Superconducting Machines and Devices: Large Systems Applications

703 Pages·1974·19.944 MB·English

by  J. Powell (auth.), Simon Foner, Brian B. Schwartz (eds.)

Superconducting
Machines and Devices
Large Systems Applications
NATO ADVANCED STUDY INSTITUTES SERIES
A series of edited volumes comprising multifaceted studies of contemporary
scientific issues by some of the best scientific minds in the world, as
sembled in cooperation with NATO Scientific Affairs Division.
Series B: Physics
Volume 1 - Super conducting Machines and Devices
edited by S. Foner and B. B. Schwartz
Volume 2 - Elementary Excitations in Solids, Molecules, and Atoms
(Parts A and B)
edited by J. Devreese
Volume 3 - Photon Correlation and light Beating Spectroscopy
edited by H. Z. Cummins and E. R. Pike
The series is published by an international board of publishers in con
junction with NATO Scientific Affairs Division
A Life Sciences Plenum Publishing Corporation
B Physics New York and London
C Mathematical and D. Reidel Publishing Company
Physical Sciences Dordrecht and Boston
D Behavioral and Sijthoff International Publishing Company
Social Sciences Leiden
E Applied Sciences Noordhoff International Publishing
Leiden
Superconducting
Machines and Devices
Large Systems Applications
Edited by
Simon Foner and Brian B. Schwartz
Francis Bitter National Magnet Laboratory
M. I. T.
Cambridge, Massachusetts
PLENUM PRESS. NEW YORK AND LONDON
Published in cooperation with NATO Scientific Affairs Division
Library of Congress Cataloging in Publication Data
NATO Advanced Study Institute, Entreves, Italy, 1973.
Superconducting machines and devices.
(The NATO Advanced Study Institutes series (Series B: Physics, v. 1»
Lectures presented at the NATO Advanced Study Institute, Entreves, Italy, Sept.
5-14, 1973.
Includes bibliographical references.
1. Superconductors-Congresses. 2. Superconductivity-Congresses. I. Foner, Simon,
ed. II. Schwartz, Brian B., 1938- ed. III. Title. IV. Series.
TK7872.S8NI8 1973 621.39 74-624
ISBN 978-1-4684-2786-8 ISBN 978-1-4684-2784-4 (eBook)
DOI 10.1007/978-1-4684-2784-4
The Francis Bitter National Magnet Laboratory is sponsored by
the National Science Foundation
Lectures presented at the NATO Advanced Study Institute, Entreves, Italy,
September 5-14, 1973
© 1974 Plenum Press, New York
Softcover reprint of the hardcover 1st edition 1974
A Division of Plenum Publishing Corporation
227 West 17th Street, New York, N.Y. 10011
United Kingdom edition published by Plenum Press, London
A Division of Plenum Publishing Company, Ltd.
4a Lower John Street, London WIR 3PD, England
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
PREFACE
This book presents detailed discussions of several of the large
scale applications of superconductivity which will have major economic
impact on technical developments in the industrial world. The world
wide concern with energy problems makes this work particularly timely.
Some of the large scale devices and systems such as superconducting
generators, motors, power transmission, large magnets, high speed
ground transportation and industrial processing clearly speak directly to
improved efficiencies of generation and utilization of energy. The articles
treat each subject in depth. The text is suitable for advanced undergradu
ate or graduate engineering or applied science courses. The text should
also be of immediate use to practicing engineers and scientists in applied
superconductivity. The unique summaries of national efforts in applied
superconductivity will also be valuable to industrial and government plan
ners.
The book is based on a NATO Advanced Study Institute entitled,
"Large Scale Applications of Superconductivity and Magnetism" which was
held September 5 to 14 in the Hotel des Alpes, Entreves, Valle d'Aosta,
Northern Italy. This Study Institute represented a departure from other
NA TO Advanced Study Institutes in that it was very strongly directed
toward engineering applications rather than purely scientifically oriented
interests. The planning of this Institute developed over several years
and would not have been possible without continued interest by several
key NATO Scientific Mfairs Division scientists. It started when one of us
(S. F. ) met with Dr. H. Arnth -J ensen of the NATO Scientific Mfairs
Division at a Conference on High Magnetic Fields in Nottingham in 1969.
In early 1971, Dr. Arnth-Jensen in several communications asked whether
it would be reasonable to consider an Institute which dealt with the prob
lems of applications of high magnetic fields to practical systems, and
whether it would be appropriate to develop an international forum on this
matter. We were faced with a number of unusual problems concerning
this Institute because we recognized that in order for it to be successful,
it would require involvement of the industrial engineering community.
Furthermore, scheduling would depend on completion of tests of some
devices going on-line. Mter Dr. Arnth-Jensen left NATO, we continued
v
vi PREFACE
correspondence with Dr. E. Kovach, and later Dr. T. Kester of the
NA TO Scientific Affairs Division. The developments of some of the large
superconducting systems were sufficiently far advanced that at the Applied
Superconductivity Conference in Annapolis, Maryland in May 1972 we re
ceived assurances from several of the proposed principal speakers and
members of our International Advisory Committee that this Institute would
be timely and valuable.
The lectures at the Institute provided reviews of the major tech
nical developments in large applied superconductivity programs. In all
cases the lecturers were outstanding scientists and engineers in the fore
front of their respective fields. The first seven chapters in this book are
review articles devoted to these main lectures. The review articles are
extensive and go beyond the lectures presented at the Institute. These
chapters cover an introduction to applied superconductivity, practical
materials, large magnet systems, dc and ac machines, magnetic levita
tion and power transmission. We believe that these chapters present an
excellent basis for developing a research knowledge of the field of applied
superconductivity. The next three chapters are shorter and are based on
seminars on the hydrogen economy, superconducting computer devices and
magnetic separation. They supplement the main chapters by focusing on
specific problem areas. The last seven chapters of this book present a
new innovation we introduced at the Institute; a series of reviews of nation
al efforts of applied superconductivity programs of France, Germany,
Italy, Japan, Switzerland, the United Kingdom and the United States. These
give a good up-to-date summary of the worldwide developments in applied
superconductivity and should lead to better national planning as well as to
international cooperation. As with earlier chapters, the national reviews
were presented by technologists in the most favorable positions to know
and write about their own countries. A subject index is included to permit
rapid access to all the material.
The leadoff lecture given by Professor L. N. Cooper on the Theoryof
Superconductivity does not appear in this volume. For a good summary
we refer the reader to his Nobel Prize acceptance speech which appeared
in Physics Today 26, 31 (1973). The Institute also included a number of
informal seminars and technology assessment sessions. In order to main
tain our very tight publication schedule, we have not included transcrip-
tions of any of the informal seminars on technology assessments unless
they were immediately incorporated in the texts on that subject.
The development of the NATO Institute which resulted in the pres
ent volume involved planning over a period of three years. We have
been very fortunate in having an effective advisory committee which
PREFACE vii
helped us with the planning. Professor J. I. Budnick served as Assistant
to the Directors. Members of the International Advisory Committee
included A. D. Appleton, H. Brechna, B. Birmingham, G. Bogner, P. P.
Craig, G. R. Fox, R. L. Garwin, R.A. Hein, J. Horowitz, J. K. Hulm,
R. Pauthenet, C. Rizzuto, G. Sacerdoti, R. Stevenson and K. Yasukochi.
In addition we had further assistance from R. H. Kropschot, E. M. Purcell
and C. H. Rosner. Throughout the development of the Institute, Dr. Appleton
has been extremely helpful to us. In addition to making many suggestions
at various stages, he also assisted us in looking for a suitable location for
the Institute. We wish to thank Drs. H. Arnth-Jensen, E. Kovach and
T. Kester for their continued interest, and the NATO Science Founcil for
their support of the Advanced Study Institute. We also wish to thank the
General Electric Company, The National Science Foundation, and The
National Research Council of Italy (C. N. R.) for their support.
In addition to the lectures, the NATO Institute had approximately
95 participants from 20 countries. Members of the host country, Italy,
and the Local Chairman, Professor Carlo Rizzuto did many things to
make our Institute a success. We would like to thank Professor Rizzuto
and his associates at the University of Genova who comprised the Local
Committee, for searching out several ideal locations for the Institute and
for their help with all phases of the operation of the Institute.
Mr. Ballabenni and the staff at the Hotel des Alpes helped ensure a well
run Institute and accommodations. We would like to thank Mr. Turchet of
the Courmayeur Tourist Office, and the Aosta Valley Regional Tourist
Office for help in arrangement of travel plans, evening entertainments,
and two bus tours of the beautiful Aosta Valley and the Italian Alps. We
also were fortunate to have two weeks of exceptionally clear, delightful
weather during the Institute, as predicted by the Local Tourist Bureau.
We received the utmost cooperation from all of the lecturers and
students at the Institute and wish to thank them. The manuscripts were
prepared by the time of the Institute and enabled us to meet our tight
publication schedule. We apologize to all the lecturers for having been
so demanding in keeping to our extremely short publication schedule.
Without the continued dedication of each lecturer before, during, and
after the Institute, we would not have succeeded. In addition to our per
sonal thanks, we hope that the Institute and the present volume justifies
their efforts.
We would especially like to thank Edward J. McNiff, Jr., Hernan
C. Praddaude and Richard Frankel for their assistance with the Institute.
We also wish to thank Mary Filoso, Nancy Galvin, Jo Dean Matthews, and
Elisabeth Taylor for typing and correcting the manuscripts. Mary Filoso
viii PREFACE
contributed to the Institute from our early correspondence to the final
stages. Her continued dedication both to the Institute and this book
guaranteed success.
Simon Foner
Brian B. Schwartz
Cambridge, Massachusetts
December, 1973
CONTENTS
CHAPTER 1: LARGE SCALE APPLICATIONS OF
SUPERCONDUCTIVITY
J. Powell
INTRODUCTION 1
ENERGY GENERATION - FUSION 5
ENERGY GENERATION - MHO 22
ENERGY STORAGE - PEAKING POWER 34
ENERGY MODIFICATION -AC AND DC GENERATORS
AND MOTORS 42
ENERGY TRANSMISSION 46
A. DC Transmission 50
B. AC Transmission 55
MAGNETIC LEVITATION - HIGH SPEED GROUND
TRANSPORTATION 62
INDUSTRIAL PROCESSING 75
CHAPTER 2: PRACTICAL SUPERCONDUCTING
MATERIALS
D. Dew-Hughes
INTRODUCTION 87
A. Applications of Type II Superconductors 87
B. Properties Required of Commercial Superconductors 89
THE CRITICAL TEMPERATURE 90
A. BCS Theory 90
B. Matthias Rules 91
C. A15 Compounds 92
ix
x CONTENTS
THE CRITICAL FIELD 95
A. Type II Superconductivity 95
B. Paramagnetic Limitation of Upper Critical Field 98
THE CRITICAL CURRENT 102
A. Introduction 102
B. Flux Flow 104
C. The Critical State 107
D. Microstructure and Flux Pinning 108
E. Mechanisms of Flux Pinning 110
F. Maximum Critical Currents 113
STABILITY 115
A. Introduction 115
B. Criteria for Propagation of Flux Jumps 116
C. Recovery 118
D. Techniques of Stabilization 119
AC LOSSES 121
FABRICATION OF SUPERCONDUCTING MATERIALS 122
A. Ductile Alloys 122
B. A15 Compounds 124
C. New Processess 125
COMMERCIAL SUPERCONDUCTING MATERIALS 126
FUTURE PROSPECTS 131
CHAPTER 3: SUPERCONDUCTING MAGNETS
H. Brechna
INTRODUCTION 139
APPLICATIONS OF SUPERCONDUCTING MAGNETS 141
EXAMPLES OF OPERATING SUPERCONDUCTING MAGNETS 145
A. Oxford University Hybrid Magnet 151
B. The MIT Hybrid Magnet 151
C. The McGill University Hybrid Magnet 153
MAGNET SYSTEMS 153
A. Axially Symmetric Magnets 156
1. Short solenoids 158
2. Long solenoids 158
3. Multipole magnets 159
SUPERCONDUCTOR STABILIZATION 166