Neutralization of low energy He+ ions by Cu in the Auger regime

Neutralization of light He-4(+) ions in backscattering geometry is studied on a single crystalline Cu(100) and on a poly crystalline Cu-poly surfaces by means of direct comparison of the ion yields. Below 2 keV neutralization is only restricted to the Auger transition involving two electrons. Measurements in this regime revealed a similar to 35% higher ion fraction for the single crystal Cu(100) with respect to the Cu-poly. The observed difference in the neutralization probability is ascribed to a different extension of the electron jellium edge, resulting from different atomic arrangement. (C) 2007 Elsevier B.V. All rights reserved.