FISSION OF METALLIC CLUSTERS IN THE LIQUID-DROP MODEL

Using the liquid drop model and the jellium model, we calculate fissio n barrier heights as a function of charge and mass asymmetry for a fam ily of shapes consisting of two spheres connected by a quadratic surfa ce. We find the fissibility for which a mass asymmetric splitting give s place to the symmetric one (Bussinaro-Gallone point) and evaluate th e size of charged clusters of alkali metals for which the fission barr ier height is equal to the evaporation energy (critical sizes). The re sults for the critical sizes agree very well with experiment.