A variationally modified Thomas-Fermi approach to the repulsive potential between noble gas atoms and positive and negative ions of spherically symmetric electron configurations

Abstract

Recent beam experiments (in the keV range) have shed light on the repulsive potentials that exist between closed-shell positive and negative ions of spherically symmetric electron configurations and noble gas atoms. It is shown that the measured repulsive potentials, which arise from such scattering events, can be calculated to within at least a factor of two, or better, on the basis of simple theoretical considerations which make use of recent variational modifications of the Thomas-Fermi (TF) model for neutral atoms, and for positive and negative ions. In advancing the present theory, a discussion is given why the criticisms of Teller and Balazs concerning the use of the original TF model in such calculations are believed to be rescinded when the variationally modified TF models of atoms and ions are used. It is concluded that the present theory might be a desirable one for obtaining estimates of the repulsive potentials that exist between colliding systems whose study might not be amenable to experiments in the laboratory. Into this category fall collision events, whose existence might be of interest in astrophysical problems.