Secondary electron emission in the scattering of fast probes by metallic interfaces

Abstract

In the frame of a nonretarded local density hydrodynamic approach nonlocal effects in the scattering of a fast probe interacting with a metallic interface are studied. In addition to quantal effects in the electron-gas response, effects derived from the interface density profile are taken into account. The relevance in the excitation spectrum of both collective and single electron excitations is studied. For probes at grazing incidence the decay of collective excitations into single electron ones is found. Around the surface plasmon frequency the momentum carried by these excitations allows identifying them as secondary electrons emerging from the target. The recoil associated with them leads to a repulsive force with qualitative agreement with experimental observations. Effects of the momentum transfer in the deflection angle of the beam are also studied.