Electron detachment of negative ions: The influence of the outermost electron and its neutral core atom in collision with He, Ne, and Ar

Abstract

A systematic investigation of the absolute total detachment cross sections of atomic negative ions is presented and a simple semiclassical model developed based on the experimental findings. The total electron detachment process for several anion species, namely ${\text{C}}^{\ensuremath{-}}$, ${\text{O}}^{\ensuremath{-}}$, ${\text{F}}^{\ensuremath{-}}$, ${\text{S}}^{\ensuremath{-}}$, ${\text{Si}}^{\ensuremath{-}}$, ${\text{Cl}}^{\ensuremath{-}}$, ${\text{Ge}}^{\ensuremath{-}}$, and ${\text{Na}}^{\ensuremath{-}}$, in collisions with He, Ne, and Ar, in the velocity range of 0.2--1.8 a.u., were studied. In the intermediate-velocity regime the experimental data are well reproduced by the proposed model, which assumes independent contributions from the outermost quasifree electron and from the neutral core atom of the negative ion.