Energy spectra of electrons backscattered from thick layers of C, Al, Cu, and Pb bombarded with 15.0- and 24.8-MeV electrons

Abstract

Energy spectra of backscattered electrons from thick layers of C, Al, Cu, and Pb bombarded with 15.0- and 24.8-MeV electrons were measured at 120°. The variation of the observed energy spectra with initial electron energy is shown graphically by plotting the data against E/E0, where E0 and E are energies of initial and backscattered electrons, respectively. Frank’s prediction concerning energy distribution of backscattered electrons is supported by two energy spectra observed in the present work. The atomic-number dependence of relative values of differential number- and energy-backscattering coefficients and average energy of backscattered electrons is shown. All of them become larger as Z increases as supporting a simple insight that predicts that a high-Z material can reflect more electrons than a low-Z material.