Bibliography

G. Herrmann and S. Wagener, Oxide Cathode. Translated from the German by engineer A. P. Ievlev, revised and supplemented by Candidate of Technical Sciences B. M. Tsarev. 508 pp., 206 figs., 57 tables. State Publishing House of Technical-Theoretical Literature, 1949, price 24 rubles.

The present monograph is a detailed work devoted to such a seemingly narrow question as the oxide cathode. Yet the publication of such a detailed monograph is timely and necessary: although the oxide cathode was discovered 45 years ago, it remains to the present day perhaps the only practically used thermionic cathode in the overwhelming majority of modern electronic devices. Being a very complex system, the oxide cathode is still the object of numerous investigations, which continue to reveal in it ever new and interesting features, in particular those connected with its semiconductor nature.

The monograph under review consists of three parts. In the first part (pp. 23–141) electron emission from metals is considered, both pure and coated with monolayers. The reviewer has no confidence that such a chapter is necessary for a monograph on the oxide cathode, which has so specifically semiconductor a character that it can scarcely be approached from the “metallic” point of view; but in the end this is not of great importance. No special novelties, for example in comparison with other rather old monographs (Reimann, de Boer), are to be found in this part of the book; moreover, the treatment of the phenomena considered (for example, the role of monolayers) is at times rather outdated.

In the second part of the book (pp. 142–273) the technology of manufacturing the oxide cathode is considered. It is immediately clear that the authors know this field well. The questions of the materials used in oxide-cathode technology, methods of preparing and activating the cathode in vacuum tubes, some of its properties, etc., are presented here with great thoroughness. The important questions of the operation of the oxide cathode in gas-discharge tubes are set forth much less well and more superficially; here, for example, absolutely nothing is said about the energy balance at the cathode, almost nothing about its sputtering, and so on.

Of particular interest is the third and largest part of the monograph (pp. 274–482), devoted to physical phenomena in the oxide cathode. The numerous results of experimental investigations of the cathode are presented here with great completeness, which will undoubtedly introduce the reader to this circle of very interesting and highly complex questions. Matters stand somewhat worse with the exposition of the theory of phenomena in the oxide cathode. First, it is broken up into parts in different places of the book and,

secondly, it suffers from great incompleteness owing to the failure to take account of Soviet research in the physics of semiconductors, which is unquestionably the most advanced.

The original of this book was written in 1943–1944. In addition to the substantial shortcoming that the work of Soviet researchers is almost entirely unrepresented in it, it is at present, in some respects, already obsolete or, more precisely, no longer up to date; the latter applies primarily to work on the oxide cathode in the pulse regime. All this required serious work on the translation, concerning which the following may be said. The translation of the book has been carried out very well—it reads easily and with pleasure. The plan of the book has been somewhat revised, and noticeably for the better. The book is supplied with a very large number of detailed editorial additions, covering the latest stage of investigations of the oxide cathode and showing that the editor has a thorough acquaintance with the literature on the oxide cathode; however, this applies only to the foreign literature. Here one must note with regret the presence of a very serious defect of the book, namely that Soviet investigations of the oxide cathode, even in the editorial additions, are quite undeservedly and contrary to promise presented very poorly in the book. I shall not cite numerous examples, but nevertheless, to illustrate what has been said, I shall point out the following: 1) in the proceedings of the Kiev Conference on Electronics (Phys. Notes 9, No. 2, 1941) eight communications on the oxide cathode were presented, yet only one of them has found its way into the bibliography here; 2) on pp. 463–464 the editor gives a detailed account of the results of Sproull’s theory, without mentioning a single word that a similar theory had been developed much more thoroughly in the Soviet work of Kalashnikov et al. (ZhTF, No. 12, 1946); 3) on pp. 404–405, in his detailed exposition and interpretation of Pomerantz’s experiments, the editor does not mention a single word that all this is an exact repetition of one Soviet work from 1938, etc., etc., etc. It should then be noted that a number of Soviet articles, even those included in the bibliography at the end of the book, are nevertheless not cited in the editorial additions. All this naturally gives rise to bewilderment, and in an inexperienced reader—to completely distorted ideas about this question.

On the whole it should be admitted that the book under review contains a large quantity of substantial and interesting contemporary material, knowledge of which will be useful to all those working on or studying the oxide cathode; however, the book would undoubtedly have been still much better and more complete if the shortcoming indicated above had not occurred.

N. D. Morgulis