Electron transfer to excited projectile states after grazing ion-surface scattering

Abstract

Abstract We have scattered 3–30 keV H+-, H2 +-, Na+-, K+-ions from clean Al(111)- and Ni(111)-surfaces at grazing angles Φ < 1° and studied electron transfer to excited projectile states by means of optical spectrometry. We observe in general a rapid decrease in level excitation probability with increasing level excitation energy. For Na+-Al scattering we find a rather strong variation of relative level excitation probabilities with projectile energy, whereas this variation for the interaction with the nickel target is poor. The data are discusseed in the framework of a two-step model: close encounter collisions in the vicinity of the surface and population of excited terms of receding ions via resonant electron transfer.