AUGER RATES AND SPECTRA FOR SIMPLE-MODELS OF HE-SURFACE( IN FRONT OF A METAL)

Within an extensive study of Auger-transition rates for a system consi sting of a He+-ion in front of a metal surface, we have previously fou nd a scaling W is-proportional-to n1.8 between the rate W(z) and the l ocal density n(z) of the electronic tails into the vacuum. In our calc ulation the use of unperturbed metal wavefunctions, made orthogonal ag ainst the He+-orbital, forms the main approximation. In this paper we study the robustness of our results by employing a second, modified mo del. The influence of the ion on the form of the metal wavefunctions i s mimicked within the jellium model by a positive charge sheet. The mo dification of the electronic states induces some quantitative changes in the Auger rate, but the scaling of the rate and the density remains preserved. Computed spectra for the two models appear to depend quali tatively on the exact form of the wavefunctions. A numerical analysis of the localness of the Auger interaction provides some insights for t he form of the scaling.