No abstract

Recently, transition probabilities for Auger neutralisation of He'+ have been calculated for the case where the ion moves parallel to the surface with constant velocity 2 and where one conduction electron is captured i n a 2p-state of He+ /l/. The neutralisation rate was evaluated as a function of d and of the distance s between ion and surface. The calculations were performed by applying a simple model developed by Horiguchi et al. /Z/.In this note we briefly discuss the dependence of the neutralisation r a t e s on the nuclear charge Z of the incident ion, a s a function of the velocity a t fixed distances s. Our main purpose i s to get some rough ideas and first estimates about some of the relevant effects. We therefore apply the crude approximations discussed in /I/. The equations given in /I/ can be applied to the present case of interest if we substitute the expression 7 u + Z /4 for the parameter a in (8) to (11) of /1/ and if we multiply the total transition r a t e P ( s , u) by (Z/2)'.In /1/ a coordinate frame was used where the z-axis was parallel to the normal of the surface and the x-axis parallel to d. For the present calculations it is useful to choose a different coordinate frame with the y-axis parallel to the normal, the x-axis parallel to $, and the z-axis (quantisation axis) p e rpendicular to the x-y plane. In this frame we calculate the transition probabilities l M n (M) 1 for Auger processes where one of the electrons is captured in a Zp-state of the ion with magnetic quantum number M. 2These probabilities can be related to the parameters I At of /1/ by applying standard formulas of the angular momentum theory:1)

Auger neutralization of fast Het+ moving parallel to a solid surface a t constant distance s is discussed. Results for the transition rate as a function of s and the impact energy of the ions are presented. The orientation for the Het2p-states is also calculated leading to the conclusion that orientation effects due to Auger neutralization cannot be neglected a priori compared to those due to charge exchange.Es wird Auger-Neutralisation von schnellen Hett-Ionen, die sich parallel zu einer Festkorperoberfliiche mit einem konstanten Abstand s bewegen, diskutiert. Ergebnisse fur die ubergangsrate als Funktion von s und der EinschuBenergie der Ionen werden angegeben. Die Orientierung fur die Het(2p)-Zustande wird ebenfalls berechnct mit dem Ergebnis, daB Orientierungseffekte durch Auger-Neutralisation nicht a priori vernachlassigt werden konnen im Vergleich zu denen durch Ladungsanstausch.

Auger neutralisation of Li3+-nuclei moving parallel to a metal surface (Al) is considered. For the case of capture of one electron in the 2porbital of the nuclei the charge distribution of the ions is calculated and interpreted.Es wird Augerneutralisation von Li3 +-Kernen, die sich parallel zu einer Metalloberflache (Al) bewegen, betrachtet. Fur den Fall des Einfangs eines Elektrons in das 2p-Orbital der Kerne wird die Ladungsverteilung der Ionen berechnet und interpretiert.