Secondary Electron Production from Metals by 1-Mev Protons

Abstract

Be, Al, Cu, and Au targets were bombarded with 1-Mev protons. The resulting secondary electrons were investigated in respect to their intensity, energy distribution, and energy distribution as a function of angle of emission. The results show that, contrary to previous investigations, electrons with energies higher than those corresponding to the so-called "local-heating" effect contribute considerably to the total yield. About 75% of the secondaries are emitted at low energies, and the remaining part is emitted with high energies (up to 2000 ev for 1-Mev protons). The electron spectrum decreases rapidly toward the high-energy end. The high-energy component is not emitted isotropically, but preferably backwards in the direction from which the protons arrive.