Positron Scattering from Xenon

Abstract

The elastic cross-sections for positron scattering from Xe have been determined by the polarized-orbital method while the excitation cross-sections have been calculated within a distorted wave framework in an energy range up to 200 eV. The total cross-section is compared with available experimental results for xenon. We analyze the relative contributions to the total cross-section of our elastic and excitation cross-sections and of the cross-sections for positronium formation and for ionization from other publications. We compare these results with experimental measurements for the total cross-section. Our results are in satisfactory agreement with the experimental measurements at low energies, but differ at energies where positronium formation is important. At energies above 100 eV our total cross-section is displaced above the experimental curve by 20%, suggesting a systematic error either in the experimental results or in one or more of our theoretical calculations.