Electron Loss Processes in Three- and Four-Electron Systems

Abstract

In this work, the Independent Event Model (IEVM) is employed to analyze the total electron loss and the loss-ionization processes in intermediate-velocity collisions between multiply-charged projectile ions and neutral targets, for collision systems with three and four electrons in processes where up to three active electrons are involved. The IEVM was applied to the analysis of the single loss of Li+ and Li2+ ions by He atoms with the simultaneous single and double ionization of the target. All the possible ionization mechanisms for both collision partners in each exit channel were considered. The probabilities were calculated using either a straight-line version of the semi-classical approximation or the coupled-channel method. The anti-screening contribution was also taken into account. The calculations describe well the experimental energy dependence and the high-velocity absolute values for the cross sections for single electron loss accompanied or not by the ionization of the target.