FUSION AND RAINBOW SCATTERING OF C60+ ON CRYSTALLINE FULLERITE FILMS

Impact of C60+ ions onto an epitaxially grown crystalline fullerite ta rget is studied at a primary kinetic energy of 275 eV as a function of the angle of incidence. Scattered ions are investigated by velocity s elective time-of-flight mass spectrometry at a fixed scattering angle of 140-degrees. In addition to scattering of intact C60+ ions we also see desorbed C70+ as well as larger ions C100+ to C130+ arising from r eactive processes (fusion, coalescence). The velocity distribution of the receding C60+ ions reveals a range of processes from nearly elasti c to fully inelastic. The angular dependence exhibits rich structure. This May be attributed to rainbow scattering, as confirmed by a simple classical trajectory calculation.