Surface-plasmon assisted Auger transitions in grazing collisions of ions with simple metal surfaces

The dependence of surface-plasmon assisted decay of excited atomic p-levels to s-levels in front of simple metal surfaces on the particle velocity parallel to the surface plane is studied within a dielectric linear-response theory. This non-radiative de-excitation channel can be rather likely, provided the atomic transition energy is close to the surface-plasmon energy. Furthermore, a strong orientational effect of this damping process on the mean orbital angular momentum of the atom is found as a consequence of the particle motion parallel to the surface plane.

The reverse process, that is, surface-plasmon assisted excitation is also discussed.