Calculations of neutral fractions and angular distributions for H(1s) and H+ impinging on Al(111) at grazing incidence

We have computed H(1s) angular distributions and the corresponding neutral fractions for ground state hydrogen atoms and protons impinging on an Al(111) surface under a grazing angle of incidence of 0.56° within the 1-100 keV impact energy range. Capture and loss for resonant and Auger processes are taken into account as well as the surface-plasmon-assisted electron capture mechanism. Comparisons between our calculations and available experimental angular distributions at 25 keV allow to some extent to discriminate between the various theoretical reports used in the present work for the resonant process transition rates. The same kind of comparison for a lower impact energy like 6.25 keV, for which we report predictive results, would allow to better identify the correct result (if any) for the resonant mode and in that way to gain insight on the theoretical description of the very near surface region.