THEORY OF THE MOMENTUM DISTRIBUTION OF SWIFT IONS AND ITS APPLICATION TO SURFACE SCATTERING

We propose a method to calculate the momentum distribution of swift ions. Since we treat the Hamiltonian by the real-space representation, the method is applicable to inhomogeneous media such as the surface system. We outline the theory and also present its applications to the surface system. The theory is useful for the study of the effect of electronic excitations on grazing-incident ions scattering from metal surfaces, and it points out a peculiarity of surface electronic excitations due to coupling between surface-parallel and -normal momenta of the surface electronic system. This coupling may be important for the skipping motion and related phenomena reported recently. © 1990.