Primer on Theory and Operation of Linear Accelerators, 2nd Ed.
Author: C.J. Karzmark & Robert MortonISBN: 9780944838662 ISBN10: 0944838669
Published: 1998 | 50 pp | Softcover
OUT OF PRINT
SCOPE | September 1992
Review of the First Edition
"This booklet, available from the Medical Physics Publishing Corporation, Madison, is an updated version of an earlier booklet, published in 1981 by the Bureau of Radiological Health. It aims to provide students with an understanding of the operation of components of a linear accelerator and how they inter-relate.
"The booklet is well organised, comprising short chapters which build from a brief overview of the major sections of an accelerator, through the basic principles of electron acceleration and beam production using a simple 'X-ray tube' accelerator analogy, to more detailed consideration of the individual components. The principles of operation and construction are covered in chapters 6 to 11.
"The description of the detailed principles of operation begins with an overview of microwave cavities. Production of microwaves is dealt with in section covering both the klystron and magnetron. The booklet then goes on to describe both travelling-wave and standing-wave accelerating structures, including methods of obtaining variable energy beams of optimal performance. Later chapters describe beam bending and some treatment head arrangements. The closing chapters of the booklet give descriptions of auxiliary systems, including beam stoppers, cooling and vacuum systems, and an overall operational overview.
The whole booklet is written in simple, descriptive language. Items of nomenclature are highlighted in bold typeface. Throughout the document, reference is made at intervals to common, everyday features in order to give an analogous mental picture. The booklet contains many drawings and photographs (42 figures within the 30 pages of main text) to help understanding. In the main, these are of reasonable quality and clearly assist the description. Some of the drawings and photographs, however, are poorly reproduced or are too small to be clearly seen (the figures occupy the bottom portion of each page). Occasionally the text and diagrams go slightly awry, reference being made to figures which do not contain the relevant information, as for example occurs with the description of the circulator in chapter 6.
The sections on principles of operation are particularly good, with descriptive text being well supported by illustrations of the process involved. The simple diagrams showing the various phases of a wave through a section of waveguide, for example, clearly illustrate the differences between standing-wave and travelling wave acceleration. Such clarity is difficult to maintain, and the section on dual X-ray energy modes would benefit by use of additional diagrams together with some editing of sentence structure to improve both readability and understanding.
"One draw-back of the booklet for the UK market is that it concentrates primarily on the features of Varian accelerators, the Clinac 18 in particular. Because of this, some features common to accelerators within the UK are overlooked--including such features as drum-mounted gantry, microwave isolators, '90 degree' bending systems, beam steering, internal wedges and segmented ionisation chambers. This omission is partly offset by the appendices to the booklet. Appendix A gives a brief description of medical accelerators from the various manufacturers, describing for each the available equipment range together with details of major design differences form those of competitors. These appear to be written as much to 'sell' the principles as to describe them. Appendix B contains a useful tabular comparison of selected, specified items for each manufacturer and equipment model. This information, although comprehensive at the time of publication, will rapidly become out of date as manufacturers introduce new models, variations and available options. Such features as multileaf collimators and dynamic wedges are not covered.
"Overall, the booklet lacks the detail and coverage of alternative texts (e.g., Greene's 'Linear Accelerators for Radiation Therapy'). It does have a role in aiding the teaching of students, and the clear language and extensive use of diagrams makes it particularly useful for non-physicists. It is well suited as an accompaniment to lectures on linear accelerators and it is interesting to note that support video tapes are available to be used in conjunction with this primer.
"In summary, the booklet is short, sharp, cheap and is a suitable addition
to supplement other texts on linear accelerators in radiotherapy."
J.E. Shaw