Stabilization of energy spectra of cesium-137 beta particles passing through substances

The energy beta-spectra of 137Cs after radiation passing through beryllium, aluminium, nickel and mica absorbers with a variable thickness are measured. The beta-particle group of the continuous spectrum shows the effect of energy distribution stabilization after passing the absorbers; the group of monoenergetic beta-particles (conversion electrons) reveals the linear decrease in the most probable energy with an increase in the thickness of an absorber. The beta-particles energy distribution characteristics of 137Cs, 90Sr, 90Y-based bulk sources have been discussed. The absorption coefficients for the sources and absorbers mentioned as well as the true range-to-cross range ratio of beta particles for these absorbers are presented