Acceleration of clusters, collision induced charge exchange at MeV energies and applications for materials science

Small clusters of C-n, Si-n and Ge-n (n less than or equal to 10) and fullerenes have been accelerated at the Zurich tandem accelerator to energies up to 8 MeV. Single positively charged cluster beam currents up to several nA have been reached. The production of negatively charged clusters, for injection into the accelerator, with a caesium sputter ion source has been studied. Measuring the transmission through the tandem as a function of the target density within the gas stripper allowed us to determine the cross sections for collision induced destruction (2-10) X 10(-15) cm(2) and the charge exchange from q = -1 to q = 1, similar to 3 X 10(-16) cm(2), in the MeV range for N-2 and Ar as target gas. In addition AFM images of C-60 impacts on mica are shown.