High Energy Electron Impact Ionisation of H(1s) in Coplanar Asymmetric Geometry

Abstract

Various effective charge approximations are explored for the high energy electron impact ionisation of H(ls) in coplanar asymmetric geometry, using a first order perturbative model. Our results are compared with other more sophisticated calculations and with experiment. It is found that effective charge prescriptions satisfying the requirement that, in the limit of zero ejection energy, the escaping electron sees the full nuclear charge while the scattered electron is totally screened, are unsuccessful. In contrast it is found that the Coulomb projected Born exchange approximation, where both electrons see the full nuclear charge, gives much better results. In general it reproduces the position and magnitude of the binary peak fairly well, although it is not so successful in the description of the recoil.