Inelastic effect in low-energy He+ ion scattering from solid surfaces

Values of the inelastic loss energy Q are investigated for the systems (He+-Ag, Au, Ta, and W) by the scattered-particle method at a fixed scattering angle of 900 and incident ion energies ranging from 300 to 1000 eV. The experiments are performed by an ISS unit with high energy resolution. It is found that the observed loss Q gradually increases and reaches about 5-6 eV even for Ag and Au surfaces at the incident energy of 1000 eV. In addition, the data for the oxygen contaminated Ta, and W surfaces suggest that two inelastic loss processes are involved and one of these is enhanced by the existence of oxygen. (orig.)