Multiple scattering of low-energy rare-gas ions at solid surfaces

We have studied the multiple scattering of He⁺, Ne⁺, and Ar⁺ from a TaC(001) surface in the energy region of the order of 1 keV. The experimental data revealed large differences between the energy spectra of these ions. The spectral peak corresponding to quasi-double scattering is clearly observed for Ar⁺ but not observed for Ne⁺. The multiple scattering effect appearing in the energy spectra of rare-gas ions is discussed on the basis of electron exchange between these ions and solid surfaces.