He(1s) angular distributions simulations for He(1s) on Al(1 1 1) collisions in the keV energy range at grazing incidences

We have calculated charge fractions and angular distributions of scattered He atoms resulting from the interaction of keV He⁺ beams at grazing incidences with an Al(1 1 1) surface. Several improvements over our earlier approaches have been incorporated. These are a more sophisticated RPA image potential for the ion-metal interaction as well as kinematic factors affecting the static rates for the Auger transfer mechanisms. For interaction cases in which both perpendicular and parallel velocities are low, we obtain angular distributions which have a better agreement with the experimental data than our earlier version of the theory, although still the theoretical results do not reach total neutralization of the beam as the experimental results show.