Triple-center determination of differential cross sections for electron transfer and elastic scattering in alpha -H collisions.

Abstract

Differential cross sections have been calculated for electron transfer and elastic scattering of 20- to 125-keV ..cap alpha.. particles on H(1s) atoms. The transition amplitudes in the eikonal expression for the scattering amplitude are those recently determined in a large triple-center, coupled-state calculation with up to 34 states on the centers, including a third center at the saddle point of the electronic potential. The differential cross sections are compared at 20 and 70 keV with recently reported results using a coupled--molecular-state approach. There is very good agreement at the lower energy, but significant disagreement at the higher energy, particularly in the smaller, more sensitive elastic differential cross section.