Spark Discharge PDF
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sp a rk Discharge E.M. Bazelyan Yu. P. Raizer s p a r k D ischarge CRC Press Taylor Francis Group Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business Published in 1998 by CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 1998 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group No claim to original U.S. Government works International Standard Book Number-10: 0-8493-2868-3 (Hardcover) International Standard Book Number-13: 978-0-8493-2868-8 (Hardcover) Library of Congress Card Number 97-14858 This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Library of Congress Cataloging-in-Publication Data Bazelian, Eduard Meerovich. Spark discharge / E.M. Bazelyan and Yu. P. Raizer ; translated by L.N. Smirnova, p. cm. Includes bibliographical references and index. ISBN 0-8493-2868-3 1. Breakdown (Electricity). 2. Electric spark. 3. Electric discharges through gasses. I. Raizer, lU. P. (lUril Petrovich.) II. Title. [DNLM: 1. Hepatitis B virus. QW710G289h] QC703.5.B39 1997 537.5'2—dc21 97-14858 informa T&F Visit the Taylor & Francis Web site at http ://www.taylorandfrancis.com Taylor & Francis Group and the CRC Press Web site at is the Academic Division of T&F Informa pic. http ://www.crcpress.com Preface This book is concerned with spark breakdown of long gas gaps. When we started writing this book, we assumed that we knew much about long sparks. One of us had studied spark discharges experimentally for thirty years. The other author had experience in generalizing experimental data available and had made an attempt at a theoretical treatment of sparks in his book ‘Gas Discharge Physics’. But, alas, our confidence vanished soon after we began to write this book. When we tried to describe the primary spark element—an ionization wave, or a streamer—we realized that the conventional sequence of material presentation would hardly provide the reader with a consistent picture of the spark discharge, because such a de scription would look like a multicolor quilt with holes between the patches. Although the amount of experimental discharge data is large, the facts nec essary for building a complete picture of the phenomenon are surprisingly scarce. Laboratory research has largely been focused on external spark characteristics, such as discharge current, transported charge, spark veloc ity, and breakdown voltage, especially for air, which has been studied in detail as the main insulation medium on the Earth. We felt disappointed each time we tried to find data on the plasma parameters, on the electric fields near the ionization wave front, in the streamer and leader channels and even in regions in front of a discharge. At best, we found descriptions of single experiments carried out with many reservations and assumptions. Some of the theoretical treatments of experimental findings published in periodicals seem questionable. Sometimes, analysis of the same data can lead one to a hypothesis totally opposite to that developed by a particular author, and our own experiments are not an exception to this. So we were faced with a dilemma: either to give up the very hope to write this book or to try to formulate general theoretical concepts of the basic stages in spark development by simplifying the physical models and focusing on the key aspects. In other words, we tried to ‘paint a picture with large strokes’. This is not a fast or easy way of writing a book, so it took us longer than we had originally thought. Preface We had no intention to compete with the well-known book by Meek and Craggs, which is probably the only fundamental publication available on long sparks in English. Neither was there an intention to give the reader a detailed survey of experimental and theoretical work on long sparks. What this book strives for is a consistent, up-to-date description of the spark discharge as we understand it. The bibliography is far from being complete, and references have been given only to those studies that are directly related to the problems under consideration. Anyone involved in developing a physical model has a strong temptation to check the calculations by direct measurements. We, too, were seeking for such a checkup, trying to find reliable experimental evidence. Good luck, however, was not our frequent guest; more frequent were our doubts concerning the data validity and the adequacy of the techniques used. The accumulated findings, no matter how negative they might be, eventually formed the basis for a whole chapter on measurements. This chapter is aimed at giving some help in data assessment to a theoretician or a special ist working in adjacent areas of physics and engineering. We believe that our analysis of common methodological errors may also come in handy to a beginning experimental reseacher. We will not speak here in detail about the problems discussed in this book—the reader can find their full list in the contents. The most impor tant chapters are those on streamers and leaders. They contain a fairly large number of theoretical speculations, but we tried to present compli cated phenomena in a simple way, without screening the physics with so phisticated mathematical formulas so popular among some theoreticians. Readers with little experience would, at best, admire such formulas without understanding their physical meaning, but more experienced researchers would rather start thinking of a theory of their own. We belong to the lat ter category. We hope that the present book will fill a gap in manuals on spark break down of gases, because it is intended not only for professional engineers and research physicists but also for undergraduate and graduate students and for those working in adjacent areas. Much attention is given here to numerical simulation. Although a com puter model is primarily expected to produce numerical results, it is more important, in our opinion, to reveal the functional relationships and the role of basic processes, when an analytical theory fails to do so. In this ap proach, a computer becomes a research instrument rather than a machine for superfast calculations. The combination of physical and computer ex periments is the principal gain from computerization of long spark studies. This trend in spark research has not made much progress yet, but we did include most of the available results in this book. The so-called return stroke has not been discussed deliberately, because this stage in the spark development is of little importance for the break down mechanism. The return stroke plays an important role in a light ning discharge, being the principal cause of the destructive action of atmo spheric electricity. We plan to consider this problem in detail in a special monograph on lightning, which will be a natural continuation of this book. The authors would like to thank L. N. Smirnova for the translation of this book. They are also grateful to M. A. Smirnova and L. N. Smirnova for the total preparation of the camera-ready copy. Authors Eduard M. Bazelyan was born in Moscow in 1936. He graduated Moscow Power Engineering Institute, where he specialized in high voltage engineer ing. Since that time, E. M. Bazelyan has been with the Krzhizhanovsky Power Engineering Institute. He learned to do high voltage experiments from I. S. Stekolnikov, a well-known specialist in long sparks. E. M. Bazely an received his Ph.D. degree in 1964 and his Doctor of Science degree in 1978. His scientific interests are focused on long sparks and lightning. He has studied spark discharges in air and other gases for 30 years, and his hobby is fundamental experiments aimed at clarifying discharge mech anisms. In recent years, he has also been concerned with numerical simula tion of spark discharges. His results have made a substantial contribution to both spark theory and engineering. E. M. Bazelyan is an author of over 100 papers and 2 books on long sparks and lightning protection. Today, he is Head of the Physical Modeling Laboratory. Yuri P. Raizer is Head of the Physical Gasdynamics Department of the Institute for Problems in Mechanics, Russian Academy of Sciences, Moscow (since 1965). He is also a Professor of Physics at Moscow Institute of Physics and Technology (since 1968). Yu. P. Raizer is a Fellow Member of the Russian Academy of Natural Science. He was born in 1927, graduated Leningrad Polytechnical Institute in 1949, and received his Ph.D. degree in 1953. He received his Doctor of Science degree in 1959 from the Chemical Physics Institute, the USSR Academy of Sciences. Yu. P. Raizer has worked in various fields of gasdynamics, explosion physics, gas discharge physics, and interaction of laser radiation with ionized gases. He is an author of over 150 papers, 3 patents, and 5 books, 4 of which were published in En glish. His Thysics of Shock Waves and High Temperature Hydrodynamic Phenomena’, co-authored by Ya. B. Zel’dovich, Academic Press, 1968, is a world-known handbook for researchers and students. Its impact parame ter is very high. His monographs ‘Laser-Induced Discharges’, Consultants Bureau, 1978 and ‘Cas Discharge Physics’, Springer-Verlag, 1991 are also
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