Backward and forward electron emission induced by helium projectiles incident on thin carbon foils: Influence of charge changing processes

Abstract

The backward and forward electron emission yields γB and γF have been calculated by Monte Carlo simulations for helium (He++, He+ or He0) ions incident on thin amorphous carbon foils with energies around the electronic stopping power maximum (0.2–2MeV). Besides the direct excitation of target electrons by the incident projectile, we have taken into account the different charge changing processes (He++↔He+↔He0) undergone by the helium ion in the target. We discuss in particular the connection between the electron emission yield γ and the electronic stopping power (dE/dx)e. We compare our results with previously published experimental results.