Tests of alkali ion-inert gas interaction potentials by gaseous ion mobility experiments

Abstract

Gaseous ion mobilities are mainly dependent on ion–neutral collision energies in the range 0.03–1 eV and, using a recently developed kinetic theory method, can be directly related to ion–neutral interaction potentials. In this paper, experimental mobilities are used to test recent theoretical calculations based on the electron–gas model of the interaction potentials for the twelve combinations of Li+, Na+, K+, and Rb+ with He, Ne, and Ar. The model potentials are quite good, but some systematic discrepancies with experimental mobilities exist. These discrepancies are analyzed in terms of the relation between the mobility and the ion–atom potential.