Si-Auger electrons from the center of nuclear tracks

Using a new ultra-high vacuum system we were able to measure ion-induced Auger electron spectra with high resolution for atomically clean amorphous Si surfaces. Measurements were performed with Ne9+ and Ar16+ ions at 5 MeV/u, Xe15+ and Xe31+ ions at 1.78 MeV/u as well as with incident electron at the two speeds, corresponding to 2.7 keV respectively 1.0 keV. The ion-induced spectra show peaks due to multiple ionization, indicating 7- or 8-fold ionization in the center of ion tracks for fast Xe ions. The Auger peaks are shifted and broadened with respect to the electron reference data. This is an indication for the nuclear-track potential and for hot electrons being present during the decay of the Auger states. (C) 2002 Published by Elsevier Science B.V.