Ion-pair dissociation of highly excited carbon clusters, size and charge effects

Ion-pair dissociation of a highly excited molecule is a relaxation process giving rise to emission of anionic and cationic fragments. We present first measurements of ion-pair dissociation of carbon clusters. We found that ion- pair relaxation is an ubiquitous, although very small, relaxation channel common to all sizes and charges of C^q+_n species produced in high velocity C⁺_n-He collisions. Quantitative interpretation of measured branching ratios is conducted on the basis of a statistical approach i.e through listing of all possible final states. (paper)