Charge state of ions scattered by metal surface

Abstract

A model for description of charge distribution for scattering of heavy ions in the keV region, on metal surfaces developing and improving the method of Van der Weg and Bierman, and taking into account the connection between the ion charge state and scattering kinematics, is proposed. It is shown that multiply charged particles come from ions with a vacancy in the inner shell while the outer shell vacancies give only single charged ions and neutrals. The approximately linear increase of degreee of ionization with normal velocity, and the non-monotonic charge dependence of the energy spectrum established by Chicherov and Buck et al. is explained by considering irreversible neutralization in the depth of the metal, taking into account the connection of the charge state with the shape of trajectory and its location relative to the metal surface. The dependence of charge state on surface structure is discussed. Some new experiments are proposed.