Survey of Recent Theoretical Results on Positron Scattering in Gases : Intermediate and High Energies

Abstract

Positron-gas collision experiments are of great interest not only because they yield direct information on the interactions of positrons with atoms and molecules, but also because they can help us to understand better electron-atom (molecule) scattering. A review of the first decade of activity in the field of e⁺-gas experiments, which started in 1972, has been given by Stein and Kauppila (1982). In addition to total cross section measurements, a new generation of experiments aiming at the determination of integrated cross sections for elastic scattering, excitation, ionization and positronium formation as well as some differential cross sections have either been performed or are being planned. In this article I shall give a survey of recent theoretical work dealing with these processes, for incident positron energies well above the ionization energy of the target, but non-relativistic. Atomic units (a.u.) will be used.