Measurement of Low-Level Radioactivity-581CB5DF

This Report describes and discusses many methods of measurement of low-level radioactivity and presents an assessment of the capabilities of various methods. The report includes guidelines developed to assist the reader in choosing those procedures best suited to particular problems. While a numerical definition of "low-level radioactivity" cannot usefully be given for an unspecified context, it may be said, in general, that the report is concerned with procedures that are particularly relevant when achievement of the desired precision of counting is difficult in the counting time available. Report 22 focuses attention on problems of special importance in the assay of low activity samples, especially those encountered in the field of environmental monitoring and in some aspects of medical and biological work. Consideration of the measurement of radioactivity in the living subject, however, is not included in the report.

The introductory chapter of the report treats extraneous counts, counting statistics, analytical procedures and standardized reference sources. This is followed by five major chapters - sample treatment, assay of gamma- and x-ray emitters, assay of beta-particle emitters, assay of alpha-particle emitters and standardized sources and reference sources.