Electron emission induced by hydrogen atoms and protons incident on aluminium: effect of the projectile charge state

It is well known that the charge state of incident ions has an influence on the stopping power as well as on the electron emission characteristics. We have studied here electron emission for protons and hydrogen atoms incident on polycrystalline Al targets for impact velocities up to 2v0 (v0 is the Bohr velocity). Besides the direct excitation of target electrons by the incident projectile, we have considered different charge changing processes that give rise to additional electron excitation, hence contributing to electron emission. These processes are also responsible for the charge state dynamics of the moving projectile. We compare our results with previous results and in particular with the predictions of the simple model proposed by Ghosh and Khare [Phys. Rev. 125 (1962) 1254]