Grazing incidence collisions of multiply charged ions on solid surfaces. Influence of the formation of intermediate Rydberg states

Abstract

We elaborate the quantum-mechanical analysis using the two-state vector model to investigate the formation of intermediate Rydberg states of multiply charged ions (core charge Z ≫ 1, principal quantum number n A ≫ 1) interacting with solid surfaces in the grazing incidence geometry. For the fixed initial and final states of the active electron, the two wavefunctions are used to describe the transitional electron state at the time t. Considering the projectile motion classically, the effect of projectile velocity is taken into account in accordance with Galilean invariance. The population probabilities of the intermediate Rydberg states are obtained in the analytical form, which enables an analysis of the localization and the selectivity of the process, for various ion-surface parameters. Ions Ar Z+, Kr Z+ and Xe Z+ with Z ∈ [5, 35] interacting with Al-surface are considered as an example. The results are compared with the classical overbarrier predictions and the measured kinetic energy gain due to the image acceleration of the ions. It is demonstrated that the ionic velocity influences the ion-surface distance at which the formation of the particular intermediate Rydberg state is mainly localized, as well as the probability for this formation. © 2012 IOP Publishing Ltd.