Glory undulations in the total cross section for ArAr, Kr, Xe and KrAr, Kr

Abstract

The glory undulations in the velocity dependence of the total cross section Q have been accurately measured for the scattering of the noble-gas systems ArAr, ArKr, ArXe, KrAr and KrKr. We present a new method to describe quantitatively the results of these measurements. A least-squares analysis of the data is performed, using a seven-parameter function, based on the semiclassical description of small-angle molecular scattering. From this function we calculate the value of the exponent s of the attractive part V a of the potential, generally described by V a = − C s r −s and we calculate the positions of the extrema in the glory undulations. We determine the product of the potential well depth ϵ and the well position r m that in first order determines the phase of the glory undulations. Small deviations from existing potentials are found. The method of analysis also offers a quantitative separation of the glory contribution and the attractive contribution to Q that is essential to find the potential parameter C 6 in case absolute values of Q are measured. The description given here offers the possibility to incorporate the total cross section data in a new multiproperty analysis.