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Páll theodórsson, “measurement of weak radioactivity”
__ i.!d
SJ
INSTRUMENTS 8 METHODS IN PHYSICS RESEARCH
Bl
ELSEVIER
Nuclear
Instruments
and Methods
in Physics
Research
A 406 (1998) 511
Book review Pdl Theodhrsson, “Measurmrnt of Weak RaWorld Scientific Publishing Co., diOdL!iQ”‘, Singapore, ISBN 9810223153, 1996. Reviewed by G.F. Knoll This 322-page book will be a very useful reference for those setting up low-level counting systems, or to users who would like to improve signal-to-background ratios in existing detection equipment. The author begins with some historical accounts of low-background measurement techniques, and leads into a detailed description of the sources of background in a variety of counting and spectroscopy systems. Reflecting the author’s primary interests, the applications most frequently illustrated are in ‘“C counting for dating purposes, and the detection of low levels of tritium in water samples. However, many of the techniques and conclusions will be relevant in other low-level radioisotope measurements. Although briefly mentioned. the ultra-low background techniques necessary for exotic experiments such as the search for double beta decay are not part of the book’s scope. This field is an interesting mix of older empirical shielding techniques and recipes with more modern efforts to reduce backgrounds through the use of highly purified materials. The book provides a valuable collection in one place of information that is generally scattered throughout published articles or symposia proceedings. The discussion of shielding and construction materials has benefited from recent work in screening materials for residual radioactivity using ultra-low background underground facilities. Accurately identifying all the important sources of background in many systems is not always an easy task, and several techniques that are useful in this effort are described. The style of the book combines a great deal of review information gleaned from published sources 016%9002/98/$19.00 (’ 1998 Published P/I SOI 68-900’(98)00204-6
with some developmental descriptions that have the flavor of a contemporary research report. A few sacred cows are challenged, such as the widely held belief that old lead is invariably better than new lead for the construction of low-background shielding, and that the lining of the inner surface of lead shields with low-Z materials is always beneficial. Recommendations are given on the best location for guard detectors to reduce the cosmic background contribution, and the optimum location of various shielding layers. By organizing the book around different detector systems, some material appears several times at different locations, but some repetition is probably warranted. A short section on the principles of operation of various detectors is also included in the book. The information found there on most devices is accurate, but some unfortunate errors are also present (for example, the confusion of Si(Li) detectors with silicon diodes used for alpha spectroscopy and some misinformation about ion implanted devices). Another disappointment is the evident lack of careful proofreading by the compositor. In three cases, the wrong illustration is used in a figure. Numerous references, called out in the text by author and year, are missing in the collection of reference citations. Three of the first four citations contain misprints. One hopes that these and other similar flaws will be rectified in future printings. I can recommend the book as a good collection of information on background and shielding of detector and spectroscopy systems that can save a great deal of library searching, and that provides a good bit of insight on the importance of different components of the background. It is definitely a valuable contribution to the resources available to the radiation measurement community.
by Elsevier Science B.V. All rights reserved
SJ
INSTRUMENTS 8 METHODS IN PHYSICS RESEARCH
Bl
ELSEVIER
Nuclear
Instruments
and Methods
in Physics
Research
A 406 (1998) 511
Book review Pdl Theodhrsson, “Measurmrnt of Weak RaWorld Scientific Publishing Co., diOdL!iQ”‘, Singapore, ISBN 9810223153, 1996. Reviewed by G.F. Knoll This 322-page book will be a very useful reference for those setting up low-level counting systems, or to users who would like to improve signal-to-background ratios in existing detection equipment. The author begins with some historical accounts of low-background measurement techniques, and leads into a detailed description of the sources of background in a variety of counting and spectroscopy systems. Reflecting the author’s primary interests, the applications most frequently illustrated are in ‘“C counting for dating purposes, and the detection of low levels of tritium in water samples. However, many of the techniques and conclusions will be relevant in other low-level radioisotope measurements. Although briefly mentioned. the ultra-low background techniques necessary for exotic experiments such as the search for double beta decay are not part of the book’s scope. This field is an interesting mix of older empirical shielding techniques and recipes with more modern efforts to reduce backgrounds through the use of highly purified materials. The book provides a valuable collection in one place of information that is generally scattered throughout published articles or symposia proceedings. The discussion of shielding and construction materials has benefited from recent work in screening materials for residual radioactivity using ultra-low background underground facilities. Accurately identifying all the important sources of background in many systems is not always an easy task, and several techniques that are useful in this effort are described. The style of the book combines a great deal of review information gleaned from published sources 016%9002/98/$19.00 (’ 1998 Published P/I SOI 68-900’(98)00204-6
with some developmental descriptions that have the flavor of a contemporary research report. A few sacred cows are challenged, such as the widely held belief that old lead is invariably better than new lead for the construction of low-background shielding, and that the lining of the inner surface of lead shields with low-Z materials is always beneficial. Recommendations are given on the best location for guard detectors to reduce the cosmic background contribution, and the optimum location of various shielding layers. By organizing the book around different detector systems, some material appears several times at different locations, but some repetition is probably warranted. A short section on the principles of operation of various detectors is also included in the book. The information found there on most devices is accurate, but some unfortunate errors are also present (for example, the confusion of Si(Li) detectors with silicon diodes used for alpha spectroscopy and some misinformation about ion implanted devices). Another disappointment is the evident lack of careful proofreading by the compositor. In three cases, the wrong illustration is used in a figure. Numerous references, called out in the text by author and year, are missing in the collection of reference citations. Three of the first four citations contain misprints. One hopes that these and other similar flaws will be rectified in future printings. I can recommend the book as a good collection of information on background and shielding of detector and spectroscopy systems that can save a great deal of library searching, and that provides a good bit of insight on the importance of different components of the background. It is definitely a valuable contribution to the resources available to the radiation measurement community.
by Elsevier Science B.V. All rights reserved