Scattering of H at Ni surfaces:charge exchange and energy loss

Abstract

Hydrogen is scattered at grazing incidence from Ni(111) and Ni(110) surfaces. Significant differences are found in the energy loss and the energy loss straggling as a function of the primary energy between 300 eV and 5keV. The energy losses of the different exiting charge states H 0, H +, H − for incident H + when scattered from Ni(110) are equal, so is the energy loss straggling for H 0 and H −. The straggling of exiting H + is enhanced. The charge state fractions as a function of the particle energy agree with previous findings, i.e. the H + yield increases with energy and the H − yield exhibits a flat maximum at about 3 keV. A theoretical model which accounts for all three charge states and reproduces the experimental findings is proposed.