SUPPRESSION OF POTENTIAL ELECTRON-EMISSION FOR IMPACT OF SLOW MULTICHARGED FULLERENES ON CLEAN GOLD

We have measured absolute total electron emission yields for impact of carbon cluster ions C-i(q+) on atomically clean gold, as a function o f cluster size (up to i = 60), charge (up to q = 5), and kinetic energ y (up to 165 keV). Besides a linear dependence on cluster size and occ urrence of electron emission well below the classical kinetic emission threshold, we find no dependence on the fullerene charge, and thus a suppression of potential electron emission. This is in contrast to the interaction of multicharged atomic ions with surfaces. We present mol ecular-dynamics calculations which provide evidence of fast quenching of the primary excitation energy via fragmentation of the projectiles.