PLASMON EXCITATION BY CHARGED-PARTICLES MOVING NEAR A SOLID-SURFACE

The interaction of fast charged particles with a semi-infinite medium is described using both quantum-mechanical and semiclassical dielectri c formulations. We consider the coupling with bulk and surface excitat ions for arbitrary trajectories of the particle and apply the solution s to several cases of special interest. Interference effects in bulk a nd surface excitations for some particular trajectories are described. We analyze in detail the process of reflection-electron-energy-loss s pectroscopy, obtaining results for the probabilities of multiple bulk- and surface-plasmon excitations. The calculations are compared with av ailable experimental results, showing a good description of the angula r dependence of the excitation phenomenon.