Table Of ContentPositron Scattering
in Gases
NATO ASI Series
Advanced Science Institutes Series
A series presenting the results of activities sponsored by the NA TO Science Committee,
which aims at the dissemination of advanced scientific and technological knowledge,
with a view to strengthening links between scientific communities.
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and Physical Sciences Fordrecht Boston, and Lancaster
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Recent Volumes in this Series
Volume 102-Magnetic Monopoles
edited by Richard A. Carrigan, Jr., and W. Peter Trower
Volume 103-Fundamental Processes in Energetic Atomic Collisions
edited by H. O. Lutz, J. S. Briggs, and H. Kleinpoppen
Volume 104-Short-Distance Phenomena in Nuclear Physics
edited by David H. Boal and Richard M. Woloshyn
Volume 105-Laser Applications in Chemistry
edited by K. L. Kompa and J. Wanner
Volume 106-Multicritical Phenomena
edited by R. Pynn and A. Skjeltorp
Volume 107-Positron Scattering in Gases
edited by John W. Humberston and M. R. C. McDowell
Volume 10B-Polarons and Excitons in Polar Semiconductors and
Ionic Crystals
edited by J. T. Devreese and F. Peeters
Series B: Physics
Positron Scattering
in Gases
Edited by
John W. Humberston
University College London
London, England
and
M. R. C. McDowell
Royal Holloway College
Egham, Surrey, England
Plenum Press
New York and London
Published in cooperation with NATO Scientific Affairs Division
Proceedings of the NATO Advanced Research Workshop on
Positron Scattering in Gases,
held July 19-23, 1983,
at Royal Holloway College, Egham, Surrey, England
Library of Congress Cataloging in Publication Data
NATO Advanced Research Workshop on Positron Scattering in Gases (2nd:1983:
Royal Holloway College)
Positron scattering in gases.
(NATO ASI series. Series B, Physics; v. 107)
"Proceedings of the NATO Advanced Research Workshop on Positron Scatter·
ing in Gases, held July 19-23, 1983, at Royal Holloway College, Egham, Surrey,
England"-T.p. verso.
"Published in cooperation with NATO Scientific Affairs Division."
Includes bibliographical references and index.
1. Positrons-Scattering-Congresses. I. Humberston, John W. II. McDowell,
M. R. C. III. Title. IV. Series.
QC793.5.P628N38 1983 539.7'214 84·1907
ISBN-13: 978-1-4612-9804-5 e-ISBN-13: 978-1-4613-2751-6
DOl: 10.1007/978-1-4613-2751-6
© 1984 Plenum Press, New York
Softcover reprint of the hardcover 1s t edition 1984
A Division of Plenum Publishing Corporation
233 Spring Street, New York, N.Y. 10013
All rights reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted,
in any form or by any means, electronic, mechanical, photocopying, microfilming,
recording, or otherwise, without written permission from the Publisher
This book is dedicated to the memory of
Sir Harrie Massey,
who died on 27th November, 1983.
No worthier testimony to his courage and
his interest in positron physics could be found
than that, despite being seriously ill at the time,
he gave the opening address at the NATO Advanced Research Workshop on
Positron Scattering in Gases.
ORGANIZING COMMITTEE
Margaret F. Dixon Royal Holloway College
T. C. Griffith University College London
J. W. Humberston University College London
M.R.C. McDowell Royal Holloway College
INVITED SPEAKERS
K.F. Canter Brandeis University, U.S.A.
M. Charlton University College London, U.K.
P.G. Coleman University of Texas at Arlington, U.S.A.
R.J. Drachman Goddard Space Flight Center, U.S.A.
D.W. Gidley Bell Laboratories, U.S.A.
T.C. Griffith University College London, U.K.
G.R. Heyland University College London, U.K.
R.H. Howell Lawrence Livermore National Laboratory, U.S.A.
L.D. Hulett, Jr. Oak Ridge National Laboratory, U.S.A.
F .M. Jacobsen Riso, Denmark
C.J. Joachain universit6 Libre de Bruxelles, Belgium
W.E. Kauppila Wayne State University, U.S.A.
K.G. Lynn Brookhaven National Laboratory, U.S.A.
R.P. McEachran York University, Canada
Sir Harrie Massey University College London, U.K.
A.P. Mills, Jr. Bell Laboratories, U.S.A.
R.M. Nieminen University of Jyvaskyla, Finland
W. Raith Universitat Bielefeld, W. Germany
D.M. Schrader Marquette University, U.S.A.
G. Sinapius Universitat Bielefeld, W. Germany
PREFACE
The first conference in this series, devoted principally to the
interaction of positrons in gases, was held at York University,
Toronto, in July 1981 immediately preceding the XII ICPEAC in
Gatlinburg, and the proceedings were published in the Canadian
Journal of Physics, volume 60 (1982). So successful was this meeting
that the decision was taken to hold a second one around the time
of XIII ICPEAC in Berlin in 1983. London was clearly a convenient
location but, rather than the obvious choice of University College
London in central London, the Organising Committee decided that the
beautiful and peaceful surroundings of Royal Holloway College would
provide a more pleasant and intimate atmosphere for a small meeting.
Even a small conference requires substantial sums of money to
pay the expenses of invited speakers and when considering possible
sources of funds the Organising Committee recognised that the
intended format of the meeting and the international composition of
the participants made it appropriate to apply to the NATO Science
Committee for support under the Advanced Research Workshop Programme.
This was one of the few successful applications made this year, and
so it was that the conference became the 'NATO Advanced Research
Workshop on Positron Scattering in Gases'.
The Workshop, with approximately sixty participants, started
after lunch on 19 July, 1983 and finished at mid-day on 23 July.
Each day was divided into a morning and afternoon session, and the
organisation of each session was the responsibility of two or three
of the invited speakers. In addition to their own talks they also
included relevant contributions from other participants. Several
contributed papers were submitted to the Workshop and these were
presented in a poster session.
Only the papers of the invited speakers are included in these
proceedings, as it is assumed that the contributed papers will
ultimately be published in the usual journals.
Approximately half the sessions were devoted to reviews of the
current state of theoretical calculations and experimental results
vii
viii PREFACE
obtained using conventional positron sources. The remainder of the
time was spent discussing various methods of producing much more
intense positron beams and speculating on some of the experiments
wllich might be done when these beams become available.
The opening address was given by Sir Harrie Massey who, in
addition to being one of the great pioneers, has maintained a
considerable interest in the field over many years. Most regrettably,
ill health has prevented him from preparing a written version of his
talk for inclusion in these proceedings.
The NATO Science Committee has already been mentioned as the
principal source of funds for the Workshop. The Organising Committee
also gratefully acknowledge contributions from EG and G Instruments
Ltd. and Vacuum Generators Ltd., who both provided exhibitions of
scientific equipment and Royal Holloway College and University
College London. An interest-free loan from the Royal Society is
also gratefully acknowledged.
Several people at Royal Holloway College helped with the
organisation of the Workshop, but a particular debt of gratitude
is owed to Mrs. Margaret Dixon who was the secretary to the Organi
sing Committee until she became ill shortly before the start of
the Workshop. Her place was most ably taken at short notice by
Mrs. Betty Alderman, whose unfailing cheerfulness and efficiency
throughout the meeting was greatly appreciated by all participants.
Mention must also be made of the help given by Mrs. Betty Diggens,
whose first day in her new job coincided with the start of the
Workshop.
It was generally agreed that the Workshop had been very useful
and that regular meetings should take place to review progress in
the field of positron collisions in gases. Already preliminary
plans are being made for a further meeting around the time of the
next ICPEAC in 1985.
J.W. Humberston
M.R.C. McDowell
25th October, 1983
CONTENTS
Survey of Recent Experimental Results on Positron
Scattering in Gases. Part I: Total Cross
Sections ................. . 1
W. Raith
Survey of Recent Experimental Results on Positron
Scattering in Gases. Part II: Beyond
Total Cross Sections •••••••••.•• 15
W.E. Kauppila and T.S. Stein
Survey of Recent Theoretical Results on Positron
. . . . . . .
Scattering in Gases: Low Energy • 27
R. P. McEachran
Survey of Recent Theoretical Results on Positron
Scattering in Gases: Intermediate a.n d. H. ig.h . . . . . . .
Energies. . . . . , . . . . . . . 39
-
C.J. Joachain
Positronium Formation Cross-Sections in Various
Gases •.• 53
T. C. Griffith
Positronium: Recent Fundamental and Applied Research 65
D.W. Gidley and P.G. Coleman
Positronium Formation in Gases and Liquids. 85
F.M. Jacobsen
Positron Lifetime Spectra for Gases . . . • . • . . . . • • . 99
G. R. Hey1and
The Calculation of Positron Lifetimes . . . . . . . • . • . 109
D.M. Schrader
Techniques for Studying Systems Containing Many
Posi trons •• ..••••..•.••......• 121
A.P. Mills, Jr.
ix
x CONTENTS
Surface Studies with Slow Positron Beams ...•.... 139
R.M. Nieminen
Intense Positron Beams: Linacs .••......... 155
R.H. Howell, R.A. Alvarez, K.A. Woodle, S. Dhawan,
P.O. Egan, V.W. Hughes and M.W. Ritter
Intense Positron Beams and possible Experiments 165
K.G. Lynn and W.E. Frieze
Intense Postiron Beams - An Evaluation of the Methods . . •. 181
M. Charlton
The Generation of Monoenergetic Positrons ••... 195
L.D. Hulett, Jr., J.M. Dale, P.D. Miller, Jr.,
C.D. Moak, S. Pendyala, W. Triftshauser, R.H.
Howell, R.A. Alvarez
Applications of Intense Positron Beams. • • . . . . . . • . . 203
R.J. Drachman
Application of Intense Positron Beams in Atomic Physics
Experirents . • • • . • • . . . . • . . . . 211
G. Sinapius
Low Energy Positron and Positronium Diffraction • . . . . .. 219
K. F. Canter
Index. 227
