The Determination of Ion?Atom Interaction Potentials

Abstract

It is shown that given the present state of both theory and experiment the magnitude and form of the well in the interaction potential for an ion-atom system cannot be determined by comparing measured and predicted transport coefficients. The theory of Kumar and Robson (1973) is used to demonstrate that significantly different interaction potentials can be used to predict essentially the same transport coefficient data. Alternative techniques for determining the potential well are discussed, with particular emphasis on the possibility of analysing differential cross-section measurements taken under conditions where the rainbow oscillations are masked by the resolution of a typical apparatus.