SELF-ABSORPTION IN SOURCES PREPARED FOR 4π BETA COUNTING

Abstract

Using the 4πβ-γ coincidence method the self-absorption of 4πβ counting sources prepared by a number of source preparation techniques has been measured for the negatron emitters Cs134 (86-kev branch only), Nb95, Hg203, Co60, Sc46, Rb86, Au198, Na24, and the positron branch of Cu64. The self-absorption varied from a few tenths of one per cent to about ten per cent for sources with a mean superficial density of 2 μg/cm2 for most of the nuclides studied. Subsidiary experiments were carried out to indicate the variation of self-absorption with source superficial density.