Image acceleration of multiply charged ions by metallic surfaces.

Abstract

We present a simulation for the acceleration of multiply charged ions approaching metal surfaces by the interaction with its image charge, based on the classical over-barrier model. The image attraction leads to a gain in velocity perpendicular to the surface. The amount of energy gain is directly related to the distance of formation of hollow atoms. The role of a transient hollow negative ion is discussed. Comparison with recent data by Winter [Europhys. Lett. 18, 207 (1992)] shows good agreement.