PROCESSES INVOLVING A CHANGE IN THE CHARGE STATES DURING INTERACTIONSOF HE2+ IONS WITH FULLERENES

The cross sections for the elementary processes involving a change of the charge states of both particles during the interaction of He2+ ion s with fullerene molecules are for the first time measured over a broa d energy range of electron-volt energies. It is found that processes i nvolving the capture of one or two electrons by the He2+ ions are acco mpanied by additional ionization of the fullerene and that the collisi onal contribution of the transfer-ionization processes increases with increasing velocity. Single-electron capture is rarely accompanied by fragmentation of the fullerene. Double-electron capture leads, with a higher probability, to fragmentation with the formation of several lig ht charged fragments and, with a smaller probability, to fragmentation with the formation of a heavy charged fragment containing an even num ber of carbon atoms and light fragments in an uncharged state. (C) 199 8 American Institute of Physics. [S1063-7842(98)00304-3].