Quantum Energy of -Rays Excited by Slow Neutrons

Abstract

IN the course of investigation on -rays excited by neutrons, we have recently determined the absorption curves of the secondary electrons due to -rays emitted from 24 elements, namely, H, Al, Cl, K, Ti, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Br, Y, Ag, Cd, Sb, I, Sm, W, Au and Hg, under the bombardment of slow neutrons, by means of the method of coincidence of two counters. The form of the curves obtained differs considerably from element to element, and the ratio of the half-value thickness to the maximum range of the electrons is by no means a constant for different elements, indicating the inappropriateness of the use of the former as the measure of -ray energy. The difference in the form of absorption curves should, of course, be understood to be due to the different heterogeneity of -rays.