Dissociation Channels for Multiply Charged Clusters

Size distributions of fragments from multiply charged clusters have been determined. On a time scale of 0.1 ms with respect to ionization, triply charged C${\mathrm{O}}_2$ clusters of size $n\approx 114$ are found to fission extremely asymmetrically, their doubly charged fragments carrying 92% of the mass. For doubly charged C${\mathrm{O}}_2$ clusters, however, evaporation of neutral monomers is the only channel for delayed dissociation. A model, based on the liquid-drop approximation, can quantitatively account for the lower size limits of multiply charged clusters as well as for the distribution of fission fragments from (C${\mathrm{O}}_2$) ≅${114}^{3+}$.