Suppression of potential electron emission for impact of slow multicharged fullerenes on clean gold

Abstract

We have measured absolute total electron emission yields for impact of carbon cluster ions ${\mathrm{C}}_{i}^{q+}$ on atomically clean gold, as a function of cluster size (up to $i=60$), charge (up to $q=5$), and kinetic energy (up to 165 keV). Besides a linear dependence on cluster size and occurrence 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 molecular-dynamics calculations which provide evidence of fast quenching of the primary excitation energy via fragmentation of the projectiles.