Charge exchange and cluster formation in an rf Paul trap: interaction of alkali atoms with C+60

A Paul ion trap was used to study the formation of clusters under controlled temperature and pressure conditions. Exposure of cold C+60 ions to Li flux leads to the formation of LinC+60 clusters (n = 1–18) occurring by the sequential association of Li atoms. Cluster formation dependence on He pressure displayed a competition between vibrational relaxation and unimolecular dissociation. Collisions with Na, K, Rb and Cs atoms resulted in dissociative charge exchange. Decay rates of C+60 ions resulting from these low-energy charge exchange collisions were consistent with Langevin capture rates.