon and its alloys are promising materials for low
cost solar cells. Stability is a major problem of many
devices using a-Si:H (1). We have developed an alternative technique for producing undoped a-Si:C thin films
with similar optical and electrical properties to those
of a-Si:H. The effects of substrate temperature (T s )
on the optical gap and the electrical conductivity of
electron beam irradiated and non-irradiated (reference)
films was studied. Initial results show, for Ts=*30
and 100°C, that electron beam irradiation, during film
deposition, can increase the room temperature resistivity by more than a factor of 300 and the conductivity
activation energy by 0.3 eV. A measurable change in the
optical gap is observed for irradiated and films at the
low substrate temperature but this change is not seen at
the high temperature. This work is continuing and
results for an extended range of T s will be reported.
*Work supported by NRC, DSS contract #01SX-31155-2-2718.
ÎGuelph-Waterloo Program for Graduate Work in Physics.
(1) Solar Cells 9, (1983).
PA6
Photovoltaic Study of a GaAs homojunction. E.
FORTIN, S. CHARBONNEAU, D. CRANDLES, Department of
Physics, University of Ottawa, A.P. ROTH, Semiconductor
Research Group, Division of Chemistry, National
Research Council, Ottawa, and S. MEIKLE, Department of
Physics, University of Calgary, Calgary, Alberta Photovoltaic spectra of Sn-doped GaAs epitaxial layers
grown by MOVPE on Cr-doped semi-insulating substrates
allow a direct evaluation of the substrate - layer
interface characteristics.
The relatively
strong
photoresponse extending to \ = 2 pm is due to carrier
excitation at the interface where a high density of
deep traps creates a depletion region and a potential
barrier.
The nature of the traps can be identified
from the shape of the spectral response.
The barrier
height at the interface deduced directly from the
spectra is
0.6 eV and is attributed to Fermi level
pinning at the Cr
•Supported by NSERC.
**Guelph-Waterloo Program for Graduate Work in Physics.
electron trap level.
rug
PA 7
Effect of Fabrication Changes on a Se-CdO Photovoltaic Cell. C.H. CHAMPNESS and J.K. CHEN, Dept. o f E l e c .
Eng., McGill University - Work has been carried out to
improve the processes involved in the fabrication of a
Se-CdO photovoltaic cell, where the CdO is deposited by
reactive sputtering from a cadmium target. In earlier
work, the oxygen needed for the CdO formation was provided from a trace of residual air introduced periodically
into the sputter.ing system. Experiments have now been
tried with fixed mixtures of argon and oxygen flowing
through the chamber. This method is more convenient than
the residual air process and should provide a device with
a comparable conversion efficiency. With either method,
it has been found that longer sputtering time, producing
a thicker CdO film, leads to a higher illuminated short
circuit current density, j s c / and a higher open circuit
voltage, V o c , due to lower series and larger shunt resistance.
Increase of j s c and V o c has also been obtained by increasing the chlorine content in the selenium.
The effect of varying the sputtering pressure is complex.
PA8
Semiconducting
and
P.V.
properties
of
a n o d i c a l l y g r o w n A g ? 0 films.
E. TSELEPIS and E.
FORTIN, Department of Physics, University of Ottawa The
semiconducting
and
photovoltaic
properties
of
p-type A g 2 0 films grown anodically on Ag electrodes
were studied, in view of possible applications in
solar
energy
conversion.
Films were
grown
in
different alkaline solutions; the best results were
obtained for (0.15 M ) A g 2 S 0 A + (6 x 10 M ) NHÔH +
(5.7 x 1 0 " 3 M ) B a ( 0 H ) 2 + (2gr) A g 2 0 pow der, stirred
mechanically at room temperature.
Film thicknesses of
up to 10 nm were thus obtained for the first time in
a n o d i c a l l y grown A g 2 0 . Photovoltaic spectra taken at
300 K give E - 1.40 ± 0.03 eV. Evaporated Au on A g 2 0
appears to E>e ohmic where A1 is rectifying.
The
barrier height of A g / A g 2 0 is 0.89 ± 0.03 eV and that
of A £ / A g 2 0 is 1.13 ± 0.03 eV.
The best cells give a
V Q C of o v e r 1 0 0 m V , I g c - 25 Â/cra 2 u n d e r A M I
illumination.
SEMI C ON D VC
TORS
PA9
S a t u r a t i o n p h o t o c o n d u c t i v i t y in CdlngS^. S.
CHARBONNEAU
and E. FORTIN, Department
of
Physics,
University of Ottawa, and A. ANEDDA, Istltuto dl Fislca
1
dell
Universita, Cagliarl, Italy. - Features in the
p h o t o c o n d u c t i v i t y spectra of CdIn 2 S^ single crystals
observed at 300 and 85 K are explained on the basis of
the known optical constants and the energy positions of
the acceptor and donor levels in the material.
At
excitation
energies
corresponding
to
definite
t r a n s i t i o n s in the extrinsic region of CdIn 2 S^, the
photoresponse is then investigated as a function of
light intensity over up to twelve orders of magnitude
(about 10
to 10
photon/m -sec). For certain wavelength ranges, a photoconductivity plateau was observed
at high excitation intensities corresponding to a saturation of the higher energy levels.
N e u t r o n I r r a d i a t i o n of S i l i c o n *
?Air
G . R . C r i p p s , J . J . I l o w s k i , P . T . W a n and A . A .
B e r e z i n , D e p t . of E n g i n e e r i n g P h y s i c s ,
M c M a s t e r U n i v e r s i t y - T h e e f f e c t s of
n e u t r o n i r r a d i a t i o n o n t h e p r o p e r t i e s of b o t h
C z o c h r a l ski and f l o a t - z o n e r e f i n e d s i n g l e
crystal silicon wafers have been studied using
the M c M a ster R e s e a r c h R e a c t o r . T h i s has
i n c l u d e d i n v e s t i g a t i o n s of d a m a g e m e c h a n i s m s
a n d « a n n e a l i n g c o n d i t i o n s for f l u e n c e s b e t w e e n
neutrons/cm .
The transmutation
l0
30*nd
off
Si to
P t h r o u g h t h e p r o c e s s of n e u t r o n
a b s o r p t i o n h a s b e e n o b s e r v e d by H a l l e f f e c t
roeasurem e n t s to h a v e ^ a p r o d u c t i o n r a ^ e of
2.3x10
P atoms/cm
p e r neutron/era .
A p p l i c a t i o n s of t h i s w o r k i n c l u d e
p r o d u c t i o n of u l t r a - h i g h r e s i s t i v i t y s i l i c o n
for p h o t o - d e c t e c t o r s .
As w e l l , t h e h i g h
m o b i l i t i e s of t h e s e m a t e r i a l s m a k e t h e m u s e f u l
for h i g h p o w e r s i l i c o n d e v i c e s .
*Work
supported
by
NSERC
PA11
Measurement of Electronic Properties oi: Grain
Boundaries*. S. DAMASKINOS and A.E. OIXON, (GUP1)**
Waterloo Campus - A Scanning Laser Microscope with a
point resolution better than 2 microns was used to study
changes in photoconductivity of Wacker polysilicon as a
function of position and beam intensity. The beam
intensity was varied over 4 orders of magnitude. For
p-type material the measured minority carrier diffusion
length (L) varied with decreasing beam intensity from
150 to 60 microns confirming the results obtained by
other workers using the same technique . For n-type
samples L changed from 90 to 18 microns as the beam
intensity was reduced.
In both n and p-type samples L
decreased with decreasing beam intensity, reaching a
constant value at the lowest intensities. The surface
recombination velocity at the GB in n-type samples
decreased from 20,000 to 3000 cm/sec with decreasing
beam intensity.
*Supported by NSERC
1
P. Panayotatos, E.S. Yang and W. Hwang, Solid State
Electronics, Vol. 25, No. 5, pp. 417-422, 1982.
Scanning Laser Microscope Measurements of
PA12
Minority Carrier Diffusion Length*. B.A. OLIVER and
A.E. DIXON, (GWP) 2 **, Waterloo Campus - A Scanning Laser
Microscope Photon Induced Current ( SLM —PIC) method of
measuring minority carrier diffusion length in semiconductors is introduced and compared with the established
Scanning Electron Microscope Electron Beam Induced
Current (SEM-EBIC) method. Two experimental geometries
are used, with the focussed laser beam either perpendicular or parallel to an ITO Schottky barrier on single
crystal silicon. Results are in good agreement with
EBIC measurements on the same samples . Lifetime
measurements with a pulsed N£ laser support these
results. Potential advantages of the laser microscope
are better beam intensity control, no sample charging,
simplified preparation, and no sample damage by
energetic electrons. The use of a chopped laser beam
and phase sensitive detection has resulted in very good
signal/noise at low beam Intensity.
*Supported by NSERC
1
A.E. Dixon, D.F. Williams, S.R. Das and J.B. Webb, to
be published.
PA13
UV Optoelectronic Switching in Diamond.
R. F.
CODE, X. J. GU, and Y. S. HU0 T , U. of Toronto ~ The
high voltage optoelectronic switching behaviour of
insulating type lia diamond has been studied for the
excimer laser excitation pulse wavelengths of 248 nm,
222 nm and 193 nm. The primary photocurrents generated
at 222 nm are shown to be consistent with a photocarrier lifetime of ^200 ps. The generation of photocurrents at shorter UV wavelengths is shown to be less
efficient. Electrode effects and internal photoemission
are shown to be important during the high-voltage,
high-current operation of the switch. An interesting
current instability is discussed which is related to
space-charge induced switching at the negative electrode. This instability has been observed for all
three excitation wavelengths.
Suitable applications
for high-speed diamond UV high-voltage optical switches
are mentioned.
T
0n leave from the Shanghai Institute of Optics and
Fine Mechanics, Shanghai, China.
'"'Supported by NSERC.
rugi
PA14
S p e c t r o s c o p i e en d o m a i n e t e m p o r e l
de la l u m i n e s c e n c e du S r T i O .* R. L E 0 N E L L I
et J . L . B R E B N E R , Un. de M o n t r é a l - Le s p e c t r e
de l u m i n e s c e n c e du S r T i O ^ , un i s o l a n t avec
E - 3 , 2 7 e V , p r é s e n t e une large b a n d e dans le
v i s i b l e . N o u s a v o n s m e s u r é l ' é v o l u t i o n de
l ' i n t e n s i t é de c e t t e b a n d e en f o n c t i o n du
temps é c o u l é à p a r t i r de l ' a r r i v é e d ' u n e
i m p u l s i o n l a s e r uv b r è v e . Ces m e s u r e s i n d i q u e n t la p r é s e n c e de d e u x v o i e s d ' é m i s s i o n
d i s t i n c t e s . L ' u n e , a t t r i b u é e à la r e c o m b i n a i son d ' e x c i t a t i o n s d é l o c a l i s é e s , se m a n i f e s t e
par une d é c r o i s s a n c g e x p o n e n t i e l l e de l ' i n t e n s i t é p o u r t < 10
s. L ' a u t r e est c a r a c t é r i s é e paj: une d é c r o i s s a n c e en t
avec
t> 5x10
s, ce qui est l ' i n d i c a t i o n de la
r e c o m b i n a i s on d ' e s p è c e s p i é g é e s . Le c o m p o r t e m e n t en f o n c t i o n de la l o n g u e u r d ' o n d e et
de la t e m p é r a t u r e des d i v e r s p a r a m è t r e s tirés
des d o n n é e s e x p é r i m e n t a l e s sera p r é s e n t é .
•Recherche subventionnée
et le F . C . A . C . - Q u é b e c .
par
le
C.R.S.N.G.
PA15
Growth of Te-Rich Se].Te1 ;t Crystals by the
Czochralski Method. N.V. QUANG, I. SHIH and C.H. CHAMPNESS.
Dept. of Elec. Eng., McGill University - It has been reported previously from work in our laboratory that
Se x Tei- x crystals can be grown by the Czochralski method
for x > 0.1 with 16% Se in the melt. In these experiments
it was found that as the selenium content was increased,
two difficulties arose. One of these was rupture of the
meniscus arising from excess selenium at the solid-liquid
interface and the other was the occurrence of scum on the
melt surface. The need to control the temperature very
carefully over long periods of time arising from the very
slow growth rates required, accentuated the problem with
the scum, since partial solidification often started at
the scum and extended to the growing interface. To minimize the scum, a two-crucible technique is being investigated to prepare Te-rich Se x Te^ - x crystals using a
Czochralski crystal puller. Growth conditions for the
ingots were: a pulling rate of 0.3 mm/hr with seed rotation of 10 rpm. Using this method, several ingots were
grown with a diameter of about 1 cm and a length of
about 1.5 cm with a selenium concentration in the melt
up to 25%. These ingots were examined by Laue diffraction for monocrystallinity and EPMA for composition.
PA17
Barrier Height Variation in Selenium-Metal
Contacts. C.H. CHAMPNESS and A. CHAN, Dept. of Elec.
Eng., McGill University. Barrier heights have been deduced frari capacitance-voltage measurements on certain
selenium-metal contacts, which are assumed to form
Schottky junctions. The rectifying device structures
used for the measurements were of the form A£-Bi-Se-Au,
Ai-Bi-Se-Cd and Al-Bi-Se-T®., where the metals Au, Cd and
TS. were evaporated on a layer of crystallized selenium.
The barrier heights increased with decrease of work function in the order Au, Cd, T£ and from this variation the
location within the band gap and density of surface
states in an assumed interfacial layer could be estimated.
From the current-voltage characteristics of the structures,
the current density change from one metal to another at a
given voltage was found to be consistent with the barrier
height variation. The Se-T^ structure in particular,
showed especially well-defined rectification characteristics with a forward-to-reverse current ratio of the
order of 10 4 at 1 volt. However, this decreased rapidly
with time, due presumably to surface oxidation of the
thallium. Capacitance-frequency and resistance-frequency
plots over the frequency range 100 Hz to 1 MHz were
found to be useful for observing changes in the diodes.
fjSR
AND
MAGNETIC
PROPERTIES
OF
SOLIDS
PA18
Giant Muon Knight Shifts in Antimony Alloys.*
J.H. BREWER, D.R, HARSHMAN, E. K0STER, S.R. KREITZMAN
and D.LI. WILLIAMS, TRIUMF and Department of Physics,
University of British Columbia - In most normal metals
the positive muon is observed to exhibit a Knight shift
K,, which is of the order of 10_lt to 10~5. By contrast
a positive muon in antimony metal exhibits a Knight
shift of the order of 1% which is strongly temperature
and orientation dependent. In an effort to understand
this behaviour we have studied Sb alloys. The addition
of bismuth results in a decrease in K u with bismuth
concentration so that at 15 at % bismuth Ky is in the
10~4 range. On the other hand addition of small
amounts of tin significantly increase Kp which can be
as high as 2% for 0.06 at % Sn.
•Supported by the NSERC IEP 107
PA16
Investigation of the Growth of Crystalline
CuInSej. I. SHIH, A.V. SHAHIDI and C.H. CHAMPNESS, Dept.
of Elec. Eng., McGill University - There is much interest
in the chalcopyrite material CuInSe2 for application in
photovoltaic and optoelectronic devices. In the present
work, results are reported on the preparation of bulk
CuInSe2 by the directional freezing method. Horizontal
growth was carried out at 1100°C with either ampoule
motion at a rate between about 0.1 and 1 cm/hr or slow
cooling by reducing the furnace temperature (gradient
freeze) at a rate of about 0.3 to 0.8°C/min. From Laue
back reflection X-ray photographs and visual inspection
it was found that the quality of the samples prepared by
the gradient freeze method was better than that of the
moving ampoule method. The gradient freeze method crystallite size was about 1x5x10 mm 3 . All samples were p-type
with an effective carrier concentration of about 10l7/cni3
and a Hall mobility of about 60 cm^
sec"^ at room
temperature. In preliminary heating experiments under
vacuum, it was found that p-type samples were readily converted into n-type, yielding a carrier concentration of
about 103-6/cm3 and a maximum room temperature Hall mobility of about 1000 tan2
see"*. Preliminary homo junction devices were also fabricated by diffusing In into
p-type samples.
PA19
Muon Spin Relaxation and Crystalline Electric
Field Effects in RERh„B„
*D.R. N0AKES, E.J.
ANSALD0,** J.H. BREWER, C.Y. HUANG,*** and D.R.
Harshman, TRIUMF and Physics Dept., University of
British Columbia _ Data on zero and longitudinal field
liSR in SmRh^B^ and ErRh^B^ between 4K and room
temperature are presented. In both materials, the
rare earth spin correlation time is found to be a
smoothly decreasing function of temperature over the
entire range studied. This function Is discussed in
terms of the crystalline electric fields in these
materials.
* *
***
Supported by NSERC
Physics Dept., University of Saskatchewan
Los Alamos National Laboratory
rug
PA20
Muonium on Amorphous SiO? Surfaces* D.R.
HARSHMAN, J.H. BREWER, R. KEITEL, M. SENBA, J.M.
BAILEY, TRIUMF and UBC, E.J. ANSALDO, Univ. of
Sask. _ The spin relaxation of muonium gn the surface
of fine silica powders (mean radius 35 A) has
been studied as a function of the concentration of
surface hydroxyl groups. The temperature dependence
(4K <T< 300K) of the transverse field muonium
relaxation rate Aû w a s m easured for samples
prepared with 0%, 50% and 70% of the surface
hydroxyls removed. Results show a dramatic decrease
in Aû as the concentration of surface hydroxyls
is reduced. A three-state diffusion and trapping
model is used to interpret the data. Zero field and
longitudinal field measurements were also made on the
samples prepared with 0% and 70% of the surface
hydroxyls removed to identify the local field
distribution and relaxation mechanism(s) at the
surface sites. In addition, gas absorption isotherm
studies on these samples were performed with 3 He and
4
He at 6K, concomitant with measurements of
The dependence of Ajû on surface coverage shows a
strong influence of the concentration of surface
hydroxyls on 2-D muonium diffusion.
* Supported by NSERC, Canada
PA23
New M20 Muon Channel. J. D00RNB0S, J.H.
BEVERIDGE, D.M. GARNER, TRIUMF - This channel replaces
the old M20 channel. It was installed in the first
half of 1983 and has been running satisfactorily
since. The channel front end consists of two
quadrupoles at a distance of 1.0 m from the T 2
production target and at an angle of 55° to the proton
beam. The solid angle of the front end is 12 msr.
The pion beam is momentum analyzed in bending magnet
Bl after which follows an array of alternating
gradient quadrupoles. The pions decay in this section
to give polarized muon beams. The 86 MeV/c backward
decay muons are bent 75° by the second bending magnet,
while the forward decay muons of 172 MeV/c are
simultaneously bent over 37.5°. Both beams are
uncontaminated by other particles. The channel is
also used for surface muons. The beam can be made
transversely polarized by a 3 m long spin rotator
placed in the 37.5° leg. Recently, a short separator
has been installed in the 75° leg to eliminate
positrons in surface muon beams. Now both legs can
give clean surface muon beams. This feature is
important for quick switching between experiments.
PA24
Electron Spin Resonance and Magnetic Susceptibility of ( C d 1 . x M n y ) ( T e 1 _ y S e y ) Alloys.
S. CHEHAB.
PA21
First Application of a Transversely Polarized
Muon Beam. S.R. KREITZMAN, J. BREWER, J. D00RNB0S, J.
BEVERIDGE, Univ. of British Columbia and TRIUMF - A
new method of doing precision high transverse-field
(TF) y + SR has recently ben tested at TRIUMF. In
surface p + (29.8 MeV/c) beam lines, the muon is
produced with its spin parallel to its momentum and so
must enter with Its momentum perpendicular to a high
TF giving its trajectory a small radius of curvature
(~lm in lkG). The resulting deflection of the muon
beam makes untenable a host of variable TF relaxation
studies together with any experiment in extremely high
TF. We have used a Wien filter on the TRIUMF M20 muon
channel to rotate the muon spin polarization so that
it is perpendicular to the muon momentum. The
resulting muon beam can be focussed on a spot 1cm2 and
used to obtain very clean TF-ySR spectra in any
practical Helmholtz coil configuration. Muon Knight
shifts have been measured to lOppm precision using
this technique.
PA22
The Beam Optics Design for M15 Dedicated
Surface Muon Facility. J. D00RNB0S, TRIUMF - This new
muon channel is presently being constructed and is
expected to be ready in October. It is intended
especially for positive, polarized, uncontaminated 28
MeV/c muon beams. The channel takes off from
production target Tl in beamline 1A at an angle of
150° to the proton beam. Its front end consists of
two permanent samarium cobalt quadrupoles placed
Inside the target shield at a distance of 27 cm from
Tl. They have an inner aperture of 10 cm, an outer
diameter of 17.8 cm and a length of 11.4 cm. The
solid angle achieved with these two quadrupoles is 50
msr. The momentum acceptance is 12% Ap/p. The
channel is capable of delivering transversely
polarized beams. This is achieved with two spin
rotators, each rotating the spin 45°. A quadrupole
triplet is placed between them to increase the
momentum acceptance. There are two legs at the end of
the channel. For a 100 yA proton beam on a 1 cm
carbon target we expect a FWHM beamspot area of 2.3
cm 2 containing a flux of 10b muons/s. This gives a
luminosity of 450,000 muons/s/cm 2 .
B.W. CHAN, A. MANOOGIAN, G. LAMARCHE and J.C. WOOLLEY.
Physics Department, University of Ottawa. - Polycrystalline samples of the alloys were prepared by the melt
and anneal technique over the whole range of cubic and
hexagonal single phase fields. ESR measurements of the
Mn
linewidth AH as a function of temperature below
300 K were made on the samples. Some samples were also
studied in the high temperature region up to 500 K. In
all cases AH was found to increase with decreasing T,
reaching a maximum at a critical temperature Tjq which
is associated with an antiferromagnetic transition.
For samples with a M n ^ + concentration < 40%, AH was
found to decrease below T^ and then reach another maximum at the spin-glass transition temperature TQ. The
transition at Tç was studied using magnetic susceptibility.
The variation of AH with T was fitted to the
expression AH = A [ T N / ( T - T N ] a + Bf 9/T + l]. In all
cases the value of a was in the range 0.50 ± 0.05,
which is the mean-field theory value.
The parameters
A, B and 0 were plotted as a function of material
composition.
PA25
Magnetic Properties of Canadian Chrysotiles of
Low Temperatures. G. STROINK, D. LIM, D. HUTT, and
R. A. DUNLAP. Dalhousie Univ. - As part of our programme to calculate, from the magnetic field profile of
the lungs of asbestos workers,the amount of dust present
in the lung, we have measured the magnetization and
Mossbauer characteristics of UICC Canadian chrysotile
and that of a chrysotile sample from the Eastern Townships (Black Lake). The results can be separated into
two parts: the first one is due to the Fe^ + and F e 2 +
replacing Si and Mg in the structure of the chrysotile; the second part is due to the magnetite present
as impurities. The Mossbauer parameters of the F e 2 +
and Fe^ + at octahedral and tetrahedral locations in
chrysotile show little change with temperature. The
Mossbauer spectra and magnetization measurements in
the UICC sample do not show evidence of superparamag netic behaviour, whereas the sample from Black Lake
does show the presence of super paramagnetic, singledomain and multi-domain particles. Despite this
complex magnetic nature, the remanent field, of about
10 respirable samples collected in Black Lake, is
constant, which suggests that the measured remanent
field of lungs of miners in this area can predict the
total dust load present in their lunys.
rugi
PA26
M é t h o d e de d i a g n o s t i q u e pour m a g n é t o m è tre à é c h a n t i l l o n v i b r a n t . * R . L E G A U L T et R.W.
C O C H R A N E , U n i v e r s i t é de M o n t r é a l - Dans un mag n é t o m è t r e à é c h a n t i l l o n v i b r a n t , la tension
induite dans les bobines de H e l m h o l t z est
f o n c t i o n de la s é p a r a t i o n entre l ' é c h a n t i l l o n
et ces b o b i n e s . Si cette s é p a r a t i o n est exp l o i t é e comme v a r i a b l e plutôt que d'y voir
une c o n t r a i n t e e x p é r i m e n t a l e , il en résulte
des p o s s i b i l i t é s de mesure et d ' a n a l y s e qui
é l a r g i s s e n t l'utilité et a u g m e n t e n t la fiabilité d'un tel i n s t r u m e n t . Ces courbes perm e t t e n t n o t a m m e n t : I) d ' o p t i m i s e r le design
de l ' e n s e m b l e é c h a n t i l l o n - b o b i n e s de m e s u r e ,
2) de choisir l ' e m p l a c e m e n t de l ' é c h a n t i l l o n
qui a u g m e n t e le rapport s i g n a l - b r u i t entre
c e l u i - c i et d'autres sources p a r a s i t a i r e s , et
3) de sonder un é c h a n t i l l o n pour y trouver
une a n i s o t r o p i e intrinsèque ou d'autres contributions magnétiques quadrupolaires.
* Recherche
subventionnée
par CRSNG et
FCAC
PA27
T h e RMC S u p e r c o n d u c t i n g Motor:
A
Progress Report.*
D . C . R A I R D , J.G. D A U N T , W . E . E D E R , H.D.
W I E D E R I C K and L.S. W R I G H T - Royal M i l i t a r y
C o l l e g e of C a n a d a , K i n g s t o n , O n t a r i o .
Tïïe use
of s u p e r c o n d u c t i n g m a t e r i a l s in electric m o t o r s
a l l o w s the d e s i g n of m o t o r s w i t h high power:
w e i g h t and power:
size r a t i o s that provide
a t t r a c t i v e p o s s i b i l i t i e s for ship p r o p u l s i o n .
At the CAP C o n g r e s s in 1983^ we provided prel i m i n a r y i n f o r m a t i o n on the d e s i g n of a 50 k i l o watt m o t o r that is intended to supply a d e m o n s t r a t i o n of f e a s i b i l i t y for m a r i n e u s e .
This
y e a r m o r e e x t e n s i v e d e t a i l s will be supplied of
the d e s i g n and construction of the d e w a r system
and of the d e s i g n of the r o t o r and c u r r e n t collection system.
i B a i r d , D . C . , Daunt J . G . , Eder W . E . ,
H.D., Wright L.S.
P h y s i c s in C a n a d a 39, 33 ( 1 9 8 3 )
• S u p p o r t e d in part
by DND
OPTICS
AND
LASERS
PBl
Controlled Switching of Infrared Radiation on
Semiconductor Etalons. P.B. CORKUM and D.W. KEITH*,
N.R.C-Semiconductor étalons have been widely explored as
bistable optical devices. In this paper we explore
their use as controlled optical switches. The infrared
reflection and transmission coefficients of a semiconductor étalon can be controlled by the creation of
free carriers with above bandgap radiation. A model of
this effect has been developed which explains the change
in reflectivity as being primarily caused by optical
path length change due to the presence of the injected
carriers. Experimental results will be presented in
which picosecond pulses switch lOym c.w. radiation with
less than 1 nano J of absorbed energy. The first c.w.
train of ultrashort infrared pulses was also
demonstrated.
*Nov at the University of Toronto.
PB2
§istability and oscillations in an integrated
acoustooptic device." R. TREMBLAY, H. JEROHINEK», J.Y.
D. POMERLEAU. LROL^ Université Laval. - Me report the
bistable and oscillatory characteristics of an integrated acoustooptic device (based on interaction between a surface acoustic wave (SAW) and a guided optical wave) fabricated on a Ti-induffused Y-cut LiNbO^
crystal. The nonlinear optical transmission characteristics (diffracted light vs applied voltage) of the
integrated nodulator is used along with an electrical
feedback relating the detected optical output intensity to the RF voltage applied to the SAW transducer in
order to produce hysteresis.
The periodic, chaotic
and frequency locked oscillation are emphasized by the
use of SAW delay lines in the electrical feedback
loop.
t
On leave from the Department of Physics,
Technical University, Gliwice, Poland.
Silisian
Wiederick
FE320F165.
PA28
An adiabatic demagnetization technique to reach
IK with â elosed-cyclé refrigerator A. M, VALERA, J.
MAIA ALVES and E. DUCLA-SOARES, Phys. Dep. Univ. Lisbon
- We describe an adiabatic demagnetization technique
requiring no liquid helium to reach temperatures in the
IK range, with a two stage closed cycle refrigerador and
GdjCSO^)^, 8K 0 as paramagnetic salt. We started from
temperatures on the 10 K region and used relatively
modest magnetic fields (-1.4T). The salt warmed up at
an initial rate of 0.3K per hour. We discuss the important parameters on the choice of a suitable paramagnetic
substance, and suggest the relevance of this technique
which involves very «mall running costs, for research
centres with no liquid helium facilities.
PB3
Ii"e resoWed thermal lensingi
relaxation of
vibrationnally excited SF .
P. GALARNEAU, X.X. MA,
S.L. CHIN.
LROL^ Université Laval. - A HeNe beam
colinear with a CO laser pulse was used to study the
temporal behavior of the relaxation of highly vibrationnally excited SF
pumped by an intense 10.6 m
P(20) CO_ laser pulse.
The axial intensity of the
HeNe light starts to increase when the CO laser pulse
passes through the SF cell, until if reaches a
maximum value then it falls below the equilibrium
value, finally getting back to that value after a long
time.
This experiment helps to visualize the relaxation process of highly vibrationnally excited SF^ and
gives us the V-T overall relaxation rate.
PB4
Proposition dlune méthode dlaççélératign des
électrons ear laser.
LABERGE, ~p7Â7 SLANGERT
LROLJ. Université Laval. - Depuis la mise au point du
laser, plusieurs personnes ont proposé des méthodes
pour accélérer des particules chargées en utilisant
l'intense champ électrique de sa radiation. On propose une autre méthode dans laquelle un électron, entraîné par une onde électromagnétique, oscille dans
une onde stationnaire.
Un champ électrique moyen non
nul s'applique alors sur l'électron. L'avantage de la
méthode est que l'interaction entre les électrons et
la radiation se produit dans le vide loin de tout support conducteur ou diélectrique, éliminant les problèmes de claquage.
Un gradient d'accéléraôn de pluj
de 1 GeV/m avec un laser CO^ produisant 10
watt/cm
peut être obtenu.
rug
PB5
Pulse compression at 10.6ym using SF .
S.
KOVAR, M. PICHE, P.A. BELANGER, LROL x Université Laval
- The nonlinear absorption of SF^ at 10.6/um is used
to compress the short pulses generated by an actively
mode-locked TEA-CO laser.
The compression factor
depends upon the SF and buffer gas pressures and the
pulse intensity;
tfie duration of the short pulse can
be reduced by 20X for a single pass through an SF
cell.
This effect is enhanced when two counterpropagating trains of short pulses collide in the SF cell.
The resulting time dependent transmission coefficient
of the SF^ cell can be used to mode-lock a second TEAC0 2 laser;
significant pulse compression is then
predicted.
Preliminary experimental results will be
presented.
1
R.S. TAYLOR, V.V. APOLLONOV, P. CORKUM, IEEE J.
Quant. Electron., QE : 16, 314 (1780).
PB6
Spectroscopie photoacoustique d'amiante chrysotile modifiée. G. ROUSSET, L. BERTRAND, Ecole Polytechnique de Montréal. - A l'aide du spectrometre photoacoustique developpé dans nos laboratoires, nous avons
obtenus des spectres photoacoustiques de l'amiante chrysotile. Comparés aux résultats obtenus par spectroscopie par transformée de Fourier (TF), ils présentent les
mêmes bandes d'absorption. Les intensités relatives des
bandes sont étudiées en tenant compte de l'analyse que
nous avons développée pour la spectroscopie photoacoustique d'éléments poudreux-. On retrouve les mêmes intensités que celles obtenues en TF. De plus la sensibilité
de la méthode et sans doute son caractère non destructif
nous permettent de mettre en évidence l'existence de
nouvelles bandes d'absorption près de la bande d'absorption des hydroxyles. Des travaux sont en cours pour
tenter d'identifier et d'analyser ces bandes.
1
Monchalin, J.-P., Bertrand, L., Rousset, G. et
Lepoutre, F. à paraître dans J. Appl. Phys., juin 84.
Optical waveguides formed in Li_NbO, crystals by
li iQdiiiysIon.
R. TREMBLAY, H. JEROMÏNEK», J.Y.D.
POMERLEAU. LROL^ Université Laval. - We present a method of producing slab and strip optical waveguides in
LiNbO^ crystals by Ti indiffusion in stationary air
atmosphere.
The required guide parameters are controlled only by adjusting the Ti film thickness
under fixed diffusion temperature and duration.
The
dependence of the guide characteristics on the Ti film
thickness has been investigated in detail.
In particular, we report the influence of the incomplete
peneration of Ti into LiNbO on the shape of the refractive index profile of the produced optical waveguides.
We also describe the experimental and computational methods of evaluating the optical properties
of the waveguides.
*
On leave from the Department of Physics,
Technical University, Gliwice, Poland.
Silesian
PB8
S o l i t o n - l i k e s o l u t i o n s o f the homogeneous wave
equation.
P.A. BELANGER, L a b o r a t o i r e de Recherches en
Optique e t Laser (LP.OL), Département de Physique, U n i v e r s i t é Laval^ Quebec, G1K 7P4
We have o b t a i n e d s o l i t o n - l i k e s o l u t i o n s t o t h e
f r e e - s p a c e homogeneous wave e q u a t i o n .
The s o l u t i o n s
are Gaussian Laguerre ( o r Hermite) beams, which propagate i n a s t r a i g h t l i n e a t l i g h t v e l o c i t y remaining
focused f o r a l l t i m e .
can be c o n v e n i e n t l y r e p r e s e n t e d by a s u p e r p o s i t i o n of
Gaussian beams.
The o p t i c a l q u a l i t y i n the f a r f i e l d i s
s t r o n g l y dependent on t h e c o u p l e r f o c a l l e n g t h .
When
the beam i s c o l l i m a t e d by the c o u p l e r , the o n - a x i s f a r
f i e l d b r i g h t n e s s can be improved by a f a c t o r of up t o
1.5.
* Work supported by the Defense Research
Valcartier.
PB10 Mode^locjong of homogeneous qain lasers through
temporally modulated phase conjugate reflectivity. C.
PARE, M. PICHE, P.A. BELANGER. LROL^ Université Laval.
- Mode-locking of homogeneous gain laser with a phase
conjugate mirror pumped by external trains of sho^t
pulses is investigated through a dispersive model .
Phase conjugation is assumed to be due to degenerate
four-wave-mixing in a Kerr medium. The analysis takes
into account the bandwidth of the homogeneous medium
and the relaxation time of the Kerr medium.
For a
thin Kerr medium, the model predicts that the laser
pulse shape will be a Gaussian whose duration is much
smaller than the pump pulse duration. The duration of
the short pulses increases as the interaction length
in the Kerr medium is increased, reaching an upper value equal to the duration of the pump pulses.
Other
effects such as pump chirping, pump detuning and pump
depletion will also be discussed.
1
M. PICHE, C. PARE, P.A.
(accepté pour publication).
BELANGER,
Opt.
Lett,
PB11 Single mode operation of a TEA-CO^ laser with §
modified Fabry-Perot interferometer.
Dr LAROUCHE, G.
KOVAR, M. PICHE, P.A. BELANGER, LR0L x Université Laval
- A modified Fabry-Perot interferometer is used to
achieve single longitudinal mode operation in
a
TEA-CO^ laser. The interferometer is made of two parallel metallic mirrors with a dielectric window positioned between the two mirrors; the window is used to
couple the laser beam in the Fabry-Perot cavity
defined by the two metallic mirrors.
The finesse of
the interferometer can be adjusted by the polarization
of the laser beam, the angle of the window or by
coating one of the window surfaces.
Partial tuning
over
the CO
rotational lines is
verified
by
heterodyne detection.
The introduction of an étalon
or a grating in the interferometer can be used to discriminate between the adjacent resonances of the interferometer.
1
P.W. SMITH, Pr-oc. IEEE, 60, 422 (1972).
PB12 Chaos and laser mode-locking.
M. PICHE, LROLx
Université Laval.
- Many nonlinear physical systems
are known to exhibit a chaotic regime of operation
even though ( their governing equations are purely
deterministic .
One example of such systems is the
optically bistable device .
In this communication,
another class of optical systems is shown to become
chaotic:
actively mode-locked lasers in which a nonlinear medium with a third order susceptibility is
introduced.
The nonlinear medium imparts a phaseshift proportional to the laser intensity.
When the
laser is operated above threshold, the nonlinear
phase-shift causes a coupling between the supermode
states which are completely independent in the linear
regime.
Such a mechanism results in a complicated
temporal structure of the short pulse propagating in
the laser cavity.
'
PB9 O p t i c a l Resonators w i t h Gaussian R e f l e c t i v i t y
Mirrors:
Output beam C h a r a c t e r i s t i c s * .
N. McCARlHY and
P. LAV1GNL, INRS-Energie, U n i v e r s i t é du Québec, Varennes
- The c h a r a c t e r i s t i c s of a Gaussian beam which i s t r a n s m i t t e d t h r o u g h a complementary Gaussian r e f l e c t i v i t y
c o u p l e r are a n a l y z e d . . I t i s shown t h a t the coupled beam
Establishment,
E. OTT, Rev. Mod. Phys., 53, 655 (1982).
K. IKEDA, 0. AKIhOTO, Phys. Rev. Lett., 49, 1457
(1982).
rugi
PB13
Excimer Laser Polarization by Intra-Cavity
Placement of Brewster Angle Windows. J.F. Hahn,
F,j. Morgan and C.H. Dugan, Phys. Dept., York U. -308 nm TE XeCl excimer laser light is effectively
polarized by intra-cavity placement of several inexpensive Brewster angle silica plates. Results showing the
degree of polarization, its dependence upon the number of
plates within the cavity and effects of the polarizer
upon laser output energy are discussed. Techniques of
measuring laser polarization will be presented.
PLASMA
PHYSICS
PCI
Expériences canadiennes & l ' a i d e du d i s p o s i t i f
WISP/HF sur l a n a v e t t e s p a t i a l e .
H.G. JAMES, MDC/CRC,
Ottawa, J . V . GORE, CAL, Ottawa e t R.S. GRUNO, CNRC/CCSS,
Ottawa - La p a r t i e h a u t e - f r é q u e n c e du programme 'Waves
i n Space Plasmas' (WISP/HF) a pour o b j e t une s é r i e
d ' e x p é r i e n c e s en plasmas s p a t i a u x â des fréquences
s i t u é e s e n t r e 0,1 e t 30 MHz. Un élément du programme
s c i e n t i f i q u e v i s e â une connaissance a m é l i o r é e du
comportement des sondes e t des antennes plongées dans
l e s magnétoplasmas.
Seront é t u d i é s éqalement d i v e r s
processus a c t i f s ou p a s s i f s subis par l e s ondes
é l e c t r o m a g n é t i q u e s de plasma.
E n f i n , l a combinaison
é m e t t e u r - r é c e p t e u r WISP/HF f o n c t i o n n e r a en mode radar
d o p p l e r pour des recherches sur l a dynamique â cirand
é c h e l l e de l a magnétosphere.
L ' i n s t r u m e n t WISP/HF comprend un émetteur e t
deux r é c e p t e u r s , dont un â bord d ' u n s o u s - s a t e l l i t e .
Le système e s t o r g a n i s é a u t o u r d ' u n m i n i - o r d i n a t e u r du
type 8086/8087 qui commande ces d i v e r s é l é m e n t s .
L'ensemble p e r m e t t r a au personnel à bord e t au sol de
c o n t r ô l e r une e x p é r i e n c e en temps r é e l pour o p t i m i s e r
son rendement.
Le NASA p r é v o i t un premier v o l du
d i s p o s i t i f WISP en 1988, en compagnie d ' a u t r e s
instruments s c i e n t i f i q u e s .
PC2
Fluctuation Spectra and Eddy Statistics In
Turbulent Flow. L. LOEWEN, B. AHLBORN, A. FILUK,
Dept. of Physics, Univ. of British Columbia - Power
spectra of velocity fluctuations in turbulent flow
(Re ~ 20,000) are measured using a hot-film probe and
compared with power spectra predicted from a coherent
structures description of the same flow. The eddies
are observed by photographing the paths of aluminum
filings on the surface of a water filled towing tank
in which the turbulent flow was generated. Both
methods yield the same turbulent length scales,
turbulent energy decay time and similar shape of the
power spectra. We see this agreement as a
confirmation of the validity and usefulness of basing
a model for turbulence on the eddy-size distribution.
PC3 Monte C a r l o S i m u l a t i o n o f Heavy I m p u r i t y T r a n s p o r t
i n t h e scrape-utt Layer or a lotcamaK. j.l.a. viiali ana
B . L . STANSFIELD, INRS-Energie - " P o n t e C a r l o t r e a t m e n t
o f the t r a n s p o r t of wa11 s p u t t e r e d metal i m p u r i t i e s i n
t h e s c r a p e - o f f l a y e r o f a tokamak has been developed.
I n c l u d e d i n the t r a n s p o r t code are the v e l o c i t y d i s t r i butions f o r sputtered wall i m p u r i t i e s , m u l t i p l e ionizat i o n , f r i c t i o n a l d r a g , plasma f l o w , and r a d i a l v a r i a t i o n
o f plasma parameters ( e l e c t r o n and i o n t e m p e r a t u r e and
electron density).
Numerical r e s u t l s o f the i m p u r i t y
atom and i o n d e n s i t y d i s t r i b u t i o n are o b t a i n e d .
From
these r e s u l t s we have a r r i v e d a t an e s t i m a t e f o r the
inward i m p u r i t y f l u x across t h e s e p a r a t r i x .
I t i s found
t h a t t h e inward d i f f u s i o n o f heavy i m p u r i t i e s can be t h e
dominant process by which i m p u r i t i e s reach the h o t p l a s ma c o r e .
F u r t h e r m o r e , c l o s e agreement o f t h e c a l c u l a t e d
" t o t a l i o n f l u x " w i t h e x p e r i m e n t a l data i s b e l i e v e d t o
be a c c o u n t a b l e f o r by t h e f r i c t i o n a l drag.
PC4
Thermomechanical E v a l u a t i o n o f P o l o i d a l D i v e r t o r P l a t e s t o r a Long-Pulse Lxperiment:
C. BUULHtK,
INRS-Energie -The Tokamak de Varennes experiment c o m p r i ses a d o u b l e - n u l l p o l o i d a l d i v e r t o r and i n t e n d s s t u d y i n g
a high duty f a c t o r sequence o f d i s c h a r g e s f o r times o f
up t o 30 s e c . , each discharge l a s t i n g between 100 msec
and 1 sec w i t h a 15 min.
i n t e r v a l between sequences. A
t o t a l energy o f up t o 6 MJ has t o be absorbed by t h e
d i v e r t o r p l a t e s r e s u l t i n g from a c o n s t a n t l o a d i n g by an
e x p o n e n t i a l power d i s t r i b u t i o n on e i t h e r s i d e o f the
separatrix.
Energy i s i n p r e s e n t e x p e r i m e n t s s t o r e d i n
d i v e r t o r p l a t e s and removed from these between s u c c e s s i ve d i s c h a r g e s .
Active c o o l i n g of p l a t e s i s r e q u i r e d f o r
high heat f l u x d e n s i t y and a l s o f o r l o n g p u l s e d i s c h a r ges. T h i s paper examines v a r i o u s m a t e r i a l s f o r i n e r t i a l
cooling.
Two designs based on a c t i v e c o o l i n g are a l s o
presented.
I t i s found t h a t i n e r t i a l c o o l i n g i s i n s u f f i c i e n t , a c t i v e c o o l i n g o f the p l a t e s d u r i n g and i n between sequences b e i n g necessary.
PC5 Mesures de l a température i o n i q u e d'une décharge
par 1'eTargissement u o p p l e r des r a i e s a ' i m p u r e t e s e t
Etudes de son comportement.
R. B O Ï V I N e t B . C . G R E G O R Y ,
INRS-tnergie, u.
du QueSëc - Le d i s p o s i t i f à s t r i c t i o n
a x i a l e p r o d u i t une colonne de plasma 0,227m de l o n g u e u r ,
» 0,036 m de d i a m è t r e , t e n s i o n moyenne maximale de 170V,
c o u r a n t maximal de 12kA, durée de 1,8ms, 8 < n e < 90 x
1 0 1 9 n r 3 , kT e < 60 eV e t k T j ~ 20eV pour une p r e s s i o n de
remplissage ( h é l i u m ) de 2.5 à 15 x 1 0 _ 3 T o r r e t un champ
magnétique a x i a l de s t a b i l i s a t i o n » 0 , 3 T .
Les d i a g n o s t i c s s o n t un i n t e r f é r o m è t r e ^-onde (4mm), une caméra
r a p i d e TRW e t l a s p e c t r o s c o p i c dans l e v i s i b l e pour T e
e t dans l ' u l t r a - v i o l e t l o i n t a i n pour T.t (par é l a r g i s sement D o p p l e r ) .
Un modèle coronal donne un a c c o r d
s a t i s f a i s a n t e n t r e l e s v a l e u r s de l a d e n s i t é , de l a
température é l e c t r o n i q u e e t de l a p r e s s i o n .
De p l u s
deux modèles t h é o r i q u e s o n t é t é a p p l i q u é s au comportement de la décharge.
Le p r e m i e r , l ' é t a t d ' é q u i l i b r e
MHD, e x p l i q u e mieux l e s r é s u l t a t s à haute p r e s s i o n de
remplissage (> 10 x 1 0 " 3 T o r r ) .
Le deuxième, basé sur l e
b i l a n é n e r g é t i q u e de l a décharge, e x p l i q u e mieux l e s
r é s u l t a t s à f a i b l e p r e s s i o n (2.5 x 1 0 " 3 T o r r ) .
Un m e i l l e u r accord des deux modèles e s t obtenu s i l e d i a m è t r e
de l a décharge augmente avec l e c o u r a n t du plasma, phénomène q u i sera é t u d i é expérimentalement prochainement.
PC6
Evidence of Discrete Alfvén Waves in a Plasma
Column* F. BRUNEL, NRC, J.N. LEBOEUF and S.M. MAHAJAN,
IFS - Discrete or global Alfvén eigenmodes (GAE)l have
been observed in a plasma column using a 3-dimensional
particle MHD code. The code was first run with a
thermal level of fluctuations (linear case) to pinpoint
the spatial structure and frequency of the modes.
Analysis of the simulation data by interferogram
techniques reveals a number of GAE's with different m
(poloidal) and n (toroidal) mode numbers and radial
locations. They all have the following predicted
properties; helical structure with helicity opposite to
the kind modes, broad spatial structure, frequency
(i) < (k..CA)mi-n, narrow symmetric spectral width
11
mi)
A mn
AU)/U) < 2%. Next, selected modes were externally
driven (nonlinear case) by antennas close to the wall
inside the column. Saturation of the modes occurs
after 10-20 wave periods with some toroidal mode
coupling and considerable asymmetric broadening of the
resonance (for the modes considered) up to Aui/iii < 15%
for perturbation levels of b/B c «10%.
^S. M. Mahajan, D.W. Ross and G.L. Chen, Phys. Fluids
26, 2195 (1983).
rug
PC7
Measurements of the Image Field In the ST0R-1M
Iokamak.* 0. MITARAI, S.W. WOLFE, A. HIROSE and H.M.
SKARSGARD, Univ. of Saskatchewan - Measurements of the
poloidal image fields due to the iron core transformer
have been made in the ST0R-1M tokamak, (R = 22 cm, a =
7.4 kA, V„
4 volt, *dur
= 1.8 x 10" Torr) constructed t or
4.5 ms,
base
turbulent heating and high g experiments. The measured
vertical field and horizontal field are in close agreement with theoretical predictions. Approximately one
half of the required vertical magnetic field is provided
by the plasma current itself through the image field.^
The image field component decreases due to core saturation. This effect has also been demonstrated for the
horizontal field. Image fields and their control will
have important implications for iron core tokamaks
having RF current drive.2
1.
2.
*
A. Hirose, STOR-M Technical Memorandum, 1981
(unpublished).
0. Mitarai and A. Hirose, Univ. of Saskatchewan
PPL-67 (1983), and to be published in Nucl. Fusion.
Supported by NSERC, Canada.
Mesure de la température ionique d'une colonne
de plasma à l'aide de la diffusion collective et la détection cohérente à 10.6 um. J.L. LACHAMBRE ET R. DECOSTE, Institut de recherche d'Hydro-Québec - Nous utilisons la diffusion laser à petjj a^gle sur une colonne de plasma stabilisée (5 X 10 m , 6 ev) pour en déterminer la température ionique. Le faisceau incident
provient d'un laser puisé O^-TEA atteignant 0.5 MW de
puissance en mode longitudinal unique. Le signal diffusé est mesuré par détection hétérodyne à l'aide d'un
oscillateur local indépendant et son spectre est analysé électroniquement par une batterie de filtres RF.
Nous présenterons plusieurs spectres expérimentaux mettant en évidence la sensibilité de la technique sur le
courant de décharge et sur le mélange gazeux. Les niveaux absolus des signaux reçus sont consistants avec
les mesures interférométriques. A fort courant, les
spectres montrent clairement la résonance acoustique
accentuée par l'augmentation de la charge ionique moyenne. En ajustant les paramètres du plasma par lissage
de la courbe théorique sur les points expérimentaux
nous déterminons, pour une température électronique
donnée, la température ionique avec une précision de
± 10%. L'application de cette technique aux plasmas
de fusion à haute température sera discutée.
PC9
Un système de tomographie pour l'émission des
rayons-X par un plasma Tokamak avec une section poloïdale arbitraire. R. DECOSTE, Institut de recherche d'Hvdro-Québec - Sur un plasma Tokamak, la reconstruction du
profil d'émission des rayons-X se fait habituellement à
partir de l'expansion d'harmoniques. Cette approche implique des visées complètes du plasma -6ous plusieurs angles avec 2 ou 3 larges matrices de détecteurs, ce qui
est très difficile étant donné l'accès restreint au plasma par les hublots. Nous proposons plutôt d'utiliser un
grand nombre de petites matrices qui individuellement ne
voient qu'une partie du plasma mais de directions différentes. On utilise ensuite des techniques de reconstruction tomographique qui implique la solution sous forme
matricielle d'équations linéaires par la méthode des
moindres carrés. Les considérations pour le design d'un
tel système seront présentées pour la géométrie particulière du Tokamak de Varennes. Des simulations par ordinateur indiquent que 68 détecteurs répartis sur 8 petites matrices donnent une bonne résolution spatiale et des
reconstructions acceptables pour divers plasmas de sections arbitraires. Le même système de détection peut
aussi être utilisé pour l'étude plus conventionnelle des
instabilités MHD.
PC10
Breakdown Studies in the RESURRECTOR
Tokamak, Y. DEMERS, and J. CASTRACANE, MPB Technologies
Inc., Montreal, Quebec - We report on the installation
and commissioning of the RESURRECTOR tokamak. This
machine is a medium-sized (R = 54 cm, a = 14 cm)
research torus. Details will be presented on power
supply and magnetic field configurations.
Optimization studies, resulting in the first plasma,
are discussed. Since achievement of this initial
breakdown, effort has been directed toward extended
pulse operation. The parameter scans involved
in these experiments will be compared to the design
parameters of the machine. The base diagnostic set
presently in place on the tokamak will be described.
Research plans for the facility are addressed.
PC11
Ion C y c l o t r o n Resonance Heating by Means o f
the Fast wave i n a L o n g i t u d i n a l l y Inhomogeneous Magnet i c Field.
V. FUCHS and M. M. SHOUCRI , IREQ, Varennes,
Quebec, and C.N. LASHMORE-DAVIES and R.A. CAIRNS,
Culham L a b o r a t o r y , Abingdon, U.K. - We c o n s i d e r the
c o u p l i n g between the f a s t wave and the slow i o n c y c l o t r o n wave i n a plasma i n which the e q u i l i b r i u m magnetic
f i e l d i s l o n g i t u d i n a l l y inhomogeneous.
Such a c o u p l i n g
can o n l y occur when a second i o n species i s p r e s e n t and
f o r f i n i t e kj_. This c o n f i g u r a t i o n i s o f relevance t o
m i r r o r s and a l s o tokamaks.
An approximate d i s p e r s i o n
r e l a t i o n i s o b t a i n e d from the usual c o l d plasma model
by r e p l a c i n g a l l s l o w l y v a r y i n g q u a n t i t i e s by t h e i r value a t the resonance.
The r e s u l t i n g e q u a t i o n preserves
the c u t - o f f p r o p e r t i e s o f the o r i g i n a l e q u a t i o n .
The
approximate d i s p e r s i o n r e l a t i o n i s then used t o a n a l y se the mode c o n v e r s i o n o f the f a s t wave t o the slow
wave a t the m i n o r i t y resonance.
PC12
On the Theory o f Mode-Conversion i n Inhomogeneous Plasmas.
V. FUCHS, IREQ, Varennes, Quebec and
A. BERS and L. HARTEN, MIT, Cambridge, USA - E a r l i e r work on mode c o n v e r s i o n t h e o r y by Fuchs, Ko and Bers
i s d e t a i l l e d and expanded upon, and i t s r e l a t i o n t o
energy c o n s e r v a t i o n i s d i s c u s s e d .
Given a l o c a l d i s p e r s i o n r e l a t i o n D(u>; k , z ) = 0 , d e s c r i b i n g s t a b l e waves
e x c i t e d a t an e x t e r n a l l y imposed frequency w = w , a
p a i r w i s e mode-coupling event embedded t h e r e i n i s e x t r a c t e d by expanding D ( k , z ) around a c o n t o u r k - k r ( z ) obt a i n e d from 80/ 9k = 0. The branch p o i n t s o f D ( k , z ) =
0 are the t u r n i n g p o i n t s o f a second-order d i f f e r e n t i a l
equation representation.
I n o b t a i n i n g the f r a c t i o n
o f mode-converted e n e r g y , the c o n n e c t i o n formula and
c o n s e r v a t i o n o f energy f l o w must be used t o g e t h e r , and
proper a t t e n t i o n must be given t o d i s t i n g u i s h the
c o u p l i n g o f f o r w a r d (u g u p h > 0) and backward
(u g u p h<
0 ) waves. Examples o c c u r r i n g i n i o n - c y c l o t r o n and l o w e r h y b r i d wave h e a t i n g are p r e s e n t e d , i l l u s t r a t i n g the use
o f the t h e o r y .
1 V. Fuchs, K. Ko, and A. B e r s , Phys. F l u i d s
(1981).
2£,1261
PC13
Quenching of the Second Stokes in a Methane Compressor .* R. Marchand, R. Fedosejevs, and I.V. Tomova, Dept.
of Electrical Engineering, Univ. of Alberta - One way of
producing the short laser pulses needed for ICF would be
to compress long (~'200ns) KrF laser pulses by pulse
stacking followed by Raman compression in a gas cell.
Recent experiments have shown that efficient (-75%) compressions with compression ratios of approximately 5 are
possible in methane cell. The main limitation here
comes from the growth of the so-called second Stokes,
which tends to deplete the compressed (first Stokes)
pulse in energy and degrade the spatial coherency of the
resulting beam. It is shown that the growth of the
troublesome second Stokes can be considerably reduced by
making the medium locally disperson free, i.e. by reducing the mismatch factor Ak of the second Stokes.
Specifically, when Akc is less than the small signal
convective growth rate of the second Stokes, the antiStokes becomes strongly coupled to the first and second
Stokes and effectively quenches the growth of the latter.
Methods for producing a dispersion free medium are also
discussed.
a
On leave from Faculty of Physics, Sofia University,
Sofia, Bulgaria.
* Supported by NSERC of Canada.
rugi
A TOMIC
PHYSICS
&
I
MOLECULAR
PDl
Formation and Dissociation of Alkali Dlmer
Ions !py a ruby laser.* G. WAGNER and N.R. ISENOR,
(GWP)^t, Waterloo Campus
Ruby laser formation and
dissociation of Na"£ has been extended to heavier
alkalis. Three-photon ionization is immediately
followed by photo dissociation of the dimer ions
from the X it state to the Z lt state,
state^ For the
g
,2„H u state leads
heavier alkalis a resonance at the I
to higher-order dissociation processes into excited
atomic states. The kinetic energy of the fragments was
measured and yielded the following: De(icj) - 0.81 ±
0.08 eV, D e (Rb^) - 0.74 ± 0.10 eV and D e (Cst) 0.80 ± 0.09 eV. Our measurements for K'j and Rb£ are
the first obtained in experiments directly involving
the ionic species. Comparison is made with experimental and theoretical results of other authors. The
effect of laser polarization upon the mechanism has
also been observed.
tGuelph-Waterloo Programme for Graduate Work in
Physics.
'Can. J. Phys. 6J_, 40, (1983).
PD2
The Valence-Core Electron Exchange Interaction
and the Collapse of 4f and 5d Orbitals in the Cesium
Isoelectronic Sequence.* J. MIGDALEK**and W.E. BAYLIS,
Dept. of Physics, U. of Windsor - As one progresses along
the isoelectronic sequence of Cs, the ground state
Ce+3
changes from 6s
(Cs ,Ba + ) to S d - j ^ C L a ) t o ^ 5 / ?
^
Pr + 4 ). Relativistic Hartree-Fock and model-potential
calculations are reported which give a better understanding of variations in the ordering of the states as the
ion charge increases. The 5d and 4f orbitals are found
to "collapse" as the increasing coulomb and exchange attractions overcome centrifugal repulsion. Core-valence
exchange is found to be crucial for the proper ordering
of the states as well as for reliable fine-structure
splittings. Furthermore, the collapse of the 5d and 4f
orbitals greatly enhances the sensitivity of the properties of these states to small perturbations, so that
even details of the exchange interaction, including nonlocal effects, as well as core relaxation and polarization effects, are required in order to compute accurate
ionization potentials and fine-structure splittings.
* Research supported by NSERC.
** On leave from the Inst, of Physics, Pedagogical U.
of Kielce, 25-509, Kielce, Poland.
PD3
Threshold Excitation Measurements in Rare Gas
Metastables Using a Laser Fluorescence Technique.* W.B.
WESTERVELD, P.W. ZETNER, G.C. KING and J.W. McCONKEY,
Dept. of Physics, U. of Windsor - Previous studies^ of
resonance structures in the excitation functions of
rare gas metastable states have relied on the use of
channel electron multipliers to detect the metastable
yield. Such devices do not discriminate between the
J=0 and J=2 metastable states which both contribute to
the observed yield. Hence, the measured cross section
corresponds to a combination of excitation cross sections for the two states. Our novel, triple beam
apparatus uses laser induced fluorescence to probe
metastables produced by electron impact on a gas beam,
thereby allowing extraction of one particular metastable cross section. Results are presented for Ne and
He.
Work supported by NSERC and NATO.
Brunt et al., J. Phys. B 9, 2195 (1976).
PD4
Polarization Correlations Following
E l e c t r o n I m p a c t E x c i t a t i o n of S i m p l e M o l e c u l e s .
K. B E C K E R , H . W . D A S S E N * a n d J . W M c C O N K E Y " " , ÏÏ7
W i n d s o r , Ont
—
The e l e c t r o n - p o l a r i z e d p h o t o n c o i n c i d e n c e t e c h n i q u e h a s b e e n u s e d to
s t u d y t h e e x c i t a t i o n of t h e p r o m i n e n t V . U . V .
e m i s s i o n s o f l^j D2 a n d N 2 . P o l a r i z a t i o n
correlation data have been obtained for inc i d e n t e n e r g i e s u p to 80 eV a n d e l e c t r o n
s c a t t e r i n g a n g l e s up to 25°. An a t t e m p t is m a d e
to r e l a t e t h e o b s e r v e d s y s t e m a t i c t r e n d s in o u r
d a t a "to t h e p r o p e r t i e s of t h e r e s p e c t i v e t a r g e t
molecule. The theoretical framework for m o l e c u l a r c o i n c i d e n c e s t u d i e s of t h e e x c i t a t i o n of
a single rotational level will also be presented.
P r e s e n t a d d r e s s : H e r z b e r g I n s t i t u t e of
„j, A s t r o p h y s i c s , N R C , O t t a w a
" Temp. a d d r e s s : J P L , C A L T E C H , P a s a d e n a
Supported by NSERC
PD5
Cross-Section
for H e +
2p-»ls
Emission
F o l l o w i n g E l e c t r o n I m p a c t o n He. K. B E C K E R , L.
F O R A N D a n d J . W . M c C O N K E Y " , U. W i n d s o r , O n t . " " —
The a b s o l u t e e m i s s i o n c r o s s - s e c t i o n of t h e He"1"
2p-»ls l i n e at 3 0 4 8 f o l l o w i n g t h e s i m u l t a n e o u s
i o n i z a t i o n a n d e x c i t a t i o n of He by e _ - i m p a c t
h a s b e e n m e a s u r e d f r o m t h r e s h o l d to 5 0 0 e V
u s i n g a crossed e l e c t r o n - g a s beam set-up. The
unresolved He and H e + emissions were detected
by a C h a n n e l t r o n a f t e r p a s s i n g t h r o u g h an X U V
f i l t e r ( A l : S i / C - o v e r c o a t ) . The H e + f r a c t i o n of
the total signal was extracted utilizing the
t r a n s m i s s i o n p r o p e r t i e s of t h e X U V f i l t e r a n d
the well-known cross-sections of the He resonance lines. Our H e + cross-section is comp a r e d w i t h two p r e v i o u s m e a s u r e m e n t s w h i c h
s h o w e d o n l y a r a t h e r p o o r agreement 1 ' 1 .
"Temp, a d d r e s s : J P L , C A L T E C H , P a s a d e n a
^ " S u p p o r t e d by N S E R C
•"•M. M o u s s a & de H e e r , P h y s i c a , 3 6 , 6 4 6 ( 1 9 6 7 )
2
E . B l o e m e n et a l . , J . P h y s . B l ^ , 7 1 7 ( 1 9 8 1 )
PD6
Collision Processes in Intense Laser Fields:
Instrumentation. B. WALLBANK, J. K. HOLMES, G. VAN
AUDENH0VE, and A. WEINGARTSHOFER, Physics Dept. St.
Francis Xavier University - The direct observation of
multiphoton free-free processes in controlled three
beam (electron, photon and atom) experiments1 has
stimulated interest among several theoretical groups
who have discussed these results and given suggestions
for new experiments. For the next generation of experiments significant improvements and innovations
were needed in our instrumentation. The following will
be dicussed: (1) a new single longitudinal mode TEACO2 laser system (~10 8 W/cm 2 ), (2) a pulsed molecular
beam valve capable of high gas densities in pulses of
100 ys duration, (3) a fast multichannel transient
recorder allowing sampling of the laser pulse at 50 ns.
time intervals and synchronous electron (and/or ion)
pulse counting.
'Weingartshofer, A., Clarke, E. M., Holmes, J. K. and
Jung, C., Phys. Rev., A19, 2371 (1979); Weingartshofer,
A., Holmes, J. K., Sabbagh, J. and Chin, S. L.,
J. Phys. B., 16, 1805 (1983).
ru
PD7
Fast Positive Ion Production in Single Collisions
of Halogen Negative Ions with Rare Gas Atoms. B. HIRD,
F. RAHMAN and I. ABBAS, University of Ottawa, Canada Measurements of the o_+ total cross_section for_fast
positive ion production from F , Cl , Br and I
negative ion beams in single collisions with He, Ne, Ar,
Kr and Xe between 10 keV and 100 keV show that double
detachment contributes significantly to the total
detachment cross section. For example a _ + is half O_Q
for I in the heavier rare gases at 100 keV. The cross
sections at the lower energies for F~ are found to be
lower for Kr and Xe than for He and Ne. This unusual
behaviour is less evident for the heavier halogen ions
and seems to be explainable as competition from target
ionization due to the lower ionization potential of the
heavier rare gases.
PD8
Fast positive Ion Production in Single Collisions
of Halogen Negative lens with Rare Gas Atoms. B. HIRD,
F• RAHMAN and I. ABBAS, University of Ottawa, Canada Measurements of the o_H. total cross_section for_fast
positive ion production from F~, CI , Br and I
negative ion beams in single collisions with He, Ne, Ar,
Kr and Xe between 10 keV and 100 keV show that double
detachment contributes significantly to the total
detachment cross section. For example a i s half a_ Q
for I in the heavier rare gases at 100 keV. The cross
sections at the lower energies for F" are found to be
lower for Kr and Xe than for He and Ne. This unusual
behaviour is less evident for the heavier halogen ions
and seems to be explainable as competition from target
ionization due to the lower ionization potential of the
heavier rare gases.
PD9
Doubly Charged Molecules.* A. GALINDO-URIBARRI,
H. W. LEE,
K. H. CHANG,
L. R. KILIUS
and
A. E.
LITHERLAND, IsoTrace Laboratory, Univ. of Toronto - A
number of doubly charged molecules have been identified
following charge changing collisions
of
negative
molecular ions with argon gas in the central electrode
of the IsoTrace tandem accelerator. So far all cases
studied have resulted in the observation of substantial
currently undergoing chemical analysis because
purities on the level of 106 are required to observe
the ddp formation. These results and future plans for
this measurement will be discussed.
U ;
S.I. Vinitskii, Sov. Phys. JETP 47(3)
444(1978)
* Supported in part by NSERC.
PD11
Pionium Formation. J.M. BAILEY, R. KEITEL,
TRIUMF, C.A. FRY, D.R. HARSHMAN, J.B. WARREN, U. of
B.C. - Measurements have been made of the yield of
pionium (ir+e-) atoms in vacuum from various surfaces
under different conditions. This atom offers the
possibility of a Lamb shift measurement without hfs or
nuclear form-factor complications, and a test of the
correct equation to describe a bound system of one
boson and one fermion with small boson structure
corrections. A tt+ beam is incident on a target, and
charged particles in the emerging beam are swept away
by a magnet. Observations of a tt+ signature in a
counter telescope after the sweeping field would
indicate that the ir+ has transversed this field while
bound in some neutral system, which can only be
pionium.
PD12
y~SR in Nuclei with Spin.* J.H. BREWER, Dept.
of Phys., Univ. of British Columbia. - A standard
negative muon spin rota tion (y SR) technique was used
to study the precession of the F + and/or F~ hyperfine
states of muonic atoms with nonzero-spin nuclei, in
particula r 6 Li, 9 Be, 2 3 Na, 2 7 A 1 , 3 5 > 3 ^C1, 3 9 K , ^ V
and 93 Nb. In the light est elements, mainly the F
frequency v+ > 0 is obs'erved, while in the heavier
elements the F~ signal (frequency v_ < 0) is "fed"
+
by transi tions from the F to the F~ states at a rate
R, so Ion, as R » (v+ •v_). R is extracted from
the field dependence of this effect.
*Supported by Natural Sciences and Engineering
Research Council of Canada.
+ 2
fluxes (>1000/s^. To date those identified are BeO
2
Bj 2 , B 0 + 2 , CH^ 2 , C 2 H + 2 and Cj . These observations
significantly increase the number of such molecules
known
and demonstrate that they are relatively
common. All are metastable and in some cases, their
spontaneous fragmentation can be easily observed. The
molecules are identified
by
their
fragmentation
patterns after coulomb explosion in a thin carbon foil
11 cm in front of a silicon heavy ion particle counter.
Some possibilities for further study will be discussed.
1. K. P. Huber and G. Herzberg, Molecular Spectra and
Structure IV Constants of Diatomic Molecules, Van
Nostrand Reinhold, 1979, pp77Î6~i
* Supported by NSERC
PD10
Muonic Molecule Formation Rates in HP and
H 2 +D ? Gases*. K. ANI0L, C. VIRTUE, F. ENTEZAMI, D.
MEASDAY, Univ. of British Colmumbia; S. JONES, Idaho
Falls National Engineering Lab., D. HORVATH, M.
SALOMON, TRIUMF; J. SMITH, Surrey University; B.
ROBERTSON, Queen's Univ., - An investigation is
underway at TRIUMF of the formation rates of the ddy
and pdy molecules in gaseous targets of hydrogen
isotopes. The formation of the muonic molecules is
signalled by a nuclear fusion, either d+d + 3 He+n or
d+p •*• 3 He+y. In a preliminary test run we have
observed the fusion neutrons and gamma rays from the
H 2 +D 2 mixture but not from the HD. A large difference
is expected^ 1 ' between H2+D2 and HD in the case of
the ddy formation. Our test run was at room
temperature and 35 atm pressure. The gas samples are
PD13
Measurement of the Lamb Shift in 2S Muonium.
C.A. FRY, R.F. KIEFL, J.B. WARREN; Univ. of British
Columbia, J.M. BAILEY, G.A. LUDGATE, C.J. ORAM, P.W.
SCHMOR; TRIUMF, G.M. MARSHALL, A. OLIN; Univ. of
Victoria. - The Lamb shift in the hydrogen-like
muonium atom has been measured for the first time by a
beam foil radio frequency technique. A beam of about
4 x 104 positive muons per second from a TRIUMF low
energy muon beam line was used to produce about 30 2S
muonium per second. The value of Lamb shift obtained
is 1070 +12/-15 MHz with a systematic uncertainty of
2MHz, compared with the theoretical value of
1047.03 MHz.
rugi
PARTICLE
ratio
a(ir)/a(K) 'v 100
experimental value of
PHYSICS
'Y. A f f e k
PEl
Mesons with Chromodynamics• S.P. GODFREY and
N. ISGUR, Dept. of Physics, U of Toronto - Meson physics
was studied in a relativistic quark model which includes
the important features of quantum chromodynamics. It
was found that all mesons, from the tt to the T, can be
described successfully. The key ingredient of the
model is a universal, one-gluon-exchange plus linear
confinement potential, motivated by QCD. However, it is
crucial to the success of the model that relativistic
effects be included. The spectroscopic results of the
model are supported by an extensive analysis of strong,
electromagnetic, and weak meson couplings. The details
of the model will be described along with some
spectroscopic and decay results. The analysis indicates
that a successful theory of the strong interactions
must be consistent with the general features expected
from QCD.
PE2
A Flux Tube Model of Meson Decay. R. KOKOSKI
and N. ISGUR, Dept. of Physics, U. of Toronto - Results
of a meson decay analysis based on a QCD-inspired flux
tube breaking model for quark-pair creation are
presented. The analysis includes all quark model meson
states which have been seen to date, as well as most of
the other low lying states predicted by the GodfreyIsgur version of the quark model. The results are found
to agree quite well with the present experimental data
demonstrating the relevance of this decay picture and
lending further support to the Godfrey-Isgur model, the
wavefunctions of which we employ. In light of our
results some puzzling aspects of the current data will
also be discussed along with some predictions
concerning as yet unseen meson states.
p
E3
Critical Temperature and Density of
S t a t e s in the Q C D - b a g M o d e l . *
R. G a g n o n , U n i v .
de M o n c t o n , N . - B . — A n a n a l y s i s o f a q u a r k g l u o n p l a s m a d e s c r i b e d b y p e r t u r b a t i v e Q C D to
f i r s t o r d e r in
as
s u p p l e m e n t e d by a b a g c o n s t a n t to a c c o u n t for n o n - p e r t u r b a t i v e e f f e c t s is
performed.
A r u n n i n g c o u p l i n g c o n s t a n t is e x plicitly implemented.
The critical temperature
and energy density are determined for d i f f e r e n t
numbers o f quark flavors.
I t is f o u n d t h a t the
dependence of
Tc
on
B*
is a l m o s t l i n e a r .
The c o n d i t i o n s u n d e r w h i c h
T c < B ^ are discussed.
N e x t , the a s y m p t o t i c d e n s i t y o f h a d r o n i c s t a t e s is d e r i v e d b y L a p l a c e - i n v e r t i n g the
partition function.
The center-of-mass degrees
of freedom are explicitly excluded.
The
r e s u l t , w h e t h e r o r n o t the c o u p l i n g c o n s t a n t
is r u n n i n g , is the s a m e as i n the s t a t i s t i c a l
bootstrap model.
• S u p p o r t e d i n p a r t by C R S N G a n d C e n .
d e l'U. de M .
de
Rech.
PE4
S t r a n g e P a r t i c l e P r o d u c t i o n in H e a v y ion Collisions.*
R. G a g n o n a n d M . - A . S i m a r d ,
U n i v . de M o n c t o n , N . - B . — W e e x t e n d a m o d e l
d e v e l o p e d by M a r g o l i s a n d c o l l a b o r a t o r s 1 to
describe inclusive central particle production
i n p - p s c a t t e r i n g a t h i g h e n e r g y to h e a v y - i o n
collisions.
A transition from h a d r o n i c m a t t e r
to a q u a r k - g l u o n p l a s m a is a s s u m e d .
Hadronization p r o c e e d s statistically.
All parameters
a r e t a k e n f r o m a p p l i c a t i o n s to p - p s c a t t e r i n g
w h i c h f i t the d a t a .
W e c a l c u l a t e the p r o d u c t i o n
rate of any p a r t i c l e of m a s s
m,
emphasizing
s t r a n g e p a r t i c l e s , a s a f u n c t i o n o f the p l a s m a
temperature.
Assuming that a temperature of
approximately
130 M e V
is r e a c h e d i n
Ne-NaF
collisions at
2 . 1 G e V / n u c l e o n , w e e s t i m a t e the
e t al., Phys.
to b e c o m p a r e d w i t h
70 ± 46.
Rev.
D2^, 1883
• S u p p o r t e d in p a r t b y C R S N G a n d C e n .
de l'U. de M.
de
the
(1982).
Rech.
PE5
The KN Scattering Length in the CBM*. E.A.
VEIT,** B.K. JENNINGS, TRIUMF, and A.W. THOMAS,
Adelaide, South Australia - A generalization of the
cloudy bag model (CBM) to chiral SU(3_)xSU(3) symmetry
has recently been applied to s-wave KN
scattering.'^ Here we use a similar approach to
describe the KN scattering length. In contrast to
KN scattering where many narrow A and E
resonances occur, the KN scattering has no low energy
resonances. This greatly simplifies the problem and
reduces uncertainties. The results are somewhat
sensitive to the bag radius and meson decay constant.
However with reasonable values for these parameter we
get good agreement with experimental results for both
1-0 and 1=1. For 1-0 the result is nonzero only
because of the vertex renormallzation.
')
E.A. Veit, B.K. Jennings, R.C. Barrett and A.W.
Thomas Phys. Lett. B. (In press)
* Supported by CNPq, FINEP (Brazil) and NSERC
(Canada)
** Universidade Federal Do Rio Grande Do Sul, Luiz
Englert, S/N - Porto Alegre - 90000, Brasil
PE6
Antlproton-Proton Interactions at Rest: I
"ASTERIX" Apparatus. M. COMYN, TRIUMF, E.G. AULD,
D.A. AXEN, K.L. ERDMAN, B. HOWARD, R. HOWARD, B.L.
WHITE, UBC; G. BEER, G. MARSHALL, L.P. ROBERTSON,
Univ. of Victoria; R. ARMENTROS, D. BAILEY, U.
GASTALDI, CERN; J.C. BIZOT, B. DELCOURT. P.
ESCHTRUTH, J. JEANJEAN, N. NGUYEN, LAL, Orsay; L.
CERRITO, W. DAHME, R. WODRICH U Munich; S. BARLAG, M.
DOSER, G. GRAFF, M. HEEL, H. KALINOWSKY, F. KAYSER, E.
KLEMPT, R. LANDAU, R. SCHNEIDER, 0. SCHREIBER U Mainz;
C. AMSLER, C. MARTOFF, U. STRAUMANN, P. TRUOL, M.
CARIA, J. RIEDELBERGER, U. SCHAFER, U Zurich; C.
SABEV, Geneva - The ASTERIX experiment measures the Xrays, charged particles and neutral particles produced
in events occuring when low momentum antiprotons from
LEAR at CERN are stopped and annihilate on protons in
atmospheric pressure hydrogen gas. The X-rays are
measured in a thin-windowed cylindrical multiwire
proportional drift chamber, charged particles are
tracked through a .8T magnetic field by seven
concentric cylindrical multiwire proportional
chambers, and neutrals (gamma rays) are detected in
position sensitive gamma detector arrays. The
performance of the apparatus will described.
PE7
Antlproton-Proton Interactions at Rest: II
"ASTERIX" Preliminary Results. M. COMYN, TRIUMF. E.G.
AULD, D.A. AXEN, K.L. ERDMAN, B. HOWARD, R. HOWARD,
B.L. WHITE, Univ. of British Columbia; G. BEER, G.
MARSHALL, L.P. ROBERTSON, Univ. of Victoria; R.
ARMENTROS, D. BAILEY, U. GASTALDI, CERN; J.C. BIZOT,
B. DELCOURT. P. ESCHTRUTH, J. JEANJEAN, N. NGUYEN,
LAL, Orsay; L. CERRITO, W. DAHME, R. WODRICH U Munich;
S. BARLAG, M. DOSER, G. GRAFF, M. HEEL, H.
KALINOWSKY, F. KAYSER, E. KLEMPT, R. LANDAU, R.
SCHNEIDER, 0. SCHREIBER U Mainz; C. AMSLER, C.
MARTOFF, U. STRAUMANN, P. TRUOL, M. CARIA, J.
RIEDELBERGER, U. SCHAFER, U Zurich; C. SABEV, Geneva
- The ASTERIX apparatus described In the preceding
paper had its first data taking run in December 1983,
and about 4.2 x 106 events were recorded. After
tracking analysis at UBC, about 0.8 x 106 events
passed the initial cuts and were identified as good
(annihilatlon-in-hydrogen) candidates. Results of
preliminary physics analyses of these events will be
presented.
rug
PE8
A Measurement of TT-ev/Tr-pv Decay Branching
Ratio. T. NUMAO, D.A. BRYMAN, E.T.H. CLIFFORD, A.
OLIN, P. SCHLATTER, Univ. of Victoria, J.M.
POUTISSOU, Univ. of B.C., J.A. MACDONALD, TRIUMF, P.
KITCHING, Univ. of Alberta, G. AZUELOS, Univ. of
Montréal and M.S. DIXIT, NRC - The Ti-ev/n-pv decay
branching ratio provides the best test of the
universality of the weak interaction. We have
proposed a new experiment to improve the existing
number ( 1.218±0.014)xl0_l+. The largest single
systematic uncertainty in the previous experiment was
the low energy tail correction of the ir-ev peak (0.7%)
under the Michel spectrum by the n+u+e decay chain.
We have developed a new technique of determining this
correction factor empirically. A measurement of total
energy in target counters enables a statistically
meaningful background subtraction in the muon decay
spectrum region. Initial tests have obtained a
suppression factor of Michel background >200 (relative
to the previous measurement), which is sufficient to
reduce the tail correction error to <0.2%. The same
TT-ev spectrum also provides a very sensitive test for
the mixing of massive neutrinos.
PE9
Measurement of the TT ° Electromagnetic Form
Factor In TTêê'y decay.* J.-M. POUTISSOU, M.D.
HASINOFF, C. VIRTUE, C. WALTHAM, UBC and TRIUMF,
P. GUMPLINGER, A. STETZ, Oregon State Univ.,
B. ROBERTSON, Queen's Univ., T. MULERA, A.F. SHOR,
Lawrence Berkeley Lab., S.H. CHEW, Oxford. - An
experiment is currently underway at TRIUMF to measure
the tt° electromagnetic form factor at low momentum
transfer. Two telescopes each consisting of a large
Nal detector preceded by a set of 3 plastic
scintillators and 3 wire chambers are used to detect
large opening angle e + e~ pairs (> 135°) corresponding
to large Invariant photon masses. A sensitivity of
.02 to the slope parameter "a" in the form factor has
been demonstrated. Preliminary results will be
reported at the conference as well as a discussion
of the various sources of background.
*
Supported in part by NSERC
PE10
Search for Muon-Electron Conversion with the
TRIUMF Time Projection Chamber.* J.-M. POUTISSOU,
R.A. BURNHAM, M. HASINOFF, UBC, D. BRYMAN, E.T.
CLIFFORD, M.J. LEITCH, I. NAVON, T. NUMAO, P.
SCHLATTER, Univ. of Victoria and TRIUMF, G. AZUELOS,
P. DEPOMMIER, J.-P. MARTIN, R. POUTISSOU,
U de Montreal, M. BLECHER, K. G0T0W, VPI and SU, M.S.
DIXIT, C.K. HARGROVE, H. MES, NRC, J.A. MACDONALD,
J.E. SPULLER, TRIUMF. - A search for the muon number
violating process y~+A->-e-+A on a Ti nucleus is underway at TRIUMF using a large atmospheric pressure time
projection chamber to detect the emitted electrons.
Thus far we have stopped 4 x 10 12 negative muons and
no electron has been observed in an energy region
around 100 MeV. On the basis of this result, we set
an upper limit for the branching ratio
r(u"Ti>e~Ti)/r(M"Ti>capture) <3 x 10"11 at the 90%
confidence level.
*
PEU
Pion Radiative Capture and Charge Exchange to
120 MeV.* D.F. MEASDAY, K. ANIOL, A. BAGHERI,
F. ENTEZAMI, M.D. HASINOFF, J.-M. POUTISSOU, and
M. SALOMON, TRIUMF and Univ. of British Columbia,
B.C. ROBERTSON, Queen's Univ. The reactions 7i~p-»-yn
and TT"~p-*-Tr°n have been studied for six energies between
50 and 120 MeV, on the Mil channel at TRIUMF. The
large Nal detector TINA was placed at 7 angles between
45° and 135°. Analysis of the radiative capture is
complete and the results are much more accurate than
previous data, and will specify more precisely the
isoscalar amplitudes in the multlpole analyses. The
charge exchange data are not yet complete, but
preliminary results indicate that the cross-section
agree with the Karlsruhe analysis and thus are
inconsistent with the recent LAMPF data of
Frank et. al.
*
Supported in part by NSERC, Canada
THEORETICAL
PHYSICS
PE12
The Integration of the Bethe-Salpeter
Equation in Four Dimensions, Using the Monte-Carlo
Methods, S.A.CURVITZ* and M. SALOMON, TRIUMF - We have
used the Monte-Carlo method*
to integrate the
Bethe-Salpeter equation in the ladder approximation
with the Yukawa potential in energy - momentum space.
The scattering amplitude was calculated for 7 energies
between 1 and 200 MeV. The results indicate that the
method is convergent for coupling constants up to
g 2 =7xl0 6 MeV 2 , but at larger values It diverges due to
low energy bound states. The phase shifts were
compared with other approximations2^ and they agree
within the statistical uncertainty of the method.
This uncertainty is mainly due to the sign changes of
the Kernel in the equation and Increases with energy.
1
2
^
'
*
M. Salomon, Phys. Rev. A28(1983) 3645
R.S. Bhalerao and S.A. Gurvitz, Phys. Rev.
£28(1983) 383
On leave from the Weizmann Institute, Israel.
PE13
Interaction Effective de Multipôles-Test dans
un Fluide Polaire.* L. MARCHILDON et G. ARSENAULT,
U. du Québec â Trois-Rivières. - L'énergie d'interaction
effective de deux particules dans un fluide est reliée
au logarithme de la densité réduite de probabilité des
positions et orientations des deux particules. Soit
deux multipôles-test électriques d'ordre arbitraire immergés dans un fluide de molécules identiques à symétrie axiale, polaires et non polarisables. Dans le cas
où le volume du fluide est infini, on obtient pour l'interaction effective des multipôles-test à grande distance une expression formellement exacte, qui s'exprime
en termes de la permittivité statique du fluide et de
deux paramètres microscopiques. Dans le cas d'un volume
fini, des termes correctifs s'ajoutent au résultat précédent, qui doivent être calculés par approximation.
L'interaction effective de deux multipôles-test ainsi
obtenue semble appropriée au calcul par simulation de
la permittivité statique.
^Subventionné par le CRSNG et le fonds FCAC.
PE14 Energy Level Fluctuations in Complex Spectra.
0.B0HIGAS, Institut de Physique Nucléaire, Orsay,France,
R.U.HAQ, Laurentian University, Sudbury,Canada, and
A.PANDEY, University of Rochester, New York - A natural
theoretical framework for the study of energy level
fluctuations (deviations from local uniformity) is
provided by the Random Matrix Theory (RMT). For
systems with rotational and time-reversal invariance
one considers the Gaussian Orthogonal Ensemble (GOE)
of asymptotically large real symmetric matrices. It
has been found that nuclear and atomic energy levels,
and recently the spectra of chaotic quantal systems
display two key features, namely level repulsion and
long-range order as predicted by GOE. In the present
work, using the nuclear energy levels as an example,
we address ourselves to the question - what is the
information content of data and how does it compare
with theory under a detailed analysis which goes far
beyond earlier comparisons? It is shown that using
suitable methods, information regarding two level
correlations as well as higher order ones can be
extracted from the available data. A close agreement
between theory and experiment is found.
rugi
SOLAR
TUESDAY, JUNE 19, 1984
ROOM 334
Chairman: L.G. Caron
CELL
DEVICES
This session is sponsored by the Centre de Recherche en Physique
du Solide de l'Université de Sherbrooke.
Cette session est commanditée par le Centre de Recherche en
Physique du Solide de l'Université de Sherbrooke.
9:00
CA1
Semiconductor Solar Cells
R. Thomas, CaAleton UrUveAAÀXy
9:45
CA2
Photoelectrochemlcal/Electrolysls Solar Cells
A.J. Frank, Solan. Enengy ReieMch
In&tUute,
Golden,
Colorado
Synthesis of fuels from abundant, renewable resources such as water, nitrogen, and carbon dioxide
based on photoelectrochemical solar energy conversion Is an Important but long-term option for
meeting many of the energy needs of the future. An economically viable photoelectrochemical solar
cell will require conversion efficiencies above 10% and long-term stability.
A major scientific
Impediment
to
reaching
these goals
is
that high
solar
conversion efficiencies
require
semiconductors with narrow bandgaps (1.0 to 2.2 eV) and these materials generally exhibit
instability.
A thermodynamic and kinetic requirement Is that the valence-band holes and the
conduction-band electrons have sufficient energy for the respective oxidation and reduction halfreactions of the desired photoproducts.
In this paper, an introduction is given to some of the
principles and approaches of photoelectrochemical solar energy conversion with ençhasis on the
cleavage of water to Hj and Oj.
10:30
11:00
CA3
Break
Organic Solar Cells
R. Loutfy, XeAox Rt&eaAdn
Centre
THEORETICAL
ROOM 154
Chairman: P. J. O'Donnell
9:00
CB1
Magnetic Monopoles and Unified Field Theories
G. Kunstatter, UniveM-iXy o(, Toronto
Magnetic monopoles were first introduced in 1931 by Dirac in order to explain
electric charge quantization. In recent years, monopoles have been the subject
of much renewed experimental and theoretical interest. A brief review of the
general properties of magnetic monopoles will first be presented, followed by
a summary of their current experimental status. Finally, some recent work on
the specific properties of monopoles predicted by GUTs and Kaluza-Klein theories
will be described.
9:45
CB2
General Charge Conjugation Operators in Simple Lie Groups
R.V. Moody and J. Patera, UniveM-iXé de
Montréal
Particular elements ("charge conjugation operators") found in any compact simple Lie group are
considered. Such elements R(i) transform a physical state (weight vector of a basis in a
representation space) into others with opposite "charge" (i-th component of the weight), sometime
changing also the sign of the state. The elements R are of order 4 in any K, i.e. RRRR«1. There
are no charge conjugating elements in the group K which would be of order 2 in all representations
of K. Exploitation of these elements and the finite subgroup N of K generated by them offer new
powerful methods for computing with representations of the Lie group. Their application to
construction of bases in representation spaces will be considered in more details. It represents
a completely new direction to the problem.
10:30
CB3
Developments in the Theory of Dilute Polymer Solutions
B. Nickel, Univeriity
11:15
CB4
oi Guelph
Random Walking on a Fractal
R.A. Guyer, Scklwnberger-Voll
Reiearc.h,
kmhehAt, MA
Some of the complex media in which particle motion occurs have fractal structure; e.g. the infinite
cluster at the percolation threshold, Wltten-Sander growth clusters. The notion of fractal structure
and its characterization by the fractal dimension, dp, is explained. For a particularly simple
motion, random walking, particle kinematics is characterized by the "dimension of the walk", dw,
xeet1' w . The relationship of geometry, as embodied in dp, to kinematics, d w , is discussed in the
context of the Alexander-Orback conjecture, dw = 2dp/3. The Einstein relation is derived, d w « dp + w.
and found to place strong restrictions on the validity of the A-0 conjecture.
PHYSICS
rug
T U E S D A Y , J U N E 19, 1984
R O O M 228
C h a i r m a n : S . P . Reddy
9:00
CCI
9:30
CC2
10:20
10:40
CC3
THIRTY-FIVE
YEARS
OF
COLLISION-INDUCED
ABSORPTION
The birth of collision-induced absorption
J.L. Locke, National
Research
Council
o<5 Canada
Collision-induced absorption: astrophysical implications and ab initio calculations
G. Birnbaum, National
Bureau of, Standards,
Washington,
V.C.
Break
Theory of induced absorption: How it began and where we stand today
J. Van Kranendonk, liwiversiMj
of
Toronto
The early history of the development of the theory of collision-induced absorption, beginning in
1950, will be outlined. The main step to be taken - so obvious now, but not so easily accepted
then - was the realization that a pair of unbound, colliding molecules (two H2 molecules) could
act as a single absorbing unit, and in particular that one molecule could make a radiative transition due to a dipole induced and located in another molecule. The relation between this idea and
the Aharanov-Bohm effect will be pointed out. A central role in the theory is played by the correlations existing between dipoles induced by different mechanisms and in different collisions,
which give rise to a number of interesting intra-and inter-collisional interference effects, some
not fully understood even today. The important role of sum rules (spectroscopic stability) will
be pointed out. The field has become of age with the recent successful "ab initio" calculations
of induced dipole moments, and "rigorous" calculations of intramolecular lineshapes.
11:30
Panel Discussion: "Future Trends in Collision-induced Absorption"
T U E S D A Y , J U N E 19, 1984
R O O M 328
C h a i r m a n : B. Ahlborn
PLASMA
SPECIAL SESSION IN HONOR OF DR. ROY NODWELL
9:00
9:15
CD1
Opening remarks
Parametric Instabilities in Laser Produced Plasmas
H.A. Baldis, National
Research
Council
of Canada
In the interaction of a high power laser witii a plasma, a variety of parametric instabilities
are excited in the plasma, resulting In the generation of electron plasma waves and/or ion acoustic
waves. In the past few years Thomson scattering has made possible the direct observation of these
waves, and improvements in the recording and analysis of the scattered light has permitted the
observation of new non-linear effects associated with the instabilities. The direct observation
of waves in the plasma (or non-theimal electron density fluctuation in general) is a unique
property of Thomson scattering, a diagnostic that lias been in use In Plasma Physics for about
20 years.
10:00
CD 2
Plasma Diagnostics using Laser-Induced-Fluorescence
B.L. Stansfield,
INRS-Energie
W i t h i n t h e p a s t few y e a r s , L a s e r - I n d u c e d - F l u o r e s c e n c e has proved t o be an i n c r e a s i n g l y u s e f u l
t o o l f o r plasma d i a g n o s t i c s .
T h i s p o p u l a r i t y i s i n l a r g e p a r t a r e s u l t o f t h e i n c r e a s e d importance g i v e n t o t h e study of w a l l - p l a s m a i n t e r a c t i o n s i n high-powered magnetic confinement f u s i o n
devices.
The e x p e r i m e n t a l t e c h n i q u e lends i t s e l f w e l l t o l o c a l measurements, and i s as w e l l
capable o f species i d e n t i f i c a t i o n .
I n t h i s p r e s e n t a t i o n I w i l l g i v e a résumé o f some o f t h e
measurements which can be made u s i n g LIF d i a g n o s t i c s as w e l l as some of the e x p e r i m e n t a l p r o blems.
Emphasis w i l l be p l a c e d on t h e e x p e r i m e n t s b e i n g performed a t t h e INRS-Energie f o r event u a l a p p l i c a t i o n t o the Varennes Tokamak Experiment.
10:45
11:15
CD3
Break
Developments of High Intensity Arc Lamps
D.M. Camm, Vortek
Industries
Ltd.
PHYSICS
I
rugi
ROOM 234
Chairman: C.C. COSTAIN
9:00
Introduction
9:05
CEI
The Josephson Volt
THE
B.M. Wood, Watlonal KucaAch
Council
QUANTUM
ELECTRONICS
PRECISION
o( Canada.
The Josephson Volt is the primary voltage standard in over a dozen countries throughout the
world. This standard utilizes the AC Josephson effect which relates the voltage of a zero
resistance source to the frequency of microwave irradiation and a set of fundamental constants
r
^
i
[ V n = n ( — ) fo, where n » integer]. The Josephson Volt will be discussed in the context of
2e
other quantum mechanical standards, fundamental constants, and the S.I. definition of units. The
details of the Josephson Volt and N.R.C.'s Implementation will be reviewed and in particular the
advantages, technical difficulties, and future trends will be outlined.
9:30
CE2
A Quantum Standard Ohm?
M. D'lorio, National
Rcieatch
Council
o6 Canada
The quantized Hall resistance of a two-dimensional electron gas (2DEG) appears to depend solely
on fundamental constants. R[(, the ratio of the Hall voltage to the current through the sample,
Is given by R H • h/e 2 i where i - 1,2,3... In a regime of high magnetic fields (~10 T) and low
temperature (~1 K). An appropriate 2DEG is found at the interface between two semiconductors
such as GaAs/AlGaAs• The problems of Implementing this type of standard resistor will be
discussed. Current knowledge of the parameters which may limit the reproducibility will be
reviewed. The expected accuracy from the experimental program at NRC will be presented, and
possible applications of these standard resistors will be outlined.
9:55
CE3
La Seconde du Cesium
J.-S. Boulanger, National
HeAcaAch Council
o$ Canada
La Conférence Générale des Poids et Mesures a décidé, en 1967, que "la seconde est la durée de
9192631770 périodes de la radiation correspondant à la transition entre les deux niveaux
hyperfins de l'état fondamental de l'atome de césium 133". La réalisation pratique la plus
précise de cette définition est l'horloge primaire au césium à long jet. Le CNRC a construit
quatre de ces horloges: CsV, CsVI-A, -B et -C; le PTB (Braunschweig, Allemagne), a construit
l'horloge Csl et en a trois autres en cours de construction; enfin le NBS (Etats-Unis) a un
étalon primaire de fréquence , NBS VI. Toutes ces horloges ont une précision de 1 x 10 - 1 3 o u
mieux et sont utilisées par le Bureau International de l'heure pour piloter l'échelle de temps
atomique Internationale (TAI). Depuis six ans les horloges CsV du CNRC et Csl du PTB sont en
accord â ± 1 us en temps absolu et l'écart de leur fréquence moyenne respective est 2 x 10-1<t •
Le dessin des horloges et l'évaluation des paramètres affectant leur précision seront exposés.
10:20
10:45
CE4
Break
The New Metre and Its Realization
G.R. Hanes, National
R&6ea*e.fi Council
Canada
From its beginning in 1799, until 1960, the metre was maintained by an artifact standard. It was
then redefined In terms of the wavelength of light emitted by a discharge lamp containing an
Isotope of krypton. Since then we have learned how to make lasers and to stabilize the frequency
of their output so that they are coming to rival good oscillators In other regions of the
spectrum. We are also learning techniques to measure frequency in this part of the spectrum.
Accurate measurement of both the frquency and wavelength of some laser sources allowed the
determination of the speed of light to essentially the full accuracy of which the 1960 metre was
capable. At this stage, wavelength measurement could be replaced by frequency measurement, and
this fact was given ultimate recognition by the Conférence (îénérale des Poids et Mesures in
redefining the metre in 1983 as "the length of the path travelled by light in vacuum during a
time interval of 1/299 792 458 of a second".
BASIS
FOR
MEASUREMENTS
rug
11:10
CE5
Recherches sur les Etalons Atomiques de Fréquence à l'Université Laval
M. Têtu, UruveAA-itz Laval et J. Vanier, CoyiAeÀZ National
de, ReckeAckeA du Canada
Le Laboratoire de Recherches sur les Oscillateurs et Systèmes (LROS) de l'Université Laval est
engagé dans un programme de recherches portant sur les étalons atomiques de fréquence. En
particulier on y étudie les étalons de fréquence à rubidium et à hydrogène. Des efforts
particuliers sont actuellement mis sur l'étude des masers au rubidium, un oscillateur atomique
dont la fréquence est 6.835 HGz et la puissance de l'ordre de 10~ 10 watt. Les travaux portent,
entre autres, sur leur stabilité de fréquence à court terme et sur l'effet de phénomènes
quantiques tels que le "light shift", le "buffer gas shift" et le "cavity pulling" sur leur
stabilité de fréquence à long terme. D'un autre coté, durant les dernières années, des efforts
on été mis sur la conception et la construction de masers à hydrogène dans le but de mieux
comprendre l'effet du "wall shift" et du "cavity pulling" sur leur stabilité a long terme. En
particulier un nouveau système d'accord automatique de la cavité hyperfréquence a été concu.
Nous décrivons les progrès accomplis durant les dernières années.
11:35
CE6
A Very Cold Hydrogen Maser
W.N. Hardy, T(xi UniveAA-ity
BsuJUAk Columbia
Hydrogen masers are the most stable of all atomic clocks, and this intrinsically excellent
stability has led to widespread applications in the area of communications and navigation.
Nevertheless there are certain areas mainly astrophysical in nature, such as the tracking
of space craft and experimental tests of the General Theory of Relativity, where substantial improvements in maser stability could be put to good use. Magnetic resonance studies
at UBC have demonstrated that one way to achieve these improvements is to operate the
maser at low temperatures with liquid helium coated walls. Thermal expansion effects are
negligible, spin exchange broadening is three orders of magnitude smaller at IK than at
room temperature and the frequency shift due to the walls undergoes a broad minimum at
0.52K. Other advantages result from the homogeneity and resilience of the helium-filmcoated walls and the natural compatibility with cooled amplifiers. This talk reports on
the status of a project to build such a cryogenic maser.
PHYSICS
T U E S D A Y , J U N E 19, 1984
ROOM
244
Chairman: W. Brouwer
9:00
CF1
Teaching about Physics and War:
Nuclear Arms and High-Tech Militarism
E. Fawcett, UniveAAJXy 0& Toronto
Physicists can provide unique insight into high-technology militarism, especially nuclear arms, which
already dominates our society and threatens to destroy us. Educational opportunities in the classroom
range from course enrichment, for example by choosing appropriate problems in the regular physics
course, through continuing education courses, to graduate work in public-policy analysis. Decisionmakers, and the public in a participatory democracy, need technical information in order to understand
the issues in the cold war. Organisations of scientists such as Science for Peace are dedicated to
educational and research activities relating to these issues, and in Canada regular workshops on peace
education are being scheduled to help university teachers deal with them.
9:45
CF2
Qualitative Physics and Conceptual Change:
G. Faucher, Ecole
10:30
Break
Polytechnique
A New Trend in Physics Learning
EDUCATION
rugi
10:45
CF3
Physics Education, 2000 A.D.
W. Brouwer, UniueAi.ity
0& AUbeAta.
This presentation will include a summary of the Science Council of Canada Education Study recommendations regarding the future of science teaching in Canada. A position paper with recommendations
regarding future developments in physics teaching and physics teacher training will be presented.
This paper will also be submitted to the membership of the Education Division of CAP for review and/
or approval.
The paper will be presented In French by Dr. A. Biffi, Collège Militaire de St. Jean and copies will
be available in English and in French.
11:05
CF4
Why should scientists get involved In peace
and security Initiatives? D.A.L. PAUL, Dept. of Physics,
Univ. of Toronto - The complex network of international
interactions, including threats and counter threats in the
E-W confrontation Is sustained by entrenched interests,
by bureaucratic habits and by obsolete modes of thinking, more suitable to the pre-nuclear age than to the
present. The scientists' role in this should not be primarily to offer technical fixes for acute security problems as they arise — in fact willingness to do this can
tend to support the false notion that military business
can proceed as usual. Scientists should rather use their
knowledge and talents (1) to dispel dangerous myths which
have become embedded in militaristic thinking, and political lies which are sustained as an exucse to feed the
arms race, (2) to advocate sound plans which have so far
failed to find favour because they contain unfamiliar
concepts, and because of entrenched thinking habits, etc.
(3) to promote and assist with the technologies of peacekeeping, and of verification of agreements. Examples of
these activities will be presented.
11:20
Annual Business Meeting of the Division of Physics Education
TIME
ROOM
12:00
12:00
244
248
Division of Aeronomy and Space Physics
Division of Atomic and Molecular Physics
rug
ROOM 1060
PLENARY
SESSION
IN HONOUR
OF
GERHARD
HERZBERG
Chairman: G.C. Hanna
13:30
DAI
Molecular Ions in the Infrared
A.R.W. McKellar, HeAzbeAg Jnititute.
of, Aifioptu-ici,
National
Re&eaAah Council
Canada
The detection of spectra of molecular ions is difficult because of their short lifetimes, and
Gerhard Herzberg has long had a special interest in this challenging field. It has now become
possible to measure microwave and infrared spectra of ions, and further stimulation has been
provided by the observation of large concentrations of some ions in interstellar space. Recent
infrared studies of molecular ions at N.R.C. have concentrated on H3 + and its deuterated isotopes,
on the protonated rare gases HeH + , ArH + , KrH + , and on the astrophysically important HC0+ and HN 2 +
molecules.
14:15
DA2
Atomic Hydrogen:
Its Behavior and its Uses Below 1 Kelvin
W.N. Hardy, UniveAAlty
15:00
DA3
0|j BsUZiih
Columbia
The Laboratory Synthesis of Nuclei:
Exploration and Consolidation
J.N. Hardy, AECL, Chalk RlveA Nucl&aA Labo/uutoKieA
15:45
DA4
TIME
Microscopic Parameters in Superconductivity
J.P. Carbotte, McMaiteA
UniViMÀXy
ROOM
16:30
16:30
16:30
228
248
244
Division of Optical Physics
Division of Plasma Physics
Division of Theoretical Physics
T U E S D A Y EVENING
Reception and Banquet
Mont Orford Music Centre
18:00
Reception
20:00
Banquet:
B.P. Stoicheff presiding
Award of CAP Medals and Prizes
44
T U E S D A Y , J U N E 19, 1984
10:00-16:00
Poster Party
Part I l / F e s t i v a l de séances de démonstration —
D e u x i è m e partie
The posters will be located in T H E TENT, except Series PF 1-24
and PL 1-7 which «ill be located in the Foyer adjacent to the
Exhibit area.
ONE AND
TWO
DIMENSIONAL
SYSTEMS
PFl
N e u t r o n D i f f r a c t i o n in 1- and 2Dimensional Magnetic Minerals.
M.G. TOWNSEND,
EMR, O t t a w a F e 0 H S 0 4 and F e 0 H C r 0 4 a r e
Heisenberg linear-chain antiferromagnets above
their 3 - d i m e n s i o n a l m a g n e t i c o r d e r i n g t e m p e r a tures at a b o u t 100 K.
Neutron-diffraction
results are discussed.
J a r o s i t e s a r e tria n g u l a r - s p i n s y s t e m s in 2 - d i m e n s i o n a l sheets
a s s h o w n from our n e u t r o n d a t a .
Results are
c o r r e l a t e d by a p p l i c a t i o n of t h e F o u r i e r
m e t h o d of B e r t a u t .
PF2
Paramagnetic Spin Waves in the One-Dimensional
Antiferromagnet CsMnBr,.* B.D. GAULIN and M.F. COLLINS,
Physics Dept., McMaster U. - CsMnBr^ is a hexagonal
quasi-one-dimensional antiferromagnet. Recently the
class of magnetic insulators to which this crystal
belongs has been of Interest as it supports collective
excitations of the chains of spins, in the absence of
long range order. A detailed neutron scattering study
of the spin wave excitations has been completed above
15k1 (-twice the Néel temperature of 8.3K). It Is
found that the dispersion relation at low temperatures
is qualitatively understood by nearest-neighbour
Heisenberg exchange with a small, dipolar-induced,
planar anisotropy. In addition the detailed temperature dependence of the broadening of the spin waves is
compared with the results of a generalized Langevin
equation approach, first considered by Lovesey.2
iCollins.M.F. and Gaulln, B.D., J. App. Phys (in press).
2
Lovesey, S.W., J.Phys.C. , ]_, 2008 (1974).
*
Supported by the Natural Sciences and Engineering
PF3
La Transition Spin-Pelerls Classique. M. MARCHAND et A. CAILLE, Département de physique, Université
de Sherbrooke - Nous présentons le comportement des
fonctions thermodynamiques d'un solide quasi unidimensionnel pouvant être décrit par un Hamiltonien SpinPeierls classique (S •*•"). Un traitement exact des
fluctuations à une dimension s'effectue en résolvant la
matrice de transfert. Nos résultats indiquent clairement aucun changement de comportement des fonctions thermodynamiques à la température de transition de champ
moyen et un ordre à longue portée est réalisé seulement
à T = 0. Cependant, l'état fondamental présente des
pics gaussiens autour des valeurs de champ moyen. C'est
seulement dans certaines conditions spéciales que le
système a tendance à se dimériser. Très prochainement,
nous étudierons le cas quantique S
».
*
Recherche subventionnée par CRSNG et FCAC.
PF4
Temperature and Pressure Dependence of the Electronic Structure of TCNQ Crystals - a Change of Phase at
12 ± 1 Kbar. C. CARLONE, L. ROUB I, Physics Department,
Université de Sherbrooke and N.K HOTA, J. ZAUHAR, Collège militaire royal, St-Jean, Qu ébec - The absorption
spectrum from 3100 ft to 8000 ft of t et racyano qu inod imethane crystals has been obtained in the (001) and (010)
directions. At room temperature the absorption maximum
occurs at 4680 ft (former) and at 4600 ft (latter). At
84K, these peaks shift to 4520 ft and 4450 ft respectively.
The (001) absorption was also obtained as a function of
pressure (0 to 50 kbars). At ambient conditions, the
change with pressure is - 37 ± 1 cm~l kbar~l, and the
temperature dependence of the electronic absorption is
dominated by electron-phonon interaction. At 12 ± 1 kbar,
an irreversible change of phase takes place. New peaks
appear both at higher energy (3900 ft) and in the infrared. We surmise that in the high pressure phase, either
the TCNQ is deformed or a chemical change takes place.
The change of phase is probably an insulator to semiconductor type.
PF5
Infrared Study of the Quasi-(one)(two) Dimensional Solid Solutions ZrS-u v Se y . J. DESLANDES and S.
JANDL, Département de physique, Université de Sherbrooke (Québec) - Infrared reflectivity and transmissivity
of the fibrous solid solutions ZrS3_ x Se x ( C ^ space
group) are reported for 0^xS3. A three and two-mode
behaviour as well as a switching from a one-mode to a
two-mode type are observed. The three-mode behaviour is
attributed to the diatomic vibration X-X' (X,X' — S or
Se) where the covalent character is confirmed by the absence of aojy-w^ splitting. In the two-mode behaviour as
in the switching from a one to a two-mode behaviour, the
gap mode appears at high concentration of Se (x"v2).
Two explanations are proposed for this feature: on implies a mass disorder effect while the other points to
a possible transition from a quasi-one-dimensional (ZrS3)
to a quasi-two-dimensional structure (ZrSe3).
PF6
Spectrum of the Quasiperiodic Noise in
Niobium Triselenide. DANIEL BRUCE MURRAY, Simon Fraser
Univ.
An additional fundamental frequency in the
quasiperiodic noise generated by Niobium Triselenide is
obtained in a model which assumes the presence of
objects which move more slowly than the sliding charge
density wave. The objects are driven by their
interaction with the charge density wave and the lattice
potential. The objects may lj>e walls between the domains
observed by Fung and Steeds. The model is in close
agreement wjth the observations of Richard, Monceau
and Renard.
K.K. Fung and J.W. Steeds, Phys. Rev. Lett. 45,
1696 (1980).
2
J. Richard, P. Monceau and M. Renard, Phys. Rev. B
25, 948 (1982).
p
F7
Delay phenomena and the onset of charge
density wave conduction.*
D.B. MURRAY, Simon Fraser
University, B. JOOS, University of Ottawa and J. GLOSLI
University of Washington, Seattle - Several models are
proposed to simulate the long delay times observed iç
the onset of the charge density wave current in NbSe->
«C
T K « . . are
„ — ,, kinetic
1,4
4 „ Islng
T„1
J _ l „ which
. .U
and TTaS
They
models
may
contain one or more of the following components: a
spontaneous depinning probability, an initial random
distribution of depinned sites and a depinning wave.
We show analytically that three one dimensional models
have similar distributions of switching rates.
It Is
conjectured that all mechanisms involving an exponentially decaying depinning rate lead to distributions of
the form exp |-x-e~ x ] where x is linear in time. This
distribution agrees well with the available experimental data.
Zettl A. and Grtiner G.
Mihaly L. and GrUner G.
Phys. Rev., B26, 2298 (1982).
preprint (1984).
rug
PF8
Percolation, Localization and Superconductivity In Sl-AJ? thin films. S.P. McAllster and
A.D. Inglls, Solid State Chemistry, N.R.C., Ottawa. Co-sputtered Si-AJl films show a metal to semiconductor
transition as a function of composition. On the
metallic side of the percolation transition the films
show minima in the temperature dependence of the
resistivity, which we suggest are due to weak
localization. We will present resistivity and
magnetoresistivity measurements on some Si-AÎ. thin
films and show how superconducting fluctuations and
weak localization manifest themselves.
PF9
Excitation Spectra and Optical Absorption by a
Two-Dimensional Electron Gas in a Strong Magnetic Field*
C. KALLIN and B.I. HALPERIN, Harvard U - We have calculated the effects of electron-electron interactions on
the excitation and optical absorption spectra of a disordered two-dimensional electron gas, at integer filling
factors, in a strong magnetic field. It is well known
that correlation effects cannot be observed, by optical
absorption in a system with translational symmetry."^
However, the presence of impurities breaks translational symmetry and allows coupling to magnetoplasma modes
at nonzero momenta. In this system, correlation effects
produce interesting structure in the magnetoplasmon
spectra, which gives rise to structure in the optical
absorption.
X
W. Kohn, Phys. Rev. 123, 1242 (1961).
^Supported by NSF grant number DMR82-07431
PHASE
TRANSITIONS
PF10
Structural Distortions in Lithium Intercalated
Chevrel Compounds. W.R. McKINNON and J.R. DAHN, Solid
State Chemistry, N.R.C. Ottawa - The rhombohedral
structures of LiÔgSeg and Li x MOgS g undergo
reversible distortions to triclinlc structures at
certain values of x. We have studied these phase
transitions with electrochemical techniques and with
in-situ x-ray diffraction (using intercalation
batteries with x-ray windows). Li x Mo 6 Se Q shows two
rhombohedral-tricllnlc transitions, one near x=2 and
the other near x=4. In contrast, Li x Mo 6 S Q shows a
single transition near x=4 which is a two-step
process, exhibiting an intermediate phase with an
incommensurate superstructure. We suggest that the
transitions may be driven by an ordering of the
Intercalated lithium.
PF11
Lithium intercalation In Li x Mo 6 Se 8 : A Model
Mean-Field Lattice Gas. J.R. DAHN, W.R. McKINNON,
Natl. Res. Coun. Canada and S.T. COLEMAN, Univ.
British Columbia—We show that lithium intercalation
in Li x MogSe 8 is accurately described by a singleparameter lattice gas model. Mean field fits to the
inverse derivative, ?»x/AV, of the voltage, V, of
Li/Li^MOgSeg cells at several temperatures are in
excellent agreement with the data. In-situ x-ray
diffraction experiments (using electrochemical cells
with beryllium x-ray windows) show that Li x Mo 6 Se g is a
single phase at room temperature for 0<x<l. Our meanfield calculations predict that spontaneous phase
separation (analogous to ferromagnetism) should occur
for T<T c =-10°C. Results of similar experiments on
Li x Mo 6 Sg are also presented.
PF12
Crystal Stability, Dynamics and Vacancies.*
L.K. MOLEKO, Dept. of Physics, Univ. of Ottawa and
H.R. GLYDE, Dept. of Physics, Univ.of Delaware - The
stability of crystals is studied using a model which
includes atomic vibration and thermal creation of
vacancies. The vibrational dynamics is treated within
an Einstein approximation to the self consistent phonon
theory including cubic anharmonic contributions. The
dynamical instability temperatures Tj of pure crystals
when cubic term is included are 3-4 times thef observed
melting temperatures for rare gas crystals(R^C
.when
the vacancies are included in the dynamics, the force
constants are reduced by a factor depending on vacancy
concentration. The predicted Tj and instability
densities pj lie within 10-20% of those "observed" in
Computer Simulations of Crystal Stability. For RGC's
the Tj are 1.3-1.5 times the observed melting
temperature Tm- The Lindemann melting rule is found to
hold. This work suggests that vacancies and
vibrational dynamics may be largely responsible for
instability in real crystals.
(1)
L . K. Moleko and H.R. Glyde Phys. Rev. B27, 6019 (1983).
*Work supported by NSERC.
PF13
Thermal Expansion Near the Curie Points of
Terbium,. Dysprosium and Holmium. * D. A. TINDALL, Dalhousie Univ. and M. 0. STEINITZ, Saint Francis Xavier
We have used a capacitance dilatometer to
Univ.
measure the thermal expansivity of single crystals
of the rare earth metals Tb, Dy and Ho, with a resolution of about 1 ppm. It is well known-* that Dy shows
very large first order length changes at its Curie
point (Tc = 85 K), but any effect in Tb (Tc = 220 K) is
smaller by two orders of magnitude. 2 Ho (Tc = 20 K)
shows first order changes intermediate in size between
the other two elements.3 in Tb, the situation is complicated by the fact that the Néel point (Tn = 230 K)
is so close to Tc- We have attempted to separate the
effects of the two transition regions by comparing the
coefficients of thermal expansion of Tb and Dy.
1-A. E. Clark, B. F. DeSavage and R. Bozorth, Phys. Rev.
138_ A216 (1965).
2
J. J. Rhyne and S. Legvold, Phys. Rev. 138 A507 (196 5).
3
D. A. Tindall, M. O. Steinitz and M. C. Plumer, J.
Phys. F (Metal Physics) 1_ L263 (1977).
*Supported in part by NSERC.
PF14
Ultrasonic Velocity and Attenuation near the Cooperative Jahn-Teller .Dilation in Cerium Ethyl Sulphate*.
J.T. GRAHAM and J.H. PAGE, Queen's U. - Cerium Ethyl
Sulphate (CeES) is believed to undergo a cooperative
Jahn-Teller dilation (a distortion of A-. symmetry) at
temperatures near 4 K. To investigate tnis, we have
measured the change in velocity and attenuation of longitudinal ultrasonic waves propagating along the c-axis as
a function of temperature between 1.5 and 40 K. The
measurements were performed at several frequencies between 30 and 300 MHz. There is a small dip in the
velocity with temperature, indicating that the elastic
constant C33 softens due to the cooperative Jahn-Teller
effect. Peaks are observed in the attenuation which
exhibit the features of relaxation behaviour, moving to
higher temperatures and increasing approximately linearly
in magnitude as the frequency is raised. The relaxation
times deduced from the data are consistent with spinlattice relaxation and are compared with data for both
pure and dilute CeES.
*Research supported by NSERC of Canada.
rugi
PF15
The Neel Transition In Cr-V Alloys. C.MUIR and E.
FAWCETT, U. of Toronto - Measurements of ultrasonic
velocity and attenuation in a single crystal of Cr - 0.5
at. XV show that the behaviour in the neighbourhood of
the Neel transition is distinctly different from that in
pure Cr. Thermal expansion measurements1 show that the
transition is continuous in a polycrystalline sample of
similar composition. The implications of these results
for the nature of the Neel transition are explored.
'Roberts, R.B., White, G.K., and Fawcett, F.. , Physica,
119B, 63 (1983).
PF16
C r i t i c a l C o r r e l a t i o n s and the Landau
T h e o r y o f P h a s e T r a n s i t i o n s . J . A . TUSZYNSKI ,
Dept. of Physics, Memorial U n i v e r s i t y of
Nfld.The p r o b l e m o f c r i t i c a l c o r r e l a t i o n s i s r e examined w i t h i n t h e framework of the Landau
t h e o r y o f p h a s e t r a n s i t i o n s . The s t a n d a r d
approach adopts a gaussian p r o b a b i l i t y
distribut i o n f o r the f l u c t u a t i o n s of the order
parameter.
T h i s r e s u l t s i n t h e h a l f - w i d t h P and t h e
correlat i o n range f
t e n d i n g t o i n f i n i t y as T a p p r o c h e s
T . H o w e v e r , as we p o i n t o u t , some i n t e r m e d i a t e
s t e p s 1n t h e d e r i v a t i o n a r e u n p h y s i c a l . Me r e c a l c u l a t e t h e c r i t i c a l p a r a m e t e r s T and
J
u s i n g a s i x t h o r d e r Landau e x p a n s i o n and r e m o v i n g
t h e i n c o r r e c t s t e p s . As a r e s u l t , r a n d f
are
a l l o w e d t o be i n f i n i t e o r f i n i t e a t T , d e p e n d i n g
on t h e c h o i c e o f t h e e x p a n s i o n c o e f f i c i e n t s .
The
l a t t e r case i s of p a r t i c u l a r i m p o r t a n c e t o
liquid
-vapour t r a n s i t i o n s which are being studied in
o u r Raman S p e c t r o s c o p y L a b . P r e l i m i n a r y
experim e n t a l r e s u l t s c o n f i r m o u r p r e d i c t i o n s as t o t h e
f i n i t e n e s s of the c r i t i c a l c o r r e l a t i o n range i n
some s e c o n d o r d e r p h a s e
transitions.
PF17 Phase Transitions in Stannous Fluoride. G. DENES,
Dept. Chem., McMaster U., Hamilton, Ont. - The study of
SnF2 vs temperature reveals the existence of two phase
transitions. One ( < X — ) is a sluggish reconstructive
first order phase transition when the other
y ) is
a displacive second order ferro-paraelectric transition.
The transitions are studied using a variety of techniques
including X-ray and neutron diffraction, thermal analysis,
electrical conductivity and 119-Sn Mossbauer spectroscopy.
Both are bidimensional order-disorder transitions, orderdisorder between Sn's and F's forot—»yand between F's
only f o r ^ i ^ Y - The kinetics of the t*—» y transition is
investigated by X-ray diffraction and D.T.A. The importance of the particle size and the presence of defects at the
surface of the particles is shown. The existence of an
intermediate phase between ot and y , called "transition
phase" is suggested. The strengthening of the lattice
going from a polymeric (Sn^Fg tetramers) to a threedimensional infinite network is evidenced by Mossbauer
spectroscopy (increase of the recoiless fraction).
The anionic nature (F~) of the electrical conductivity
is shown and related to relevant structural features.
an upper limitation of electronic (hole)
mobility in (otherwise " i d e a l " ) isotopically
blended c r y s t a l s (e.g. Si or Ge), [2], More
exotic areas may involve a l t e r n a t i v e m o d e l s of
genetic code (or even entire l i f e f o r m s ! ) based
on isotopic c o m b i n a t i o n s [3] as well as ROM- t y p e m e m o r i e s using isotopically ordered crystalline and/or thin film s t r u c t u r e s .
[1] A.A. B e r e z i n , J . C h e m . P h y s . 8Q, 1241 (1984).
[2] A.A. B e r e z i n , Bull. APS, 29, 504 (1984).
[3] A.A. B e r e z i n , N a t u r w i s s . 71, 45 (1984).
SUPERCONDUCTORS,
FERMI
GAS
PF19
Non-Perturbative Theory of Magnetic Flux Penetration
into a Superconductor. N. GAUTHIER and P. ROCHON,
Royal Military College of Canada, Kingston - We have
developed a non-perturbatlve theory of the total transition time and induced surface electric field for the
case of destruction of superconductivity by magnetic
field H 0 which is suddenly impressed parallel to the
axis of a wire. This theory is concerned primarily with
the electromagnetic aspects of the transition and is
applicable when the reduced field parameter p =
(H0 - H c )/H c is arbitrary: 0 < p < °°;HC is the critical
field. Previous theories , 2 were based on a quasiequillbrium approach and their range of validity is
narrow: 0 < p « 1. Expressions for the important
quantities of the theory are presented and evaluated
numerically. The present results constitute an
extension to the cylindrical case of a solution
recently proposed for the case of a flat sample.3
'j.c. Swihart, J. App. Phys. 34, 851 (1963).
J.B. Keller, Phys. Rev. Ill, 1497 (1958).
3
P. Rochon and N. Gauthier, J. Frank. Inst., in print.
2
PF20
Evidence of Morphological Structural Changes in
Superconducting NbTl Fibers.* L.S. WRIGHT, H.D.
WIEDERICK and T.S. HUTCHISON, Royal Military College of
Canada, Kingston - Stress/strain data has been obtained
for 18.3 ym diameter NbTi (39.5 at. X Nb) fibers at
293 K, 77 K and 4.2 K. The fibers were chemically
extracted from commercial (Magnetic Corp. of America)
180 fiber copper clad composite. The fibers show
essentially elastic elongation to fracture at 293 K,
and non-linear tensile behaviour with increased
fracture strain as the temperature is reduced; we find
no evidence of large serrations during elongation.
This is contrary to the behaviour exhibited by thicker
wires of similar composition. Fracture stress is also
larger in the fibers. SEM pictures generally show
thinning with ragged rupture at 273 K, but always clean
45° slant rupture with dimpling at 4.2 K. This change
in mechanical behaviour suggests a change with temperature in structural morphology.
'Koch, C.C. and Easton, O.S., Cryogenics, 17, 391 (1977)
PF18
Isotopic r a n d o m n e s s and o r d e r i n g in solid state and sott state physics. A • A • B E R E Z I N .
- M c M a s t e r U. - With some e x c e p t i o n s , the v a r i o us m a n i f e s t a t i o n s of isotopic d i s o r d e r and possible e f f e c t s of "isotopic o r d e r i n g " c o n s t i t u t e
an o v e r l o o k e d area of e x p e r i m e n t a l and theoretical r e s e a r c h . One known case is the s u p p r e s sion of thermal c o n d u c t i v i t y in isotopically
mixed c r y s t a l s (G.A. S l a c k , 1957). Recently I
d i s c u s s e d the m e c h a n i s m of Anderson e l e c t r o n i c
l o c a l i z a t i o n due to an isotopic d i s o r d e r in
c r y s t a l s with narrow bands [1], Another p o s s i bility c o n s i s t s in the p r i n c i p l e e x i s t e n c e of
•Supported by a contribution from the Chief of Research
and Development, Dept. of National Defence.
rug
PF21
Diffusion of Magnetic Flux into Long Type I
Superconducting Cylinders.* B.K. MTJKHERJEE, Royal
Military College of Canada, Kingston, Ontario,
K. ASWATHY, G. RANGARAJAN and R. SRINIVASAN, Indian
Institute of Technology, Madras, India - When an axial
magnetic field H a greater than the critical field H c is
suddenly applied to a Type I superconducting cylinder
of negligible demagnetizing coefficient, magnetic flux
diffuses into the specimen and superconductivity is
destroyed with the entire process taking a finite time
T which is a function of the reduced field p = (Hfl H c )/H c . Early theories were based on a quasi-equilibrium approach and were in accord with measured values
of T only for p
0.2. Recently Gauthier and Rochon1
have proposed a generalized theory of the flux diffusion
process. We have measured T(p) for a pure indium specimen for values of p up to 15 and find reasonably good
agreement with the Gauthier-Rochon model.
1
Gauthier, N. and Rochon,
this volume.
see their abstract in
^Supported in part (BKM) by the Department of National
Defence Contribution No. 3610-320.
PF22
Low Magnetic Fields using Superconducting Shielding*. C.J. PURCELL, B.L. BLACKFORD and G. STROINK. Dalhousie Univ. - We report on our progress in reducing the
magnetic field inside a cryostat to be used for experiments with rotating superconductors.-* Our objective is
a field of about 10 7 gauss over a volume of about 500
cm 3 . The field reduction is obtained by expanding a Pb
bag made from torch welded thin Pb foil (0.006 mm). The
bags are cylinders 15 cm in diameter by 60 cm long and
closed on the bottom. They are folded flat in lengthwise
pleats, cooled through their superconducting transition
temperature and then expanded to reduce the flux density
inside the bag. 2 Field reduction factors as high as 200
have been achieved for the axial field and about 20 for
the transverse field, using a single bag starting from
a field of about 10~3 gauss. The effect of the orientation of the folded Pb bag, with respect to the initial
transverse field, on the final field is being studied.
The design of the SQUID magnetometer used to measure
these small fields will also be discussed.
^Blackford, B.L., et al., Can. J. Phys. 57, 39 (1979).
2
Cabrera, B. Ph.D. Thesis, Stanford Univ. (1975).
•Supported in part by a grant from NSERC.
PF23
Properties of Fully Sp i n-po 1 a r i zed -^He.
H.R. GLYDE, University of Delawar
and S.I. HERNADI,
University of Ottawa
The g roung state energy (E),
Landau paramet ers CF), the s ngle particle energy
spectrum and e f f ect i ve mass (i k)) in fully sp i npola r i zed 1i quid ^He are calc ulated directly from
the bare inter.atomic potentia I within the Galitski iFeynman T-matr x and Hartree Fock approximations.
This is a firs t principles ca Iculation, making use
of the HFDHE2 pa i r potent i a 1of Az iz et al. The
ground state e nergy agrees we II with var iat iona1
ca1 eu 1 at ions wh i1e the ca1cu lated Landau parameters
agree with mod el calculations
It appears that
the effective interaction in fully spin-polarized
3He is dominât'"ed by hard-core repulsion and Fermi
statistics, w th induced inte Tactions playing a
minor role.
unphysical contributions to the entropy leads us to
define an effective Planck constant (h = h(E), where E
is the energy of the system). Finaly,we discuss consequences related to the existence of a minimum fermionic
mass and show that it depends on the chemical potential
of the system.
NUCLEAR
AND
INS TR L MEN TAT!
ACCELERATOR
ON
PG1
A Relatively Inexpensive Cooled Array Defector
System
F.J MORGAN, York UnTversitv7 G.S.~ R0SE and
R.P. LOWE, University of Weste'rn Ontario - We have
assembled a 128-channel linear array detection system
for use in our studies of line shapes in ion-atom
collisions. Commercially avai lable components were used
throughout with a minimum of miodification. The detector
is a Reticon mounted on a MMR refrigeration unit inside
a vacuum housing and can be coioled to temperatures of
- 150°C. The Reticon is used in conjunction with a
standard evaluation board modi fied to provide
integration times of up to ^10 hours. The details of
operation and performance will be described and compared
with that of the single-channe 1 cooled photomultiplier
used previously.
PG2 SysL£me_dlAnalvse_j1agn
Nucléaires P. BR1CAULT, R. J. SL0B0DR1AN, La$9ratgir§_de_Physigue_Nyçiéaire
Université__Lavai - Nos dernieres mesures des sections efficaces de rayonnement de freinage dans les interactions nucléaires ' nous ont montré qu'il
était nécessaire d'avoir un taux de comptage plus élevé. Nous envisageons de
construire un système d'analyse magnétiaue a double courbure, lequel oermet
une grande transmission pour les processus inéîastiques et une transmission
nulle pour les particules élastiques. Ce système est composé de deux dipôles
symétriques â champs magnétiques opposés. Les .trajectoires sont calculées
selon le formalisme des matrices de transfert " . le calcul est effectué
jusqu'au second ordre de façon à tenir compte de la dispersion en énergie
des particules. ._a focalisation des particules se fait dans les deux plans,
radial et axial. La mise en place d'obturateurs sur les trajectoires des
particules diffusées éiastiquement permet de les éliminer complètement avant
qu'elles n'atteignent les détecteurs placés aux points focaux des dipôles de
partie.
P. Bricault,R. J. 51obdnan,
Rioux
Potvin R. Roy, R. Larue et !
Frois, J. Phys. 44 (1963) 461-465.
*" H.A. Enge, Focusing of Charged Particules vol.2 ed. A. Septier t.Acade'
mic Press, New York, London, 1967).
Travail supporté en partie par le (C.R.S.N.G.) du Canada et par le
(F.C.A.C.) du Guébec.
PG3
Supported by NSERC (Canada) and University of
Delaware.
ation d'une nouvelle source
jIF.G'JX et R . J . SL030DRIAN, Laboralre, Université Laval. - Un
l'étst métastable 2 3 S, peut
re des électrons polarisés. Il
Les él serrons 2s des atomes metastade la méthode proposée recem;S électrons polarisés peuvent
inventionnelle par photoionisa? simple consiste à utiliser
ibles avec une surface métalli•t en cours visant à mesurer la
ex roiis produits par cette dernière
sont "base?es sur la diffusion à 50keV
électrons par une mince feuille
?ut être déduite des mesures
rae l e ro
oir d'analyse de cette diffuit at s expérimentaux obtenus sepresences ainsi que les calculs de polarisation teconnte des fausses i symétries.
PF24
On the entropy of a Fermi-gas. R. DANDOLOFF,
U. de Sherbrooke - Using an expression for the entropy
as a functional of the correlation functions, we investigate the structure of the leading term for the entropy
of a Fermi-gas at low temperatures. Eliminating some
1)
2)
3)
*
R.«J. Slofccdrian, Nucl. Instr. Meth. (sous presse)
M.J. Alguard et al, ITucl. Instr. Meth. 163, 29 (1979)
voir par exemple K.Sherman, Phys. Rev.llH, 15Ul(l959)
Recherche supportée par le CRSNG CMADTTët le FCAC QUE.
rugi
PG4
Nouveaux détecteurs â scintillation pour la tomographic par positrons à haute résolution. D. SCHMITT,
R. LECOMTE et G. LAMOUREUX, U. de Sherbrooke, R.J.
McINTYRE et A. LIGHTSTONE, RCA, St-Anne-de-Bellevue Nous avons démontré qu'un détecteur formé d'un cristal
de Nal couplé à une nouvelle photodiode à avalanche de
grande surface permet d'obtenir d'excellents résultats
(1). Nous rapportons les premiers résultats obtenus en
couplant une photodiode â avalanche à des scintillateurs
de BGO de petites dimensions: avec un cristal de 5x5x3
mm, des résolutions de l'ordre de 9.5X FWHM à 23°C et de
7% FWHM à -15°C ont été mesurées à 662 keV. Grâce à la
haute efficacité quantique (~70% â 480 nm) et au gain
interne (M=20 à 50) des photodiodes, les nouveaux détecteurs démontrent des performances comparables aux détecteurs conventionnels utilisant des PMT et permettent de
surmonter plusieurs limitations inhérentes à ces derniers (encombrement, stabilité, perturbations magnétiques..). L'intérêt de cette nouvelle technologie de détection est discuté â la lumière de son utilisation en
tomographic par positrons à haute résolution (2).
1
G.A.Petrillo et al.,IEEE Trans.Nucl.Sci.,NS-31(1984)417
2
R.Lecomte et al., IEEE Trans.Nucl•Sci•,NS-31(1984)556
PG5
Charge Ratio Mass
Spectrometry
of
Heavy
Elements.* L. R. KILIUS, J. C. RUCKLIDCE, G. C. WILSON,
H. W. LEE, and A. E. LITHERLAND, IsoTrace Laboratory,
Univ. of Toronto - A method of high energy mass
spectrometry is described that is applicable to trace
heavy element ( M > 1 0 0 ) analysis at the part per billion
level using accelerator mass spectrometry.
Fragments
which result from the breakup of heavy molecules and
which have a mass equal to some integral multiple of
the charge state q, selected after acceleration, will
be transmitted to the final detector system through
both electric and magnetic analysis. Although these
ions are resolved in energy, copious quantities of
fragments will introduce backgrounds and may contribute
to solid state detector damage. These fragments can be
substantially reduced by an additional charge change
between any two analysers and choosing a new charge
state q' which has no common factors with q or M.
Details of this technique and examples from the
successful assay of platinum and other heavy trace
elements will be presented.
* Supported by NSERC and the Province of Ontario.
PG6
Radiocarbon Dating Using 1 4 C + 2 . * H. W. LEE,
A. GALINDO-URIBARRI,
K. H. CHANG,
L. R. KILIUS and
A. E. LITHERLAND, IsoTrace Laboratory, Univ. of Toronto
- The meta8tability of the molecule
has so far
discouraged the use of charge state +2 ions for C-14
dating.
This molecule is being studied at Toronto and
we have found that it is possible to eliminate it as a
serious
background by adjusting the stripper gas
pressure in the terminal of the tandem accelerator.
The
few
residual
^CHj2
molecules
are
then
disintegrated by passage through a carbon foil In front
of a silicon particle detector. The fragments can be
separated in energy from the 1 4 C ions. At 1.4 MV on
the terminal and at a stripper gas pressure optimum for
14
14
C
production,
the
natural
C*2
ions
from
contemporary sample can be resolved from the molecular
fragments.
The resolved background corresponds to
about 1Z of the 1 4 C yield. Work on the optimization of
conditions for C-14 dating will be presented.
1. A. E. Litherland, Ann.
(1980) 437-473
* Supported by NSERC
Rev.
Nucl.
Part.
Sci.
30
PG7
Ion Probe Capability for Accelerator
Mass
Spectrometry.*
G. C. WILSON, J. C. RUCKLIDGE, W. E.
KIESER and R. P. BEUKENS, IsoTrace Laboratory, Univ.
of Toronto - The Ion Microprobe project at IsoTrace is
a response to the need for trace element analysis in
unprepared samples at the part per billion level. By
using a sputter source in which the primary beam can be
focussed to micron spot sizes, an accelerator mass
spectrometer can extend the sensitivity of existing ion
microprobes by three orders of magnitude.
The IsoTrace Ion Probe will consist of a sample
stage which can be positioned in three dimensions, a
caesium primary microbeam and
a
sample
viewing
microscope, all mounted on an Ion source block which
can be placed on any of the injection lines to the
accelerator.
The sample stage Is currently built and
connected to the source block on the 90° ion source
line.
Computer control of the XY positioning of the
stage has been developed and the entire system has been
tested using the existing caesium gun. A detailed
description of the system will be presented as well as
designs for the primary column and the microscope.
* Supported by NSERC and the Province of Ontario
PG8
Booster Design for a TRIUMF Kaon Factory.
J.I.M. BOTMAN, TRIUMF, M.K. CRADDOCK, U.B.C. and
TRIUMF - Present designs for a kaon factory at TRIUMF
are based on two proton synchrotron stages, a booster
to accelerate the 100 uA beam from TRIUMF energy to
3 GeV, and a main ring to continue acceleration to
30 GeV. One design for the booster synchrotron is
based on a separated function lattice with four empty
cells; a tune v x just below 4 then drives the
transition energy above the final energy of the
machine thereby avoiding serious beam losses. An
alternative design uses combined function magnets.
The straight sections in the empty cells are used for
RF accelerating cavities and injection and extraction
systems; a scheme for fast extraction is described.
PG9
A High Transition Energy Lattice for a TRIUMF
Kaon Factory Synchrotron. R.C. GUPTA, U. of Manitoba,
J.I.M. BOTMAN, TRIUMF, M.K. CRADDOCK, U.B.C. and
TRIUMF - Lattice designs using either separated
function or combined function magnets are presented
for the main synchrotron of a TRIUMF kaon factory to
accelerate a 100 uA proton beam from 3 GeV to 30 GeV.
Beam loss at the transition energy would be significant In such a high current synchrotron. Several
methods have therefore been investigated to raise the
transition energy of this lattice above the acceleration range. These methods require a periodic perturbation in either the bending properties of the lattice
or the focusing properties or both. In the separated
function lattice missing magnet cells provide the
required superperiodicity. In the combined function
lattice the perturbation is provided by an irregular
distribution of the magnets within each superperiod.
In both cases, the lattice provides long drift spaces
suitable for Injection, extraction and RF accelerating
systems. A fast extraction scheme using kicker and
septum magnets is described.
PG10
Detection Equipment for a Test of Charge
Symmetry In n-p Elastic Scattering.* J. BIRCHALL,
C.A. DAVIS, N.E. DAVISON, H.P. GUBLER, W.P. LEE, P.R.
POFFENBERGER, J.P. SVENNE, W.T.H.van 0ERS AND Y.P.
ZHANG, Univ. of Manitoba; E. CAIRNS, H. COOMBES, P.W.
GREEN, L.G. GREENIAUS, W.J. MacDONALD, G.A. MOSS, G.
ROY, J. S0UKUP and R. TKACHUK, Univ. of Alberta: R.
ABEGG and C.A. MILLER, TRIUMF; G.R. PLATTNER Univ. of
Basel - A test of charge symmetry by determination of
the difference in cross-over angle (to ± 0.04°) of
AA - A n -Ap in n-p scattering is now underway at
the neutron beam facility of TRIUMF. A p is obtained
by scattering an unpolarlzed neutron beam from a
polarized frozen spin hydrogen target and A n is by
scattering a polarized neutron beam from the same
target unpolarlzed. The scattered neutron Is detected
In two large position sensitive plastic scintillator
rug
arrays placed at equal angles (32°) on either side of
the beam. The recoil proton is detected in two proton
range counters equipped with multiwire proportional
chambers to reconstruct the proton trajectory.
Information is obtained on opening angle, noncoplanarity, proton range, neutron and proton time-offlight as a function of angle over 10° in the lab.
* Supported in part by NSERC Canada.
PG11
The Frozen Spin Target at TRIUMF. P. DELHEIJ,
D. HEALEY and G. WAIT, TRIUMF - At TRIUMF, a polarized
proton target has been constructed which has a
diameter and height of 4 cm. In a magnetic field of
2.5 T at a temperature of 0.5 K, the free protons of a
butanol sample are pumped with microwaves to reach a
polarization of 90%. The polarization is frozen in by
cooling the target with a ^He/^He dilution
refrigerator to about 0.07 K. The ^He circulation
rate is about 5 mmol/s. When the beam is turned on
the magnetic field is lowered to 0.25 T to decrease
the deflection of the charged particles. Since the
fall of 1983 the target has made several runs, that
were up to two weeks long. Everyday the polarization
and/or magnetic field were reversed for an experiment
that will test charge-symmetry breaking^ .
1
^ Birchall J. et. al., High Energy Spin Physics 1982, ed. by G.M. Bruce, AIP Conf. Proc. no 95, pl65.
PG12
Secondary Beam Intensities For Kaons, Pions
and Antiprotons at a Kaon Factory. J. D00RNB0S,
TRIUMF - Six possible kaon channels have been
considered. For a 100 yA 24 GeV proton beam on a 3"
Pt production target kaon intensities are of the order
of 10 8 /s. Detailed results and characteristics for
the six channels are given in an internal report. 1
Channel characteristics such as solid angle and
momentum acceptance, channel length and separator
length were based on a consideration of existing
channels or on new design studies, keeping in mind
that channels will be longer for increased beam
purity. The kaon flux predictions are based on cross
section data which are in agreement with the fluxes
observed on the Brookhaven kaon channels. Antiproton
fluxes are expected to be 2 x 10 7 /s at 0.8 GeV/c and
10 8 /s at 2.5 GeV/c.
PG14
Plans for the Extraction of Intense Beams of
H" Ions from the TRIUMF Cyclotron, G.H. MACKENZIE,
M. ZACH, R.E. LAXDAL, J.R. RICHARDSON, TRIUMF, M.K.
CRADDOCK, U.B.C. and TRIUMF - Plans are presented for
the c.w. extraction of H~ ions from TRIUMF for subsequent injection into an accumulation ring. For the
injection of thousands of turns only charge changing
processes are practicable and H~ ions offer more flexibility than H° atoms. The mean radius gain/turn at
extraction, 1.5 mm, can be tripled by auxiliary RF
cavities which increase the energy gain/turn from 0.3
to 1.0 MeV. The turn separation at a deflector entrance may also be augmented by precessional techniques
using the v r = 3/2 resonance. The H~ beam will then
enter an electrostatic deflector with a positive voltage followed by a second deflector and standard magnetic channels. Our orbit codes have been modified to
obtain trajectories in extended regions of time-varying
electromagnetic fields. Calculations made on the
emittance, intensity and efficiency of extraction are
presented together with the tolerances required. The
conceptual design of the deflection elements and the
RF cavities and amplifiers is described.
Alternative
schemes for the extraction of H° atoms and H~ ions in
200 turn packets are briefly reviewed.
PG15
The Neutron Beam Facility at TRIUMF.*
E. CAIRNS, H. COOMBES, P.W. GREEN, L.G. GREENIAUS,
W.J. MCDONALD, G.A. MOSS, G. ROY, J. SOUKUP and
R. TKACHUK, Univ. of Alberta; J. BIRCHALL, C.A. DAVIS,
N.E. DAVISON, H.P. GUBLER, W.P. LEE,
P.R. POFFENBER, J.P. SVENNE, W.T.H. VAN OERS and
Y.P. ZHANG, Univ. of Manitoba; R. ABEGG and
C.A. MILLER, TRIUMF; G.R. PLATTNER, Univ. of Basel The polarized neutron beam facility at TRIUMF has been
upgraded for use in high precision neutron scattering
experiments. Polarized neutrons are produced via
transverse polarization transfer in the D(p,n)2p
reaction at 9° in the lab. Proton beam position on
the LD^ production target is stabilized to better than
± 0.2 mm using a feedback system controlling beam line
elements. The region of uniform neutron beam Intensity at the experimental target location is a rectangular area 56 mm wide and 39 ram high. In that
area the neutron beam intensity is 9 xlO^/lOO nA«cm^«s
and the neutron polarization is 50%. The facility
.is being used to determine charge-symmetry breaking in
n-p elastic scattering, to study neutron radiative
capture by hydrogen and a measurement of the spin
correlation parameter A n n .
*Supported in part by NSERC.
Doornbos, TRI-DN-83-48 (1983).
PG13
Status Report on the TRIUMF Cyclotron. R.
BAARTMAN, J. CAREY, D. DOHAN, G. DUTTO, D. GURD, G.H.
MACKENZIE, D. PEARCE, R. POIRIER and P. SCHMOR; TRIUMF
- During the last two years TRIUMF has operated at
currents of up to 150 yA; these are available on
demand, with 250,000 yAh/yr delivered for meson
production, an increase of more than a factor of two
over any previous year. Simultaneously, currents
between 1 nA and ~10 yA were extracted stably to the
proton area. Currents of 170 yA cw and 250 yA
equivalent In a 30% pulsed mode have been
demonstrated. The polarized beam current was
increased from 300 nA to 600 nA. Reliability, defined
as the percentage of available beam time to the
scheduled beam time, was around 85% for the various
beam lines. Key factors in achieving these
performance levels were the uninterrupted operation of
the resonating cavity resulting from improved
alignment and diagnostics, the availability of bright
ion sources with beam output exceeding requirements,
the prompt reproducibility of the beam in the
injection line and the stable operation of the main
magnet. These Improvements are described together
with planned future Improvements.
PG16
The Investigation of Self-Quenching Streamer
Chambers as UV Photodetectors in Conjunction with BaF^
Scintillators. M. SALOMON, TRIUMF _ We have
investigated the possibility of a position sensitive
Y _ r a y detector using BaF 2 scintillators and
Self-Quenching Streamer chambers. The UV
scintillation light from BaF 2 is used to produce
photoelectrons in a multiwire chamber operating in the
streamer mode. Several gas mixtures and geometries
have been investigated and the efficiency of the
device has been measured. The main advantage of this
mode of operation is the large anode signal, which
eliminates the need of amlifiers for each wire. The
speed and dead time of this device has also been
measured.
rugi
PG17
An Optically-Pumped Nuclear-Polarized H~ Ion
Source. P. LEVY, M. McDONALD, P.W. SCHMOR, TRIUMF An optically pumped Ion source, capable of producing
30 to 50 yA of polarized H~ in a dc mode suitable for
Injection into the cyclotron, is being constructed at
TRIUMF. In this technique, protons from an electron
cyclotron resonance (ECR) ion source pick up an
aligned electron from an optically pumped alkali
vapour to produce an electron spin polarized atomic
beam. Nuclear polarization of the atomic beam is
obtained through a diabatic field reversal scheme.
Charge exchange In a second alkali vapour produces
polarized H~. In a preliminary step, optically dense
sodium vapours have been highly electron-spin
polarized by optical pumping on the sodium D1 line
with CW dye lasers. The polarization has been
investigated using the Faraday rotation effect and an
absorption technique. The degree of polarization,
when pumping with a broad band laser, Is enhanced by
the use of a nonuniform magnetic field and through
pumping with counter-propagating beams.
PG18
High Energy G r a d i e n t s i n Room Temperature CW
Linear Accelerators:
What i s t h e L i m i t ? .
J . - P . LftRRIE,
H. EUTENE1IER* and 0 . MçKEOUN, AECL, Chalk R i v e r Nuclear
L a b o r a t o r i e s , Chalk R i v e r , O n t a r i o , Canada - This paper
d e s c r i b e s the e v o l u t i o n i n the desiqn and the high power
operation of
room temperature cw l i n e a r
accelerator
s t r u c t u r e s at Chalk R i v e r Nuclear L a b o r a t o r i e s which
l e a d t o the c o n s t r u c t i o n of a p r o t o t y p e t h a t w i l l be
t e s t e d at an average energy g r a d i e n t of 4 MeV/m.
Comp u t e r modeling i s used t o p r e d i c t t h e behaviour of t h i s
s t r u c t u r e d u r i n g o p e r a t i o n and t o determine i t s power
handling c a p a b i l i t i e s .
S c a l i n g laws f o r the design of
high power s t r u c t u r e s are d e r i v e d and d i s c u s s e d .
*
I n s t i t u t f a r Kernphysik der Johannes-GutenbergU n i v e r s i t a ' t , Mainz, West Germany.
PG19
A Target Transport System for Short-lived
Radioisotopes.* D.W. HOLDSWORTH and D.A.L. PAUL, Dept.
of Physics, University of Toronto - Equipment has been
developed to transport self supporting target films in
vacuo at high speeds. The targets may be transferred
over 3 m in less than 2 seconds and are gently accelerated and decelerated. In addition, the targets are
accurately positioned at each end to within 25 microns.
Non-magnetic materials are used throughout and wear is
reduced such that 5 x 10 5 transfers should be possible
without loss of accuracy or reliability. Such a system
should have many applications for on-line experiments
using short-lived isotopes. Prototype construction and
testing is described.
*Supported by NSERC grant 0A2224.
PG20
y-ray Detection with the TRIUMF TPC.
G. AZUELOS, G. BAVARIA, P. DEPOMMIER, L. LESSARD,
J.P. MARTIN, R. POUTISSOU, Univ. de Montréal,
J. BAILEY, A. BENNETT, J.A. MACDONALD, TRIUMF,
M. BLECHER, K. GOTOW, Virginia Polytechnic,
R.A. BURNHAM, M. HASINOFF, J.-M. POUTISSOU, U.B.C.
E. CIFFORD, T. NUMAO, P. SCHLATTER, Univ. of Victoria,
M. DIXIT, C. HARGROVE, H. MES, NRC, D.A. BRYMAN,
TRIUMF, Univ. of Victoria -Photons produced by the
reactions: ir~p + yn (E~" 129 MeV) and v~p * u°n,
»' + 2 y (55 MeV < Ey <83 MeV) were converted by
0.6 mm Pb sheet In the central region of the TRIUMF
TPC and the two tracks from the e e~ pair were
observed. Targets of CHj and LiH were used. Runs
with a carbon target were taken to subtract background
from radiative pion capture in carbon. Results
clearly prove that the TPC can be used as a pair
spectrometer. Monte Carlo simulations indicate that
de-multiplexing of the signals on the end caps and
wire chambers will greatly enhance the resolution,
efficiency, acceptance and background rejection
capability. Ultimately the TPC will serve for study
of the induced coupling constant g p in radiative
muon capture on hydrogen.
PROJECT
CENTAUR
PHI
Analysis of Ground-Based Measurements of Atomic
Oxygen Emission in the Dayside Cleft. R. LINK and
G.G. SHEPHERD, CRESS, York University, Toronto, Ontario
and A.W. YAU, Herzberg Institute of Astrophysics,
National Research Council of Canada, Ottawa, Ontario Ground-based measurements of dayside cleft atomic oxygen
emission intensities at 6300Â and 5577Â were obtained at
Cape Parry in conjunction with the CENTAUR IV B-38 launch.
A linear multistream Boltzmann equation model of electron
transport/energy degradation, together with a model of
dayside auroral chemistry, is used to examine the production of atomic oxygen emission in the twilight cleft
ionosphere near solar maximum. The linear transport
model allows a separate examination of production due to
solar EUV irradiance and that due to precipitating cleft
electron fluxes. Using the MSIS83 model of thermospheric
composition calculated for the time and location of the
observations, the solar EUV spectrum (at 1A resolution)
appropriate for that date, and the rocket measurements
of the precipitating electron energy and pitch angle
distribution, quantitative estimates of the contribution
of the various production mechanisms to the observed
cleft emission intensities are reported.
PH2
Electron Temperatures and Densities in the Dayside Cleft. A.G. MCNAMARA, Herzberg Inst, of Astrophysics, N.R.C. - Langmuir probes were flown on rocket AAFIVB-38 during the CENTAUR campaign at Cape Parry on 6
Dec. 1981. Launch occurred at 13:15 local magnetic time
into optical auroral forms in the cleft region.
Electron temperatures and densities were measured from
100 km up to the apogee of 602 km. Maximum densities of
approximately 1 x 10 e/cm 3 were reached at an altitude
of 400 km with an electron temperature of approximately
2800°K. Around apogee, the rocket crossed a region of
enhanced auroral emissions where the probes recorded
enhancements of about 30% in the density and
temperature.
PH3
Particle Precipitation and Ionospheric
Convection in Dayside Aurora. A.W. YAU and B.A. WHALEN,
Herzberg Institute Astrophysics, NRCC - We present
particle precipitation and ionospheric ion measurements
from Black Brant rocket IVB-38 which was launched from
Cape Parry, Northwest Territories, Canada on December 10,
1981 at 23:14:58 UT as part of Project Centaur. The
payload reached an apogee of 603 km and crossed two
regions of electron precipitation. In both precipitation regions, the spectra were soft, with peak
intensities of 'ÎO 10 cm" 2 s" 1 keV"1 at 200 eV. The
hundred-eV electrons were anisotropic in the downcoming
hemisphere (field-aligned). The spectra varied with the
electron pitch-angle. They had larger characteristic
energy at small pitch-angles and revealed appreciable
atmospheric degradation (and hence predicted optical
auroral emissions) in the 300-km altitude region. No
proton precipitation was observed. The topology of the
ionospheric convection was found to be correlated with
both the location and the drift motion of the aurora.
PH4
Observations of the 01 6300 and 5577 Cleft
Emissions with a meridian-scanning, Fabry-Perot Spectrometer. W.A. GAULT, G.G. SHEPHERD and R.H. WIENS,
Centre for Research in Experimental Space Science,
York University - Ground-based measurements of the
01 6300 and 5577Â emissions were made at Cape Parry,
N.W.T. during December 1981, in support of the Centaur
magnetospheric cleft campaign. The instrument was a
Fabry-Perot spectrometer with a bandwidth of 0.2Â which
was stepped over a small wavelength range to allow
accurate subtraction of the background intensity.
Meridian scans were obtained using a rotating mirror.
The small bandwidth allowed useful measurements to be
made through the noon twilight period. Considerable
day-to-day variability exists in the 6300 emission's
behaviour and on some occasions it appears to be
unexpectedly bright.
rug
PH5
The CENTAUR TEOL Probe Experiment - observations
and Reflections.* R.A. KOEHLER and J.G. LAPRAMBOISE,
Physics Dept., York Univ. - A new multi-electrode plasma
probe, designed for orbit-limited current measurements,
was flown on the rocket AAF-IVB-38 during the December
1981 CENTAUR Campaign at Cape Parry, N.W.T. The
theoretical basis for this probe, its operating
conditions and data obtained during the flight are
presented. Electron and ion densities and temperatures
are discussed in relation to other measurements obtained
during this rocket flight.
* supported by NSERC
PH6
Convection Measurements i n the P o l a r C l e f t
Region.
.), MACDOUGALL. U n i v e r s i t y o f Western O n t a r i o Measurements o f c o n v e c t i o n i n the v i c i n i t y o f the p o l a r
c l e f t are r e p o r t e d f o r w i n t e r and summer measurement
campaigns. The w i n t e r r e s u l t s are f o r the 1981
' C e n t a u r ' campaign.
These r e s u l t s are not i n agreement
w i t h a narrow c o n v e c t i o n t h r o a t model except p o s s i b l y
on d i s t u r b e d days.
The summer measurements are f o r a
campaign i n 1982 which used s e v e r a l s t a t i o n s .
These
r e s u l t s w i l l be compared w i t h t h e Centaur r e s u l t s .
PH10 Two Supernovas in SNR HB3?
D.A. LEAHY and
D. VENKATESAN, Univ. of Calgary, Calgary, Canada,
S. NARANAN, TIFR, Bombay, India and KNOX S. LONG, Johns
Hopkins University, Baltimore, MD, USA - The Supernova
Remnant HB3 was observed with the Imaging Proportional
Counter (IPC) onboard the Einstein X-Ray Astronomy Satellite. X-rays from HB3 were first detected with the A2
LED detectors onboard the X-Ray Astronomy Satellite, HEAO
-1, by Galas et al (1978). The current observations are
the result of a Guest Observer Proposal by D. Venkatesan,
CMF. Galas and S. Naranan. The data was processed in Aug.
1983 to yield a contour map of the x-ray brightness and
the spectra of various regions across the HB3 remnant.
The spatial structure is compared with the radio morphology. HB3 is found to be in the adiabatic blast wave
phase, with a reduction in the temperature gradient, due
to thermal electron conduction. The suggestion is made
that HB3 may be a young remnant (^ 7000 years old)
superposed on an older remnant (^ 30000 - 50000 years
old).
Galas, CMF., Tuohy, I., Garmire, G. 1978, I.A.U.
circular 3254.
LA SER-PLA
PH7
Rocket Measurements of Mid Day Electron
Influx Across the Auroral Oval. D.J. McEWEN and
P.P. STEELE, Inst, of Space and Atmos. Studies,
Univ. of Sask. - An analysis of the electron
precipitation measurements (12 eV - 18 keV) from
Black Brant IVB-38 rocket flight across the
dayside auroral will be presented. The rocket was
launched at 23:14:58 UT on December 10, 1981,
approximately 1 hour after local magnetic noon.
The electron data show the rocket was within the
region of soft electron precipitation for over 10
minutes, exiting on the poleward side of the oval
at about
on its descent. These data will be
compared with the simultaneous photometric data
obtained from a ground station at Sachs Harbour
located below rocket apogee.
PH8
Inverted V Structures in the Post Noon
Auroral Oval. D.J. McEWEN, Inst, of Space and
Atmos. Studies, Univ. of Sask. and F. CREUT7.BERG,
HIA, NRC - Transient enhancements of the 6300 and
5577A emissions in the post noon auroral oval are
frequently observed. An analysis of these events as
recorded by meridian photometers and TV all-sky
cameras during the CENTAUR cleft campaign at Cape
Parry and Sachs Harbour, NWT, November 18 - December
21 has been undertaken. The characteristics of
these transient forms are discussed and some
inferences made on the incoming electron energies
involved. Their signatures as recorded by rocket
and satellite electron detectors will be discussed.
PH9
Synopsis of Geomagnetic Pulsation Activity at
High Latitude* TOMIYA WATANABE, Dept. of Geophysics
and Astronomy, Univ. of B.C. - Geomagnetic pulsation
data acquired at Cape Parry, N.W.T. in December 1981
were analyzed through five band-pass filters covering
a frequency range from 0.001 Hz to 1 Hz. Activity
through each frequency window was compared with
behaviour of aurorae observed simultaneously at Cape
Parry. Geomagnetic pulsation activities at Cape Parry
were also compared with those observed at middle
lat itudes.
*Supported by Natural Sciences and Engineering Research
Council of Canada.
SMA
1I\ TER A C
TIONS
PJl
Etude c i n é t i q u e du f l u x de c h a l e u r é l e c t r o n i q u e
dans l ' i n t e r a c t i o n l a s e r - m a t i e r e T
J . P . MATTE, T.W.
JOHNSTON, INftS-Energie, U. du Québec, J. DELETTREZ,
R.L. McCRORY, LLE, U. Rochester, J .
VIRMONT, P a l a i s e a u
- Dans 1 ' i n t e r p r e t a t i o n des e x p é r i e n c e s d ' i n t e r a c t i o n
l a s e r - m a t i è r e à l ' a i d e de modèles f l u i d e s , i l e s t nécess a i r e d ' i m p o s e r une l i m i t e ad hoc au f l u x de c h a l e u r
é l e c t r o n i q u e ( f a c t e u r f = 0 . 0 3 - 0 . 0 5 ) parce que, à f o r t e
i n t e n s i t é l a s e r , des g r a d i e n t s r a i d e s de t e m p é r a t u r e
sont p r o d u i t s e t l e s hypothèses de l ' a p p r o x i m a t i o n f l u i de ( l i b r e p a r c o u r s moyen << longueur de g r a d i e n t ) ne
sont plus v é r i f i é e s .
Dans ce régime, i l e s t n é c e s s a i r e
de c o n s i d é r e r l e s é l e c t r o n s de façon c i n é t i q u e , ce q u i
s i g n i f i e q u ' o n f a i t é v o l u e r l a f o n c t i o n de d i s t r i b u t i o n
é l e c t r o n i q u e dans l ' e s p a c e de phase ( x , v x , v x ) .
Notre
code c i n é t i q u e FPI conprend l e s processus s u i v a n t s :
c o n v e c t i o n , champ é l e c t r i q u e a u t o c o n s i s t a n t , c o l l i s i o n s
é l e c t r o n - i o n e t é l e c t r o n - é l e c t r o n , hydrodynamique, abs o r p t i o n ( c l a s s i q u e ) par Bremsstrahlung i n v e r s e .
Les
r é s u l t a t s du code F P I , comparés à un modèle f l u i d e ,
i n d i q u e n t un f a c t e u r f = 0 . 0 8 , ce qui e s t encore t r o p
élevé.
Nous a j o u t o n s au code une source de c h a l e u r
s u p p l é m e n t a i r e , l ' a b s o r p t i o n r é s o n n a n t e , e t nous montrerons comment c e c i m o d i f i e l ' é c o u l e m e n t de l a c h a l e u r .
pj2
Weak R e f l e c t i o n s from Gradual T r a n s i t i o n s i n
Underdense Plasma"! G.R. M i t c h e l , IREQ, Varennes and
n r JOHNSTON, INRS-Energie, U. du~17ïïëbec, Varennes —
Calculations f o r feedback-assisted parametric a m p l i f i cation pertinent to stimulated backscatter ( B r i l l o u i n
or Raman) i n l a s e r f u s i o n plasma experiments r e q u i r e
t h e c a l c u l a t i o n o f r e f l e c t i o n from d e n s i t y v a r i a t i o n s
i n r a t h e r underdense plasma.
The zero o r d e r WKB app r o x i m a t i o n g i v e s no r e f l e c t i o n .
The a p p r o x i m a t i o n
t e c h n i q u e discussed by Brekhovskikh compares f a v o r a b l y
w i t h exact r e s u l t s .
The i n f l u e n c e o f t h e n a t u r e of the
t r a n s i t i o n ( s t r a i g h t l i n e , odd o r d e r p o l y n o m i a l ) i s
d i s c u s s e d w i t h r e s p e c t t o the a s y m p t o t i c behaviour as
the t r a n s i t i o n i s made very g r a d u a l .
1.
L.M. Brekhovskikh "Waves i n Layered Media"
Academic Press (1980) sec. 25.
rugi
PJ3
I n t e r a c t i o n L a s e r - M a t i è r e m u l t i ' - r a i e s sur c i b l e
s o l i d e à l U . b ^m».—P. LAVlUNt, I.W. JUHNS1UN, H. PtPIN
ÏÏ: PASCALE, r . MARTIN, R . DECOSTE and S. AITHAL, INRSEnergie - L ' u t i l i s a t i o n de sources l a s e r s m u l t i - r a i e s a
e t e suggérée comme moyen de r é d u i r e l e s e f f e t s n é f a s t e s
de c e r t a i n e s i n s t a b i l i t é s l o r s de l ' i n t e r a c t i o n l a s e r m a t i è r e dans l e c o n t e x t e de l a f u s i o n t h e r m o n u c l é a i r e
contrôlée.
Nous avons donc é t u d i é c e r t a i n s aspects de
l ' i n t e r a c t i o n à deux r a i e s avec un l a s e r C02 capable
d ' é m e t t r e des i m p u l s i o n s de 1 nsec dans une gamme de
f l u x comprise e n t r e 6 x 1 0 1 1 W/cm2 e t ÎO1*1 W/cm 2 . Nous
avons mesuré , e n t r e a u t r e , l ' e f f e t de l ' i l l u m i n a t i o n à
deux r a i e s s u r l a d i f f u s i o n B r i l l o u i n , l a t e m p é r a t u r e
chaude e t l a p r o d u c t i o n de signaux à l a somme de l a
fréquence sur des c i b l e s de CH 2 . Nous avons aussi mesuré l ' e f f e t de l ' i l l u m i n a t i o n m u l t i - r a i e s sur l a product i o n d ' é l e c t r o n s r a p i d e s en a r r i è r e de c i b l e s minces de
carbone.
*
PJ7
Non-Maxwellian Hot Electron Distribution in
C0 2 Laser-Produced Plasmas* G.D. ENRIGHT and N.H.
BURNETT, National Research Council of Canada At incident intensities of~2 x 1014 W/cm2 most of the
absorbed energy can be accounted for in a hot electron
component with a temperature of 15-20 keV. Recently we
have confirmed the existence of very energetic electrons
with a "temperature" in excess of 100 keV. Careful
analysis of the x-ray emission spectrum in the range
100-300 keV has indicated that the electron distribution
is non-Maxwellian. The fraction of laser energy that
is accounted for in these very energetic electrons is
-0.1 percent but it increases very strongly with laser
intensity. It is estimated that at intensities
>10i6 W/ cm^ this component will dominate the energy
balance. Experiments on layered target x-ray yields
have provided further evidence for the non-Maxwellian
nature of the electron distribution.
T r a v a i l subventionné par l e Conseil de recherches en
s c i e n c e e t en g é n i e Canada
PJ4
Etude sur l e s champs magnétiques générés dans
l e s plasmas p r o d u i t s par l a s e r C O , ^
F. MARTIN, J .
SAHBAUH, y. LflvmNL, iNKb-Lnergie - Les champs m a g n é t i ques associés aux plasmas p r o d u i t s par l a s e r CO, de
haute i n t e n s i t é ( I « 4 x 1 0 1 3 W/cm 2 , x « 1 nsecî ont é t é
c a r a c t é r i s é s par l a t e c h n i q u e de r o t a t i o n de Faraday.
Une p a r t i e du f a i s c e a u p r i n c i p a l e s t u t i l i s é comme f a i s ceau sonde. La r o t a t i o n du plan de p o l a r i s a t i o n de
c e t t e sonde par l e champ magnétique du plasma e s t e n s u i t e t r a n s f é r é à une sonde r u b i s d'une durée de 35 psec en
u t i l i s a n t l ' e f f e t Kerr optique.
Ceci perrmet une bonne
r é s o l u t i o n t e m p o r e l l e e t l a f a c i l i t é de d é t e c t i o n sur
f i l m d ' u n e sonde v i s i b l e .
Les mesures i n d i q u e n t une
r o t a t i o n du plan de p o l a r i s a t i o n d ' e n v i r o n 2 ° .
Le sens
de l a r o t a t i o n e s t opposé de chaque c ô t é de l a t â c h e
focale.
Les champs magnétiques sont p r é s e n t s seulement
d u r a n t l a montée de l ' i m p u l s i o n l a s e r C02 (= 600psec) e t
s ' é t e n d e n t j u s q u ' à un (1) mm de l a s u r f a c e de l a c i b l e
où l a d e n s i t é é l e c t r o n i q u e e s t f a i b l e ( n e < 1 0 1 8 c m ~ 3 ) .
* T r a v a i l subventionné par l e Conseil de recherches en
s c i e n c e e t en g é n i e Canada
PJ5
Fast E l e c t r o n s from L o c a l i z e d Strong Coherent
T r a v e l l i n g waves.
I.W. JUHNSIUN, I N R S - t n e r g i e , U. du
Quebec--Ihe p r o d u c t i o n o f f a s t e l e c t r o n s by l o c a l i z e d
t r a v e l I i n g e l e c t r o s t a t i c waves w i l l be d i s c u s s e d , w i t h
s p e c i a l a t t e n t i o n p a i d t o t h e e f f e c t o f the i n p u t p a r a meters ( t e m p e r a t u r e o f the incoming e l e c t r o n s , the
t r a p p i n g parameter (~ t r a n s i t t i m e / t r a p p i n g t i m e ) ) on
t h e f a s t e l e c t r o n o u t p u t ( r e l a t i v e number o f f a s t e l e c t r o n s , h o t " t e m p e r a t u r e " , energy w i d t h o f hot t a i l ) .
The r e l a t i o n t o the q u a s i l i n e a r d i f f u s i o n o p e r a t o r w i l l
a l s o be d i s c u s s e d .
Image des ions rapides avec une caméra à trou pour
l'interaction laser-CO? plasmas. D. PASCALE, R.DECOSTE,
J.-C. KIEFFER, P. LAVltlNE, INRS-Energie, IREQ. Des images de l'émission des ions rapides sont utilisées pour
corréler spatialement le transport d'électrons chauds avec l'émission des ions énergétiques et pour déterminer
la direction et le cône d'émission du faisceau d'ions
des différentes régions sur la surface de la cible. Les
effets de charges d'espace sur le faisceau ionique après
le trou sont minimisas en ajustant la filtration énergétique, le grossissement de la caméra et la distance cible-trou. Pour des énergies laser entre 10 et 75 joules
sur cible, l'émission des ions rapides se produit sur line zone comparable à celle du transport latéral d'électrons chauds (q>.alques mm). Une émission très forte est
observée près de la zone focale pour les ions les moins
énergétiques seulement. D'autres caractéristiques de
l'émission ionique seront présentés et reliées au transport d'électrons.
PJ8
Energy Balance and Temperature in a C0 o laser
plasma.* R.Popil,J.Meyer,B.Ahlborn,J.E.Bernard, H.
Houtman.and G.Mcintosh University of British Columbia
- An underdense C0_ laser produced plasma is experimentally investigated to determine the electron temperature
explained in terms of an energy balance. Soft x-ray
diagnostics measure a 300 eV thermal and a 2 keV suprathermal temperature. Ulbricht integrating sphere data
in conjunction with interferometric information on the
electron density indicate sufficient absorption of
25% of the incident laser energy to allow the plasma
to attain sub-kilovolt temperatures. A novel method of
analysis of streak photographs of the radial expansion
is introduced which implements a modified blast wave
theory which incorporates radiative transfer. This
analysis allows an independent determination of the
thermal plasma temperarure and absorbed laser energy.
The observed thermal T is found to be consistent with
linear inverse bremsstrahlung absorption at laser
intensities <_ 10ll+ W/cm 2 . The energy balance and the
x-ray spectrum permit an estimate of the fraction of
suprathermal electrons and appears to be about 20%.
* supported by N.S.E.R.C.
PJ9
Thomson Scattering from Non-Thermal Ion Fluctuations in a CO? Laser-Gas Jet Experiment*. J.E.
Bernard, J. Meyer, H. Houtman, G. Mcintosh, R. Popil,
University of British Columbia-Ruby laser Thomson scattering has been used to study the enhanced ion fluctuations driven b^stimulated Brillouin scattering in
a high power (~10 W/cm ) C0 2 laser-nitrogen gas jet
experiment. Temporaly resolved spatial and wave vector
spectrum measurements have been made using a high speed
streak camera. The SBS was found to occur in the low
density (*-0.1n ), long scale length (~lmm) plasma
occurring on the front side of the jet. The Thomson
scattered light was found to be correlated with both
the temporal behavior and the reflectivity of the SBS
backscatter. Maximum values of £n/n~5% were observed.
A rapid (^50ps) modulation of the Thomson scattered
light was often observed. The majority of the Thomson
scattering was from fluctuations with k~2k as expected for SBS backscatter. However, much weaker scattering occurred from fluctuations with k>3.4kQ and is believed to be related to two-plasmon decay as well as to
the SBS ituelf. These results will be discussed in
terms of possible models.
* supported by N.S.E.R.C.
rug
PJ10
Plasma Wave Production by Stimulated Raman
Scattering*, D.M. VILLENEUVE, H.A. BALDIS and C.J. WALSH
National Research Council of Canada - We have used
temporally- and spectrally-resolved Thomson scattering
in a CO2 laser plasma interaction experiment to identify
the electron plasma waves driven by SRS. Two preformed
plasma geometries were used: exponential and gaussian.
Plasma waves at n c /4 were observed in both geometries
and were k-resolved to demonstrate that they were
produced by SRS rather than two-plasmon decay. For
plasma densities less than n c /4, waves were only seen
in the gaussian geometry due to the longer gain length
and hence lower threshold, and only in the density
range (0.01-0.05)nc. The onset of Brillouin scattering
caused the plasma waves to disappear early in the pulse,
and may explain the absence of SRS between 0.05 and
0.25 n .
PJ11
Equation of State and Shock Wave
Calculations at M-bar Pressures. L. da SILVA,
G. McINTOSH, D. PARFENIUK and B. AHLBORN, Dept. of
Physics, Univ. of British Columbia - The enthalpy
coefficient g has been calculated for aluminum using
both Thomas-Fermi and ideal gas equations of state
for pressures up to I0 15 atm. Using these results
and conservation equations for a planar shock,
various shock parameters have been determined for
conditions similar to laser driven shock
experiments. The resulting shock velocity compares
favourably with that previously measured
experimentally by Trainor et al.
PJ12
Initial KrF Laser-Plasma Interaction Experiments.
R. Fedosejevs, D.C.D. McKen and A.A. Offenberger, Dept.
of Electrical Engineering, University of Alberta - A
first generation KrF laser system has been developed for
laser/matter interaction experiments. The system is comprised of four discharge laser modules, an E-beam excited amplifier which delivers i25J in three 20ns pulses
and a pulse compression scheme utilizing beam multiplexing and stimulated Raman scattering in methane. When
fully operational the system should be capable of producing nominal 10J, 3ns pulses with 150 /irad beam divergence. Laser-plasma interaction experiments are just
beginning and preliminary target irradiation measurements will be presented for focused intensities on
target of 1 0 1 3 W/cm 2 .
ATOMIC
PHYSICS
AND
II
MOLECULAR
PK1
Theory of Helium Scattering from Adsorbed
CO.* W.-K. LIU** and B. GUMHALTER***, (GWP)2t Waterloo Campus - The cross sections for thermal He
scattering from C0/Pt(lll) at low coverage have been
measured experimentally.1
Using the Feynman diagrammatic technique, we have shown that the Van der Waals
interaction between an atom and an adsorbate derives
from three contributions: the direct interaction, the
image force and an interference term. The last two
contributions are three-body interactions due to the
presence of the surface. The asymmetry of the
adsorbate has also been taken into account. Employing
the flat hard wall approximation, the atom-adsorbate
total cross section is expressed in terms of T-matrix
elements for collision in the absence of the surface,
and an expression using the distorted wave Born
approximation has been derived.
*Supported by NSERC of Canada. **Department of Physics
and (GWP)2. ***Department of Physics and Applied
Math. Pemanent address: Institute of Physics of the
University, Zagreb, Yugoslavia.
tGuelph-Waterloo program for Graduate Work in Physics.
!
B . Poelsema, et. al. Surf. Sci. 126 641 (1983).
PK2
Rotationally Inelastic Scattering of Openshell Molecules from Solid Surfaces.* G.C. COREY** and
W.-K. LIU*** - U. of Waterloo - By combining laser
induced fluorescence techniques with a seeded supersonic
nozzle beam of NO scattered from a clean Ag(lll) surface, the relative populations between final rotational,
spin-orbit and A-doublet states have been measured.
The effective potential between an open-shell molecule
and the surface has an additional azimuthal dependence
not present in the case of a close-shell molecule.
Expressions for the diffraction intensities using Hund's
case (a), case (b), and intermediate coupling
representations for the molecule have been derived.
Experimental population distributions as a function of
final rotational j' states exhibit distinct behavior for
the low and high j' regimes, and it is possible to
explain qualitatively this phenomenon within a direct
inelastic scattering mechanism.
*Supported by NSERC. **Dept. of Chemistry and GuelphWaterloo Centre for Graduate Work in Chemistry.
***Dept. of Physics and Guelph-Waterloo Program for
Graduate Work in Physics.
1
A.W. Kleyn, A.C. Luntz and D.J. Auerbach, Surf. Sci.
117 33 (1982), and references therein.
PJ13
Equation of State Studies in Laser-Hatter
Interactions. * A. NG, D. PARFENIUK, and L. DaSILVA,
Physics Dept., Univ. of British Columbia - In laser irradiation of solids, a high pressure shock wave is generated which propagates into the target. Consequently,
the shock-compressed material can attain pressures >1 TPa,
temperatures >10^ °K and densities exceeding the normal
solid density of the target. We have irradiated planar
aluminum foils with 0.53 ym, 2nsec (FWHM) laser light at
intensities of 10 1 2 -7*10 1 3 W/cm 2 . The shock speed was
obtained by measuring the on-set of shock-induced
luminescence of the target rear surface. The ablation
pressure driving the shock wave was determined independently from measurements of the ablatively driven ion
expansion on target front side. These yielded the
Hugoniot data which was compared with calculations using
different equations of state. Our results showed good
agreement with theory based on the Thomas-Fermi-Corrected
(TFC) model.
PK3
Absorption Intensity Measurements of the 0-3 band
of NO. G. CHANDRAIAH, Memorial Univ. of Nfld. - The
measured intensity values of t he 0-3 band of NO at 1.8 u
spread out between 0.0153 and 0.0458 cm"2 amagat"! 1-4;
and this wide variation of the data is a disturbing fact,
In the present work the method employed, to determine the
absolute intensity of the 0-3 band of NO, is essentially
the Wilson-Wells extrapolation technique. Atransmissiontype high pressure stainless s teel absorption cell with
an optical path length of 171. 5 cm and a Perkin-Elmer 99G
double pass grating spectromet er were used to obtain
several spectra. Argon gas se rved as a pressure
broadening gas. The intensity of the band obtained is in
close agreement with that of S churin and Ellis (1966),
who used pure nitric oxide gas and Wilson-Wells method.
* Supported by N.S.E.R.C. and B.C. Hydro and Power
Authority.
2
Dinsmore, H., thesis, University of Minnesota, 1949.
Ply1er, E.K., Benedict, W.S., and Silverman, S., J.
Chem. Phys. 20, 175 (1952).
3
Meyer, C., Haeusler, C., Barchewitz, P., J. Phys.
(paris) 26, 305 (1965).
4
Schurin, B. and Ellis, R.E., J. Chem. Phys. 45, 2528
(1966).
rugi
PK4
Collision-Induced Absorption in N? , CHt, and
N^-CHi, Mixtures Below 400 cm - 1 . I.R. DAGG, A. ANDERSON,
L.A.A. READ*, W. SMITH and S. YAN**, (GWP) t, Waterloo
Campus - Collision-induced absorption in N2, CH 4 and
certain N2-CHu mixtures has been measured in the region
below 400 cm" at four different temperatures in the
range 126 to 223K. A Michelson Fourier Transform
spectrometer was used in the 40-400 cm - region and an
FIR laser was used to provide additional data at 15
cm - *. Previously obtained microwave data1 were also
included in analyzing the results according to theoretical expressions for the first and second spectral
moment . Agreement with theory is generally good at or
above 180K but the experimental results at the lower
temperatures are approximately 20% higher than expected
for N 2 and only slightly high for CH,,. The initial mixture results are consistent with theoretical estimates.
1
0agg, I.R., Reesor, G.E. 4 Urbanlak, J.L. Can.J.Phys.
52, 821 (1974).
^Cohen, E. 4 Birnbaum, G. J.Chem.Phys. 66, 2443 (1972).
*Wilfrid Laurier University, Waterloo, Ontario.
**Nankai University, Tianjin, China.
tGuelph-Waterloo Program for Graduate Work in Physics.
PK5
Impact Broadening and Shifts of Even Parity
Rydberg States of Barium.
K.S. BHATIA"1", D. BRUCE and
W.W. DULEY, Department of Physics, York University,
Downsview, Ontario.- Impact broadening and shifts of
even parity levels of neutral barium using rare gases as
perturbers has been^studied. A N2 laser pumped dye
laser
4600-5200 A) combined with ionisation detector
was used to record the spectral line profiles of 6 sns
('s.) and 6 snd ('D, 3 D) Rydberg series from n = 8 ->• 35.
Final states were populated by two photon pulsed laser
excitation technique. Effects of perturbation due to
configuration interaction on the shifts and broadening
of spectral lines will be discussed. Relative broadening
due to He, Ar, Kr and Xe perturber gases will be described. The profiles of hybrid transitions will be presented.
*
PK8
Mesure de la structure hyperfine dans le bore IV,
par battements quantiques. J.-P. MOREAU et E.J. KNYSTAUTAS, Département de physique (CRAM), Université Laval Le déclin radiatif de niveaux rapprochés vers un niveau
inférieur donne lieu à une modulation de l'intensité de
lumière en fonction du temps,ajoutée à la décroissance
exponentielle. Les fréquences de modulation donnent directement la différence d'énergie entre les niveaux rapprochés. Nous utilisons un faisce&u de bore ionisé (E ~
5 MeV), excité par son passage au travers d'une cible
mince de carbone.
Nous présentons le développement théorique propre aux niveaux étudiés, la description du dispositif expérimental, la méthode d'analyse, ainsi que les
résultats obtenus pour la structure hyperfine dans la
transition ls2s 3S - ls2p 3 P 0 1 2 (* ~ 2830 S), dans le
1
°B IV et le n B IV.
PK9
V a r i a t i o n o f E l e c t r o n i c T r a n s i t i o n Moment o f the
B-X System o f I . : .
G.L. BHALE*, S.F. AHMAD AND S.P.
REDDY, M e m o r i a l U n i v . o f N f l d . - Fluorescence i n the
B 3 n 0 + U - X 1 Z g + system o f I 2 e x c i t e d w i t h 5145 3 r a d i a t i o n o f an argon i o n l a s e r was recorded p h o t o e l e c t r i c a l l y i n the r e g i o n 5200-8500 8 on a SPEX 0.85 m double
monochromator.
Using the measured i n t e n s i t i e s o f P(17)
r o t a t i o n a l l i n e s o f t h i r t y e i g h t ( v ' = 43, v " ) bands and
the Franck-Condon f a c t o r s based on the r e c e n t m o l e c u l a r
data o f the B and X s t a t e s , the v a r i a t i o n o f the square
o f the e l e c t r o n t r a n s i t i o n moment, | M ( R ) | 2 , w i t h Rc e n t r o i d i n the range R = 2 . 6 5 - 3 . 1 A was s t u d i e d .
It
was n o t i c e d t h a t the^ e l e c t r o n i c t r a n s i t i o n s t r e n g t h has
a maximum value a t R = 2.83 8 and i s r e p r e s e n t e d by the
relation
| M ( R ) | 2 = c o n s t a n t ( - 5 0 0 . 3 5 8 + 377.125 R - 38.483 R2 25.429 R3 + 4.9831 R 1 *).
Present r e s u l t s are discussed i n r e l a t i o n w i t h
o b t a i n e d from e a r l i e r s t u d i e s .
* P r e s e n t address:
those
Bhabha Atomic Research C e n t r e , Bombay
400 085, I n d i a .
Supported by a grant from the NSERCC
+
On sabbatical leave from Kuwait University, Kuwait.
PK6
Analysis of Seven-times Ionized Antimony: Sb
VIII*. Th. A. M. VanKleef1, M. Barakat 1 , A. N.
Ryabtsev2, N. Y. Joshi 3 ; 'Univ. of Amsterdam,
institute Spectrosc. (Moscow), ''St. F. X. University
(Antigonish) - The spectrum of antimony was photographed in the 173-264A region on a variety of grazing
incidence spectrographs using a triggered spark source.
All levels of the 4d configuration and 102 of 110
levels of the 4d 7 5p configuration of Sb VIII have been
established. The least-squares fit energy parameter
calculations support the analysis. Two hundred and
fifty-six lines have been classified in this spectrum.
Improved wavelength values have also led to obtaining
a better value of 10397±2 cm"1 for the Id 2 2 D interval
and revision of four levels of Sb VII reported earlier.
PK10
Collision-Induced Absorption of H2 and D2 in
Their Second Overtone Regions. P.G. CILLARD AND
S.P. REDDY, Memorial U. of Nfld. - Spectra of collisioninduced absorption of normal H2 in the 3-0 band region
were recorded for gas densities in the range 500-930
amagat at 77 K with a 2 m absorption cell. The absorption profiles show a dip at 11793 cm -1 with its low- and
high-frequency maxima Qp and QR,respectively, which is
characteristic of the contribution of the short-range
electron overlap interaction! to the intensity of the
band. Absorption peaks observed for the first time at
12345, 13100, and 13310 cm"' in addition to the peaks reported earlier^ have been assigned to the double transitions Q3(J)+So(l), S2(1)+S1(0) and S2(0)+Si(l), and
S2(l)+Si(l), respectively. From the measured integrated
absorption coefficients, the binary and tenary absorption
coefficients have been determined. Re suits of the analysis of the absorption profiles will be also presented.
The first observation of the spectra of the 3-0 band of
D2 and their analysis will be also reported.
^Partially supported by NSERC.
l
Reddy, S.P., Varghese, G. and Prasad, R.D.G. Phys. Rev.
A 1_5, 975 (1977).
2
McKellar, A.R.W. and Welsh, H.L. Proc. Roy Soc. London
A322, 421 (1971).
PK£
Inner-sheel excitation of Se I and Te I below
300A using absorption flash pyrolysis". A. Nencioni1,
Y. N. Joshi 1 , A. Cantu2 and Th. A. M. VanKleef3, ' s t . F
X. Univ., 2Univ. of Florence, 3Univ. of Amsterdam - The
inner-shell excitation spectra of Se I and Te I have
been studied in the 200-500X region using a 2-m grazing
incidence spectrograph and absorption flash pyrolysis
technique. The experimental and theoretical results on
the nd^n'sSip* - nd 9 n 1 s 2 n 1 p 5 transitions will be
presented,
*Supported in part by NSERC and NATO Scientific Affairs
Division.
rug
PK11
Spectroscopic Studies of Rare-Gas Dimers Using
VUV Laser Excitation. P. E. LAROCQUE, R. H. LIPSON, and
B. P. STOICHEFF, U. of Toronto - Rare-gas dimers Xe 2 and
Kr 2 were formed in a pulsed supersonic jet and probed
with tunable coherent vacuum-ultraviolet radiation.
Fluorescence emission bands corresponding to transitions
from the first two excited electron states to the ground
states were observed. The bands of Xe 2 at 149.0 and
129.5 nm were excited with VUV radiation generated by
4-wave mixing in Mg and Zn vapours, respectively, and
those of Kr 2 at 125.5 and 124.5 nm using Hg vapour.
Rotational and vibrational cooling of the dimers resulted in resolution of the many isotopic vibronic bands of
Xe 2 and Kr 2 , and enabled the unambiguous numbering of
the excited levels for the first time. Thus, analyses
of the spectra were possible, yielding values of electronic origins and potential-well depths, as well as
vibrational and anharmonic constants for these excited
states. The experimental techniques used here will be
applicable to the whole family of rare-gas dimers and
other Van der Waals' molecules as suitable tunable laser
sources are developed in the VUV and XUV regions.
PK12
Hydrogen dimers on Jupiter and Saturn.
A.R.W. McKELLAR, Herzberg Institute of Astrophysics,
N.R.C.C., Ottawa.- Far infrared (100-700 cm" 1 ) spectra
of Jupiter and Saturn obtained by spectrometers on the
Voyager spacecraft show relatively sharp features near
the S(0) and S(1) pure rotational transitions of H 2 .
These features were recently analyzed by Gautier et al.1
but their precise origin has not yet been convincingly
explained. It is proposed here that the features arise
from transitions of bound and quasibound (H2)2 Van der
Waals dimers located in the planetary tropospheres.
The experiments required for laboratory observation of
the (H 2 ) ? spectrum in the far infrared have not yet been
performed, but it may be approximated using the known^
mid-infrared spectrum or calculated ab initio.^ It
seems clear that most or all of the observed structure
at the S(0) and S(1) line centers is due to (H 2 ) 2 .
1
D. Gautier et al.. Can. J. Phys. 6_1_, 1455 ( 1983).
2
A.R.W. McKellar and H.L. Welsh, Can. J. Phys. 5_2, 1082
(1974) .
"^L. Frommhold and G. Birnbaum, private communication.
PK13
Brillouin Pulse Compression of KrF Laser Radiation in SF^ Gas. R Fedosejevs, I.V. Tomov ", D.C.D.
McKen, and A.A. Offenberger, Department of Electrical
Engineering, University of Alberta - Experimental measurements will be presented of the generation and amplification of Brillouin shifted pulses in SF^ gas pumped by
narrow linewidth KrF laser radiation. The conversion
efficiency into backward radiation produced by focussing
0.08 cm 1 and 0.4 c m - 1 linewidth radiation using 50,100
and 200 cm. focal length lenses into SF, at pressures of
1 to 10 atm has been measured. The small signal gain was
also measured for the same pressure range giving values
in qualitative agreement with theoretical predictions.
In addition, an energy extraction efficiency of 20% has
been achieved in compressing pulses from 20ns to 1.5ns.
These results will be presented together with their
implications for the use of SF^ in high power UV laser
pulse compression systems.
*
on leave from Faculty of Physics, Sofia
BG1126, Sofia, Bulgaria.
University,
INDUSTRIAL
AND
APPLIED
PHYSICS
PL1
Pulsed uv Laser Annealed Gold, Silver and
Aluminum Ohmic Contacts n -GaAs.
P. SIRCAR, Bishop's University, Lennoxville, Quebec.
-Formation of ohmic contact to the important semiconductor material GaAs is yet to be standardized. In
the last few years laser annealed gold based ohmic contacts on GaAs has resulted into better ohmic contacts
(superior surface morphology, smaller contact resistance)
than obtained by the usual method of furnace annealing.
We have used a pulsed, uv excimer laser to form gold,
silver and aluminum based ohmic contacts on n + GaAs
single crystals. Similar contacts were also furnace
annealed, whereupon, only gold and silver gave ohmic
contacts, but aluminum failed to give an ohmic contact.
PL2
Mesure de la resistance d'une couche d'inversion induite par un electret. J.M. LANGLOIS, L.CARON,
Université de Sherbrooke^ A. FILION, B. NOIRHOMME,
College militaire royal de Saint-Jean - En vue de réaliser une pile solaire MIS a jonction induite, un matériau charge (l'electret) est juxtapose sur un semiconducteur pour obtenir une inversion en surface. On
cherche a minimiser la resistance de la couche d'inversion afin d'augmenter le rendement de la pile. La
mesure de cette resistance necessite un dispositif
particulier du type MOSFET où la grille est remplacée
par l'electret. La source et le drain du "transistor"
forment des contacts MIS, analogues à ceux de la pile,
qui isolent la surface du semiconducteur de son volume.
Les courbes courant-tension du
transistor donnent la mobilité des electrons et le nombre d'electrons par unite de surface dans la zone d'inversion.
La charge dans l'electret est evaluee a l'aide d'un
dispositif témoin où la grille est métallique.
PL3
An NMR Study of Lung Tissue - W.T. SOBOL,
I.G. CAMERON, J.C. MACTAVISH, M.M. PINTAR - (GWP) 2 * Waterloo Campus - R. INCH** and F. PRATOt - Molecular
dynamical parameters of lung tissue are difficult to
characterize by NMR techniques because of low signal
intensity, the interference of blood flow and artifacts due to breathing motions. The 1/e value of
inflated and deflated rodent lungs was measured with a
Technicare imager employing Hahn's sequence with a
variable repetition period. The Ti values obtained
were 381 ± 22 and 378 ± 8 msec, respectively. In an
effort to characterize the tissue better and obtain a
correlative data base, T^, T 2 and T^ p (with wj
dispersion) measurements were performed on freshly
excised rodent lung sections. Through the application
of spin grouping, lung tissue was determined to have
three Ti components and five Ti p components. The
signal recovery was modelled using the fast exchange
two site relaxation assumption selectively.
*Guelph-Waterloo Program for Graduate Work in Physics.
**Nuc. Med. Dept., St. Joseph's Hospital, London, Ont.
"("Experimental Oncology Group, The Ontario Cancer
Treatment & Research Foundation, London Clinic,
London, Ontario.
rugi
PL4
Cellules photovoltaiques à jonction induite:
Electret-semiconducteur.
B. NOIRHOMME, A. FILION,
^t Â~! RAMBO, Collège militaire royal de Saint-Jean Ces dernières annees beaucoup d'efforts ont ete consentis pour diminuer le coût de fabrication des cellules solaires tout en gardant un haut rendement de conversion. Les piles MIS (metal-isolant-semiconducteur)
a jonction induite présentent une solution intéressante. Un procédé de fabrication simple a basse temperature donne une bonne reponse spectrale et un cout
de fabrication réduit. Nos cellules sont constituées
d'un peigne métallique d'aluminium depose sur une couche d'oxyde de silicium de 15Â creee sur un monocristal de silicium p.
Nous avons choisi le polymere
PVDF(fluorure de polyvinylidène) comme électret pour
induire une couche d'inversion n dans les parties non
métallisées (1). Les premières cellules montrent une
surface active de 7% de rendement pour un systeme non
optimisé. La fabrication, les caractéristiques J-V et
C-V seront discutees en details.
PL6
La diffusion du lithium dans l'aluminium à basse température. C. MOREAU et E.J. KNYSTAUTAS, Département de Physique (CRAM), Université Laval - Nous avons
mesuré le coefficient de diffusion du lithium dans l'aluminium pur (99.99%) pour des échantillons mono- et
polycristallins à des température variant de 150 à 400°C
Pour surmonter la difficulté que représente la couche
d'oxyde à la surface des échantillons, les couples de
diffusion ont été formés par implantation ionique du Li
à des profondeurs de 0,3 à 0,6 gm. Le changement de la
distribution du Li, suite à un étuvage à température
contrôlée, est suivi par la technique de détection des
ions de recul élastique^. Dans cette technique, un
faisceau de Ne à 20 MeV frappe l'échantillon étudié,
les atomes de Li arrachés sont détectés et leur énergie
mesurée. La concentration en profondeur est alors déduite. Grâce à la haute résolution de la technique
utilisée^ des coefficients de diffusion de l'ordre de
10" 15 cmz/sec peuvent être mesurés.
(1) A. Filion, B. Noirhomme, V. Gelfandbein et
A. Rambo.
Seventeenth IEEE Photovoltaic Specialists
Conference Proceedings, Orlando, May, 1984.
1
PL5
Design o f a D i f f e r e n t i a l A b s o r p t i o n L i d a r
f o r Sulphur D i o x i d e and Ozone Measurements.
R.M.
HOFF, Atmospheric Environment S e r v i c e - STnce t h e
problem o f l o n g - r a n g e t r a n s p o r t o f a i r p o l l u t a n t s and
a c i d r a i n has gained widespread i m p o r t a n c e , i t has
become i n c r e a s i n g l y necessary t o be a b l e t o o b t a i n
v e r t i c a l p r o f i l e s o f p o l l u t a n t s i n t h e lower
atmosphere on a r e g u l a r b a s i s .
The DIAL t e c h n i q u e
o f f e r s t h i s p o s s i b i l i t y f o r a number o f a i r
pollutants.
T h i s paper w i l l d e s c r i b e t h e design o f
t h e AES DIAL system c u r r e n t l y under c o n s t r u c t i o n .
The DIAL c o n s i s t s o f a 750 mj Nd-Yag pump l a s e r ,
f r e q u e n c y - d o u b l e d t o 532 nm, which e x c i t e s a Lumonics
dye l a s e r l a s i n g a t 600 nm. The dye l a s e r o s c i l l a t e s
on two o u t p u t l i n e s , which are both doubled i n t o t h e
u l t r a v i o l e t t o o b t a i n t h e necessary a b s o r p t i o n
wavelengths a t 299.5 and 300.05 nm.
M0REAU, C., Knystautas, E.J., Timsit, R.S., Groleau,
R., Nucl. Instr. Meth., 218 (1983) 111.
PL 7
Nonlinear Resistors: Metal Oxide Arresters.
C.C. Erven, P. Kirkby, and P.W. Redden, Research
Division, Ontario Hydro - Original research and
developed worV first reported in Japan on the nonlinear
resistive properties of ceramics made of metal oxide(l)
has been vigorously pursued throughout the world. This
has resulted in the development of new products such as
gapless metal oxide surge arresters for the protection
of electric power transmission systems. We are investigating the thermal stability of these new ceramic valve
elements, which are used as nonlinear resistors In surge
arresters. Results will be presented of the thermal
stability of materials from various manufacturers. We
are also studying the surge capability of these devices
to limit the lightning and power system overvoltages
without failure or degradation of the valve element. To
study the surge capability of valve elements, we have
developed a system for delivering pulses up to 100 kA
and 25 kV. Examples will be given to demonstrate the
voltage limiting capability of the devices to various
surge voltages.
1
M. Matsuoka et al Japan, J. App. Phys 8, 1275 (1969).
rug
W E D N E S D A Y , J U N E 20. 1984
R O O M 1060, S C I E N C E
PLENARY
SESSION
—
and ANNUAL
GENERAL
BUILDING
Chairman: A.I. Carswell
9:00
EA1
Deriving Nuclear Physics from the Quark Model
N. isgur, University
of Toronto
Particle physics was born out of attempts to understand the nucleus. Recent work in the context of the
quark model shows that we can now understand some of the basic features of nuclear physics using quantum
chromodynamics.
9:45
EA2
Inertial Confinement Fusion and Opportunities for Canada
M.P. Bachynski, MPS Tenh.nologj.eA Inc.
10:30
Break
W E D N E S D A Y , J U N E 20, 1984
R O O M 1060, S C I E N C E B U I L D I N G
Chairman: B.P. Stoieheff
10:45
Annual General Meeting of the Canadian Association of Physicists
12:00
Luncheon:
Division of Aeronomy and Space Physics
Address :
Auroral Associated Emissions Below 5000 Hz
N.c. Gerson, Laboratory
for Phyiicxl
ScienceA,
College Park, Maryland
An improved system has been designed for the collection and analysis of emissions in the frequency
range DC - 5000 Hz. Natural radiations in this spectral range arise primarily from lightning strokes
and auroral associated processes. Wide band width and high sensitivity was obtained by utilizing a
3-axis cryogenic receiver. Man-made noice was minimised by using a thermoelectric power source.
Spurious reception was avoided by digitizing the data at the source andtransmitting them via a fibre
optics link to the processor. The sensor sensitivity of 10 1 0 gauss Hz * is flat across the band with
a noise temperature of 4oK. The system is now installed near the Alaskan Panhandle, well away from
the North American 60 Hz power grid. Results obtained during the preliminary test period will be
presented.
TIME
ROOM
12:00
12:00
334
154
Division of Condensed Matter Physics
Division of Nuclear Physics
MEDALLISTS
MEETING
58
W E D N E S D A Y , J U N E 20, 1984
R O O M 334
NON-STANDARD
STRUCTURES
Chairman: M. Plischke
13:30
FA1
Noise in Chaotic Fluid Systems
J.A. Libchaber, UntveAilXy 0& Chicago
14:15
FA2
Phonons in Bose-Condensed Systems
What are They?
A. Griffin, UniveAAlty 0{, Toionto
The possibility of studying dilute, weakly interacting Bose gases (such as "He in vycor glass,
spin polarized H + and excitons in CU2O) has recently focussed attention on Bose-condensation in
such systems and how their dynamical properties may differ from superfluid He. Bosecondensation of particles into the zero-momentum state gives rise to a broken symmetry described
by a macroscopic wavefunction <¥> (the order parameter /N^). This couples the single-particle
spectrum to the density fluctuation spectrum. In a Bose liquid like superfluid He, where the
condensate fraction is always small (^ 15%), we argue that the collisionless phonons observed by
neutron scattering are density fluctuations which arise from the self-consistent field due to
non-condensate atoms. Thus it is no surprise that they exist above as well as below T^. We will
show how the existence of the condensate allows such zero sound modes to play the role of elementary excitations below T^. The physics is quite different in a dilute Bose gas. In this case,
phonons arise from the coherent field imposed by the condensate wavefunction and have a sound
velocity proportional to <¥>. Dilute Bose-condensed gases may finally allow us to observe this
kind of soft mode, first predicted by Bogoliubov in 1947.
15:00
15:30
FA3
Break
How to Get Your Money's Worth from Your Favorite Model of Disorder
A.-M. Tremblay, M.-A. Lemieux, P. Breton, UnivCUttê.
de
SheAbnooke
Disordered tight-binding electrons, harmonic oscillators or random walks form a class of problems
whose solution can in principle be found by straight inversion of large symmetric random matrices.
However, standard inversion techniques are impractical for the sample sizes needed in realistic
calculations. We propose a new very efficient numerical scheme which uses a complex generating
function and renormalization ideas to compute the experimentally relevant quantity. This method,
applicable in any dimension, is efficient because it extracts only the relevant information. It
is a generalization of the negative eigenvalue theorem which has been used for a long time to
compute total densities of states. It can also be used for transport properties. The method
seems to be as efficient as the Haydock-Lanczos recursion method but is applicable to different
situations and is easier to implement. Applications to Raman scattering in mixed crystals and
to the spectral properties of percolation clusters are discussed.
W E D N E S D A Y , J U N E 20, 1984
R O O M 228
Chairman: E.J. Fjarlie
13:30
FBI
OPTIQUE
Fibres optiques monomodes:
MODERNE:
NOUVEAUX
Filtres, coupleurs, capteurs
J. Bures et J. Lapierre, Ecole
Polytechnique
Après un rappel de quelques généralités sur les guides d'ondes optiques, on présente l'état actuel
de nos recherches sur les fibres optiques. D'abord le phénomène de photosensibilité conduisant à
la réalisation de filtres réflecteurs induits et permanents est décrit; les effets de température
et les propriétés de polarisation de ces filtres sont discutés. Ensuite on expose la méthode de
fabrication des coupleurs bidirectionnels à fibres monanodes fusionnées ainsi que le modèle mathématique permettant de prévoir l'utilisation de ces coupleurs comme commutateurs électro-optiques.
Enfin, un aperçu de nos travaux sur certains types de capteurs à fibres sera présenté.
14:30
FB2
Les systèmes bistables, instruments versatiles
C. Delisle, UniveM-ité
Laval
L'invention du laser et la aise au point de fibres optiques À faibles pertes ont rendu possible
l'utilisation de la luaière comme véhicule de transport de 1'information.
Après le
reaplaceaent des fils électriques par des fibres optiques, on tente maintenant d'agir
directement sur le faisceau optique porteur de 1'information.
En effet, il serait avantageux
de ne plus avoir A transformer le signal optique en signal électrique pour le traiter par
moyens électroniques et ensuite, au besoin, le reconvertir en signal optique.
Les systèmes
optiques bistables sont capables d'effectuer diverses opérations sur les faisceaux optiques et,
à ce titre, sont appelés À jouer un rûle important dans la technologie du futur.
Dans cette
communication, on traitera de certaines applications des systèmes bistables, de même que de
phénomènes qui leur sont étroitement liés.
L'exposé sera basé sur quelques systèmes bistables
de type hybride mis au point dans nos laboratoires.
SYSTEMES
rug
15:30
FB3
Capteur de Vision Tridimensionnelle pour l'Automatisation Industrielle
J. Domey et M. Rioux, ConAQÀZ national
de AeckeAche
du Canada
La vision par ordinateur a pris un essort considérable depuis quelques années, conjointement avec
l'arrivée des robots industriels. Cependant les systèmes de vision bidimensionnelle utilisant des
caméras vidéo exigent de placer les objets dans des situations très bien contrôlées à cause, par
exemple, de leur susceptibilité à l'éclairage, au contraste avec l'arrière plan et à ce que les
objets soient dans une de leurs positions stables. Une façon d'éliminer certaines des limites
actuelles de ces systèmes de vision est d'utiliser un capteur de vision tridimensionnelle permettant de faire l'acquisition des coordonnées spatiales de la surface visible des objets. Un tel
capteur faisant usage d'une nouvelle géométrie de triangulation par laser permettant un balayage
synchronisé sera décrit et les résultats expérimentaux seront présentés.
Les avantages principaux
de cette technique sont la vitesse d'acquisition des données, de faibles dimensions par rapport
aux dimensions des objets mesurés et une grande versatilité. Les propriétés géométriques de cette
technique seront présentées, de même que les sources d'erreurs et les solutions envisagées. Les
autres activités du groupe dans des domaines connexes seront aussi décrites brièvement.
WEDNESDAY, JUNE 20. 1984
NUCLEAR
R O O M 154
Chairman: R.J. Slobodrian
14:00
FC1
Heavy Ion Reactions at Low Energies
B. Cujec, UniveAiiXz
Laval
Nucleus-nucleus reactions at energies "below and around the Coulomb "barrier, measured for
numerous systems comprising nuclei with mass number 9 ^ A < 20, will "be reviewed. A systematics of fusion cross sections in terms of a proximity potential model will be presented and the nuclear structure effects discussed. The nucléon and cc-transfer reactions
will also "be discussed.
14:45
FC2
Nuclear Parity Violation: A Needle in a Haystack
E.D. Earle, Chalk R-LveA. NucteaA. La.bolaXotU.zA
Parity nonconservation is a unique property of the weak interaction and it is the only measurable
signature of the purely hadronic, flavour conserving weak interaction. Parity violation
experiments have been essential in confirming the validity of the standard electroweak theory of
Glashow, Weinberg and Salam. Such experiments are being performed to check predictions of the
weak quark-quark interaction and to determine the effect of the strong interaction
renormalization. The status and relevance of several nuclear parity violation experiments will be
presented with particular emphasis on the problems and progress of a deuterium photodisintegration
experiment at Chalk River.
15:30
FC3
Meson Exchange and Isobar Currents in Neutron-Proton Radiative Capture
J.M. Cameron, UrUvMA-iXij of klb&xXa
Recent analyzing power data for the radiative capture of polarized neutrons by protons are found to
be senitive to the coupling of photons to isobars and virtual plons in the nuclear medium. Measurements carried out using the polarized neutron facility at TRIUMF will be described and the results
compared to microscopic model calculations to illustrate the contribution of meson-exchange and isobar currents in the production of intermediate energy photons.
16:15
FC4
Search for Right-Handed Currents in Muon Decay
C.J. Oram, TRIUMF
New limits are reported on right-handed currents, based on precise measurement of the e + spectrum end
point in
decay. Highly polarized muons from the TRIUMF "surface" beam were stopped in metal foils
within a 1.1-T spin-holding longitudinal field or a 70-G spin-precessing transverse field. For the
spin-held data, the V-A decay rate vanishes in the beam direction at the end point. Measurement of
this rate sets the 90%-confidence limits ÇP v6/p > 0.9959 and M(W R ) > 380 GeV, where W R is the
possible right-handed gauge boson.
SCIENCE
rugi
WEDNESDAY, JUNE 20, 1984
PLASMA
R O O M 328
Chairman: R. Decoste
13:30
FD1
Approaches to High - Beta Tokamak
A. Hirose, UniveAA-Uy o(J Saskatchewan
14:15
FD2
Laser-Plasma Interaction Experiments at 351 nm.*
w. Seka, LaboJuUoAij (,oa LaieA EneAg&tid,
UrUveAA-Uy
RocheAAteA
In support of laser fusion e x p e r i m e n t s at the L a b o r a t o r y for Laser E n e r g e t i c s we
h a v e investigated and identified a number of linear and nonlinear interaction
processes.
At UV i r r a d i a t i o n w a v e l e n g t h s the basic energy transfer from the
laser to the plasma o c c u r s via inverse b r e m s s t r a h l u n g a b s o r p t i o n .
In addition,
r e l a t i v e l y small a m o u n t s of energy are absorbed by p a r a m e t r i c p r o c e s s e s , many of
which involve the g e n e r a t i o n of p l a s m a w a v e s .
T h e s e waves, in turn, can become
s o u r c e s of e n e r g e t i c e l e c t r o n s which may be d e t r i m e n t a l to laser fusion.
The
v a r i o u s p r o c e s s e s typically have e x p e r i m e n t a l s i g n a t u r e s in the e l e c t r o m a g n e t i c
spectrum between 1 eV and 200 keV.
T h e s e s i g n a t u r e s can thus be used for
i d e n t i f i c a t i o n of interaction p r o c e s s e s and, in some cases, they may also be used
for p l a s m a d i a g n o s t i c s and/or the e v a l u a t i o n of the amount of energy transfer
involved.
A g e n e r a l d i s c u s s i o n of c u r r e n t u n d e r s t a n d i n g of these interaction
p r o c e s s e s , their u s e f u l n e s s for plasma d i a g n o s t i c a p p l i c a t i o n s , and their
r e l e v a n c e to laser fusion w i l l be p r e s e n t e d .
*This work was p a r t i a l l y supported by the U . S .
D e p a r t m e n t of Energy Inertial
F u s i o n P r o j e c t under c o n t r a c t N o .
D E - A C 0 8 - 8 0 D P 4 0 1 2 4 and by the Laser Fusion
F e a s i b i l i t y P r o j e c t at the L a b o r a t o r y for Laser E n e r g e t i c s .
15:00
15:30
FD3
Break
Current Research in Space Plasma Physics
H.G. James, VepaAtmeyut oi Communicctiioni, Communicationi HeAeaAch Centfie
The objective of plasma physics research in space is to understand both fundamental processes and
plasma systems such as magnetospheres. The research 13 carried out in the atmospheres of the
solar-system planets and the solar wind. The magnetospheres yield data on processes which are also
observed in the laboratory, such as field-line reconnection, kinetic and fluid instabilities and
beam-plasma interactions. In typical experiments, fields and particles are measured with passive
or active nonperturbing techniques. One significant constraint on experiments has been the
uncontrollabllity of the medium. Recently, this has been partially overcome through the use of
intentional perturbations. An important example is ionospheric modification with rf heating. The
large 3ize and the short time constants of magnetospheres are another problem for experimentalists.
To remove temporal-spatial ambiguities, simultaneous multipoint measurements have been made.
Coordinated studies at very low frequency of wave-particle interactions and studies at high
frequency of ionospheric irregularities illustrate this development. Future spacecraft experiments
with multidisciplinary payloads or simultaneous multi-point recordings are also being organized.
In spite of the operational challenges of space research, the similarity of processes in laboratory
and space plasmas provides a basis for interdisciplinary interest in the future.
W E D N E S D A Y , J U N E 20, 1984
R O O M 234
Chairman: G. Atkinson
13:30
DASP Experimenters' Meeting
W E D N E S D A Y , J U N E 20, 1984
R O O M 244
Chairman: G.C. Hanna
17:00
Meeting of CAP Council
PHYSICS
//
rug
W E D N E S D A Y , J U N E 20, 1984
10:00-16:00
Poster Party — Part I l l / F e s t i v a l de séances de démonstration — Troisième partie
The posters will be located in T H E TENT, except Series PM 1-37
which will be located in the Foyer adjacent to the Exhibit area.
VIBRATIONAL
SPECTRA,
LOCAL
MODES,
NMR
PMl
Les Spectres Infrarouge et Raman de Vibrations
et Rotations du CO3
ques de Type K T a - ^ N b y O y
D- HOUDE et S. JANDL, Département de physique et Centre de recherche en physique
du solide, Université de Sherbrooke - Le KTa^_ x Nb x 03 (KTN)
représente l'un des ferroélectriques les plus étudiés.
La constante diélectrique e a un comportement Curie-Wiess
pour des grandes valeurs de x alors que pour les faibles
valeurs de x elle dévie significativement du cas classique. Nous présentons des spectres d'absorption infrarouge et de diffusion Raman pour x = 0, x = .018, x = .09.
L'absorption infrarouge met en évidence les fréquences
de vibrations du COq
La diffusion Raman met aussi en
relief des modes de vibrations du carbonate ainsi que 3
groupes de fréquences de vibration-rotation. De ces valeurs d'énergie de rotation, nous déduisons qu'il y a
une différence d'énergie de 10 K entre les différents
niveaux successifs de rotation. Cette valeur correspond
parfaitement à la température de l'anomalie de conduction thermique bien connue dans ces matériaux. De plus,
celle-ci correspond à la valeur de l'énergie de l'impureté mobile nécessaire au couplage des paramètres d'ordre
invoquée pour expliquer le comportement critique de S-q
(compliance élastique).
PM2
Monochromatic Phonon Generation in a Semiconductor under High Magnetic Field. G. W. SLATER, Université de Sherbrooke - A theoretical study of a system of
coupled hot electron and hot phonon gases in a semiconductor under high magnetic field is presented. An exact
solution for the phonon distribution function is obtained under the assumption that the electronic distribution function is a hot Maxwellian. Conditions are found
for which a strong and quasi-monochromatic cyclotron
beam of phonons is produced in the plane perpendicular
to the field. All results are analytic, and all energies, frequencies and temperatures scale like m*s2 (m is
the electron effective mass, and s is the speed of
sound), which makes the results applicable to a wide
class of semiconductors. Examples are given for GaAs
and InSb. Some experimental approaches are also sugges
ted.
PM3^ Jin Vibrational Anisotropy in ct-SnFp. T. BIRCHALL,
G. DENES, J. PANNETIER and K. RUEBENBAUER, Dept. of
Chemistry, McMaster University and Institut
Laue-Langevin - Vibrational anisotropy of tin at oms in a-SnF2 has
been measured at several temperatures by two techniques,
i.e., neutron diffraction upon single crystals and
Mossbauer transmission on powder. The anisotropy param e t e r s * ^ g ^ obtained by these two me thods are the same
within the experimental error. This r esult indicates,
that the vibrational density matrix of the tin sublattice
is well approximated as a sum of densi ty matrices for
individual atoms, i.e., long-wave phonons are rather irrelevant for the scattering of neutron s and the resonant
absorption of y-rays. The experimenta 1 data support the
theory of Karyagin.3
1.
2.
3.
Ruebenbauer, K. and Birchall T., Hyperfine Interactions 7, 125 (1979) .
Birchall T., Demis G., Pannetier J. and Ruebenbauer
K., J. Chem. Soc. (Dalton Trans.)
1831 (1981).
Karyagin S.V., Solid State (Sov. Phys.) 8, 1397 (1966).
PM4 Diffusion Broadened Mossbauer Spectra in Single
Crystals of FCC Metals. K. RUEBENBAUER, Dept. of Chemistry,
McMaster University and Institute of Nuclear Physics,
Cracow, Poland. - The self-correlation f unctions for longrange diffusion via the monovacancy mech anism in FCC lattices have been calculated^ within the encounter approximation^ by varying the parameters of the f ive-frequency
model.^ The validity of this approach t o the existing
single crystal Mossbauer data has been d iscussed. The socalled high temperature limit has been 0 utlined and its
applicability considered especially for the most recent
data obtained for diffusion of iron in copper.^
1.
2.
3.
4.
Ruebenbauer K., Hyperfine Interactions 14, 139 (1983).
Wolf, F., Appl. Phys. Lett. 30, 617 (1977).
Le Claire A.D., J. Nucl. Mat. 63 and 70, 70 (1978).
Petry, W. - unpublished.
PM5
Indirect Evidence for Localised Vibrational
Modes in Sintered Heat Exchangers.*
J.H. PAGE,
J.P. HARRIS0N+ and M. MALIEPAARD+, Queen's University The Rutherford et al 1 model for heat transfer between
liquid 3 He and sintered sub-micron metal powder heat
exchangers near 1 mK was based upon a postulated band of
localised vibrational modes extending from 50 MHz, the
upper limit of effective medium phonons, to 5 GHz, the
lower limit of bulk metal Debye phonons in the powder.
An ultrasonics study, in the range 1-20 MHz, using
copper sinters with powder diameters, d, of 1, 10 and
300 pm has confirmed the existence of effective medium
phonons with reduced velocity at large A / d and the crossover into the localised "inhomogeneity" band at A / d ^ 10
to 20. This confirms the lower band-edge at least to
the extent that propagating modes do not exist within
the postulated band. The upper band edge is set by the
cross-over to Debye phonons at A c d .
(1) A.R. Rutherford, J.P. Harrison and M.J. Stott, J.
Low Temp. Phys. 55, 157 (1984)
*Research supported by NSERC and School of Graduate
Studies and Research
tKillam Research Fellow.
+ NSERC Summer Student.
PM6
Population Transfer Between Coupled Proton
Zeeman and Tunneling Energy Levels - W.T. SOBOL,
I.G.CAMERON and M.M. PINTAR-(GWP)
- Waterloo Campus
- In small symmetric molecular groups such as CH3 the
degenerate ground torsional energy state may be
split, at low temperatures, into several levels due
to rotational tunneling provided the hindering potential is not too strong. These tunneling splittings
can be detected with NMR techniques when the splitting
is less than 1 yeV. This can be done by setting the
applied magnetic field,H 0 , so that the Zeeman
splitting hw 0 = hyH 0 , where y is the gyromagnetic
ratio, is approximately equal to the tunneling
splitting hcL)t. This enables a fast population
transfer to occur between the coupled levels. The
population transfer, which can be detected with a
saturation sequence of N n/2 r.f. pulses, was measured
in Ge(CH3)t+, Si(CH3)l+ and C 6 (CH 3 ) 5 H. The results of
these experiments will be presented and compared with
the population transfer model. The tunneling lineshape
was also measured as a function of temperature. These
results will be presented and discussed in terms of a
three bath relaxtion model.
*Guelph~Waterloo Program for Graduate Work in Physics.
rugi
PM7
uSR Llneshapes In the Presence of Coherent
Tunnelling. S.R. KREITZMAN, J. BREWER, Univ. of
British Columbia and TRIUMF - Traditionally,
interpretations of transverse-field (TF) tiSR data in
the presence of muon motion have relied upon
phenomenological parameterizations of the data.
Adopting a more fundamental microscopic approach, we
present detailed calculations which, for local
coherent tunnelling, predict sharp spectral features
In the uSR spectrum. Llneshapese for two, three, and
four site tunnelling modes have been explicitly
evaluated in second order perturbation theory. For
nonlocal band states an explicit solution has been
found. In this case, the llneshape depends on both
the symmetry of the motion and the space group of the
crystal. Results are shown to yelld the fundamental
microscopic motional and structural parameters in
terms of spectral splittings and widths.
PM10
Evaluation of the First Excited State Energy of
the Bound Frbhlich Polaron*. Y. LEPINE, Département de
physique, Université de Montreal - The first excited
state energy of the bound Frbhlich polaron is evaluated
using the Fock approximation of Matz and Burkey. From
a discussion of a variational-type expression of this
energy, it is concluded that a singularity in the space
of variational parameters separates the ground state
and the defect excited state from the first relaxed excited state of a defect where the polaron has lost its
identity. For small values of electron-phonon coupling and of electron-defect coupling, a defect excited
state is found with an effective mass behaviour. For
large values of coupling, either a defect excited state
or a polaron excited state or a mixted state is found.
In the limits of small and large couplings, these results compare well with those of other theories. This
approach is valid for any values of the coupling constants.
•Supported by the Natural Sciences and Engineering Research Council of Canada and Le Ministère de l'Education du Québec (FCAC).
PM8
Temperature Dependence of IR Spectral Features
in Proton-irradiated Solid Deuterium. R.L. BROOKS, J.L.
HUNT, JACK R. MacDONALD, and J.D. POLL. Guelph-Waterloo
Program for Graduate Work in Physics, J.C. WADDINGTON,
McMaster Univ.—Three additional absorption features appear in the fundamental band of solid D2 whenever the
sample is irradiated by 15 MeV protons at 4.2K1 These
features persist for very long times, typically hours, at
4.2K following termination of the proton beam. Results
will be presented for a series of experiments in which
the growth and decay of two of these spectral features
following onset and termination of the beam have been
studied as a function of temperature. More than a two
order of magnitude decrease in the turn-off time and a
factor of 20 decrease in the amplitude of the B-line
have been observed between 6 and 9K. The A-line does
not appear when the sample is irradiated above 7K, but
if irradiated at 4.2K does not disappear until the sample
is warmed above 12K. The consequences of these measurements within the framework of our tentative model will
be discussed.
PM11
First-Principles Calculations of
Thermodynamic and Electronic Properties of Liquid
Non-transition Metals.* D.H. LI, X.R. LI and S. WANG
(GWP) 2 ** ~ Waterloo Campus - We demonstrate how our
recently suggested calculation of the Helmholtz free
energy , which includes the usual high-order
pseudopotential perturbation (HOPP) corrections, can
be further improved. The improved method is applied
to the theoretical determination of the mean atomic
volume and the related thermal quantities with good
accuracy, even for those liquid non-transition metals
for which the NFE model is less applicable. In
addition, the calculation of the liquid-metal
electrical resistivities, including HOPP effects, are
discussed in relation to the t-matrix approach.
1
1. R.L. Brooks, M.A. Selen, J.L. Hunt, Jack R. MacDonald,
J.D. Poll and J.C. Waddington (1983), Phys. Rev. Lett.
1077.
Ii, D.H., Matsuura, M. and Wang, S., J. Phys. F, _14,
April issue (1984).
*Supported in part by NSERC of Canada.
PM9
On the Formation of Small-polaronic states in
Solid Deuterium. S.K. Bose and J.D. Poll, Department
of Physics, University of Guelph, Guelph, Ontario NlG 2W1
- Certain infrared absorption features in proton-beam
irradiated samples of solid Deuterium have been attributed to the formation of bubble-like small polaronic states localised in the latticed Calculations based on a
continuum model of the solid yield the radius of such
bubbles in close agreement with that obtained directly
from the spectral features. These bubble-like electronic
states are shown to be energetically stable in the
Wigner-Seitz model of the crystal and the gap between
the groun state energy and the conduction band edge is
calculated. The model is being further investigated to
explain the width and the shape of the spectral lines
believed to be due to such localised electronic states.
PM12
Transition-Metal Pseudopotentials Applied
to Thermo- and Lattice-Dynamic Calculations.* D.H.LI,
R.A. MOORE and S. WANG (GWP) 2 ** - Waterloo Campus - A
model pseudopotential approach, applicable to both 3dand 4d-transition metals, is proposed and applied to
(i) variational thermodynamic calculations, using the
hard-sphere model as the reference system, and (ii)
first-principles calculations of the lattice properties
of the simple 3d- and 4d-transition metals. It turns
out that the applicability of the proposed
pseudopotential approach is at least as good for simple
transition metals as that of the usual nonlocal
pseudopotential approach for the heavy non-transition
metals and appears to be quite appropriate for
self-consistent first-principles lattice-dynamic
calculations for the transition metals considered.
J.D. Poll, J.L. Hunt, P.C. Souers, E.M. Fearon, R.T.
Tsugawa, J.H. Richardson and G.H. Smith
(submitted
for publication).
PMI3
Dipolar Spin Order in a Quadrupolar System.*
M. SINGH and R.L. ARMSTRONG, Dept. of Physics, Univ. of
Toronto - The Jeener-Broekaert^ pulse sequence can be
used to generate observable amounts of dipolar order if
a common dipolar spin temperature (Tp) is established
upon application of the first pulse pair. This technique has been applied to a number of NMR systems
and, recently, to spin systems with quadrupolar interactifs.
An NQR study has been made of the response
of
CI in polycrysta11ine KÔsCl^ to the J-B pulse
sequence. The validity of the assumption that TQ
exists is examined by considering the consequences of
two extreme situations; dipolar couplings treated as
negligible; dipolar couplings considered sufficient
to ensure the existence of TQ. The latter condition
has been shown to hold and measurements of the relaxation of the dipolar order are reported.
^Jeener, J. and Broekaert, P., Phys. Rev., 157, 232
(1967).
Segebarth, C. and Jeener, J., Phys. Rev. B, 29 1176
(1984).
2
-«•Supported by NSERC.
PM14
NMR Spin Grouping and Neutron Quasi-Elastic
Scattering Studies of Water Sorbed in Oriented NaDNA.
L.J. SCHREINER, J.C. MACTAVISH and M.M. PINTAR,
(GWP)2* - Waterloo Campus and A. RUPPRECHT** - The
results of NMR spin grouping experiments on oriented
Na DNA containing between .2 to .77 gm water per gm
dry DNA are presented. In all cases a minimum of two
groups of protons are resolved. These groups are
characterized dynamically by their NMR spin
relaxation times and by their contributions to the
total spin mass. Upon such characterization, the
respective groups can be identified with protons on
water in various environments or with protons on the
DNA molecules. The results are correlated with
neutron quasi-elastic scattering measurements on
samples with high and low hydration which show that
the motion of the water is highly localized. A
clearer view of the dynamics of the water in this
model system is obtained through this correlation.
**Arrhenius Laboratory, Stockholm, Sweden.
PM15
Spin Grouping in Oil Sands - W.T. SOBOL,
L.J. SCHREINER, M.M. PINTAR - (GWP) 2 * - Waterloo Campus
- A new two dimensional NMR method called the spin
grouping technique was applied to heterogeneous wet oil
sands samples. This technique correlates the
spin-lattice and spin-spin relaxation of the sample.
Using this method the free induction decay of this
material was resolved into three groups of spins with
different dynamical behaviour. The first two groups,
characterized by T 2 f s of 15 and 100 ps respectively,
have solid- like character; while the third one, having
T 2 of 600 ys, was in a mobile semiliquid state. From
the compar-ative analysis of wet and dried samples we
can identify two different kinds of water in oil
sands. The liquid-like water group (about 30% of the
water), is identified as the water present in bridges
connecting the sand grains, while the other water group
is identified as the clay surface water.
METALS
PM16
Pressure Dependence of de Haas-van Alphen Frequencies
and Cyclotron Mass of Antimony.* A.A. EL RAHMAN AND
W.R. DATARS, McMaster University - The de Haas-van
Alphen frequencies and cyclotron mass of holes in
antimony have been measured between 0 and 5 kbar with
helium as the pressure medium. The pressure derivative of the frequency, dlnF/dP, is (-0.92 + 0.12) x 10"2
kbar--'- at the minimum of the principle branch and is
(-0.73 + 0.24) x 10
kbar
11° from the maximum of the
branch. This contradicts previous work by Schirber
indicating that the minimum frequency increases with
pressure above 4 kbar. The angular pressure dependence
of the dHvA frequencies of the principle hole branch
has also been studied. The cyclotron mass at the minimum was found to be independent of pressure within
experimental error. This shows that the band mass does
not depend on pressure and that the change in mobility
with pressure that has been reported does not depend
on change in mass.
^Supported by the Natural Sciences and Engineering
Research Council.
PM17
Transport Properties of GdBfi and DyBr, .* NAUSHAD
ALI and S.B. WOODS, Dept. of Physics, U. of Alberta The electrical resistance and absolute thermoelectric
oower (TEP) have been measured for polycrystalline GdB6
and DyBe in the temperature range from 2K to 30K. GdBg
and DyB6 order antiferromagnetically below T^-15.2K and
20.3K respectively. Below T^ the resistivity has a T 3
dependence associated with conduction electron-spin wave
scattering but at the lowest temperatures there is a T 2
dependence that is thought to be due to Baber type
electron-electron scattering. Above T^ the resistivity
has a small contribution due to electron-phonon
scattering that is linear in T. A minimum in the TEP is
found in these compounds below ~6K which is associated
mainly with phonon drag and possibly a magnon drag
contribution. Above T^ the spin-disorder TEP (Sg
has
been evaluated and found to be linear in T. A b fgld
peak in the TEP of DyB 6 near ~16K is thought to be due
to crystalline electric field effects. A divergence in
the temperature derivative of resistance and TEP has
been found at T^ which is consistent with the present
theories.
*Supported by NSERC of Canada.
PM18
Magnetoresistance of GdRhi _iSn^ _ ?.* NAUSHAD ALI,
ScB. WOODP, G. KOZLOWSKI and A. ROJEKJ, Dept. of Physics,
U. of Alberta - The electrical resistivity (p) and
magnetoresistance (MR) of single crystal GdRhi . iSni+. 2
have been studied from 4.2K to 25K and in a magnetic
field up to 3QK0e. GdRhi. iSni+,2 crystallises in a simple
cubic structure with lattice constant a 0 -9.6OA and
orders antiferromagnetically below T^-11.48K. Above T^
p«T, attributable to phonon scattering, whereas below
Tjq p is expected to be mainly due to electron-spin wave
scattering. The MR is found to be positive and increases
with increasing field. A positive MR is thought to be a
characteristic property of antiferromagnetic metals below
T^ and is due to the field induced enhancement of the
spin fluctuations. The field dependence of the MR is
observed to be quadratic at low fields and becomes
linear at high fields. The magnitude of the MR decreases
with increasing temperature and at T^ it shows a rapid
decrease.
*Supported in part by NSERC of Canada,
tlnst. of Low Temp, and Structure Research, Wroclaw,
Poland.
rugi
PMI9
Etude de l'effet Hall et de la m a g n é t o r é s i s t a n c e dans les alliages de CoZr amorphe •* M. T R U D E A U , R.W. C O C H R A N E et J. D E S T R Y ,
U n i v e r s i t é de M o n t r é a l - Nous p r é s e n t o n s les résultats de m e s u r e s de l'effet H a l l , dans des
alliages de CoZr a m o r p h e , entre 48 et 80 pourcent atomique de Zr. Dans c e u x - c i , la grandeur
de R
est c a r a c t é r i s t i q u e d'un métal cristallin de t r a n s i t i o n . C e p e n d a n t , comme dans le cas
d ' a u t r e s a l l i a g e s a m o r p h e s (NiZr, C u Z r , . . . ) , on
note une grande v a r i a t i o n de R^ en fonction des
c o n c e n t r a t i o n s relatives des c o n s t i t u a n t s . En
e f f e t , on peut o b s e r v e r une inversion complète
de signe en p a r c o u r a n t la gamme de concentration m e n t i o n n é e p r é c é d e m m e n t . De p l u s , entre
4k et 300K on ne note aucun effet m a r q u a n t de
la température dans la valeur de R^; mais l'on
note l ' a p p a r i t i o n à très basse température
d'une m a g n é t o r é s i s t a n c e m o d i f i a n t la résistivité
de
0,0-1% pour 1 tesla.
* Recherche
subventionnée
par CRSNG et
FCAC
PM20
E t u d e des c o n f i g u r a t i o n s b i m é t a l l i q u e s
A g / A u a v e c faibles r e c o u v r e m e n t s d ' o r â l'aide
des p l a s m o n s de s u r f a c e . *
D. P e l l e t i e r , F. E.
G i r o u a r d e t V. V. T r u o n g , Univ. de M o n c t o n
— Des films c o m p o s é s d ' a r g e n t e t d ' o r o n t été
préparés par évaporation thermique e t étudiés
dans la r é g i o n s p e c t r a l e d u v i s i b l e .
La m é thode de r é f l e x i o n totale a t t é n u é e (R.T.A.),
p e r m e t t a n t le c o u p l a g e de p h o t o n s aux o n d e s de
p l a s m a de s u r f a c e (O.P.S.), e s t u t i l i s é e dans
le b u t de d é t e r m i n e r les r e l a t i o n s de dispersion des O . P . S .
S u i v a n t cette t e c h n i q u e , q u a tre é c h a n t i l l o n s c o n s t i t u é s d'une couche d'arg e n t (52.5 nm) e t d'une couche d'or v a r i a n t de
2.0 n m â 5.0 n m d ' é p a i s s e u r s o n t é t u d i é s .
A
l'aide de m o d è l e s t h é o r i q u e s d é c r i v a n t le comp o r t e m e n t o p t i q u e des films, o n a p u tirer des
c o n c l u s i o n s sur la s t r u c t u r e g é o m é t r i q u e des
r e v ê t e m e n t s e t la c o m p o s i t i o n de ces d e r n i e r s .
E n t r e a u t r e s , on a m o n t r é q u e les films d ' o r
d'une é p a i s s e u r i n f é r i e u r e a 4.0 n m s o n t discontinus e t p e u v e n t ê t r e c o n s i d é r é s c o n t i n u s p o u r
des é p a i s s e u r s s u p é r i e u r e s o u é g a l e s â 4.0 nm.
•Supporté par
'Wait, J.R., Can. Jour. Phys. 33, 189, 1955.
PM23
P r o f l l o m é t r l e de l ' h y d r o g è n e dans l e s m a t é r i a u x ,
G.G. ROSS e t B. TERREAULT, INRS-Enerqie - Une n o u v e l l e
méthode q u a n t i t a t i v e , peu coûteuse e t non d e s t r u c t i v e
pour mesurer l e p r o f i l de profondeur de l ' h y d r o g è n e
i m p l a n t é a é t é mise au p o i n t .
E l l e é v i t e l a p l u p a r t des
i n c o n v é n i e n t s des méthodes t e l l e s l e "SIMS" e t l e s r é s o nances n u c l é a i r e s .
E l l e a de nombreuses a p p l i c a t i o n s en
physique des s u r f a c e s , e t en science des m a t é r i a u x .
E l l e n ' u t i l i s e q u ' u n p e t i t a c c é l é r a t e u r de 350 keV, un
f i l t r e ExB e t un d é t e c t e u r au s i l i c i u m .
La s e n s i b i l i t é
e s t I I e t l a r é s o l u t i o n 35 A. E l l e s ' a p p l i q u e a u s s i au
deutérium.
La c a l i b r a t i o n de l a méthode a e x i g é l a
mesure des f r a c t i o n s de charge H + /H" des atomes émergeants des s o l i d e s à 25-350 keV, dans Be, C, A l , S i , T i ,
N i , Cu, Ge, Z r , Nb, SiC, I n o x , N i 0 x e t CuO-. Ces mesures p r é s e n t e n t aussi un intérêt
fondamental e t t h é o r i q u e
q u i sera a n a l y s é .
PM24
Umklapp Annihilation of e + and e~ in Li and K.*
A.T. STEWART, T. HY0D0, Queen's Univ., Canada, L.P.L.M.
RABOU, P.E. MIJNARENDS, Energie. Cen. Nederland, L.
OBERLI, A.A. MANUEL, M. PETER, Univ. de Genève - Our
study of positron effective mass in metals has shown the
need to measure directly the higher (umklapp) components
of the distribution of momentum from positron-electron
annihilation. We report both a high resolution measurement of these components and a KKR calculation of them.
The data are very well reproduced by the calculation and
are quite different in Li and K. The "enhancement" of
annihilation rate seems to be comparable with that in
the central zone.
*
Supported in part by NSERC and N.A.T.O.
le CRSNG.
PM21
Vacancies in B2 Intermetallic Compounds:
Structural or Thermal?
S.M. KIM, Atomic Energy of
Canada Limited, Chalk River, - For many years it was
believed that structural vacancies exist in several of
the B2 intermetallic compounds.
In formulating a
theory of vacancy formation in ordered stoichiometric
as well as non-stoichiometric bcc alloys using the
nearest-neighbour bond energy concept, we have found
that such structural vacancies cannot exist.
It will
be shown that in a typical B2 intermetallic compound,
NiGa, frozen-in thermal vacancies can account for the
observed composition dependence of vacancy concentration.
1
diffraction as proposed by Wait.
We have also
observed a deviation of the pattern from the theory in
the case where the sample surface roughness becomes
important. In order to explain these results, the
electric field inside the wire was calculated. This
permitted us to evaluate the currents in the wires,
and then perturb their distribution in order to
account for the effects of surface roughness on the
patterns.
S.M. Kim, Phys. Rev. B 29, 2356 (1984)
PM22
The Use of Diffraction In the Determination of
the Optical Constants of Small Metallic Wires.
T.J. RACEY, N. GAUTHIER and P. ROCHON, Royal Military
College of Canada, Kingston - We have experimentally
obtained precise values for small angle optical diffraction patterns of various small metallic wires.
The patterns were obtained using an HeNe laser with the
light polarized both parallel and perpendicular to the
wire axis. The optical constants for the metals were
then obtained by fitting the data using the theory for
ELECTRON
SCATTERING
PM25
Charging of Thin Dielectric Films by Low-Energy
Electrons (0-20 eV). R.M. MARSOLAIS, L. SANCHE and
L.G. CARON, Groupe du CRM de l'U. de Sherbrooke - We
describe a technique to investigate the mechanisms of
charge localisation in thin dielectric films deposited
on metallic substrates. A magnetically collimated beam
of low-energy electrons (from 0 to about 20 eV; and a
resolution FWHM^150 eV) , generated by a trochoidal
monochromator, is incident on a thin molecular film
(e.g. C0 2 , H 2 0, C-HL.,...), which is vacuum deposited at
low temperature (^.12 K)^gn a metal substrate held in a
ultra-high vacuum ( ^.10
Torr). Thicknesses ranging
from one to tens of monolayers are then obtained. The
injection curve, which is the sharp increase in transmitted current near zero energy, is sensitive to the
condition of the substrate surface. For instance, the
injection curve can be shifted by more than half a volt
for a single monolayer of deposited material. Charges
on the surface, or into the dielectric, also alter this
curve. We observed a rate of charging dependent on
thickness and energy. Films of CO and HÔ charge much
faster at low energies (0-5 eV). At higher energies, the
films can be discharged. We discuss a possible general
technique to study charge effects in dielectric films.
65
PM26
Transmission d'Electrons Lents (0-20eV) dans des
Couchés Minces d'Ar, Ng et n-Hexane.* R. BOUDREAU et L.
G. CARON, Centre de recherche en physique du solide, Université de Sherbrooke, G. PERLUZZO et L. SANCHE, Groupe
CRM en sciences des radiations, Département de médecine
nucléaire et de radiobiologie, Faculté de médecine, Université de Sherbrooke - Les spectres de la transmission
d'électrons lents dans des couches minces moléculaires
pour lesquelles l'énergie au bas de la bande de conduction, V 0 , est au-dessus du niveau d'énergie zéro dans le
vide (ex.: Ar, N2, n-hexane) présentent une transmission
pour des énergies des électrons incidents inférieures à
V 0 , ce qui implique qu'il y a de la conductivité électronique dans le gap. Une étude en fonction de l'épaisseur
de la couche mince montre que l'intensité du courant
transmis décroît exponentiellement en fonction de
l'épaisseur dans le cas de Ar, alors qu'il décroît en
fonction inverse de l'épaisseur pour un grand nombre de
monocouches dans le N2. Le courant transmis sature rapidement dans le n-hexane. Nous expliquons l'origine de
ces différents types de comportements.
* Avec l'appui financier du CRSNG des fonds FCAC, du
CRMC et du CRSQ.
PM27
Simulation du Spectre en Perte d'Energie d'Electrons à Faible Energie sur le N2 Solide.* R. BOUDREAU
et L.G. CARON, Centre de recherche en physique du solide, Université de Sherbrooke, et G. BADER, Département
de physique et de mathématiques, Université de Moncton
- Le modèle à deux faisceaux 1 déjà utilisé avec succès
sur la propagation diffusive des électrons dans des
films de gaz rares solides a été généralisé à n faisceaux. Il permet de simuler l'effet de collisions élastiques et un nombre indéterminé de collisions inélastiques. Il a été utilisé sur le spectre en pertes d'énergie du N2 solide et est concordant avec les résultats
publiés 2 .
1
G. Bader, G. Perluzzo, L.G. Caron et L. Sanche, Phys.
Rev. B 26, 6019 (1982).
PM29
Determination of the energies of the lowest
conduction state V n in thin solid films by electron
transmission spectroscopy.* G. PERLUZZO and L. SANCHE,
Groupe CRM en Sciences des Radiations, Fac. de Médecine,
Université de Sherbrooke. - We studied systematically
the transmission of monochromatic
40 meV FWHM) low
energy electrons through thin films of organic and
inorganic compounds as a function of electron energy
(0-20 eV) and film thickness. For compounds having
positive V Q values, this latter is determined from the
apparent shift of the energy of the vacuum level with
thickness. When V 0 is negative, we compare the energy
of inelastic thresholds in the solid (measured from
our spectra) with the accepted spectroscopic values.
The difference between the two values determines V Q .
*
Supported by the MRCC and the CRSQ.
OPTICS
AND
LASERS
PNl
Variations of diffraction efficiency and angular selectivity for multiplex holograms composed of N
coupled gratings.* Jean J.A. COUTURE and R.A. LESSARD,
LROL 3 dept.. of Physics A Université Laval - Sequential
superimpositions of many holograms on the same recording
medium introduce high coupling effects principally when
the N recordings were done with low angular separation.
Applications,
e.g.
as optical elements synthesis,
require the knowledge of the response of the recording
medium under such conditions. Angular selectivity and
diffraction efficiency of multiplex holograms made under
those conditions have been studied using coupled wave
theory.
Theoritical
results
and
experimental
measurements show that the efficiency seems to follow a
behavior in 1/N instead of 1/N when gratings are highly
coupled.
this possibility serves to amélioré
the
holograms in some applications.
^L. Sanche et M. Michaud, à paraître.
*Avec l'appui financier du CRSNG et des fonds FCAC.
PM28
Transmission d'électrons 0-20 eV à travers des
Films minces solides à 300 K.* G. LECLERC et L. SANCHE,
Groupe CRM en Sciences des Radiations, Fac. de Médecine,
Univ. de Sherbrooke. - Nous présentons ici la méthode
expérimentale permettant la transmission d'électrons
(0-20 eV) à travers des films minces solides à 300 K
et 10" 7 Torr 1 . L'épaisseur des films est déterminée
à 20% d'erreur, ce qui permet d'évaluer grossièrement
les libres parcours moyens de l'électron dans le solide.
L'étude des variations du courant transmis en fonction
de l'énergie des électrons incidents détermine les
énergies de transition électroniques optiquement permises et interdites dans la gamme 0-10 eV. La méthode
est appliquée à deux solides bioorganiques importants,
soit Thymine et D-L. Tryptophane.
1
Sanche, L., J. Chem. Phys. 7J_, 12 (1979).
* Subventionné par le CRM.
* Work supported by NSERC A-D360.
PN2
Synthetization of rotation invariant h0l.0g.ra3
phic filter by means of optical holographic method^* Li
SONG and R.A.LESSARD, LROL-Dept^ of Physics^ Université
Laval ~ Optical pattern recognition is one of the most
useful application of coherent optics.
Consequently,
holographic matched filters recorded by using all information from a reference signal were developped for that
particular application. Although MSF (Matched Spatial
Filters) are shift invariant, they suffer from variation
of orientation of the input signal. The mismatch introduced by the rotation of the input signal and the MSF
causes a rapid decrese of the correlation peak. To
palliate that effect, a partial matched filter, using a
part of the reference signal, was introduced . In general , the function may be expended into a Fourier series
in polar coordinates because it is a periodic function
of angle. A component is chosen as reference . This
filter is then shift-and-rotation invariant. Hologram
recorded
by rotating Fourier spectrum of the reference
signal corresponds to the zero order of the Fourier
series.
(1) XU, Yuan-neng, "Shift-and-rotation invariant pattern
recognition", Ph. D. Thesis, Université Laval 1982.
* Work supported by NSERC A-0360.
rugi
PN3
General On§-steg Rainbow Holography With No
Slit.* A. BEAUREGARD and R.A. LESSARD, LR0L - Dég^ de
Ph^siguei Université Laval - One of the methods of onestep rainbow holography makes use of a slitlike modulation of the object beam amplitude during recording. This
modulation will result in an aperture of transmittance
proportional to the sine function at the reconstruction.
Since the energy filtered by the sidelobes of the sine
function is a small fraction of that of the central
peak, it will actually act as a slit. The slitlike
function is produced by a transiational motion imparted
to the abject during recording. However, this moving
object recording scheme yields to completely different
experimental setups depending on whether the object is
2-D or 3-D. Moreover, in the 3-D case, the direction of
the translation of the object must be carefully aligned,
a constraint not present in the 2-D case. We propose a
new one-step method of rainbow holography in which the
slitlike modulation of the object beam is produced by a
small translat-ional motion of an imaging lens during
recording. The object itself remains stationary. This
method is applicable to 2-D and 3-D objects as well
without any further complications in the 3-D case and
can be regarded as a general method to obtain one-step
rainbow holograms.
*Work supported by NSERC A-036G.
PN4
Optica^ metrology using the diffraction edge
wave.» P. LANGLOIS, R.A. LESSARD and Â. BOIVIN, LROL =
DéPi de physique A Université Laval - When a laser beam
arrives at grazing incidence on a cylinder, it produces
on an observation screen a bright spot and a luminous
line perpendicular to the cylinder's axis.
In the diffraction edge wave context, the bright spot corresponds
to the geometrical wave and the luminous line to the
edge wave.
Moreover, diffraction fringes appear where
these two waves overlap.
But the interesting point in
this set up is found in the effective separation of the
edge wave from the incident beam.
Thus it becomes very
easy to measure the edge wave intensity as a function of
the diffraction angle.
These measurements of the edge
wave obliquity factor contain the information on the
edge parameters (cross-sectional geometry, nature of the
material) as well as on the polarization state.
We
apply this technique to measure the curvature radius of
conducting circular cylinders. This obviously is relevant to the exact electromagnetic diffraction theory
which is used in our analysis.
*
Work supported by Natural Sciences and Engineering
Research Council of Canada under grants A-0360 and
A-2205.
PN5
Holographic Dyed Plastic Behavior*. S. CALIXT0,
R. A. LESSARD, LROL Dept.. Çhysigue Université Laval Recently it has been shown"1" the possibility of using
dyed plastic in real time holography. Due to the bluegreen light
absorption of the plastic an Ar
laser
giving green
light (wavelength 514.5 nm)
has been
used to record the hologram.
Red light (632.8nm),
which
is poorly absorved, is used to reconstruct the
hologram simultaneously with the recording process.
Recent experiments show that this plastic behaves like
coulored crystals which respond to polarized
light.
Several experimental characteristics,
involving the
recording of polarized light, have been found, namely
the behavior of the photostationary diffraction efficiency as a function of the writing beams power, the
diffraction efficiency as a function of the polarization
angle of the reconstruction light and the diffraction
efficiency as a function of the polarization angle of
the writing beams. Also a method is presented by means
of which it is possible to reduce by 8 times the erasing
period of the hologram.
l.-S. Calixto and R.A. Lessard,Appl. Opt.,23,211 (1984).
*Work supported by the NSERC-A-D360.
PN6
Interférométrie à l'aide de l'Holographie
Infrarouge sur de minces couches d'huile.* M. CORMIER,
J. LEWANDOWSKI, B. MONGEAU, LLCMR, College militaire
royal de St-Jean - A l'aide d'un faisceau laser infrarouge
on enregistre un hologramme dynamique
d'un objet sur un milieu enregistreur constitue d'une
mince couche d'huile sur un substrat de verre . Les
faisceaux d'ordre 0 et + 1 reconstruits dans le
spectre visible (0,63vim) a partir de cet hologramme
sont superposes, et leur interference donne une mesure
du déplacement ou de la déformation de l'objet. En
tenant compte des aberrations et de l'isolement des
vibrations, on mesure ainsi de façon precise les
déplacements et les deformations, et on peut effectuer
en temps réel une analyse de la qualité des composantes optiques pour l'infrarouge. Un enregistrement
vidéo des résultats sera montré.
1
Cormier M. et al., Applied Optics, 17, 3622 (1978).
*Projet subventionné par le CRDév #3610-371.
PN7
Electro-Optic Displacement Sensing Interferometer. C.P. GROVER and A.K. AGARWAL, Physics
Division, National Research Council - The visibility of
fringes in a speckle interferometer has been analysed as
a function of source position. The active element consists of a double exposure speckle recording producing
rectilinear fringes in the plane conjugate to that of a
point source of monochromatic light 1 . The reduction In
the fringe visibility caused by a longitudinal displacement of the object coupled to the source is measured by
positioning a line detector in the fringe plane. The
sensitivity, which depends upon the size and location of
the line detector with respect to the fringe profile,
has been estimated to be 0.1 micrometers. This study
has been applied to the design and operation of a remote
electro-optic displacement sensor. Furthermore a
discussion of the range, sensitivity and linearity of
this device has been included.
^ROVER, C.P., Opt. Commun., 24, 113 (1978).
PN8
Spectral
Sensitization
of
Dichromated
Gelatine*.
Cristina SOLANO, R.A. LESSARD and P.C.
Roberge(l), LROL - Dept.. of Physiçsj Université Laval Dichromated
Gelatine is a well known
holographic
recording material though its spectral sensitivity is
limited.
Overcoming this disadvantage would increase
the number of applications where this material could be
used. The experimental results presented will show an
investigation made in order to extend the spectral
sensitivity of dichromated gelatine to red light. In
particular, different buffer solutions have been used to
change the PH of the sensitizing solutions to simplify
the methods already published.
* Work supported by the NSERC-A-0360.
(1) Dept. of Chemistry, Université Laval.
rug
PN9
L'image d i f f r a c t i o n n e l l e d ' u n système o p t i q u e
a b e r r a n t ayant une t r a n s m i s s i o n p u p i l l a i r e n o n - u n i f o r m e .
J-E VILLENEUVE e t S.C. BISWAS, Céqep de S e n t - I l e s , SeptI l e s , Ouébec - L ' é t u d e de l ' i m a g e d i f f r a c t i o n n e l l e dans
l e cas d ' u n système o p t i q u e ayant des a b e r r a t i o n s r é s i d u e l l e s e t des f i l t r e s n u p i l l a i r e s n o n - u n i f o r m e s p r é sente d'énormes d i f f i c u l t é s .
En d é n i t de ces d i f f i c u l t é s , ce s u j e t s u s c i t e un i n t é r ê t soutenu chez l e s c h e r cheurs comme l e démontre l e s nombreuses p u b l i c a t i o n s
des d e r n i è r e s années.
Nos recherches nous amènent à
proposer une f o r m u l a t i o n t h é o r i q u e remarquablement simp l e e t é l é g a n t e pour l ' é v a l u a t i o n des p r o p r i é t é s d i f f r a c t i o n n e ï l e s d ' u n t e l système o p t i q u e .
Dans c e t t e
f o r m u l a t i o n , l a f i g u r e de d i f f r a c t i o n sur un p l a n donné
qui e s t obtenue e s t une t r a n s f o r m é e f i n i e de Hankel ou
une forme s i m i l a i r e .
Notre méthode permet d ' é v a l u e r
numérinuement l e s d i f f é r e n t e s c a r a c t é r i s t i q u e s d i f f r a c t i o n n e l l e s du système o p t i q u e avec une r a p i d i t é e t une
s i m p l i c i t é considérables.
La méthode e s t v a l a b l e pour
les f i l t r e s possédant une s y m é t r i e de r é v o l u t i o n .
Nous
l ' a v o n s aussi a p p l i q u é e pour é v a l u e r l a performance de
p l u s i e u r s f i l t r e s sous l ' i n f l u e n c e de coma p r i m a i r e .
De nombreux r é s u l t a t s sous l a forme graphique sont p r é sentés.
p
N13
Numerical Ray T r a c i n g Methods f o r G r a d i e n t Index
Media.*
D.W. HEWAK and J.W.Y. L I T ,
Dept. o f P h y s i c s ,
WLU and GWP2, U. o f Waterloo - The
accuracies
and
efficiencies
of several
numerical r a y t r a c i n g methods
for
g r a d i e n t index o p t i c a l media are i n v e s t i g a t e d .
Our
comparisons o f e x i s t i n g a l g o r i t h m s r e v e a l t h a t to o b t a i n
diffraction-limited
accuracy
i n numerical ray t r a c e s ,
the Runge-Kutta a l g o r i t h m i s best. 1
However, when rays
are t r a c e d t h r o u g h index d i s t r i b u t i o n s w i t h no simple
mathematical
forms,
such as the g e n e r a l i z e d Luneburg
lens2,
a considerable
amount o f
time i s
spent
in
obtaining
the i n d e x .
As more complex g r a d i e n t index
media are developed, and when many rays are t r a c e d ,
the
computation time i n
performing
a
trace
becomes
increasingly long.
We s h a l l
present
two new
ray
t r a c i n g methods, based on the p r e d i c t o r and p r e d i c t o r corrector
algorithms.
Comparison w i t h e x i s t i n g methods
r e v e a l s t h a t comparable a c c u r a c i e s c o u l d be o b t a i n e d
w i t h o n e - t h i r d and t w o - t h i r d s o f the index computation
t i m e , r e s p e c t i v e l y . Numerical r e s u l t s w i l l be p r e s e n t e d .
Sharma, e t a l . , A p p l . O p t . , 21, 984 (1982)
S. D o r i c and E. Munro, A p p l . O p t . , 22, 443 (1983)
• s u p p o r t e d by NSERC
PNIO Le traitement des images en présence de bruit
dépendant du signal^ dont le modèle est inconnu.
M.
LEVESQUE, H.H. ARSENAULT, LROL^ Univeriité Laval. Nous avons récemment mis au point une méthode de
rehaussement des images dégradées par le bruit dépendant du signait.
Cette méthode combine une transformation homomorphique qui a pour effet de rendre le
bruit indépendant du signal avec un traitement statique local appliqué successivement sur une petite fenêtre de l'objet à la fois.
Quand on ne connaît pas
la dépendance du bruit sur le signal, cette méthode
peut être modifiée en utilisant les mesures faites sur
la fenêtre pour estimer la moyenne et la variance du
bruit.
Des résultats expérimentaux seront présentés,
accompagnés d'une discussion de l'efficacité de la méthode.
*
H.H. ARSENAULT,
presse).
M.
LEVESQUE,
Appl.
Opt.
(sous
PN11 The
Ngn-Symmetrical Fourier Iransfgrm
Ho;
logram.
H.H. ARSENAULT, T. SZOPLIK, LROL, Laval University. - When holograms are recorded on a medium
with limited resolution, the full resolution of the
recording medium is fully used only in one dimension.
A non-symmetrical Fourier transform system can be used
to scale the object or the Fourier transform in such a
way that the maximum value of the storage capacity of
the medium is used.
Conditions for the maximum value
of the storage capacity are found for circular and
rectangular formats.
PN12
Les e f f e t s combinés de l a r é s o l u t i o n , du cont r a s t e e t du b r u i t s u r l a p e r c e p t i o n * .
H.H. ARSENAULT,
G. APRIL, LROL, U n i v e r s i t é L a v a l . - Plus de 300 images
de 6 n a v i r e s ayant des r é s o l u t i o n s , des c o n t r a s t e s e t
des niveaux de b r u i t précisément c o n t r ô l é e s o n t été
préparées par o r d i n a t e u r e t imprimées sur d i a p o s i t i v e s .
Ces images f u r e n t montrées à des o b s e r v a t e u r s a f i n de
d é t e r m i n e r l e s e f f e t s de ces paramètres sur l a p r o b a b i l i t é de r e c o n n a î t r e les n a v i r e s .
Les r é s u l t a t s obtenus
p o u r r a i e n t o u v r i r l a v o i e a l ' é l a b o r a t i o n d'un modèle de
l a p e r c e p t i o n q u i t i e n n e compte en même temps pour l a
première f o i s des t r o i s paramètres r é s o l u t i o n , c o n t r a s t e
et b r u i t .
*
Recherche accomplie dans l e cadre du c o n t r a t 8SD8100139 pour l e M i n i s t è r e de l a Défense N a t i o n a l e du
Canada.
PN14
Frequency Pushing and P u l l i n g i n a 3.39|. He-Ne
Laser. A. D. MAY, W. JAÎ1R0Z, D. HUGON, and T. CAVE,
Dept. o f P h y s i c s , U n i v e r s i t y o f Toronto - We have measured t h e beat frequency between a p a i r o f modes i n a
3.39p He-Ne l a s e r b o t h w i t h and w i t h o u t CH<, i n an i n t r a cavity cell.
We f i n d t h a t d e t a i l e d c a l c u l a t i o n s based
on w e l l known d i s p e r s i o n and h o l e b u r i n g e f f e c t s agree
o n l y i n a s e m i - q u a n t i t a t i v e way w i t h t h e o b s e r v a t i o n s .
Some reasons w i l l be g i v e n f o r t h e l a c k o f p r e c i s e
agreement. The r e l e v a n c e o f the experiment t o t r a c e
d e t e c t i o n o f CHi, and t o l a s e r based p a r i t y v i o l a t i o n
experiments w i l l be d i s c u s s e d .
PN15
Passive Optical Slip Ring. R. C. GAUTHIER and
B. i;. PATON. Dalhousie Univ. - Rotating systems of
fibre optics require an optical analogue to the electrical slip ring. Historically, the problem has been
solved by using electrical components, but these are
complex, require a power supply, and are expensive. A
new type of optical slip ring has been developed, which
is purely passive. These slip rings exhibit several
advantages over active devices: first, an on-axis slip
ring is used in situations where the mechanical axis of
rotation is free. This device has shown low insertion
loss, biodirectionality, and a bit error rate better
than 1 in 10 ; the second, the off-axis slip ring is
used in situations where the mechanical axis of rotation
is riot free. Due to its complex construction, larger
insertion losses are observed. In situations where more
than one independent channel is needed, both devices can
be combined to form a multi-channel slip ring.
PN16
Fibre Optic Laser Doppler Velocimetry.
O. SEZERMAN, B. E. PATON and G. A. KLASSEN, Dalhousie Univ. The technique of Laser Doppler Velocimetry
(LDV) has
been widely used in university and industrial applications, due to the fact that flow velocities can be
measured directly without disturbing the media. The
potential applications of the LDV vary from very low
velocity measurements, such as flow in small veins, to
measurements in hostile environments, such as in flames,
chemically reacting flows, turbulent fields created by
rotating machinery, etc. Two different LDV techniques
(reference beam and dual beam), enhanced by fibre optic
technology, will be presented. These devices have been
used to measure blood flow in small veins and velocities
in transparent media, respectively.
rugi
PN17
T r a n s m i s s i o n P r o p e r t i e s o f a Multimode O p t i c a l
F i b e r Taper?* YI FAN L I and J.W.Y. L I T , Dept. o f P h y s i c s ,
W i l f r i d L a u r i e r U n i v e r s i t y - A simple and u s e f u l formula
governing the skew r a y s p r o p o g a t i n g t h r o u g h a multimode
f i b e r t a p e r has been d e r i v e d by u s i n g g e o m e t r i c a l
optics :
COS^=
N ^ O S Q
C O
5 V L
r2
where
and V 2 a r e r e s p e c t i v e l y , the i n i t i a l and f i n a l
angles o f i n c i d e n c e o f a skew r a y on the w a l l o f the
f i b e r t a p e r ; £2 i s the h a l f t a p e r a n g l e ; r, and r 2 are
the r a d i i o f the i n c i d e n t and e x i t planes o f the f i b e r .
Using the above f o r m u l a , we have s t u d i e d the
t r a n s m i s s i o n p r o p e r t i e s o f the f i b e r t a p e r , such as the
t o t a l l i g h t t r a n s m i t t e d and the e f f e c t i v e numerical
a p e r a t u r e . We compared these r e s u l t s w i t h the m e r i d i o n a l
rays i n the t a p e r as w e l l as the skew rays i n a u n i f o r m
fiber.
* s u p p o r t e d by NSERC
PP3
Photoneutron Cross-sections for 1 **(:.* R.E.
PYWELL, (U of Saskatchewan), B.L. BERMAN, J.G. WOODWORTH,
(LLNL), J.W. JURY, (Trent U.), K.G. McNEILL, (U of Toronto) , M.N. THOMPSON, (U of Melbourne) - Using monoenergetic photons the cross sections for the (y,n) and (y,2n)
reactions in 1 4 C have been measured from threshold to
36 MeV. There is little evidence of a pygmy resonance
(a peak at 11.2 MeV probably is an Ml transition). At
15.5 MeV a prominent peak may represent the maximum of
the T< GDR. The (y,n) cross section has a valley centred
around 26 MeV, coincident with the major peak in the
(y,2n) cross section; this is probably near the location
of the T GDR. Other features are interpretable in terms
of the opening of the (y,p) and (y,np) channels and the
opening of T states in I 3 C. The expected isospin splitting of the ÈDR of ''•C is 8.6 MeV. This is consistent
with the above interpretation of the 15 MeV peak in the
(y,n) cross section and the peak in the (y,2n) cross
section. The (y,p) cross section (threshold 20.8 MeV)
is expected to be large based on sum-rule considerations
and will also result mainly from decay of the T reson
ance. This interpretation is consistent with the
theoretical calculations of Kissener et al.1
^Kissener HR et al. Nuc Phys A236 289 (1979)
NUCLEAR
FISSION
REACTIONS
AND
PHOTONUCLEAR
PPl
Photon Absorption by Uranium.
N.K. SHERMAN,
W.F. DAVIDSON, M. KOSAKI and A. NOWAK, National Research
Council, Ottawa, and W. DELBIANCO and G.
KAJRYS,
ITniversité de Montréal—The absorption of pulsed 42
MeV bremsstrahlung by natural uranium is being measured
at the NRC linac using a photon spectrometer consisting
of a liquid deuterium target viewed by a neutron timeof-fllght detector. The total cross section for photon
absorption Oj. at photon energy OJ is obtained with energy
resolution varying from 0.6% at 6 MeV to 1.9% at 25 MeV.
By subtracting from Oj.(u>) both the photonuclear cross
section measured in other experiments and the calculated
cross sections for all atomic processes other than pair
production we obtain an experimental value for o^(ii)),
the cross section for electron pair creation on the
nucleus. At 10 MeV we find that o R is (15.14 ±0.06)
barn and at 20 MeV where it contributes 87% of Oj. it is
(22.34 ± 0.22) barn. Kosik and Wright have computed c^
by distorted wave techniques at these energies for
uranium.
Their results exceed the measured values by
about 4% and 7% respectively. Semi-empirical values of
(V tabulated by Hubbell, Gimm and 0verbo are larger by
2% at 10 MeV and
1% at 20 MeV than the experimental
values•
PP2
Photoneutrons from the Reaction 1 6 5 H o ( y , n )
Ho.
J - S . TSAI, W.V. PRESTWICH and T.O. KENNETT, Dept. o f
le4
P h y s i c s , McMaster Univ. - A s t u d y o f the ^ H o t y . n )
Ho
r e a c t i o n u s i n g the h i g h l y c h r o m a t i c photons generated by
n e u t r o n c a p t u r e on n i c k e l i n the core o f the McMaster
Nuclear Reactor and a high r e s o l u t i o n 'He n e u t r o n
detector' is reported.
Photoneutron en ergy s p e c t r a were
recorded and analyzed. The r e s u l t s enable us t o i n f e r
t h e energy l e v e l s o f l ^ H o g p ^ a s a consequence,
supplement t h e r e a c t i o n 1 6 5 H o ( d , t ) 1 6 4 H o 2 .
I n the
p r e s e n t measurement, the ground s t a t e Q-value was d e t e r mined t o be -7989±1 keV which i s i n e x c e l l e n t agreement
w i t h mass s y s t e m a t i c s ' .
In a d d i t i o n , a t o t a l photon e u t r o n cross s e c t i o n o f ' " H o f o r a gamma-ray o f energy
9 MeV i s i n v e s t i g a t e d .
The r e s u l t s w i l l be discussed
and compared w i t h e a r l i e r r e p o r t s 4 .
I f l c F e e , J . E . , Ph.D. T h e s i s , McMaster U n i v e r s i t y ( 1 9 7 7 ) .
Jones, H.D and S h e l i n e , R . K . , N u c l . Phys. A150, 497
,(1970).
Grove, N.B. and Wapstra, A.H
Nuclear Data Table 11,
(1972).
4 127
Hayward, E, Nuclear S t r u c t u r e and E l e c t r o m a g n e t i c
I n t e r a c t i o n s , e d i t e d by N. MacDonald, 1964, p. 141
PP4
Plon Double Charge Exchange at 50 MeV on ^ C .
G. AZUEL0S, R. POUTISSOU, Univ. de Montréal, I. NAV0N,
M.J. LEITCH, D.A. BRYMAN, T. NUMA0, P. SCHLATTER, Univ.
of Victoria, R.A. BURNHAM, M. HASINOFF, J.-M.
POUTISSOU, Univ. of British Columbia, J.A. MACDONALD,
J.E. SPULLER, TRIUMF. C.K. HARGROVE, H. MES, NRC,
M. BLECHER, K. G0T0W, Virginia Polytechnic, M.
MOINESTER, Tel-Aviv Univ. H. BAF.R, LANL - The first
measurement of pion double charge exchange at low
energy is reported. The reaction 1I,C(it+,iT-)1',0 at an
incident pion energy of 50 MeV was studied on the Time
Projection Chamber of TRIUMF. Differential cross
sections to the double analog transition are given in
the angular range 50°-120°. Strong non-analog
transistlons were also observed.
PP5
Measurement of Broad Plonlc X Rays. G.A. BEER
D.I. BRITT0N, G.R. MASON, T. NUMAO, A. 0LIN, P.R.
POFFNBERGER, U. Of Victoria; J.A. MACDONALD, TRIUMF;
and A.R. KUNSELMAN, U. of Wyoming - The effects of the
strong interaction on pionic levels In atoms are
generally described very well by a phenomenologlcal
optical model potential. For broad pionic X rays, the
use of a BG0 Compton suppression system results in a
significant improvement in the peak to background
ratio. Contrary to previous experiments, we have
recently obtained a value for the width of the 2p-ls
transition in pionic Na which is in good agreement
with theory. The trend indicated by this result ha6
been corroborated by a measurement on pionic
magnesium. On the other hand, for the broad 4f-3d
transitions in heavy elements we confirm, through a
measurement for pionic Pb, the trend towards smaller
shifts and widths than those predicted by the
phenomenologlcal model.
PP6
Pion-Induced Fission of Lithium-6. B.J.
MCPARLAND, E.G. AULD, P. COUVERT, G.L. GILES, G.
JONES, W. ZIEGLER; Univ. of British Columbia, D. GILL,
D. OTTEWELL, P. WALDEN; TRIUMF, G. HUBER, G. LOLOS, Z.
PAPANDREOU; Univ. of Reglna - The angular distribution
of the differential cross-section of the reaction
6
Li (ir+,3He) 3 He will soon be measured at several plon
energies. Preliminary measurements have been made at
three angles (6* - 16.7", 49.7° and 81.2°) for a pion
energy of 80 MeV.
The fission channel has been
clearly observed at the two forward angles and
preliminary cross-sections have been extracted. These
tentative results are compared to two theoretical
predictions assuming different reaction mechanisms and
are found not to be in agreement with either.
rug
PP7
Radiative Muon Capture in **uCa*. C.J. VIRTUE,
K.A. ANIOL, F. ENTEZAMI, M.D. HASINOFF, H. ROSER,
Univ. of British Columbia, D. HORVATH, Central
Research Institute, Hungary, B.C. ROBERTSON, Queen1s
Univ., ~ The induced pseudoscalar coupling constant,
gp, in weak semi-leptonic interactions may be deduced
from a study of the radiative capture of negative
muons in nuclei. An experimental measurement of the
photon energy spectrum and the angular asymmetry of
the photon with respect to the muon spin have recently
been completed at TRIUMF for the reaction
l+u
Ca(p, v y Y )1+0K. The measurement of the weak
radiative branch in the presence of a high neutron
background was accomplished using an active convertor
gamma-ray telescope. The performance of this
telescope and preliminary results representing
1.7 x 1011 stopped muons will be presented.
*Supported by the Natural Sciences and Engineering
PP8
Sodium Iodide Response Functions*.
C.E. WALTHAM, M. HASINOFF, J.-M. POUTISSOU, Univ. of
British Columbia, P. GUMPLINGER, A. W. STETZ, Oregon
State Univ. T. MULERA, Lawrence Berkeley Lab., B.
ROBERTSON, Queen's Univ., M. SALOMON, TRIUMF - The two
large sodium iodide spectrometers at TRIUMF (TINA and
MINA) have recently undergone surface recompensation.
TINA was recompensated by Harshaw using a 2.6 MeV y
source, and MINA was recompensated by BIcron using a
6 MeV source. Their response functions have since been
measured with electrons of energies from 30 to 90 MeV,
over the full range of the detectors' acceptances,
and with emphasis on linearity, uniformity and
resolution. The electron data has been compared with
Y data obtained from Tr~p interactions at rest (55-83,
129 MeV) and the energy loss of electrons in the
crystal containers has thus been calculated. The
experimental data has been compared to Monte-Carlo
simulations using the EGS program. After
recompensation, an overall Improvement of about 30% has
been achieved in resolution and uniformity.
*Supported in part by NSERC
NUCLEAR
STRUCTURE
PP9
Elastic and Inelastic Scattering of 50 MeV Pions
from 3 2 S and 3 l 4 s"
R.J. SOBIE, T.E. DRAKE, U. of Toronto,
K.L. ERDMAN, R.R. JOHNSON, H.W. ROSER, R. TACIK, U. of
British Columbia, E.W. BLACKMORE, D.R. GILL, S. MARTIN,
C.A. WIEDNER, TRIUMF - Pion inelastic scattering near
the (3,3) resonance has been shown to be useful in determining neutron and proton transition matrix elements.
However at energies below the (3,3) resonance the pion
shows much larger sensitivities to neutron and proton
effects. At T^ = 50 MeV, for example, the ratio of T r + p
and iT~p differential cross sections varies rapidly with
angle, increasing from
at 0 = 90° to greater than 20
for 6 > 120°. Thus at backward angles the TT + interacts
only with the proton and the TT~ only with the neutron.
In this paper we will demonstrate that this sensitivity
makes the low energy pion a unique probe to separately
determine neutron and proton transition matrix elements.
Data will be presented for 3 2 S and 31*S.
PP10
Decay o f
Gd and
Gd by P o s i t r o n Emission
and E l e c t r o n C a p t u r e . * R. TURCOTTE, H. DAUTET and S.K.
MARK, Foster R a d i a t i o n L a b o r a t o r y , M c G i l l U n i v . - - T h e
decay p r o p e r t i e s o f the n e u t r o n d e f i c i e n t n u c l i d e s 1 4 2 ^
and ' 4 ' G d are i n v e s t i g a t e d by means o f b e t a , gamma and
i n t e r n a l c o n v e r s i o n e l e c t r o n spectroscopy t e c h n i q u e s .
Sources are o b t a i n e d from a gas j e t r e c o i l t r a n s p o r t
system a f t e r i r r a d i a t i o n of e n r i c h e d 1 4 4 Sm t a r g e t s w i t h
3He p a r t i c l e s . I d e n t i f i c a t i o n o f the n u c l i d e s i s based
on t h e i r e x c i t a t i o n f u n c t i o n s measured t h r o u g h the Xray,ray coincidence technique.
Decay h a l f - l i v e s of l ^ g d
and 1 4 1 Gd are measured t o be 6 8 . 6 ± . 9 sec and 2 0 . 5 + . 6
sec, r e s p e c t i v e l y .
Level schemes are presented and
d i scussed.
*Work supported by NSERC, Canada.
PP11 A S h e l l - M o d e l Study o f N=48 and N=47 N u c l e i . * K.
OXORN, S.K. MARK and S.S.M. WONG, Foster R a d i a t i o n
L a b o r a t o r y , M c G i l l U n i v . - - T h e N=48 8 « Z r , 90m o , 87Y, 89fjb
and t h e N=47 8 7 z r , 88Nb n u c l e i are s t u d i e d w i t h i n the
framework o f the n u c l e a r s h e l l model. A 8 8 $ r C O r e was
chosen w i t h valence p r o t o n s and n e u t r o n - h o l e s i n the
l g g / 2 and 2 p ] / 2 s i n g l e - p a r t i c l e o r b i t a l s .
The f o u r
s i n g l e - p a r t i c l e e n e r g i e s and 29 o f the 38 two-body
m a t r i x elements were taken d i r e c t l y from a p r e v i o u s
a n a l y s i s o f n u c l e i i n the N=50 and 49 i s o t o n e c h a i n s
u s i n g the e f f e c t i v e i n t e r a c t i o n .
In t h a t c a l c u l a t i o n ,
charge independence was preserved which enabled us t o
deduce the n i n e a d d i t i o n a l two-body m a t r i x elements
r e q u i r e d f o r the p r e s e n t c a l c u l a t i o n .
We have found
t h a t a l t h o u g h the l o w e s t s t a t e s appear t o be v i b r a t i o n a l
i n c h a r a c t e r , the h i g h e r - l y i n g s t a t e s are w e l 1 - d e s c r i b e d
by t h i s model.
From 68 l e v e l s i n s i x n u c l e i , we have
achieved a mean l e v e l d e v i a t i o n o f 130 keV, an
encouraging r e s u l t c o n s i d e r i n g t h a t these n u c l e i l i e
f u r t h e r from the core than those which were used t o
deduce the s i n g l e - p a r t i c l e e n e r g i e s and two-body m a t r i x
elements. E2 t r a n s i t i o n r a t e s and magnetic d i p o l e
moments f o r the N=48 n u c l e i were a l s o i n v e s t i g a t e d .
*Work supported by NSERC, Canada
PPI2
Towards a Se 1f-Consis tent Microscopi c Mass Formujj. J.-M. PEARSON, A. K. DUTTA and J.-P. ÀRC0RAGI ,
Université de Montréal. - We are attempting to establish
a mass formula on the basis of a n ï ne-pa rame ter Skyrmetype force with
m. The ideal approach with this
starting point, giving the most reliable extrapolation
towards the drip lines, would be simply to do HartreeFock-BCS, with the force parameters being fitted to the
mass data. However, this is too time-cons un ing and one
is forced back to the usual two-part approach. The macroscopic term is calculated by the extended Thomas-Fermi
method, with a Fermi parametrisation of the density distribution, while shell corrections are calculated by the
Strutinsky method, using semi-c1 assical smoothing; the
essential point is that both parts are calculated selfconsistently from the same two-body force. Tests made
with a given force show very good agreement between the
present method and HF, confirming that we have here a
viable approach to the mass formula that is almost as
reliable, i.e., microscopically well founded, as the
HF-BCS method.
PP13
Systematic C o r r e c t i o n s to Low-e DSAM Nuclear
Lifetimes.
B. M. LATTA, Memorial U n i v . o f N f l d . - This
paper addresses the q u e s t i o n o f e r r o r s i n n u c l e a r l i f e times t h a t are due t o the c h o i c e o f n u c l e a r s t o p p i n g
power.
The work c o n s i s t s o f a s y s t e m a t i c study o f
n u c l e a r l i f e t i m e s as determined by independent methods,
p l u s a s y s t e m a t i c study o f n u c l e a r s t o p p i n g powers as
determined from range measurements, from energy l o s s
measurements and from r e c e n t t h e o r e t i c a l c o m p u t a t i o n s .
The general c o n c l u s i o n i s t h a t the n u c l e a r l i f e t i m e s
t h a t have been determined by low-energy D o p p l e r - s h i f t a t t e n u a t i o n - m e t h o d should be s y s t e m a t i c a l l y c o r r e c t e d by
the m u l t i p l y i n g f a c t o r 1.51 ± 0.10 t o c o r r e c t f o r the
e x i s t i n g e r r o r s i n the n u c l e a r s t o p p i n g power t h a t has
been used i n the a n a l y s i s .
rugi
PP14
Model Independent Determinations of the Proton
Density Differences In ' b ' 1 B 0xygenI B.M. BARNETT,
K.L. ERDMAN, W. GYLES, R.R. JOHNSON, H.W. ROSER,
R. TACIK, U.B.C., R.J. SOBIE, T.E. DRAKE, U. of
Toronto, D.R. GILL, TRIUMF, S. MARTIN, K.F.A. Jullch,
C.A. WIEDNER, M.P.I. HEIDELBERG - Differential ir"1"
elastic scattering cross section ratios have been
measured on 1 6 > 1 8 0 at 50 and 65 MeV. Scattered
plons were momentum analysed by the QQD low energy
spectrometer at TRIUMF. The data are subjected to
optical potential analyses to extract proton nuclear
matter distribution differences, described by a 'model
independent' sum of Fourier Bessel terms, between
nuclei. The results are compared to precision
electron scattering measurements. Potential
dependence and the implications with regard to it~
ratlo measurements of neutron density distribution
differences are discussed.
PP15
Isospln Dependence of Plon Absorption by 1 2 C
at T„-65 MeV. H.W. ROSER, A. ALTMAN, K.A. ANIOL,
R.R. JOHNSON, R. TACIK, W. GYLES, B. BARNETT, Univ. of
British Columbia, D.R. GILL, J. VINCENT, TRIUMF, S.
LEVENSON, Argonne National Lab., J. ALSTER, D. ASHERY,
J. LICHTENSTADT, M.A. MOINESTER, E. PIASETZKY, TelAviv Univ., R.J. SOBIE, Univ. of Toronto, H.P. GUBLER,
Univ. of Manitoba - The (u T , 2p) and (ir~,pn) reactions
on 1 Z C were measured with 65 MeV pions on the Mil
channel at TRIUMF. The two nucléons were detected in
coincidence. The contribution to the above process
from absorption on a nucléon pair (n,p (p,p) pair for
n+(it-)) can be identified with the help of the angular
nucleon-nucleon correlation and the two dimensional
energy spectrum of the two outgoing nucléons. The
shape of the (ïï+,2p) cross-section is similar to the
n+d+pp cross-section. The ratio of (3.0±1.0) for the
two cross-sections, Indicating a corresponding number
of quasi-deuterons participating in the process, is a
factor of two higher than for 165 MeV plons.
The cross-section for ir~ is more than an order of
magnitude lower than for n + .
''
A. Altman et. al. Phys. Rev. Lett. 50. 1187
(1983)
PP16
Strength Function Measurement from the
Au(p,Y) Reaction at E - 4.0 MeV.*
197
D. ARMSTRONG, S.K. SAHA, E. ADAMIDES, S.-S. WANG,
C.-Y. CHENG, A. HENRIKSON, M.A. LONE', and
B.C. ROBERTSON, Queen's Univ., Kingston - The
gamma-ray spectrum from the (p,Y) reaction on 1 9 7 Au
has been measured for E > 3 MeV at E - 4.0 MeV.
Y
P
A gamma production cross section of ~0.24 Ub was
obtained. The El strength function for 1 9 8 H g was
deduced from the Y-ray intensity distribution using
a spectrum fitting method and Is compared with an
extrapolation of the Giant Dlpole Resonance and with
strength function Information from other reactions.
•Supported in part by NSERC (Canada).
"Atomic Energy of Canada Limited, Chalk River
Nuclear Laboratories, Chalk River, Ontario.
PP17
Parity Mixing of Qr States in u F.
H.C. EVANS, G.T. EWAN, S.P. KWAN, J.R. LESLIE,
J.D. MacARTHUR, H.-B. MAK, W. McLATCHIE, S.A. PAGE,
P. SKENSVED, S.-S. WANG, Queen's U-, A.B. McDONALD,
Princeton, C.A. BARNES, Caltech, T.K. ALEXANDER and
E.T.H. CLIFFORD, AECL, Chalk River Nuclear
Laboratories - The mixing of the 1.042 MeV (0 ) and
I.081 MeV (0") levels in l e F provides an ideal case
for studying the effective weak nucleon-nucleon
Interaction mediated by the long range n exchange and
to deduce information on weak hadronic neutral current.
All the nuclear parameters needed to Interpret experi-
mental data h^ve been measured. The parity mixing
between the 0 and 0 pair produces a circular
polarization In the El + decay from the 1.081 MeV level
to the ground state (1 ) level, which is being
measured at Queen's University using four transmission
magnetic polarimeters each viewed by a 150 c.c. n-type
germanium detector. The states are populated by the
0( 3 He,p) 1 8 F reaction using a water target which is
Isolated from the beam vacuum by ~1 mg/cnr Ti foils.
Approximately 1200 hours of data has been accumulated
and the statistical uncertainty In the measurement of
the circular polarization is ~10 x 10" . The status
of our experiment will be reported.
PP18
The PeslRn and Calibration of a Polarimeter
to Measure the Circular Polarization of Y-rays.*
H.C. EVANS, G.T. EWAN, S.P. KWAN, J.R. LESLIE,
J.D.MacARTHUR, H.-B. MAK, W. McLATCHIE, S.A. PAGE,
P. SKENSVED, and S.-S. WANG, Queen's Univ.,
Kingston - Magnetic polarimeters have been designed
to measure the circular polarization of the 1.08 MeV
Y-ray from 1 8 F . The cores of the polarimeter are
made from Permendur alloy and are 7.2 cm long. The
circular polarization is deduced from the ratio of
transmitted Y-ray Intensity for the two longitudinal
magnetization states. The complete polarimeter
consists of four Individual polarimeters placed
symmetrically about the target position. The
polarimeter has been calibrated by using a pair of
cores the first to circularly polarize the Y-rays
from a 6 0 Co source and the second to analyse them.
The result is close to the expected sensitivity of
I.7%.
*Research supported by NSERC (Canada).
PP19
A Fast Data Acquisition System.* P. SKENSVED,
R.L. STEVENSON, A.L.~BELL, and H.-B. MAK, Queen's
Univ., Kingston - As part of the 1 8 F parity mixing
experiment we have developed a fast data acquisition
system which greatly reduces pile-up and deadtime.
The four 30% n-type germanium detectors which are
used in the Y-ray polarimeter are connected to Ortec
673 amplifiers and gated Integrators. The use of
short time constants (.25 Us) eliminates most of the
pile-up. The integrators restore the resolution to
~3.2 keV at 1.3 Mev for a 60 KHz rate. A logic unit
built at Queen's multiplexes the four analog signals
between three standard 200 MHz ADC's. As the probability of having three pulses in four detectors
within 13 Us is very small, the overall deadtime Is
virtually zero.
•Research supported by NSERC (Canada).
PP20 Radiative Proton Capture to Levels in '"N l . C.
PRUNEAU, M.B. CHATTERJEE, C. RAHGACHARYULU* and C. STPIERRE, Laboratoire de physique nucléaire, U. Laval We have measured the angular distributions, gamma decay
schemes and radiative widths of selected levels in
N
through
C(p,y) reaction. These studies were carried
out to resolve the apparent discrepancies between the
old (p,Y) results and the more recent (e,e') data. Our
measurements indicate that though the earlier (p,Y)
studies provided the proper branching ratios, the radiative widths were overestimated. The angular distributions helped determine the mixing ratios. Results for
the levels E X (J*,T) MeV: 8.91 (3 + ,l); 9.7(l + ,0);
10.1 (2 + ,0); 9-51 (2",l); and 10.1*3 (2 + ,l) will be
presented. Comparison will be made with the earlier
works.
1
Work supported by the Natural Sciences and Engineering
2
Visitor from Accelerator Lab., University of Saskatchewan, Saskatoon, Sask., S7N 0W0.
ru
PP21
Response of the Core of the 8TT Spectrometer.
J. Gascon and P. Taras Université de Montréal;
0. Hausser, Simon Fraser University; H.R. Andrews and
D. Ward, Chalk River Nuclear Laboratories. - The 8TT
Spectrometer will compr ise an array of 20 hyperpure Ge
detectors equipped with Compton suppression and an
inner, nearly spherical core consisting of 72 BGO
detector elements. The response of this core for the
measurement of total y ray energy and multiplicity has
been simulated by Monte Carlo calculations. The
ensuing performance fac tors will be presented.
NUCLEAR
PHYSICS
PP22
Study of the Pion-Nucleus Reaction Mechanism
with 12C(TR,7r'Y) . R.J. SOBIE, T.E. DRAKE, J. GAYDOS, U. of
Toronto, R.R. JOHNSON, R. TACIK, U. of British Columbia,
D.R. GILL, B.K. JENNINGS, TRIUMF, N. DE TAKACSY, McGill
U. - A 1 2 C (TTJTT'Y) angular correlation experiment at
TTT = 65 and 90 MeV from the
state was used to study
the pion nucleus reaction mechanism. The results indi+
cate that the 2i transition proceeds only through the
nuclear matter density. This is an agreement with
current static models and indicates that delta-hole formation may not be important at these energies.
PP23
New Treatment o f the Coulomb I n t e r a c t i o n i n FewBody S c a t t e r i n g . * H. KROGER, A.M. NACHABE and R . J . SL0BODRIAN, Dépt. de P h y s . , U n i v e r s i t é L a v a l , Quebec, P.Q.
- A new method i s presented t o c a l c u l a t e n o n - r e l a t i v i s t i c
few-bod.y s c a t t e r i n g amplitudes f o r s t r o n g and Coulomb i n teractions.
I t i s based on a c a l c u l a t i o n o f approximate
wave o p e r a t o r s .
The f u l l and t h e a s y m p t o t i c H a m i l t o n i a n s
are s u b s t i t u t e d by p r o j e c t i o n s on f i n i t e dimensional subspaces. That leads t o r e a l symmetric m a t r i c e s , which
can be d i a g o n a l i z e d .
Then t h e wave o p e r a t o r can be simp l y expressed i n the eiqen r e p r e s e n t a t i o n s o f t h e f u l l
and a s y m p t o t i c H a m i l t o n m a t r i c e s .
The method has been
proven m a t h e m a t i c a l l y 1 » 2 and has been t e s t e d s u c c e s f u l l y
i n t h e two-body system. The method has been a p p l i e d t o
c a l c u l a t e the p+d break up cross s e c t i o n near the t h r e s h o l d and gives r e l a t i v e l y good agreement w i t h r e c e n t e x periments . An e x p l a n a t i o n f o r t h e d i f f e r e n c e i n absol u t e magnitude between low energy n+d and p+d break up
X - s e c t i o n s due t o the Coulomb f o r c e i s g i v e n .
1
H. K r o g e r , 0. Math. Phys. 24, 1509 ( 1 9 8 3 ) .
H. K r o g e r , J . Math. P h y s . , i n p r e s s .
H. K r o g e r , Phys. L e t t . B135, 1 ( 1 9 8 4 ) .
* s u p p o r t e d by NSERC-Canada.
2
3
PP24
Etude du Système 9 Be t 9 Be aux energies Sousroulcmbiennes. 7. LAHLOU, B. CUJEC et B. DASMAHAPATRA*
Université Laval, Quebec
'Ileus avons et-lié la distribution angulaire de la diffusion élastique à 2 energies sous-coulombiennes:
2.2, 2.7 et 3 - - M e V et la section efficace totale entre
Z c< _ r# = 1.3r et 3.26 MeV avec un pas d'environ 0.1 MeV.
Une fonction d'excitation pour chacune des voies de
sertie est aussi presentee. Pour déterminer par quel
méoanisme - et dans quelle proportion - chacun des
noyaux finaux est forme, nous avons étudié aussi la
reaction 'Li qui conduit au même système composé
A=
3 et avons alors compare les produits des deux réactions aux têtes énergies d'excitation du système composé. Il semble eue les transferts de particule a
et de neutron sono très importants à ces énergies.
tellement à l'Université de Burdvan, Bengale Ouest,
PP25 ÎJ§5y£§5_?i_?OLIRISATIGN_de_Ia_Rêaçtigr. ~C'."He,-P»
J.?OULIOÏ,
P.BRÎCAULT, H.NACHABE, L.POÎViN, P.P.ÔVtNC.iER, R.ROV 8.V.51NHA et
R.J.S1060DRIAN, Université Lavai Département ce physique LaDoratc-.rs tie
1 accélérateur Var-_de_Sraaf i Vué&eç_fa-; 7*4 - Dans ie cadre ce »a vérificeLion du tneoréme ce poiai;isatiQn-pouvoir r analyse
nous avons e•treeris
l'étude ce ia réaction
Les mesure1 e polarisation ort- ete
réalisées â l'aioe du faisceai "He ce N . j .lev ce . fceéiérateur
:t
àraail et ae l'installation de poiariPétrie qt : conprenc * polariser, ces
analyseur de caroone utilisés sirou.oanêffie.it par prure 5 des angles s.-.Tiê:ricues de chaque côté eu faisceau. i:s sort ces si nés pc.T :.rtr par1: i ce iê
moyenne géométrique iors de 1 ana. y se des cor-nées. _.ne attention psrticuiiére a été portés â l'élimination des fausses as/métrées duet â la - r. a t:on âQçuiaire rapide de .a section efficace je cetts :éscî.i:>r et res réactions . He,Pi en général -j'. Pour atteindre une grande précision cans . =-.
liçnement eu faisceau et des poi a ri métrés, c- s> sterne asser-vi cont : à
1s
position horizontale du faisceau a été sonstruit. L? sectLC* sff,c=ce es if
réaction, un paramétre nécessaire â l'évaltetion
pouvoir d ' ê ' c " > : s effectif de nos polarimètres, a aussi été mesurée. Les cète.îs et tes premiers
résultats expérimentai.--- se rent présentés.
1- R.Roy, Hadronic J. t M°83> 1619 et
réfêre.ês citée-» le
^ > J. Pou h o t Et al., J. Can. de Phys., 61 12 1983 :60e-: r • ;
'ravail supporté en partie par le C.f.B-N.G. ou- Canada et par le c .*.A,C.
du Québec.
PP26
Réaction d+p->p+p+n près iu seuil ie cassure : Force à trois corps.t A.M. NACHABE, H. KROEGER, R.J. SLOBODRIAN, B.K. SINHA, P. BRICAULT, J. POULIOT, R. ROY et P.
DOLESCHALL, Lab. Physique Nucléaire, Dépt. Physique,
Univ. Laval, Que. G1K 7P^• - La première indication de
l'anomalie dans la reaction de cassure du deutor. a été
revue récemment1>2 dan s l'étude des spectres de corrélation des protons très près du seuil. Dans le but d'améliorer les résultats expérimentaux, des mesures de très
haute précision ont été prises, en réduisant les angles
solides et en utilisant une cible de polyéthylène mince.
La plupart des spectres ont été pris à 13°-13°. Les nouveaux résultats montrent une augmentation des événements pour E -Ep 2 . Cela semble être une évidence directe des effets à trois corps3. L'addition incohérente
d'un calcul à trois corps avec le Champ Coulombien^
et la force à trois corps3, montre
un accord raisonnable avec les données expérimentales.
1) R.J. Clobodrian et al. J. ?hyr,.
L3«l)l;,.
2) A.M. Nachabe et al. Few body X, Karlsruhe (1963)^50;
H. Kroeger et al. ibid. p. 1230.
3) R.J. .'lob ai ri an, ib:d. , p. . - .
t Subventionné par NSERC - CANADA et FCAC-QUEBEC.
PP27
High Energy Deuterons in 3 He + 3 He - u He + ? t
B.K. SINHA, A.M. NACHABE, P. BRICAULT, J. POULIOT, L.
POTVIN, R. ROY, and R. J. SLOBODRIAN, Lab. Physique Nucléaire , Dept. Physique, Univ. Laval, Que. G1K
.
Previous experiments1 using a single four detector telescope have shown evidence for the production <j)f deuteron
2
pulses, consistent with the
+
H * e + v fusion
reaction in the final state. New measurements using
improved techniques have been performed: A) The target
gas was windowless B) a-d correlation detection with
5ns resolving time and antipileup circuitry. Calibrations were obtained from the 7 Li + 3 He ->- 2 H + ^He + ^He
reaction spectra. Nineteen spectra were accumulated
simultaneously on-line using eight ADC's and their combinations. The correlation angles were 30° and 97° for
the alphas and deuterons respectively. Deuteron pulses
have been observed, correlated with alpha partirl.es. The
cross section magnitude appears to be consistent with
previous measurements
1
' R.J. Slobodrian, R. Pigeon and M. Irshad, Phys. Rev.
Lett. 35. (1975) 19; Nuovo Cim. 52A (1979) 387; and
Refs. therein,
t Supported by NSERC-CANADA and FCAC-QUEBEC
rugi
PP28
Etude d u potentiel de convolution appliquée è^
des r é a c t i o n s à basse énergie.* P.-P. PROVENCHLR, R.
RUT, a. PUULIOT, B.K. SINHA et R.J. SLOBODRIAN, Laboratoire de Physique Nucléaire, Université Laval - L E potentiel de c o n v o l u t i o n (folding p o t e n t i a l ) vise à inclure les effets de distribution spatiale de la densité
nucléaire dans un calcul de la partie réelle du potentiel entre deux noyaux. Nous présenterons une méthode
de calcul de ces potentiels valable pour un grand nombre de cas.
Le but de l'étude consiste premièrement à
a p p l i q u e r ce m o d è l e à l ' a n a l y s e de la diffusion
lz
3
14
*N( He, H e ) N qui fut réalisée à l'aide du faisceau
d ' H e + + de 14 M e V de notre accélérateur.
Nous avons
également mis à profit la chambre à cible gazeuse sans
fenêtre du laboratoire.
L'analyse en DWBA des réactions accompagnant cette diffusion conclut cette première étape. La deuxième partie du travail est analogue à la première.Elle porte sur l'étude de la diffusion
N( He, H e ) N.
Il sera intéressant de voir
l'effet de l'ajout d'un neutron sur le noyau cible.
Les détails d'analyse et les résultats e x p é r i m e n t a u x
acquis seront présentés.
Travail s u p p o r t é en partie par le CRSNG du Canada
et le F.C.A.C. du Québec.
PP29
The Ti~+3He + n+d Reaction at 65 MeV and
85 MeV*. K. ANIOL, A. ALTMAN, H. ROSER, R. TACIK,
R. JOHNSON, W. GYLES, B. BARNETT, Univ. of British
Columbia; D. ASHERY, M. MOINESTER, J. LICHTENSTADT,
Tel-Aviv Univ., D. GILL, J. VINCENT, TRIUMF, S.
LEVENSON, Northwestern Univ., E. PIASETZKY Los Alamos
National Lab., R. SOBIE, Univ. of Toronto; H.P.
GUBLER, Univ. of Manitoba - Simultaneously with the
measurement of the 2N absorption of TT~ in 3 H e it is
possible to measure the process ir~+3He + n+d. We
measured this process with two entirely different
cryogenic 3 He targets. In the first case^ 1 ^ we
used the n.d coincidences to determine the target
thickness. In our second run with an improved target
design we were able to measure the target thickness
independently and thus were able to establish the
absolute scale for the ir~+3He •» n+d differential
cross-section. We will present the 65 MeV
differential cross-sections and some points at 85 MeV
as well. A comparison of our results with several
other data sets will be made.
PP31
Absorption of
on a T-l Pair In 3 H e at
Tn~-=65 and 85 MeV. A. ALTMAN, K.A. ANIOL, R.R.
JOHNSON, H.W. ROSER, R. TACIK, W. GYLES, B. BARNETT,
Univ. of B.C., D. ASHERY, M.A. MOINESTER, J. ALSTER,
J. LICHTENSTADT, Tel-Aviv Univ., D.R. GILL,
J. VINCENT, TRIUMF, S. LEVENSON, Northwestern Univ.,
E. PIASETZKY, LASL, R.J. SOBIE, Univ. of Toronto,
H.P. GUBLER, Univ. of Manitoba - Angular distribution
of differential cross-sections were obtained for pion
absorption on a T»1 ^ o nucléon pair, (ir~,pn), In 3 H e
at bombarding energies of 65 and 85 MeV. The
measurements were performed at TRIUMF, and the two
outgoing nucléons were detected. The data was fitted
to Legendre Polynomial in the form:
do/dïî - I AiPi(cos6). The coefficients are: A„-53±3,
u
i
Aj'-SSi?, A 2 -79±7(ub/Sr) for Tir-65 MeV, and A 0 =68±2,
A j — 55±10, A2=113±5 (ub/Sr) for Tit-85 MeV. The
angular distributions show a significant asymmetry
about 90° (C.M.) which is a signature of a mixture of
even and odd partial waves, indicating that part of
this reaction proceeds through non-A absorption 1 ).
O
D. Ashery, Invited Talk, Symposium on DeltaNucleus Dynamics, Argonne, Illinois, 1983
PP32
Three Body Absorption of T T + and TT~ on 3 H e at
TH-65 and 85 MeV. A. ALTMAN, K.A. ANIOL, R.R.
JOHNSON, H.W. ROSER, R. TACIK, W. GYLES, B. BARNETT,
Univ. of B.C., D. ASHERY, M.A. MOINESTER, J. ALSTER,
J. LICHTENSTADT, Tel-Aviv Univ., D.R. GILL,
J. VINCENT, TRIUMF, S. LEVENSON, Northwestern Univ.,
E. PIASETZKY, LASL, R.J. SOBIE, Univ. of Toronto, H.P.
GUBLER, Univ. of Manitoba - The three body part of
plon absorption on 3 H e was measured at bombarding
energies of 65 and 85 MeV for both w + and
This
process, in which all three nucléons share the
absorbed energy, is assumed to be distributed over the
outgoing particles' angles and energies according to
the phase space factor. These factors were obtained
by comparing the cross-sections of the 3-body
absorption along the 3-body line in the Ej.Ej, plane
to the calculated phase space far enough from the 2body kinematics. The results for 65 and 85 MeV are:
0.13+0.01, O.lltO.Ol ub/Sr 2 *MeV respectively for it+,
and 0.07±0.005, 0.06±0.005 (ib/Sr2-MeV for i".
'1' M. Molnester et. al. Submitted to Phys. Rev.
*
Supported in part by the NSERC.
PP30
Coincidence Studies of rr+ Absorption on 3 H e at
T t 65 and 85 MeV* K. ANIOL, A. ALTMAN, H. ROSER, R.
TACIK, R.R. JOHNSON, U. WEINANDS Univ. of British
Columbia, D. GILL, J. VINCENT, TRIUMF, D. ASHERY, J.
ALSTER, M. MOINESTER, Tel-Aviv University - Pion
absorption on 3 H e has been studied using a coincidence
technique. Protons from the quasi-two body absorption
of the
on the proton-neutron pairs in 3 H e were
measured In coincidence. A new cyllndrlcally
symmetric 3 He target was built for this measurement.
We remeasured the 65 MeV data which are reported in
réf. 1. In the earlier data 1 we use the p+d+t+n +
cross-sections for normalization. With the new target
we were able to determine the target thickness by two
Independent techniques. This changed the 65 MeV d o / d n
by about 20%. The preliminary Legendre polynomial
coefficients in ub/sr for the
absorption are; at
65 MeV, A„-1628 ± 54, A2=1838 ± 148, and at 85 MeV
AQ"2130 ± 37, A 2 -2366 ± 95. In addition there is an
overall error of 10% in absolute normalization.
1
*
M. Molnester et al, submitted to Physical Review
Letters.
Supported in part by the NSERC
PP33
The Analyzing Power and Differential CrossSection of the pp-IT+d Reaction at Intermediate
Energies. G.L. GILES, E.G. AULD, G. JONES, G. LOLOS,
B.J. MCPARLAND, W. ZIEGLER; Univ. of British Columbia,
D. OTTEWEL, P.L. WALDEN; TRIUMF, W.R. FALK, Univ. of
Manitoba - The analysing power An() of the pp—ir+d
reaction was measured to statistical precision of
better than 0.01 at incident proton beam energies of
375, 450 and 500 MeV, for center-of-mass angles from
20° to 150°. The polarization dependent differential
cross-sections were fit by associated legendre
functions (using published data for the shapes of the
of the unpolarlzed differential cross-sections. The
no
energy dependence of the resulting b^ coefficients
were compared with existing data and theoretical
expectations. The differential cross-sections were
measured with the same apparatus at energies of 350,
375, 425 and 500 MeV. The results of this analysis
will be presented.
rug
PP34
Low Energy ÏÏ+ Interactions with s-d Shell
Nuclei.* R. TACIK, K.L. ERDMAN, R.R. JOHNSON, H.W.
ROSER, Univ. of British Columbia, D.R. GILL, E.W.
BLACKMORE, TRIUMF, R.J. SOBIE, T.E. DRAKE, Univ. of
Toronto., S. MARTIN, KFA Julich, W. Germany, C.A.
WEIDNER, Max-Planck Institut fur Kernphysik^ W.
Germany - Angular distribution for 50 MeV IT- elastic
and inelastic scattering from 1 2 C , * 8 C and 2 6 Mg have
been measured. The
elastic differential cross
sections for all nuclei have been fit simultaneously
with an optical model calculation. The insights
gained by including, for the first time, ir" data in
such a fit will be discussed. The ÏÏ~ inelastic
differential cross sections for low-lying states in
each nucleus have been fit with a distorted wave
calculation. The ratio of neutron to proton matrix
elements for these states has been extracted, and will
also be discussed.
*
PP36
Monte Carlo Simulation of a Two-step Reaction.
I.M. SZÔGHY, Q. HAIDER and R. 0UELLET, Dept. de Physique,
U. Laval, Quebec, P.Q., GlX "PU - ïhe !'-C+12c system was
1
recently investigated! in the lÔ+^Be
"0+2a channel at
sub-barrier energies. However, the experimental alpha
yields could not be converted into beryllium cross sections in the c.m. system, because for each beryllium atom
the corresponding alphas (i) have a spread in laboratory
energies (up to a factor 2) and angles (up to 20°), (ii)
can be detected as singles or doubles in the plastic detector, (iii) are arbitrarily cut off by the size of the
detector and (iv) are transmitted differently by the mylar absorbers placed to stop the diffused carbon atoms.
A Monte Carlo simulation permitted to overcome these
difficulties and even to include the energy dependence
of cross sections in thick targets, as approximated by
the astrophysical S factor. The method will be discussed
in details, including the art and the pitfalls of random
number generation! by small computers.
!Hunyadi I., Szoghy I.M. and Cujec B., 12 t h Int. Conf.
on Solid State Nucl. Detectors, Acapulco, ed. Espinosa,
in print.
^-Private communications with Prof. Scheiblirig, Strasbourg.
PP35
Differential Cross-Section and Analyzing Power
for 12C(p,TT"t")i:}C at 350 MeV Incident Proton Energy.
W. ZIEGLER, E.G. AULD, P. COUVERT, G. GILES, G. JONES
B. MCPARLAND; Univ. of B.C., R.A. BENT, IUCF, Indiana
Univ., X. Aslanoglou, G.J. L0L0S, I. NAQVI; Univ. of
Reglna, D.F. OTTEWELL, P.L. WALDEN, S. YEN; TRIUMF,
W.R. Falk, Univ. of Manitoba - Theoretical models
presently being developed for the exclusive pion
production reactions are dominated by the A-isobar in
the reaction mechanism. The purpose of this ongoing
experiment is to provide (p,T ) data at an incident
proton energy 350 MeV where the effect of the A
resonance is maximal. To date, the differential
cross-section and analyzing power for the ground state
and 9 . 5 MeV excited state of 1 2 C ( P , T T + ) 1 3 C have been
determined over the angular range from 20° to 80°,
lab, using the MRS on beam line 4B at TRIUMF. The
effective acceptance of the MRS, the efficiency of the
detection system, and the absolute measure of the
Incident proton beam current were determined by
normalizing to the known pp + dTr+ cross-sections. The
data, to date, are presented along with a comparison
with previously obtained data at lower incident proton
energies.
PP37
Radioisotope Activities and Ratios in
Vegetation by Alpha Spectroscopy.* E. LAMOTHE and E.D.
HALLMAN, Dept. of Physics,Laurentian U.- Some species
of vegetation have been shown to be good indicators of
the presence of pollutant elements in the soil and air.
In particular, mosses and lichens can entrap dust
particulates and also incorporate soluble pollutants
and metals from the soil. We have set up an alpha
spectroscopy system to investigate alpha-emitting
radionuclides present in mosses and lichens from
uranium mining, milling, refining and tailings areas.
Typically, a 5 g sample is ashed, digested and eluted
through an exchange column to separate thorium and
uranium fractions. The radioisotopes are electroplated
on to planchets and activities are measured in an
evacuated surface-b arrier detector cell, with counting
times of up to 20 hours. Minimum sample activities of
0.0014 Bq (0.00028 Bq/g) can be measured, corresponding
to 0.023 ppm U-238 for uranium and 0.011 ppm Th-232 for
thorium. Peak energy resolution is near 1%. Of particular interest in the samples are: thorium, uranium
content and sample location dependences, isotope ratios
and activities. Current results will be outlined.
rugi
Author Index/Index des auteurs
A B B A S , I., PD7, PD8
A B E G G , »., PG1Û, PG15
A D A M I D E S , E., PP16
A G A R W A L , A.K., PN7
A H L B O R N , B., PC2, PJ8,
PJ11
A H M A D , S . F . , PK9
A I T H A L , S., PJ 3
A L E X A N D E R , T . K . , PP17
ALI, N., PM17, PM18
A L S T E R , J., PP15, PP30,
PP31, PP32
A L T M A N , A., PP15, PP29,
P P 3 0 , PP31, PP32
A M S L E R , C., PE6, PE7
A N D E R S O N , A., PK4
A N D R E W S , H.R., P P 2 1
A N E D D A , A., PA9
A N G E R , C.D., BE6, BE8
A N I O L , K.A., PD10, P E U ,
P P 7 , PP15, PP29, PP30,
P P 3 1 , PP32
A N S A L D O , E.J., P A 1 9 , PA20
APRIL, G., PN12
A R C O R A G I , J.-P., PP12
A R M E N T R O S , R., PE6, PE7
A R M S T R O N G , D., PP16
A R M S T R O N G , R.L., A A 2 , PM13
A R S E N A U L T , G., PE13
A R S E N A U L T , H.H., PNlO,
PN11, PN12
A S H E R Y , D., P P 1 5 , PP29,
PP 30, PP31, PP 32
A S L A N O G L O U , X., PP35
A S W A T H Y , K., PF21
A U D A S , R.D., PA5
A U L D , E.G., PE6, PE7, PP6,
P P 3 3 , PP35
AXEN, D.A., PE6, PE7
A Z U E L O S , G., PE8, PE10,
PG20, PP4
B A A R T M A N , R., PG13
BABEY, S.K., BE6
B A C H Y N S K I , M.P., EA2
B A D E R , G., PM27
BAER, H., PP4
B A G H E R I , A., P E U
BAILEY, D., PE6, PE7
B A I L E Y , J.M., PA20, PD11,
PD13, PG20
BALDIS, H.A., CD1, PJ10
B A N D R A U K , A.D., BD1
B A R A K A T , M., PK6
B A R L A G , S., PE6, PE7
B A R N E S , C.A., PPI7
B A R N E T T , B.M., PP14, PP15,
P P 2 9 , PP31, PP 32
B A V A R I A , G., PG20
BAYLIS, W.E., PD2
B E A U R E G A R D , A., PN3
B E C K E R , K., PD4, PD5
BEER, G.A., PE6, P E 7 , PP5
B E L A N G E R , P.A., PB4, PB5,
PB8, PB10, PB11
BELL, A.L., PP19
B E N N E T T , A., PG20
BENT, R . A . , PP35
B E R E Z I N , A.A., P A 1 0 , PF18
B E R M A N , B . L . , PP 3
B E R N A R D , J.E., PJ8, PJ9
BERS, A., PC12
B E R T R A N D , L., PB6
B E U K E N S , R . P . , PG7
B E V E R I D G E , J . H . , PA21,
PA23
BHALE, G . L . , PK9
BHATIA, K.S., PK5
B I R C H A L L , J., PG10, PG15
B I R C H A L L , T., PM3
B I R G E N E A U , R.J., A A 1
B I R N B A U M , G., C C 2
B I S W A S , S.C., PN9
BIZOT, J . C . , PE6, PE7
B L A C K F O R D , B.L., PF22
B L A C K M O R E , E.W., PP9, PP34
BLECHER, M., PE10, PG20,
PP 4
B O H I G A S , O . , PE14
B O I V I N , A., PN4
B O I V I N , R., PC5
BOSE, S.K., PM9
B O T M A N , J . I . M . , PG8, PG9
B O U C H A R D , C., BC3
BOUCHER, C . , PC4
B O U D R E A U , R., PM26, PM27
B O U L A N G E R , J . - S . , CE3
BREBNER, J . L . , PA14
BRETON, P., FA3
BREWER, J . H . , AB2, PA18,
PA19, P A 2 0 , P A 2 1 , P D 1 2 ,
PM7
BRICAULT, P., PG2, PP25,
PP26, PP27
B R I T T O N , D.I., PP5
BRODIE, D.E., PA2, PA3,
PA4, PA5
BROOKS, R . L . , PM8
B R O U W E R , W., C F 3
BRUCE, D., PK5
BRUNEL, F., PC6
B R Y A N T , D.A., A E 2
B R Y M A N , D . A . , PE8, PE10,
PG20, PP4
B U H R M A N , R . A . , AC3
BURES, J., FBI
B U R N E T T , N.H., PJ7
B U R N H A M , R . A . , PE10, PG20,
PP4
B U R R O W S , J . R . , BE4
C A I L L E , A., PF3
C A I R N S , E., PG15
C A I R N S , R . A . , PC11
C A L I X T O , S., PN5
C A M E R O N , I.G., PL3, PM6
C A M E R O N , J.M., FC3
C A M M , D.M., CD3
C A N T U , A., PK7
C A R B O T T E , J.P., DA4
C A R E Y , J., PG13
CARIA, M., PE6, PE7
C A R I N S , E., PG10
C A R L O N E , C., PF4
C A R O N , L.G., PL2, PM25,
PM26, PM27
C A S T R A C A N E , J., PC10
C A V E , T., PN14
C E L O T T A , R.J., AD1
CERNY, J., AB1
C E R R I T O , L., PE6, PE7
C H A M P N E S S , C . H . , PA7, PA15,
PA16, PA17
C H A N , A., PA17
C H A N , B.W., PA24
C H A N D R A I A H , G., PK3
C H A N D R A S E K H A R , S., PA1
C H A N G , K.H., PD9, PG6
C H A R B O N N E A U , S., PA6, PA9
C H A T T E R J E E , M.B., PP20
C H E H A B , S., PA24
C H E N , J.K., PA7
C H E N G , C . - Y . , PP16
CHEW, S . H . , PE9
CHIN, S.L., PB3
C L I F F O R D , E.T.H., PE8,
PE10, PG20, PP17
C O C H R A N E , R.W., PA26, PM19
CODE, R.F., PA13
C O G G E R , L.L., BE8, BE10
C O I N V E S T I G A T O R S , W., BE11
C O L E M A N , S.T., PF11
COLLINS, M.F., PF2
C O M Y N , M., PE6, PE7
C O O M B E S , H., PG10, PG15
COREY, G.C., PK2
C O R K U M , P.B., PB1
C O R M I E R , M., PN6
C O U T U R E , J . J . A . , PN1
C O U V E R T , P., PP6, PP35
C R A D D O C K , M.K., PG8, PG9,
PG14
C R A N D L E S , D., PA6
C R E U T Z B E R G , F., PH8
CRINE, J.-P., BC2
C R I P P S , G.R., P A 1 0
C U J E C , B., FC1, PP24
E R D M A N , K.L., PE6, PE7,
PP9, PP14, PP34
E R V E N , C.C., PL7
E S C H T R U T H , P., PE6, PE7
E U T E N E U E R , H., PG18
E V A N S , H.C., PP17, PP18
E V A N S , W.F.J., BF1
EWAN, G.T., PP17, PP18
FALK, W.R., PP33, P P 3 5
F A U C H E R , G., C F 2
F A W C E T T , E., C F 1 , PF15
F E D O S E J E V S , R., PC13, PJ12,
PK13
F I L I O N , A., PL2, PL4
FILUK, A., PC2
F O R A N D , L., PD5
FORTIN, E., PA6, PA8, PA9
F R A N K , A.J., C A 2
F R A N K , G.W., BE2
FRY, C.A., P D 1 1 , PD13
FUCHS, V., PC11, PC12
D E L B I A N C O , W., PP1
D E L C O U R T , B., PE6, PE7
D E L E T T R E Z , J., PJ1
DELHEIJ, P., PG11
D E L I S L E , C., FB2
DEMERS, Y., PC10
DENES, G., PF17, PM3
D E P O M M I E R , P., PE10, PG20
D E S L A N D E S , J., PF5
D E S L A U R I E R S , J., AC2
DESTRY, J., PM19
DIXIT, M.S., PE8, PE10,
PG20
DIXON, A.E., PAll, PA12
D O H A N , D., PG13
D O L E S C H A L L , P., PP26
DOMEY, J., FB3
D O O R N B O S , J., PA21, PA22,
PA23, PG12
DOSER, M., PE6, PE7
D R A K E , T.E., PP9, PP14,
PP22, PP34
D U G A N , C . H . , PB13
D U L E Y , W.W., PK5
D U N L A P , R.A., PA25
DUTTA, A.K., PP12
DUTTO, G., PG13
G A G N E , J . - M . , BD2
G A G N O N , R., PE3, PE4
G A L A R N E A U , P., PB3
G A L I N D O - U R I B A R R I , A., PD9,
PG6
G A R N E R , D.M., PA23
GASCON, J., PP21
G A S T A L D I , U., PE6, PE7
G A T T I N G E R , R.L., BE7
G A U L I N , B.D., PF2
G A U L T , W.A., PH4
G A U T H I E R , N., PF19, PM22
G A U T H I E R , R . C . , PN15
G A Y D O S , J., PP22
GILES, G.L., PP6, PP33,
PP35
GILL, D.R. , PP6, PP9, PP14,
PP15, PP22, PP29, PP30,
PP31, PP32, PP34
G X L L A R D , P.G., PK10
G I R O U A R D , F.E., PM20
G I R O U X , J., PG3
G L O S L I , J., PF7
GLYDE, H.R., PF12, PF23
G O D F R E Y , S.P., PE1
GORE, J.V., P C I
GOTOW, K., P E 1 0 , PG20, PP4
G R A F F , G., PE6, PE7
G R A H A M , J . T . , PF14
G R E E N , P.W., PG10, PG15
G R E E N I A U S , L.G., PG10,
PG15
GREGORY, B.C., PC5
G R I F F I N , A., FA2
G R O V E R , C . P . , PN7
GRUNO, R.S., PCI
GU, X . J . , PA13
GUBLER, H.P., PG10, P G 1 5 ,
PP15, PP29, PP31, PP32
G U M H A L T E R , B., PK1
G U M P L I N G E R , P., PE9, PP8
G U P T A , R . C . , PG9
GURD, D., PG13
G U R V I T Z , S.A., PE12
G U Y E R , R.A., CB4
G Y L E S , W., PP14, PP15,
PP29, PP31, PP32
EARLE, E.D., F C 2
E G E L S T A F F , P.A., A A 4
EL R A H M A N , A.A., PM16
E N R I G H T , G . D . , PJ7
E N T E Z A M I , F., PD10, P E U ,
PP7
HAHN, J.F., PB13
HAIDER, Q., PP36
H A L L M A N , E . D . , PP37
HALPERIN, B.I., PF9
HANES, G.R., C E 4
HAQ, R.U., PE14
D'IORIO, M., C E 2
DA S I L V A , L., PJ11, PJ13
DAGG, I.R., PK4
DAHME, W., PE6, PE7
DAHN, J.R., PF10, PF11
D A M A S K I N O S , S., PA11
D A N D O L O F F , R., PF24
D A S M A H A P A T R A , B., PP24
DASSEN, H.W., PD4
DATARS, W.R., PM16
DAUTET, H., PP10
D A V I D S O N , W.F., PP1
D A V I S , C.A., PG10, PG15
D A V I S O N , N.E., PG10, PG15
DE T A K A C S Y , N., PP22
DECKER, R . B . , BEI
DECOSTE, R., PC8, PC9, PJ3,
PJ6
rug
HARDY, J.C., DA3
HARDY, W.N., CE6, DA2
HARGROVE, C.K., PEXO, PG20,
PP 4
HARRISON, J.P., BAI, PM5
HARSHMAN, D.R., PA18, PA19,
PA20, PD11
HARTEN, L., PC12
HASEGAWA, A., AE 3
HASINOFF, M.D., PE9, PE10,
PE11, PG20, PP4, PP7,
PP8
HASLETT, J.W., BE6
HAUSSER, O., PP21
HEALEY, D., PG11
HEEL, M., PE6, PE7
HENRIKSON, A., PP16
HERNADI, S.I., PF23
HEWAK, D.W., PN13
HIRD, B., PD7, PD8
HIROSE, A., FD1, PC7
HOFF, R.M., PL5
HOLDSWORTH, D.W., PG19
HOLMES, J.K., PD6
HOPPER, M.A., BC1
HORVATH, D., PD10, PP7
HOTA, N.K., PF4
HOUDE, D., PM1
HOUTMAN, H., PJ8, PJ9
HOWARD, B., PE6, PE7
HOWARD, R., PE6, PE7
HUANG, C.Y., PA19
HUBER, G., PP6
HUGHES, T.J., BE4
HUGON, D., PN14
HUNT, J.L., PM8
HUO, Y.S., PA13
HUTCHISON, T.S., PF20
HUTT, D., PA25
HYODO, T., PM24
ILOWSKI, J.J., PA10
INCH, R., PL3
INGLIS, A.D., PF8
ISENOR, N.R., PD1
ISGUR, N., BB2, EA1,
PE2
PE1,
JAFFE, R.L., BB4
JAMES, H.G., BE3, FD3, PCI
JAMROZ, W., PN14
JANDL, S., PF5, PM1
JEANJEAN, J., PE6, PE7
JENNINGS, B.K., PE5, PP22
JEROMINEK, H., PB2, PB7
JOHNSON, B., BA2
JOHNSON, R.R., PP9, PP14,
PP15, PP 22, PP29, PP 30,
PP31, PP 32, PP34
JOHNSTON, T.W., PJ1, PJ2,
PJ3, PJ5
JONES, A.V., BE7
JONES, G., PP6, PP33, PP 35
JONES, S., PD10
JOOS, B., PF7
JOSHI, Y.N., PK6, PK7
JURY, J.W., PP3
KAJRYS, G., PP1
KALINOWSKY, H., PE6, PE7
KALLIN, C., PF9
KAYSER, F., PE6, PE7
KEITEL, R., PA20, PD11
KEITH, D.W., PB1
KENNETT, T.J., PP2
KIEFFER, J.-C., PJ6
KIEFL, R.F., PD13
KIESER, W.E., PG7
KILIUS, L.R., PD9, PG5,
PG6
KIM, S.M., PM21
KING, G.C., PD3
KIRKBY, P., AC4, PL7
KITCHING, P., PE8
KLASSEN, G.A., BE6, PN16
KLEMPT, E., PE6, PE7
KNYSTAUTAS, E.J., PK8, PL6
KOEHLER, R.A., PH5
KOKOSKI, R., PE2
KOSAKI, M., PP1
KOSTER, E., PA18
KOVAR, G., PB5, PB11
KOZLOWSKI, G., PM18
KREITZMAN, S.R., PA18,
PA21i PM7
KRIMIGIS, S.M., AE1, BEI
KROEGER, H., PP23, PP26
KUNSELMAN, A.R., PP5
KUNSTATTER, G., CB1
KWAN, S.P., PP17, PP18
LABERGE, M., PB4
LABRIE, J.-P., PG18
LACHAMBRE, J.L., PC8
LAFRAMBOISE, J.G., PH5
LAHLOU, F., PP24
LAMARCHE, G., PA24
LAMOTHE, E., PP37
LAMOUREUX, G., PG4
LANDAU, R., PE6, PE7
LANGLOIS, J.M., PL2
LANGLOIS, P., PN4
LAPIERRE, J., FBI
LAROCQUE, P.E., PK11
LAROUCHE, D., PB11
LASHMORE-DAVIES, C.N.,
PC11
LATTA, B.M., PP13
LAVIGNE, P., PB9, PJ3, PJ4,
PJ6
LAXDAL, R.E., PG14
LEAHY, D.A., PH10
LEBOEUF, J.N., PC6
LECKIE, B.M., BE6
LECLERC, G., PM28
LECOMTE, R., PG4
LEE, H.W., PD9, PG5, PG6
LEE, W.P., PG10, PG15
LEGAULT, R., PA26
LEITCH, M.J., PE10, PP4
LEMIEUX, M.-A., FA3
LEONELLI, R., PA14
LEPINE, Y., PM10
LESLIE, J.R., PP17, PP18
LESSARD, L., PG20
LESSARD, R.A., PNI, PN2,
PN3, PN4, PN5, PN8
LEVENSON, S., PP15, PP29,
PP31, PP32
LEVESQUE, M., PN10
LEVY, P., PG17
LEWANDOWSKI, J., PN6
LI, D.H., PM11, PM12
LI, X.R., PM11
LI, Y., PN17
LIBCHABER, J.A., FA1
LICHTENSTADT, J., PP15,
PP29, PP31, PP 32
LIGHTSTONE, A., PG4
LIM, D., PA25
LINK, R., PHI
LIPSON, R.H., PK11
LIT, J.W.Y., PN13, PN17
LITHERLAND, A.E., PD9, PG5,
PG6
LIU, W.-K., PKI, PK2
LOCKE, J.L., CCI
LOEWEN, L., PC 2
LOLOS, G.J., PP6, PP 33,
PP35
LONE, M. A . , PP16
LONG, K.S., PH10
LOUTFY, R., CA3
LOWE, R.P., PG1
LUDGATE, G.A., PD13
MA, X.X., PB3
MACARTHUR, J.D., PP17,
PP18
MACDONALD, J.A., PE8, PE10,
PG20
MACDOUGALL, J., PH6
MACKENZIE, G.H., PG13,
PG14
M A C T A V I S H , J.C., PL3, PM14
M A H A J A N , S.M., PC6
MAK, H.-B., PP17, PP18,
PP19
MALIEPAARD, M., PM5
M A N O O G I A N , A., PA24
MANUEL, A.A., PM24
MARCHAND, M., PF3
M A R C H A N D , R., PC13
MARCHILDON, L., PE13
MARK, S.K., PP10, PP11
MARSHALL, G.M., PD13, PE6,
PE7
MARSOLAIS, R.M., PM25
M A R T I N , F., PJ 3, PJ4
MARTIN, J.-P., PE10, PG20
MARTIN, S., PP9, PP14,
PP34
MARTINUZZI, S., ?A1
MARTOFF, C., PE6, PE7
MASON, G.R., PP5
MATTE, J.P., PJ1
MAY, A.D., PN14
MCALISTER, S.P., PF8
MCCARTHY, N., PB9
MCCONKEY, J.W., PD3, PD4,
PD5
MCCRORY, R.L., PJ1
MCDONALD, A.B., PP17
MCDONALD, M., PG17
MCDONALD, W.J., PG15
MCEWEN, D.J., PH7, PH8
MCINTOSH, G., PJ8, PJ9,
PJ11
MCINTYRE, R.J., PG4
MCKELLAR, A.R.W., DA1,
PK12
MCKEN, D.C.D., PJ12, PK13
MCKEOWN, J., PG18
MCKINNON, W.R., PF10, PF11
MCLATCHIE, W., PP17, PP18
M C N A M A R A , A.G., PH2
MCNEILL, K.G., PP 3
MCPARLAND, B.J., PP6, PP33,
PP35
MEASDAY, D.F., PD10, PE11
MEIKLE, S., PA6
MERIWETHER, J.W., BE10
MES, H., PG20, PP 4
MESS, H., PE10
MEYER, J., PJ8, PJ9
MICHAUD, M., AD3
MIGDALEK, J., PD2
MIJNARENDS, P.E., PM24
MILLER, C.A., PG10, PG15
MITARAI, O., PC7
MITCHEL, G.R., PJ2
MOINESTER, M.A., PP4, PP15,
PP 29 , PP 30, PP 31, PP 32
MOLEKO, L.K., PF12
MONGEAU, B., PN6
MOODY, R.V., CB2
MOORCROFT, D.R., BE2, BE5
MOORE, C.J.L., PA5
MOORE, R.A., PM12
MOREAU, C., PL6
MOREAU, J.-P., PK8
MORGAN, F.J., PB13, PG1
MOSS, G.A., PG10, PG15
MUIR, C., PF15
MUKHERJEE, B.K., PF21
MULERA, T., PE9, PP8
MURPHREE, J.S., BE8, BE10
MURRAY, D.B., PF6, PF7
NACHABE, A.M., PP23, PP25,
PP26, PP27
NAGUIB, H.M., AC 1
NAQVI, I., PP35
NARANAN, S., PH10
NATAREN, F.Z., PA1
NAVON, I., PE10, PP 4
NENCIONI, A., PK7
NG, A., PJ13
NGUYEN, N., PE6, PE7
NICKEL, B., CB3
NOAKES, D.R., PA19
NOIRHOMME, B., PL2, PL4
NOWAK, A., PP1
NUMAO, T., PE8, PE10, PG20,
PP4, PP5
OBERLI, L., PM24
OFFENBERGER, A.A., PJ12,
PK13
OLIN, A., PD13, PE8, PP5
OLIVER, B.A., PA12
ORAM, C.J., FC4, PD13
OTTEWELL, D.F., PP6, PP33,
PP 35
OUELLET, R., PP34
OXORN, K., PP11
PAGE, J.H., PF14, PM5
PAGE, S.A., PP17, PP18
PALMADESSO, P., AE4
PANDEY, A., PE14
PANNETIER, J., PM3
PAPANDREOU, Z., PP6
PARE, C., PB10
PARFENIUK, D., PJ11, PJ13
PASCALE, D., PJ 3, PJ6
PATERA, J., CB2
PATON, B.E., PN15, PN16
PAUL, D.A.L., CF4, PG19
PEARCE, D., PG13
PEARSON, J.M., PP12
PELLETIER, D., PM20
PEPIN, H., PJ3
PERLUZZO, G., PM26, PM29
PETER, M., PM24
PIASETZKY, E., PP15, PP29,
PP31, PP32
PICHE, M., PB5, PB10, PBll,
PB12
PINTAR, M.M., PL3, PM6,
PM14, PM15
PLATTNER, G.R., PG10, PG15
POFFENBERGER, P.R., PG10,
PG15, PP5
POIRIER, R., PG13
POLL, J.D., PM8, PM9
POMERLEAU, J.Y.D., PB2,
PB7
POPIL, R., PJ8, PJ9
POTVIN, L., PP25, PP27
POULIOT, J., PP25, PP26,
PP27, PP28
POUTISSOU, J.-M., PE8, PE9,
PE10, PE11, PG20, PP4,
PP8
POUTISSOU, R., PE10, PG20,
PP 4
PRATO, F., PL3
PRESTWICH, W.V., PP2
PROVENCHER, P.-P., PP25,
PP28
PRUNEAU, C., PP20
PURCELL, C.J., PF22
PYWELL, R.E., PP 3
QUANG, N.V., PAIS
RABOU, L.P.L.M., PM24
RACEY, T.J., PM22
RAHMAN, F., PD7, PD8
RAMBO, A., PL4
RANGACHARYULU, C., PP20
R A N G A R A J A N , G., PF21
READ, L.A.A., PK4
REDDEN, P.W., PL7
REDDY, S.P., PK9, PK10
RICHARDSON, J.R., PG14
RIEDELBERGER, J., PE6, PE7
RIOUX, M., FB3
ROBERGE, P.C., PN8
ROBERTSON, B.C., PD10, PE9,
PE11, PP7, PP8, PP16
ROBERTSON, L.P., PE6, PE7
ROCHON, P., PF19, PM22
ROJEK, A., PM18
ROSE, G.S., PG1
ROSER, H.W., PP7, PP9,
PP14, PP15, PP 29, PP30,
PP 31, PP 32, PP34
ROSS, G.G., PM23
ROTH, A.P., PA6
ROUBI, L., PF4
ROUSSET, G., PB6
ROY, G., PG10, PG15
rugi
ROY, R., P P 2 5 , PP26, PP27,
PP28
R U C K L I D G E , J . C . , PG5, PG7
R U E B E N B A U E R , K., PM3, PM4
R U O H O N I E M X , J . M . , BE5
R U P P R E C H T , A., PM14
R Y A B T S E V , A.N., PK6
S A B B A G H , J., PJ4
S A B E V , C., PE6, PE7
SArtA, S.K., PP16
S A L O M O N , M., PD10, P E U ,
PE12, PG16, PP8
S A N C H E , L., AD3, P M 2 5 ,
P M 2 6 , PM28, PM29
S C H A F E R , U., PE6, PE7
S C H L A T T E R , P., PE8, PE10,
PG20, PP4
S C H M I T T , D., PG4
S C H M O R , P.W., PD13, PG13,
PG17
S C H N E I D E R , R., PE6, PE7
S C H R E I B E R , 0 . , PE6, PE7
S C H R E I N E R , L.J., PM14,
PM15
S E K A , W., F0 2
SENBA, M., PA20
S E Z E R M A N , O., PN16
S H A H I D I , A.V., PA16
S H E P H E R D , G . G . , BE9, BE11,
PHI, PH4
S H E R M A N , N.K., P P I
S H I H , I., PA15, PA16
SHOR, A . F . , PE9
S H O U C R I , M.M., P C 1 1
S I M A R D , M . - A . , PE4
SINGH, M., PM13
SINHA, B.K., P P 2 5 , PP26,
PP27, PP28
S I R C A R , P., P L I
S K A R S G A R D , H.M., P C 7
S K E N S V E D , P., P P 1 7 , P P 1 8 ,
PP19
SLATER, G . W . , P M 2
S L O B O D R I A N , R . J . , PG2, PG3,
PP23, PP25, PP26, PP27,
PP28
S M I T H , J., PD10
SMITH, W., PK4
SOBIE, R . J . , PP9, PP14,
PP15, PP22, PP29, PP31,
PP32, PP34
SOBOL, W.T., PL3, PM6,
PM15
S O L A N O , C., PN8
SONG, L., PN2
S O U K U P , J . , P G 1 0 , PG15
S P U L L Ë R , J . E . , PE10, PP4
S R I N I V A S A N , R., PF21
S T - P I E R R E , C., PP20
S T A I R S , D . G . , BB1
S T A N S F I E L D , B.L., CD2, PC3
S T A T T , B.W., BA3
S T E E L E , D . P . , PH7
S T E I N I T Z , M.O., PF13
S T E T Z , A.W., PE9, PP8
S T E V E N S O N , R.L., PP19
S T E W A R T , A.T., PM24
S T O I C H E F F , B.P., PK11
S T R A U M A N N , U., PE6, PE7
S T R O I N K , G., PA25, PF22
S T U R T E V A N T , T . E . W . , PA2,
PA4
SULAK, L., BB3
S U T T O N , M., A A 3
SVENNE, J . P . , PGIO,
SZOGHY, I.M., PP36
SZOPLIK, T., PN11
PG15
T A C I K , R., PP9, PP14, PP15,
PP22, PP29, P P 3 0 , PP31,
PP32, PP34
T A R A S , P., PP21
T E R R E A U L T , B., PM23
T E T U , M., CES
T H O M A S , A . W . , PE5
T H O M A S , R., CAl
T H O M P S O N , M.N., PP3
T I N D A L L , D.A., PF13
T K A C H U K , R., PGIO, PG15
T O M O V , I.V., PC13, PK13
T O W N S E N D , M.G., PF1
T R A J M A R , S., AD2
T R E M B L A Y , A.-M., FA3
T R E M B L A Y , R., PB2, PB7
T R I C K E Y , J.D., BE4
T R U D E A U , M., PM19
T R U O L , P., PE6, PE7
T R U O N G , V.V., PM20
TSAI, J.-S., PP2
T S E L E P I S , E., PA8
T U R C O T T E , R., PP10
T U S Z Y N S K I , J.A., PF16
VAN A L L E N , J . A . , BEI
VAN A U D E N H O V E , G., PD6
VAN K R A N E N D O N K , J., CC3
VAN O E R S , W . T . H . , PGIO,
PG15
V A N K L E E F , T . A . M . , PK6, PK7
V A R G A , L., BE8
VEIT, E.A., PE5
V E N K A T E S A N , D., BEI, BE8,
PH10
V I L L E N E U V E , D.M., PJ10
VILLENEUVE, J . - E . , PN9
V I N C E N T , J., PP15, PP29,
PP30, PP31, PP32
VIRMONT, J., PJ1
VIRTUE, C.J., PD10, PE9,
PP7
VITALI, J . C . A . , PC3
VON S A C K E N , U., PA3
W A D D I N G T O N , J.C.,
W A G N E R , G., PD1
WAIT, G., PG11
PM8
W A L D E N , P.L., PP6, PP33,
PP35
W A L L B A N K , B., PD6
W A L S H , C . J . , PJ10
W A L T H A M , C.E., PE9, PP8
W A N , P.T., PA10
W A N G , S., PMll, PM12
W A N G , S.-S., PP16, P P 1 7 ,
PP18
W A R D , D., PP21
W A R R E N , J . B . , PD11, PD13
W A T A N A B E , T., PH9
WEIDNER, C.A., PP34
W E I N A N D S , U., PP30
W E I N G A R T S H O F E R , A., PD6
W E S T E R V E L D , W.B., PD3
WHALEN, B.A., PH3
WHITE, B.L., PE6, PE7
W H I T E H E A D , L., BC4
W I E D E R I C K , H.D., PF20
WIEDNER, C . A . , PP9, PP14
WIENS, R.H., BE9, PH4
W I L L I A M S , D.L., PA18
WILSON, G.C., PG5, PG7
WODRICH, R., PE6, PE7
WOLFE, S.W., PC7
WONG, S.S.M., PP11
WOOD, B.W., C E I
WOODS, S.B., PM17, PM18
W O O D W O R T H , J . G . , PP3
WOOLLEY, J . C . , PA24
W R I G H T , L.S., PF20
YAN, S., PK4
YAU, A . W . , PHI,
YEN, S., PP35
PH3
ZACH, M., PG14
ZAUHAR, J., PF4
ZETNER, P.W., PD3
ZHANG, Y.P., PGIO, PG15
ZIEGLER, W., PP6, PP33,
PP35
NOTES
DEPARTMENT OF PHYSICS
QUEEN'S UNIVERSITY
POSTDOCTORAL POSITION IN
LIQUID STRUCTURE RESEARCH
U N I V E R S I T Y OF G U E L P H
Applications are invited for a position at the Assistant Professor level. The position requires a Ph.D., research
experience in an area related to the research activities of
the Department, and some teaching experience. The
Department is active in research in the areas of nuclear
physics, applied and engineering physics, astronomy and
astrophysics, and condensed matter and low temperature
physics. Experimental and theoretical programs are being
pursued in these areas.
This replacement position is available for a three year term
from September 1, 1984 and applications are invited until
the position is filled. Opportunities may exist for continuation of the position through, for example, application for an
NSERC University Research Fellowship by suitably qualified
candidates or through research funding Salary will be
negotiable: the current Assistant Professor floor is $24,250.
In accordance w i t h Canadian immigration regulations
Canadian citizens and permanent residents will be given
preference in making this appointment and candidates of
either sex are equally encouraged to apply.
Applications, including a curriculum vitae and the names of
three referees, should be sent to:
Dr. H.J. Wintle, Chairman of the
Search Committee,
Department of Physics,
Queen's University,
Kingston, Ontario, Canada
K7L 3 N 6
ISOTRACE LABORATORY
UNIVERSITY OF TORONTO
RESEARCH ASSOCIATE
POSITION
A p p l i c a t i o n s are i n v i t e d f o r t h e p o s i t i o n of R e s e a r c h
Associate to work on problems connected w i t h ultras e n s i t i v e i s o t o p i c a n a l y s i s of g e o l o g i c a l m a t e r i a l s .
A p p l i c a n t s s h o u l d h a v e P h D a n d at least t w o y e a r s
p o s t - d o c t o r a l e x p e r i e n c e in t h e field of ion m i c r o p r o b e
techniques applied to geochemistry and materials
science. A f a m i l i a r i t y w i t h n u c l e a r p h y s i c s (especially
a c c e l e r a t o r m a s s s p e c t r o m e t r y ) t e c h n i q u e s is h i g h l y
desirable.
T h e p o s i t i o n w i l l b e c o m e a v a i l a b l e in S e p t e m b e r
1 9 8 4 , at $ 1 9 , 0 0 0 p a. or up t o t h e m a x i m u m a l l o w e d
by NSERC g r a n t r e g u l a t i o n s . In a c c o r d a n c e w i t h
Canadian immigration requirements, this advertisem e n t is d i r e c t e d t o C a n a d i a n c i t i z e n s a n d p e r m a n e n t
residents. Applications, w i t h c u r r i c u l u m vitae and
l e t t e r s f r o m t w o r e f e r e e s , s h o u l d be s e n t , b e f o r e
J u n e 18, 1 9 8 4 , to:
Dr. J . C . Rucklidge,
IsoTrace Laboratory,
University of T o r o n t o ,
6 0 St George St,
Toronto, Ontario
CANADA, M5S 1A7
T h e l i q u i d s t r u c t u r e g r o u p in t h e P h y s i c s D e p a r t m e n t
is s e e k i n g a P o s t d o c t o r a l R e s e a r c h F e l l o w t o w o r k in
t h e a r e a of s t r u c t u r e a n d d y n a m i c s of g a s e s a n d
liquids. Current programs include m e a s u r e m e n t s
a n d s i m u l a t i o n of t h e d y n a m i c s of d e n s e n o b l e g a s e s
a n d of L o r e n t z gas m o d e l s y s t e m s , s t r u c t u r a l m e a s u r e m e n t s on water and other molecular liquids, and
t h e s t r u c t u r e of w a t e r at t h e clay i n t e r f a c e . A s w e l l
as o p e r a t i n g t w o n e u t r o n d i f f r a c t o m e t e r s at
M c M a s t e r University and Chalk River N u c l e a r
L a b o r a t o r i e s , t h e g r o u p has a n X - r a y d i f f r a c t o m e t e r
a n d is p i o n e e r i n g t h e d e v e l o p m e n t of a l i q u i d s
Gamma-ray diffractometer. Occasional trips to major
f a c i l i t i e s in t h e U.S. a n d E u r o p e are a l s o m a d e . T h e
a p p l i c a n t s h o u l d h a v e a r e c e n t Ph.D. i n e x p e r i m e n t a l
physics or c h e m i s t r y or a related d i s c i p l i n e a n d s h o u l d
be c o n v e r s a n t in c o m p u t e r p r o g r a m m i n g .
Please s e n d a p p l i c a t i o n s , i n c l u d i n g
n a m e s of at least t w o r e f e r e e s to:
resume
and
P A . Egelstaff or A . K . S o p e r
D e p a r t m e n t of Physics
University of G u e l p h
Guelph, Ontario
Canada
N1G 2W1
UNIVERSITY OF BRITISH
COLUMBIA
Postdoctoral and Research Associate
Positions
Intermediate Energy Physics
Postdoctoral and Research Associate positions are available
for experimental physics w i t h the University of British
Columbia groups at the TRIUMF 500 MeV cyclotron. Candidates should have experience in a relevant field of physics
and have completed a Ph.D. in nuclear or particle physics
within the past two years. Graduate students expecting to
complete their degrees within the next few months are also
invited to apply.
These appointments can be renewed annually (subject to
the usual budgetary confirmation) up to a maximum period
of three years. Salary will depend on experience, w i t h a
minimum of $22,000 per annum.
Curriculum vitae, list of publications and names of three
referees should be forwarded as soon as possible to:
Dr. G. Jones
Department of Physics
University of British Columbia
6 2 2 4 Agriculture Road
University Campus
Vancouver, B.C. Canada
V6T 2A6
In accordance with Canadian immigration requirements,
priority will be given to Canadian citizens and permanent
residents of Canada. This advertisement is valid for a two
year period.
1+
National Research
Council C a n a d a
Conseil national
de recherches Canada
Chercheurs Scientifiques
Research Scientists
H i g h E n e r g y Physics
The National Research Council of Canada invites applications for several Research Scientist term positions with
its experimental High Energy Physics group. These positions are initially for two years with a possibility of renewal.
The NRCC group is based in Ottawa, Canada and works
in association with Carleton University. The OPAL project
at LEP (an international collaboration in agreement with
CERN) is the main effort of the group and the successful
candidates would be required to concentrate on it. The
group is also involved in the TPC at TRIUMF and the Tagged
Photon Spectrometer at Fermilab. This effort requires
that the successful candidates spend some time at these
accelerator laboratories.
Applicants should have a doctorate in particle physics
or nuclear physics with experience in particle physics
techniques.
Salary: Commensurate with qualifications.
Apply in writing to the Employment Officer, National
Research Council of Canada, Ottawa (Ontario), Canada,
K1A 0R6. In reply, please quote P-84-1/4-PC.
en physique des hautes énergies
Le Conseil national de recherches du Canada sollicite les
mises en candidature à un certain nombre de postes de
chercheurs scientifiques, d'une durée limitée, au sein du
groupe expérimental de la Physique des hautes énergies.
Ces postes sont pour une période initiale de deux ans avec
possibilité de renouvellement.
Ce groupe du CNRC travaille à Ottawa (Canada) en
collaboration avec l'Université Carleton. Le projet OPAL
du LEP (une collaboration internationale convenue avec
le CERN) constitue la principale entreprise de ce groupe
et les candidat(e)s reçu(e)s seront appelé(e)s à axer leurs
efforts sur ce projet. Le Groupe étudie également le TPC
au centre TRIUMF et le spectromètre pour les photons
marqués à Fermilab. Dans le cadre de cette initiative, les
candidat(e)s retenu(e)s devront travailler quelque temps
dans les laboratoires des accélérateurs.
Les candidat(e)s doivent avoir un doctorat en
physique des particules ou en physique nucléaire
et avoir de l'expérience des techniques de la physique
des particules.
Traitement: selon la formation et l'expérience.
Prière d'adresser un c u r r i c u l u m
complet à l'Agent d'emploi, Conseil
national de recherches du Canada.
Ottawa (Ontario), Canada, K1A
0R6. Veuillez donner la référence
P-84-1/4-PC.
APPLICATIONS ARE INVITED
for a
POST-DOCTORAL FELLOWSHIP or
RESEARCH ASSOCIATESHIP
in
ASTROPHYSICS
at the University of Alberta in Edmonton
A n i m m e d i a t e v a c a n c y e x i s t s in t h e l a b o r a t o r y
a s t r o p h y s i c s g r o u p of t h e P h y s i c s D e p a r t m e n t at t h e
U n i v e r s i t y of A l b e r t a for a p o s t - d o c t o r a l f e l l o w or
r e s e a r c h a s s o c i a t e t o w o r k in t h e a r e a of e l e m e n t a l
a b u n d a n c e s in astronomical
objects. The
successful
c a n d i d a t e w i l l be e x p e c t e d t o w o r k in c l o s e c o l l a b o r a t i o n w i t h l a b o r a t o r y a s t r o p h y s i c i s t s e n g a g e d in t h e
m e a s u r e m e n t of o s c i l l a t o r s t r e n g t h s f o r a t o m i c
t r a n s i t i o n s , w i t h a v i e w t o t h e a p p l i c a t i o n of laboratory
m e a s u r e m e n t s t o c u r r e n t p r o b l e m s in a s t r o n o m y .
Interested candidates should send their curriculum
vitae, a s t a t e m e n t of r e s e a r c h i n t e r e s t s a n d t h e
n a m e s of t h r e e r e f e r e e s to:
Dr. E . H . P i n n i n g t o n
Physics D e p a r t m e n t
U n i v e r s i t y of A l b e r t a
E D M O N T O N . Alberta
T6G 2J1
Canada
T h e level of t h e a p p o i n t m e n t w i l l d e p e n d o n t h e
q u a l i f i c a t i o n s a n d e x p e r i e n c e of t h e s u c c e s s f u l
a p p l i c a t i o n , b u t t h e s a l a r y w o u l d be at least $ 1 9 , 0 0 0
per a n n u m .
McMASTER
UNIVERSITY
POST DOCTORAL FELLOWSHIPS
TEACHING FELLOWSHIPS
RESEARCH ASSOCIATESHIPS
A N D GRADUATE ASSISTANTSHIPS
Applications are invited for post doctoral fellowships,
teaching fellowships, research associateships and graduate assistantships in the Physics Department Areas of
research include theoretical physics, solid state physics,
nuclear physics, quantum optics, mass spectrometry,
chemical physics and astrophysics Experimental research
at McMaster features a tandem accelerator, a swimmingpool reactor and the Institute for Materials Research.
Applications for post doctoral fellowships, teaching fellowships and research associateships should include curriculum
vitae and the names of three referees.
Applicants for graduate assistantships should write for
further information. Write :
Dr. C.V. Stager
Chairman, Department of Physics
McMaster University
Hamilton, Ontario L8S 4 M 1
rugi
RESEARCH ASSOCIATE
Qualifications: Electromagnetic geophysicist w i t h Ph D
degree to work in two- or three-dimensional finite difference
modelling of conductive structures in the Earth, for interpretation of magnetovariation and magnetotelluric field
data Experience in numerical solution of such problems is
necessary. The successful candidate should also be prepared to participate in field work with magnetometer arrays.
2 kV : 2 mA
POWER SUPPLY
Salary: The salary will be in the $24,000 range depending
on qualifications. A fringe benefits package including group
life, disability, health and dental insurance is available.
Employment Date: The appointment will be for a minimum of three years, and may be extended by mutual agreement, depending on availability of funds. The commencing
date is 01 March 1985.
Interested candidates should submit a complete curriculum
vitae, including the names of three (3) referees, by 15 June
1984 to:
NEG
Professor D.I. Gough
Department of Physics
Edmonton, Alberta
T6G 2J1
•
Ph. (403) 4 3 2 - 3 0 4 1
The University is an equal opportunity employer but in
accordance w i t h Canadian immigration requirements, this
advertisement is directed at Canadian citizens and
permanent residents.
»
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ÉCOLE P O L Y T E C H N I Q U E
DE M O N T R É A L
Model 255
$840.00
BOURSIER POST-DOCTORAL
POSTDOCTORATE FELLOWSHIP
(Génie physique)
m
Le group de recherches en spectroscopie moléculaire et
techniques photoacoustiques du département de Génie
physique de l'École Polytechnique de Montréal est à la
recherche d'un boursier post-doctoral.
QUALIFICATIONS
Le candidat doit avoir une expérience récente (Ph D. ou
diplôme équivalent) en optique et notamment en spectroscopie moléculaire. Une connaissance en techniques
photoacoustiques est souhaitable.
• Single Width NIM
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DURÉE DE L'EMPLOI
L'emploi, d'une durée minimale d'un an, débutera en
septembre 1984.
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Protected
fllechTronics
N U C
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Mississauga. Ontario
L5N 2 8 8
Les candidats doivent transmettre leur curriculum vitae et
le nom de deux références avant le 15 juin 1984.
Service du personnel
École Polytechnique de Montréal
C.P. 6 0 7 9 , Succursale " A "
Montréal (Québec)
H3C 3 A 7
A R
Technical Marketing
Associates Limited
Head Office
6620 Kifimat Road
Unit 6
TRAITEMENT
Le salaire sera déterminé selon les qualifications du candidat et la politique salariale en vigueur à l'École Polytechnique.
y
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TIMING
SCA
UNIVERSITY OF ALBERTA
Plasma Physics Group
Department of Electrical Engineering
A p p l i c a t i o n s are i n v i t e d for a R e s e a r c h A s s o c i a t e in
a n a l y t i c a l a n d n u m e r i c a l s i m u l a t i o n s t u d i e s of f u s i o n
r e l a t e d C0 2 a n d KrF l a s e r - p l a s m a i n t e r a c t i o n e x p e r i m e n t s . S a l a r y for t h i s p o s i t i o n is in t h e r a n g e $ 2 5 , 0 0 0
t o 3 0 , 0 0 0 per year. A d d i t i o n a l f u n d i n g m a y be
a v a i l a b l e for t e a c h i n g up to 2 h a l f - c o u r s e s / y e a r
S e n d c u r r i c u l u m v i t a e a n d t h e n a m e s of t h r e e
r e f e r e n c e s to:
5.
is a n e q u a l
WINDOW
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Professor C . E . C a p j a c k
D e p a r t m e n t of Electrical E n g i n e e r i n g
U n i v e r s i t y of A l b e r t a
E D M O N T O N . Alberta
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T h e U n i v e r s i t y of A l b e r t a
employer
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€
opportunity
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University
Model 607
$1,015.00
FACULTY P O S I T I O N S IN P H Y S I C S
The Department of Physics invites applications for two
tenure-track positions (subject to budgetary approval) at the
rank of assistant professor, commencing as early as 1
September 1 984 Preference will be given to applicants in
the experimental fields of condensed matter physics, high
energy physics and physics of atoms and nuclei using laser
techniques. Excellent candidates in other fields of departmental endeavour will also be considered. The successful
candidates are expected to contribute to the undergraduate
and graduate teaching programs of the Department.
Applications, together w i t h curriculum vitae and names of
three referees, should be sent to:
Professor S.K. Mark, Chairman
Ernest R u t h e r f o r d Physics Building
M c G i l l University
3 6 0 0 University Street
Montreal, Quebec, Canada
H3A 2T8
Applications are invited until the positions are filled
In accordance w i t h the Canadian immigration regulations,
priority will be given to Canadian citizens and permanent
residents of Canada
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D E P A R T M E N T OF PHYSICS
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New from LINK and APTEC, the
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HR SERIES
DETECTORS
A term renewable (tenure-track) appointment at the
Assistant or Associate level will be available from July 1,
1985. The Department is active in research in the areas of
nuclear physics, applied and engineering physics, astronomy and astrophysics, and condensed matter and low
temperature physics. Preference will be given to candidates w i t h extensive experience in experimental nuclear
physics and a strong interest in the role of fundamental
symmetries in atomic nuclei. Outstanding candidates in
other areas are also encouraged to apply
Duties w i l l include teaching and research. Salary
negotiable; the current floors are: Assistant Professor
$24,250 per annum, Associate Professor $31,600 per
annum Applications are invited until the position is filled.
In accordance with Canadian immigration regulations
Canadian citizens and permanent residents will be given
preference in making this appointment and candidates of
either sex are equally encouraged to apply.
A curriculum vitae and the names of three referees should
be sent to:
Dr. H.J. Wintle. Chairman of the
Search Committee,
Department of Physics.
Queen's University,
Kingston, Ontario, Canada
K7L 3 N 6
8010 PULSE
PROCESSOR
S I M O N FRASER UNIVERSITY
5?
8020
D E P A R T M E N T OF P H Y S I C S
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A P o s t d o c t o r a l or R e s e a r c h A s s o c i a t e p o s i t i o n in
P a r t i c l e T h e o r y is a v a i l a b l e in t h e P h y s i c s D e p a r t m e n t of S i m o n Fraser University. T h e c u r r e n t interests
of o u r s m a l l g r o u p are in s u p e r s y m m e t r y , s u p e r g r a vity, a n d K a l u z a - K l e i n t h e o r i e s . T h e a p p o i n t m e n t w i l l
b e g i n S e p t e m b e r 1 9 8 4 a n d w i l l i n i t i a l l y be f o r o n e
year b u t r e n e w a b l e f o r a s e c o n d year. S a l a r y w i l l be
c o m m e n s u r a t e w i t h experience.
Applicants should send their resumes and the names
of t h r e e r e f e r e e s as s o o n as possible to:
Dr. K . S . V i s w a n a t h a n ,
D e p a r t m e n t of Physics,
S i m o n Fraser University,
Burnaby, B . C . , C A N A D A
V5A 1S6
In a c c o r d a n c e w i t h C a n a d i a n I m m i g r a t i o n r e g u l a t i o n s , t h i s a d v e r t i s e m e n t is d i r e c t e d , in t h e f i r s t
instance, to Canadian citizens a n d p e r m a n e n t
residents.
The ND62 Multichannel Analyzer offers many extras to
match your ordinary and extraordinary applications.
High Speed Pulse Height Analysis. The ND62 can be
equipped with an 8K, 80 or 100 MHz Wilkinson ADC or a
4K, 10 microsecond fixed dead-time ADC for fast, high linearity pulse processing.
High Resolution Spectroscopy. The ND62 acquires a
IK or 2K portion of an 8K spectrum at full resolution.
Nal Spectroscopy. With the addition of the built-in scintillation detector preamplifier, amplifier and high voltage power
supply, the ND62 becomes a completely self-contained Nal
spectroscopy system.
Mossbauer Spectroscopy. An optional Mossbauer Interface allows up/down scaling, full or half-scale sweeps, and
internal or external control including a mid-scale indication.
Particle Sizing. An optional built-in logarithmic amplifier
makes the ND62 ideal for many particle sizing applications.
Physics Teaching. An external RS-170 video interface
allows projection of the display on a large screen for demonstration purposes. And, the ND62 is easy for students to use.
Plus, the ND62 operates as a computer terminal for direct
communication to your computer system. Regardless of
your application, the ND62 provides the extra power to
perform the task. Call or write for more information or a
demonstration of the ND62, an extraordinary MCA.
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ÉCOLE POLYTECHNIQUE DE
MONTRÉAL
BROCK UNIVERSITY
T h e D e p a r t m e n t of P h y s i c s i n v i t e s a p p l i c a t i o n s f o r a
t e n u r e - t r a c k a p p o i n t m e n t at t h e A s s i s t a n t P r o f e s s o r
level, s t a r t i n g J u l y 1 , 1 9 8 4 . T h e c a n d i d a t e is e x p e c t e d
t o h a v e a n e x c e l l e n t r e s e a r c h b a c k g r o u n d in t h e f i e l d
of e x p e r i m e n t a l s o l i d s t a t e p h y s i c s . P r e f e r e n c e w i l l
be g i v e n i n t h e f i e l d of light s c a t t e r i n g or o p t i c a l
p r o p e r t i e s of solids. T h e p r i n c i p a l d u t i e s w i l l be in
t h e area of u n d e r g r a d u a t e a n d g r a d u a t e t e a c h i n g
a n d p a r t i c i p a t i o n in t h e d e p a r t m e n t ' s r e s e a r c h
p r o g r a m in c o n d e n s e d m a t t e r p h y s i c s . D e p e n d i n g o n
c i r c u m s t a n c e s , a t e m p o r a r y a p p o i n t m e n t ( t h e o r y or
e x p e r i m e n t ) m a y be c o n s i d e r e d .
D é p a r t e m e n t de génie physique
Le département de génie physique de l'École Polytechnique
de Montréal est à la recherche d'une personne qualifiée
pour participer à l'enseignement de la physique fondamentale et appliquée, au premier cycle et aux grades supérieurs. De plus, le candidat choisi devra participer à des
recherches en physique des couches minces, un des
domaines majeurs de recherche du département : les activités actuelles de recherche dans ce domaine portent
notamment sur la microélectronique, les processus photovoltaïques et l'étude des revêtements par plasma.
Le poste d'Attaché de Recherche actuellement disponible
pourra devenir, à court ou à moyen terme, un poste régulier
de professeur et la personne choisie sera de ce fait nommée
professeur.
C l o s i n g date for a p p l i c a t i o n s : M a y 3 1 ,
1984.
In a c c o r d a n c e w i t h C a n a d i a n I m m i g r a t i o n r e q u i r e m e n t s , t h i s a d v e r t i s e m e n t is d i r e c t e d t o C a n a d i a n
citizens and permanent residents.
Le candidat doit posséder un doctorat (Ph.D.) ou l'équivalent en physique ou en ingénierie. La préférence sera
accordée à celui qui possède une expérience dans le
domaine des couches minces et qui est membre d'un Ordre
des ingénieurs. Les candidats doivent adresser leur curriculum vitae avant le 15 juin 1984 à l'adresse suivante:
A r e s u m e a n d t h e n a m e s of t h r e e r e f e r e e s s h o u l d be
s e n t to:
Dr. R.C. Shukla
Chairman
Brock University
St. Catharines, Ontario
L2S 3 A 1
Directeur
Département de génie physique
École Polytechnique de Montréal
Case Postale 6 0 7 9 , Succursale " A "
Montréal (Québec)
H3C 3 A 7
CANADA
NATO ADVANCED STUDY INSTITUTE
IMPROVED METHODS FOR
EXAMINING THE SUBMICRON WORLD
Antigonish and Baddeck
Nova Scotia, Canada
July 28 to August 11, 1984
SCOPE
T h e Institute is designed for Biologists, Physicists, Engineers and Material Scientists. It is to encourage cross
fertilization of ideas concerning established microscopies and newer techniques such as x-ray microscopy. Limited
financial support is available. For further information contact:
J. Wm. McGowan
Director
National Museum of
Science and Technology
1867 St. Laurent Blvd.
Ottawa K1A 0M8
Douglas M. Schinozaki
Faculty of Engineering Science
The University of Western Ontario
London N6A 5B9
Ralph Feder
Thomas J. Watson Research Laboratory
1MB
P.O. Box 218
Yorktown Heights, New York 10598, USA
I
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SPECTRUM.
to the visible and near-visible regions of the spectrum, Quanta-Ray
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these processes require the high degree of beam coherence and the
high peak power characteristics our users have come to associate with
Quanta-Ray systems. If this powerful capability is of interest to you.
contact your local Spectra-Physics representative.
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Physics in Canada La Physique au Canada

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