Neutralization of charged fullerenes during grazing scattering from a metal surface

The neutralization of C-60(+) and C-60(2+) fullerenes with keV energies is studied for grazing scattering from a clean and flat Al(001) surface. From the measured shifts between the angular distributions for scattered projectiles of different incident charge, we derive image-charge interaction energies, which relate to the distances of electron transfer for C-60(+) and C-60(2+). These neutralization distances are in accord with a classical over-the-barrier model taking into account the image-charge effects of the Al target and the polarization of the fullerene.