Forward and backward electron emission induced by protons from copper foil

Forward and backward secondary electron emission induced by normal incidence of 1.5 MeV protons from 5 μm copper foil was experimentally studied. Measurements were carried out by means of two low-aperture retarding field energy analyzers, which were installed symmetrically on each side of the target at the angle of 53 degre with respect to the projectile beam. The relation of electron yields of forward and backward emission was obtained. Electron distribution functions were measured in 0...90 eV energy interval. The comparative analysis of electron distribution for forward and backward cases was performed and possible reasons for the differences observed were discussed.