Coulomb interaction in the final state of electron impact ionization: Effects on the triple differential cross section.

Abstract

An approach to the calculation of the impulsive (e,2e) cross section, which extends the plane-wave-impulse approximation to include the long-range tails of the Coulomb interaction in the final state, is presented. The model divides the collision space into two regions: an inner sphere where short-range forces are active and responsible for the impulsive character of the collision, and an outer region where the tails of the Coulomb interactions act on the charged free particles, which can be treated in a semiclassical way. An extensive comparison between the predictions of this model and experimental data relative to atomic hydrogen and helium, as derived from the literature, is presented. The model constitutes an improvement over previous impulsive models, mainly for the angular distributions of (e,2e) events.