Fission and liquid-drop behavior of charged gold clusters

Fragmentation measurements on doubly charged Au clusters show that clusters smaller than 18 atoms decay by fission (i.e., two charged cluster fragments) and neutral-atom evaporation. The fission probability is found to increase relative to the evaporation probability with decreasing cluster size, roughly as an exponential function of ${\mathit{z}}^2$/n, where n is the number of atoms in the cluster. The results are found to be in good agreement with an adapted version of the nuclear liquid-drop model.