Classical description and calculation of ionization in collisions of 100 eV electrons and positrons with He and H2

Abstract

In order to explore the range of applicability of the classical trajectory Monte Carlo technique concerning the phenomena associated with light-particle impact of atoms and molecules, the authors present calculations of the singly and doubly differential cross sections for 100 eV electron and positron impact of He and H2. Through comparison with experimental measurements it is noted in what regimes of ejection energy and angle the classical model describes reasonably the process of ionization by electrons. They find that reasonable agreement is obtained regarding the integrated (singly differential and total) cross sections, while the features of the doubly differential cross section which evidently come about due to quantum mechanical aspects of the collision are not reproduced. In these instances the classical cross sections reflect an averaging over electron angles and energies of the observed doubly differential cross sections.