Neutralization of hyperthermal multiply charged ions at surfaces: Comparison between the extended dynamical overbarrier model and experiment

Within a semiclassical model, we investigate the dynamic neutralization and relaxation of slow (E kin 100 eV) multiply charged ions which are reflected on metal surfaces. Special emphasis is devoted to nearsurface interaction mechanisms. Our model includes a Monte Carlo sampling over projectile parameters and detailed ionic structure calculations of projectile energy levels. In a full trajectory simulation, our results simultaneously comply with measured trends in projectile kinetic energy gains and finalcharge-state distributions of the reflected ions as well as total electron yields and spectra. Recently discovered characteristic features in the electron spectra can be uniquely assigned to distinct above-surface regions of the projectile trajectory. S1050-2947 99 03009-7