Interaction of He and Ne with Cu surfaces

he extensive data available for He and Ne beam elastic scattering from Cu surfaces are analysed by full quantum mechanical calculations and by describing the atom-surface interaction potential according to the present knowledge on van der Waals pair potentials. It is shown that Ne penetrates the surface electron cloud much deeper than He and that the ratio of Ne-to-He adsorption energies exceeds the ratio of the atomic polarizabilities.