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

Abstract

Within a semiclassical model, we investigate the dynamic neutralization and relaxation of slow ${(E}_{\mathrm{kin}}<100\phantom{\rule{0ex}{0ex}}\mathrm{eV})$ multiply charged ions which are reflected on metal surfaces. Special emphasis is devoted to near-surface 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 final charge-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.