Secondary electron/reflected particle coincidence studies during slow highly charged ion-surface interactions

We have measured the secondary electron emission statistics (ES) for 5 keV Nq+ (q = 1-4) ions incident at 10 degrees on polycrystalline aluminium, in coincidence with specularly reflected N-0. In this arrangement the kinetic contribution to secondary electron emission is minimised. The experimental data shows that the coincident electron yield, gamma, increases linearly wi th incident ion charge state. The kinetic emission contribution has also be en determined from this data. The ES due to 2 and 4keV He2+ impact on polyc rystalline aluminium in coincidence with specularly reflected He+ and He-0 have also been determined. The process He2+ --> He-0 yields a larger gamma value than the process He2+ --> He+.