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Handbook of electron tube and vacuum techniques
Book reviews
Handbook of Electron Tube and Vacuum Techniques by Fred Rosebury, Addison-Wesley Publishing Company, Inc, Reading (Mass), 1965, 596 pages, 154 illustrations, numerous tables, $17.50. This b o o k is a revision and extension of the Tube Laboratory Manual issued by the Research Laboratory of Electronics of M I T in a first and second edition in 1951 and 1956, respectively. The wide distribution and the popularity which these Manuals have enjoyed a m o n g practitioners of the art of tube-making augur well for the success of the new book. Numerous recipes for cleaning, electropolishing, plating, brazing, and heat-treating of metals and alloys are given; procedures are presented for glass-to-metal and ceramic-to-metal sealing, as well as for the preparation and activation of oxide-coated cathodes and thoriated tungsten emitters. The various types of vacuum pumps and the techniques required to assemble a vacuum system and to test its performance are described. Many of these items, together with material descriptions, are alphabetically arranged so that the book is essentially an encyclopedia, as the author points out in the preface. It is also stated in the preface, that the author had " n o intention of invading the domains of physics, physical electronics, metallurgy, a n d other scientific disciplines which are basic and supportive to the making of successful devices". Such a statement is apt to disarm the reviewer, because much of the criticism which could justifiably be offered would be directed to the insufficient emphasis of these basic principles on which technology ultimately rests. The author's general attitude may perhaps be illustrated by his equating 1400°C with 1700°K when discussing the design of heaters on page 81. A few degrees one way or the other does not seem to make much difference. There are cases where this philosophy can be applied, but there are others where it is definitely out of order. On page 80 it is stated that the temperature of an oxide-coated cathode should be raised to 1150°C and be held at this level for several minutes, but on page 100 a maximum temperature of I100°C is recommended for up to 30 seconds to ensure the complete conversion of the carbonates. Apart from the contradiction, these temperatures are too high for normal activation procedures and would cause sintering of the coating if maintained for several minutes. A more reasonable figure would be 1000 °C. The introduction of the term "real temperature" for the customary " t r u e temperature" on page 100 in the footnote contradicts the author's plea in the preface for using established terms, unless the new ones are properly explained; "emission effectiveness" on page 91 is another example and so is the symbol " w f " for work function no page 433. Although the cataphoretic coating of heaters with alumina is described in some detail, there is no mention of anaphoretic coating, n o r is there a discussion of the cataphoretic coating of oxide cathodes; electrophoretic coating as a generic term also does not appear in the book. The remark that it does not make any difference whether to connect the heater to the positive or the negative electrode in the coating bath is misleading (page 85). Non-aqueous suspensions are used for high-voltage anaphoretic coatings and aqueous suspensions for low-voltage coatings, the two resulting in markedly different performance, especially in terms of heater• cathode leakage. It is difficult to understand why the table giving the properties of tungsten (pages 556-557) reproduces vapour pressures published by Jones and Langmuir in 1927 which have been superseded by more recent values contained in the graphs shown on page 145, according
to Honig. (It would have been helpful to n u m b e r the tables and to give them legends, as has been done for the illustrations.) The values for electron work functions of the elements given on page 571 are arranged in a peculiar sequence and in many cases refer to a tabulation published by Henney in 1935, confronting these with the range of values listed in the H a n d b o o k of Chemistry and Physics (1960). A n up-to-date list of specific values would have served better. The headings for the columns containing work functions should have been electron volts and not just volts. To use the term work function interchangeably with electron affinity is misleadirg, to say the least; but this argument leads into electron physics, so the author is excused. The symbols k and b in the expression for ~ are not explained--why then present the equation on page 570 at all? The hydrogen-firing of " K o v a r " - t y p e glass-to-metal seals in order to remove oxide from the metal is surely a dangerous procecure that should not be listed, even though caution is recommended (page 9). On tbe other hand, the simple laboratory procedure for cleaning and outgassing mica by exposing it to the flame of a bunsen burner until the flame turns yellow is not mentioned. The book is well printed, and there are very few misprints and errors; for some of these, not mentioned here, the author has provided a list of errata. There are blank page references on pages 530 and 570; this reviewer was given the wrong initials and his book the wrong title on page 63; Mr Houskeeper was not a housekeeper. Being engaged in similar pursuits in the same field, this reviewer fully appreciates the painstaking effort which has gone into the preparation of Mr Rosebury's Handbook. It is unquestionably a useful book that contains a great deal of information otherwise not readily available. But the reader should use it with discretion and be aware of the book's shortcomings. Walter H Kohl
Magnetic Thin Films by Ronald F Soohoo, Harper and Row, New York (1965), ix and 316 pages, £3 3s. Whilst research on magnetic films has been going on for some decades, the suggestion by Blois, 10 years ago, that magnetic films might find application as computer storage elements stimulated an ever-increasing interest in the fundamental properties and technology of magnetic films. Most of this work has been directly in support of this computer storage application and has been mainly restricted to the study of permalloy films. This book, which concentrates on the physical properties of magnetic films, reflects this interest in nickel-iron films. F r o m the wealth of material available D r Soohoo has selected those aspects of general interest which are a basis of an understanding of the physics of ferromagnetic films. "Physical reasoning, substantiated by mathematical rigor is stressed throughout the text; the degree of mathematical complexity involved varies with the nature of the subjects discussed." The various methods of preparing films are briefly reviewed and compared in Chapter 2 which also deals with film structure and the determination of film composition and film thickness. The final Chapter is a brief review of the various applications of magnetic films. The main part of the book deals with the physics of magnetic films. The treatment of the various chapters follows a general pattern; after an introductory background from bulk magnetism, the theory of the thin film property is developed and discussed, this is
Vacuum / volume 15/number 11. Pergamon Press Ltd / Printed in Great Britain
547
Handbook of Electron Tube and Vacuum Techniques by Fred Rosebury, Addison-Wesley Publishing Company, Inc, Reading (Mass), 1965, 596 pages, 154 illustrations, numerous tables, $17.50. This b o o k is a revision and extension of the Tube Laboratory Manual issued by the Research Laboratory of Electronics of M I T in a first and second edition in 1951 and 1956, respectively. The wide distribution and the popularity which these Manuals have enjoyed a m o n g practitioners of the art of tube-making augur well for the success of the new book. Numerous recipes for cleaning, electropolishing, plating, brazing, and heat-treating of metals and alloys are given; procedures are presented for glass-to-metal and ceramic-to-metal sealing, as well as for the preparation and activation of oxide-coated cathodes and thoriated tungsten emitters. The various types of vacuum pumps and the techniques required to assemble a vacuum system and to test its performance are described. Many of these items, together with material descriptions, are alphabetically arranged so that the book is essentially an encyclopedia, as the author points out in the preface. It is also stated in the preface, that the author had " n o intention of invading the domains of physics, physical electronics, metallurgy, a n d other scientific disciplines which are basic and supportive to the making of successful devices". Such a statement is apt to disarm the reviewer, because much of the criticism which could justifiably be offered would be directed to the insufficient emphasis of these basic principles on which technology ultimately rests. The author's general attitude may perhaps be illustrated by his equating 1400°C with 1700°K when discussing the design of heaters on page 81. A few degrees one way or the other does not seem to make much difference. There are cases where this philosophy can be applied, but there are others where it is definitely out of order. On page 80 it is stated that the temperature of an oxide-coated cathode should be raised to 1150°C and be held at this level for several minutes, but on page 100 a maximum temperature of I100°C is recommended for up to 30 seconds to ensure the complete conversion of the carbonates. Apart from the contradiction, these temperatures are too high for normal activation procedures and would cause sintering of the coating if maintained for several minutes. A more reasonable figure would be 1000 °C. The introduction of the term "real temperature" for the customary " t r u e temperature" on page 100 in the footnote contradicts the author's plea in the preface for using established terms, unless the new ones are properly explained; "emission effectiveness" on page 91 is another example and so is the symbol " w f " for work function no page 433. Although the cataphoretic coating of heaters with alumina is described in some detail, there is no mention of anaphoretic coating, n o r is there a discussion of the cataphoretic coating of oxide cathodes; electrophoretic coating as a generic term also does not appear in the book. The remark that it does not make any difference whether to connect the heater to the positive or the negative electrode in the coating bath is misleading (page 85). Non-aqueous suspensions are used for high-voltage anaphoretic coatings and aqueous suspensions for low-voltage coatings, the two resulting in markedly different performance, especially in terms of heater• cathode leakage. It is difficult to understand why the table giving the properties of tungsten (pages 556-557) reproduces vapour pressures published by Jones and Langmuir in 1927 which have been superseded by more recent values contained in the graphs shown on page 145, according
to Honig. (It would have been helpful to n u m b e r the tables and to give them legends, as has been done for the illustrations.) The values for electron work functions of the elements given on page 571 are arranged in a peculiar sequence and in many cases refer to a tabulation published by Henney in 1935, confronting these with the range of values listed in the H a n d b o o k of Chemistry and Physics (1960). A n up-to-date list of specific values would have served better. The headings for the columns containing work functions should have been electron volts and not just volts. To use the term work function interchangeably with electron affinity is misleadirg, to say the least; but this argument leads into electron physics, so the author is excused. The symbols k and b in the expression for ~ are not explained--why then present the equation on page 570 at all? The hydrogen-firing of " K o v a r " - t y p e glass-to-metal seals in order to remove oxide from the metal is surely a dangerous procecure that should not be listed, even though caution is recommended (page 9). On tbe other hand, the simple laboratory procedure for cleaning and outgassing mica by exposing it to the flame of a bunsen burner until the flame turns yellow is not mentioned. The book is well printed, and there are very few misprints and errors; for some of these, not mentioned here, the author has provided a list of errata. There are blank page references on pages 530 and 570; this reviewer was given the wrong initials and his book the wrong title on page 63; Mr Houskeeper was not a housekeeper. Being engaged in similar pursuits in the same field, this reviewer fully appreciates the painstaking effort which has gone into the preparation of Mr Rosebury's Handbook. It is unquestionably a useful book that contains a great deal of information otherwise not readily available. But the reader should use it with discretion and be aware of the book's shortcomings. Walter H Kohl
Magnetic Thin Films by Ronald F Soohoo, Harper and Row, New York (1965), ix and 316 pages, £3 3s. Whilst research on magnetic films has been going on for some decades, the suggestion by Blois, 10 years ago, that magnetic films might find application as computer storage elements stimulated an ever-increasing interest in the fundamental properties and technology of magnetic films. Most of this work has been directly in support of this computer storage application and has been mainly restricted to the study of permalloy films. This book, which concentrates on the physical properties of magnetic films, reflects this interest in nickel-iron films. F r o m the wealth of material available D r Soohoo has selected those aspects of general interest which are a basis of an understanding of the physics of ferromagnetic films. "Physical reasoning, substantiated by mathematical rigor is stressed throughout the text; the degree of mathematical complexity involved varies with the nature of the subjects discussed." The various methods of preparing films are briefly reviewed and compared in Chapter 2 which also deals with film structure and the determination of film composition and film thickness. The final Chapter is a brief review of the various applications of magnetic films. The main part of the book deals with the physics of magnetic films. The treatment of the various chapters follows a general pattern; after an introductory background from bulk magnetism, the theory of the thin film property is developed and discussed, this is
Vacuum / volume 15/number 11. Pergamon Press Ltd / Printed in Great Britain
547