IMAGE CHARGE ATTRACTION OF MULTICHARGED XE-IONS IN FRONT OF INSULATORSURFACES

Multicharged Xe-q+-ions (q < 20) are scattered with keV energies under a grazing angle of incidence from the surface of two different insula tors: LiF(100) and KI(100). From the analysis of angular distributions for scattered projectiles we deduce energy gains caused by the dielec tric response of the target material due to the presence of the extern al charge (''image charge interaction''). A direct comparison of the i nteraction energies gained by the projectiles on the incident path wit h the two different targets is consistent with the assumption of a dom inant population of Rydberg levels (''hollow atom'') in front of insul ators for grazing ion-surface scattering.