Suppression of Auger-neutralization in the scattering of noble gas ions from the surface of an insulator

We have scattered noble gas atoms and ions from a clean and flat LiF(100)-surface under a grazing angle of incidence and observed for He+- and Ne+-projectiles a substantial survival in the collision. We interpret our findings in terms of a suppression of the Auger-neutralization for these ions in the interaction with the surface of the insulator. Due to the high binding energies of valence band electrons and the large energy gap for LiF Auger transition rates seem to be clearly reduced in comparison to those rates for metal targets.