INTERACTION OF SLOW MULTICHARGED IONS WITH SOLID-SURFACES - CURRENT CONCEPTS AND NEW INFORMATION ON SLOW-ELECTRON EMISSION

Slow multicharged ions (MCI) approaching a solid surface are transient ly converted into highly excited complexes, involving a potential ener gy possibly much larger than the kinetic projectile energy. De-excitat ion of such complexes proceeds within less than one pico-second via a manifold of interrelated reaction channels, giving rise to characteris tic signatures as slow and fast electron emission, and X-ray radiation . For impact on MF, also potential-energy dependent ejection of neutra l and ionized target particles has been observed. Before their close c ontact with a metal surface, MCI are converted by multiple capture of target electrons into the so-called hollow atoms which rapidly decay b y autoionization, at the surface loose outer electrons due to shieldin g, and eventually become de-excited inside the solid. At insulator sur faces, MCI neutralization and de-excitation is less well understood. R ecently measured electron number statistics for MCI impact on clean me tal (Au) as well as insulator (LiF) surfaces deliver interesting new i nformation.