Bibliography

K. K. DARROW, Electrical Phenomena in Gases, Baltimore, 1932, p. 432. Edition Williams and Wilkins Company.
K. K. DARROW, Electrical Phenomena in Gases.

The present book is the first detailed American exposition of the physics of gas discharges and contains 13 chapters, whose contents may be divided into 3 groups: 1) the basic elementary processes involved in the passage of electricity through a gas, 2) the motion of charge carriers, 3) breakdown of the discharge gap, glow and arc discharge.

The first two chapters deal chiefly with questions of ionization: ionization by electron impact, ionization of excited atoms, the action of X-rays and gamma rays on a discharge gap, ionization by proton impact and by positive ions, and ionization upon contact with excited atoms and molecules.

The questions of ionization by electron impact, as important for the theory of discharge, are presented in especially great detail. The corresponding apparatus for determining the probability of ionization is described, the newest work on the identification of ions is set forth, and questions concerning the formation, under electron impact, not only of singly, but also of doubly and so forth charged ions are discussed. Questions of ionization by fast particles and phenomena of recharging are also analyzed in some detail.

In the following chapter (Chap. III) questions of gas excitation are considered. As in the preceding chapters, various methods of measurement are examined, and diagrams of terms are given, which make it possible almost not to resort to other books in order to understand questions of gas excitation and luminescence.

Chapters IV and V cover the questions of slowing down, scattering, and give a general theory of the motion of charge carriers. These questions are important for the theory of discharge and are analyzed here very thoroughly. Chapters VI and VII examine questions of the mobilities of ions and electrons and diffusion phenomena. More complex problems are included here as well, for example, the case of the joint action of an electric field and diffusion.

Chapters IV–VIII are among the best in the whole book. The questions touched upon here are presented with sufficient completeness and clarity. Not only ready-made results are given, but the apparatus used by various authors is analyzed in detail. The results of the investigations are critically compared, which undoubtedly makes it easier for the reader to master the scientific literature.

Chapter VII is devoted to recombination phenomena and to the question of the formation of heavy charge carriers (electron attachment).

A characteristic feature of the book is that questions connected with spatial charges in discharges are singled out into a separate, comprehensive chapter (Chap. X). This, of course, is now quite timely, for these questions in the physics of gas discharges are extremely important. Not only do the phenomena in an established discharge depend on the distribution of spatial charges, but even the occurrence of a discharge, as has now been clarified, is governed by the development of spatial charges. The question of plasma and probes is likewise assigned to a special chapter (Chap. XI). A large number of investigations in which a new probe method—Langmuir’s “success”—has been used to study the mechanism of gas discharge fully justifies the great attention paid to this method. A valuable feature of the book is the comparison, in many places,

theory with experiment, which allows the reader to approach the use of one or another formula critically.

Chapters IX, XII, and XIII cover breakdown, glow, and arc discharge. It must be noted that they are not written with the same thoroughness as the chapters devoted to elementary processes. These chapters, which describe gas discharge itself, are far from as complete as the preceding ones. Here, for example, such questions are omitted as the theory of separate parts of the discharge, the development of individual discharge forms, cathode sputtering, detailed optics of the discharge, the high-frequency discharge and its theory, etc.

It should be noted that even in the chapters devoted to elementary processes, a number of important questions are given insufficient attention or are not discussed at all (thermal ionization, thermionic emission, the photoelectric effect).

In recent years the technical applications of the physics of gas discharges have grown extraordinarily (gasotrons, thyratrons, powerful mercury rectifiers, new gas light sources, gas relays, photocells with gas filling, etc.). However, there is absolutely none of this material, which is of interest to the Soviet reader, in the book.

It should also be noted that the terminology used by the author is not always generally accepted.

A great merit of the book is its lively and vivid language. Although the book is quite serious and is not popular in character, it is nevertheless widely accessible. It is also valuable that the author has assembled on a number of questions all the literature, chiefly the most recent, which allows the reader easily to deepen his knowledge.

The appearance of a book with important material on the discharge itself and its applications would be highly desirable.

Thanks to its lively and clear exposition, the book will help the physicist independently master the fundamentals of the study of electrical phenomena in gases.

G. V. Spivak.