Spatially resolved $K$-Auger emission of hyperthermal highly charged ions at an Al(111) surface

Within the framework of a scattering model for electrons leaving the solid, the location of emission of Auger electrons ejected by highly charged H-like and He-like ions impinging on Al(111) can be determined when comparing the Auger electron spectra at observation angles 45° and 0.8° with respect to the surface plane. The distinct modifications of the spectra due to plasmon energy loss structures allow to attribute locations of emission to specific K-Auger processes of H-like and metastable He-like C5,4 + ions and N6,5 + at 1 eV per charge experimental vertical kinetic energy.