The efficiency tracing technique for eliminating self-absorption errors in 4π β-counting

Abstract

This paper examines in detail the validity of a standardization technique recently described by Merritt et al. in which the advantages of the 4π β-γ coincidence method in eliminating self-absorption errors are extended to pure β-emitters by the addition of suitable β-γ “tracer” nuclides. Calculations based on several models for the self-absorption process together with further experimental results supporting the method are presented and compared. The use of these theoretical considerations in making corrections for complex disintegration schemes in coincidence counting is discussed. The application of this “tracer” technique to nuclides having complex disintegration schemes is demonstrated for Rb 86 and the result used to obtain a value of 8·7 ± 0·2 per cent for the fraction of disintegrations populating the 1·08 MeV level in Sr 86.