Atomic structure calculations of KLL Auger spectra from highly charged ion-solid-surface collisions.

Abstract

Systematic atomic structure calculations of [ital KLL] Auger electron spectra from hollow'' atom configurations 1[ital s]2[ital l][sup 2]3[ital l][sup [ital Z][minus]3] are performed for atomic numbers 6[le][ital Z][le]10. In comparison with the corresponding 1[ital s]2[ital l][sup 2] Li-like configurations it is shown that the additional [ital Z][minus]3 [ital M] electrons, apart from taking part in [ital LLM] Coster-Kronig transitions, can be regarded basically as mere spectator electrons, neither severely influencing the peak structure due to the Li-like core nor affecting the [ital KLL] Auger transition rates. However, due to screening effects the spectra are shifted to higher energies by an amount scaling with [radical][ital Z][minus]3 when adding the [ital Z][minus]3 [ital M] electrons. The results facilitate the identification of distinct narrow peaks in projectile [ital K] Auger spectra observed in slow highly charged ion-surface interactions. It is shown that especially competing [ital LLM] Coster-Kronig transitions have to be considered in order to account for the measured relative peak intensities. A cascade model of the last deexcitation steps of a highly charged ion in front of the surface based on the atomic structure data provides detailed insight into the time scales involved.