Bibliography

A. M. Bonch-Bruevich. Application of Vacuum Tubes in Experimental Physics. Moscow–Leningrad: State Publishing House of Technical-Theoretical Literature, 1951, 486 pp. Print run 10,000 copies. Price 20 rubles 70 kopecks.

The author of the book under review has taken on an important, though by no means easy, task—to collect and systematize the already considerable accumulated material on the use of vacuum tubes in experimental physics. And it may be considered that the author has coped with this task to a certain extent, especially if one takes into account the great diversity in the purpose and character of the use of physical instruments, the variety of functions performed by tubes, and, finally, the abundance and novelty of the material.

The book contains descriptions of certain tube instruments used in the practice of physical experiment. Chapter VI describes conversion circuits; Chapter VII gives a sufficiently detailed account of electrometric circuits. Chapter VIII contains information on pulse counting, the registration of coincidences and anticoincidences, and also on the analysis of pulse amplitudes. The final chapter, IX, is devoted to problems of power supply (rectifiers and voltage- and current-stabilizers). The author does not restrict himself to describing only tube instruments. Thus, Chapter VIII describes particle counters, while Chapter I gives a general description of electrical processes in linear circuits and, what is very important, considers transient processes in them. Chapter II contains information on vacuum tubes, and Chapters III and IV on amplifiers. Harmonic oscillation generators are described in Chapter V, and relaxation generators and triggers in Chapter VI.

Thus, the first chapters of the book contain material of a general character and are intended to serve as an introduction to the later chapters, but they do not agree well enough with the latter. In presenting the operation of special instruments, the author usually uses descriptions from journal articles and makes almost no use of the mathematical apparatus of the first chapters. The frequency characteristics often used by the author for analyzing circuit elements in the first chapters do not explain the operation of pulse devices sufficiently well and do not fully characterize the circuit. Moreover, they may be different for different parts of a pulse. The determination of phase characteristics under laboratory conditions usually presents considerable difficulties. A large part of the material in the first chapters had previously appeared in separate books, in particular in textbooks. The material of the later chapters is drawn mainly from scattered journal articles. Therefore it is the later chapters that are of greatest interest. They are, however, written less well than the first.

In the discussion of individual instruments (for example, counting and coincidence circuits), the question of resolving time is emphasized, but the no less important question of input devices—pulse converters—is not touched upon. The book contains no calculation of losses in counting, no counting of random coincidences and pile-ups. Fast coincidences are not discussed at all; integrators (intensimeters), delayed-coincidence circuits, fast coincidence circuits, and scintillation counters are described too briefly. It would also have seemed advisable to describe amplifiers with ultrashort pulse rise times, small time-interval meters, interval analyzers, and other very important modern physical instruments.

This could have been done, while remaining within the size of the book, by reducing sufficiently well-known material (sinusoidal-oscillation generators, multivibrators, etc.), as well as material of a different nature, for example on quenching circuits, most of which are now of no practical interest.

The book also lacks material on pulse oscillography, on methods for adjusting and testing the instruments described, and on the apparatus used for this purpose. The specific character of the operation of instruments under conditions in which the events being studied are distributed at random in time is almost not reflected; there is no analysis of errors and no calculation of corrections.

Let us consider some not entirely successful passages or direct errors by the author in the section on coincidence circuits. On the whole, unfortunately, the material on coincidence circuits cannot be considered successful. In our time, the author’s statement that, when recording coincidences of pulses from Geiger–Müller counters, a resolving time of several tenths of a microsecond is a very good result looks plainly outdated.

Some of the author’s statements on p. 421 are incorrect or require clarification, where he identifies the operation of a coincidence circuit with the operation of an amplifier. The author does not distinguish between the resolving time of the coincidence circuit proper, determined only by the parameters of the circuit, and the resolving time of the entire coincidence system, which depends on the duration and shape of the incoming pulses. The definition of coincidence resolving power cannot be considered successful.

Neither the amplitude, nor the maximum value of the steepness, nor the position on the pulse of the beginning of the segment with the greatest steepness of the pulse, for both self-quenching and non-self-quenching counters, depends in the first approximation on the trajectory or on the energy of the particle. Yet on p. 422 the author speaks of the influence of the trajectory, causing a loss of coincidence counts. At the same time he says not a word about the influence of the distance of the point at which the particle strikes from the ends of the self-quenching counter and about fluctuations in the drift time of the electrons. It is precisely these two factors (and the second also in a proportional counter) that can limit the choice of resolving time for coincidences. If, however, one tries to relate the author’s remarks about losses of counts to these two factors, then it is impossible to make ends meet.

On the same page 422 the author speaks of false coincidences due to the delay of pulses from different particles.

But if the moments at which the particles enter are independent, as is usually the case, then the number of such false coincidences will be exactly the same as with non-delayed pulses. In such a case, to speak of extra counts due to delay is meaningless.

On p. 424 it is said that a proportional counter gives great possibilities for decreasing the resolving time for coincidences,

moreover, the comparison is evidently made with the counters mentioned immediately before this, in which an independent discharge is used. If one is speaking (as the author does) precisely of high resolving power due to the use of the initial portion of the pulse front, then the indicated assertion is completely incorrect, since the steepness of the pulse front in an independent discharge in the counter is greater and, consequently, better results can more readily be obtained with it.

The section on coincidence circuits is not some exception; there are errors in other parts of the book as well. For example, on p. 412 it is for some reason stated that a discriminator with the smallest displacement should register as many pulses as all the others taken together.

In order to eliminate the loss of gain of a stage as a result of negative feedback with its cathode circuit, it is by no means sufficient to choose the capacitance of the capacitor blocking this circuit in accordance with condition (148). Here the common error of N. A. Zheleznov is repeated, who assumed that a stage with a capacitive cathode load has a negative input resistance and for this reason alone self-oscillates. The total number of inaccuracies or errors by the author concerning the stage with a cathode load is no smaller than in the section on coincidence circuits.

The author’s statement that in measuring amplifiers one can practically always disregard the influence of fluctuations of the anode current in comparison with the influence of the grid circuit sounds strange (p. 134).

The recording of frequent microsecond electromagnetic pulses with an electromagnetic oscillograph looks altogether incomprehensible (p. 390).

A number of errors are contained in the description of delay lines and in the section devoted to triggers.

Many inaccuracies which, in our view, require correction, or outright errors no less important than those indicated, have been made by the author in a number of other places. We are unable to dwell on them.

A year has passed since the first printing was issued (the first 6000 copies). The author made some minor changes and corrections, but the basic errors remained uncorrected. Therefore the remarks made in the present review apply equally to both printings.

The list of misprints noted for the second printing proved even larger than for the first, and half of them were not in the first printing. Here the substantial fault of the printing office is obvious, while the author was chiefly responsible for the misprints of the first printing. Unfortunately, the number of unnoticed misprints in both printings is considerable. A number of figures contain conspicuous errors; individual illustrations are surprising in their inconsistency with reality.

The book is written in decent language, although some rough spots occur. It is printed on good paper and has a sturdy calico binding.

Summing up all that has been written, one may say that the book is unquestionably useful. It is written on a very timely subject and contains much that students and experimental physicists need; however, it requires thorough revision and, in any case, correction of obvious errors. It would have been more proper if Gostekhizdat had appointed, if possible, a sufficiently erudite scientific editor for the book of a beginning author.

A. Markov