Ion induced kinetic electron emission from highly oriented pyrolytic graphite by impact of H +, C +, N +, and O +

Total electron yields from highly oriented pyrolytic graphite (HOPG) have been measured for perpendicular impact of H ⁺, C ⁺, N ⁺, and O ⁺ projectile ions with kinetic energies from a few hundred eV up to 30 keV. The data are interpreted within a model for kinetic electron emission based on non-adiabatic time-dependent perturbation of valence-band electrons by the moving particle. The microscopical parameters of this excitation processes describe well the qualitative trends in the experimental data when changing the target from HOPG to polycrystalline gold.