Self- and foil-absorptions of low energy internal conversion electrons in 4πβ-counting

Abstract

By means of the 4πe-X coincidence method and simple 4π- counting, the self- and foil-absorptions of low energy internal conversion electrons from 103Ru− 103Rh m (16.8 keV), 127Te m (56.9 keV) and 99Tc m (120–142 keV) were measured for sources prepared by deposition from radioactive solutions with several different carrier concentrations. The minimum self-absorption obtained by the use of colloidal silica can be kept within a few tenths of 1% for 56.9 keV electrons. However, for 16.8 keV electrons, it amounts to about 5%. Although the absorption by the source-mount depends considerably upon the self-absorption, it remains small enough when an ordinary VYNS backing is used. The experiments include the measurements of the self-absorption of β rays from various nuclides which were made in order to check the universality of the source preparation techniques.