Evaporation and cluster abundance spectra

Statistical fragmentation can give valuable information on the internal str ucture of clusters due to the:strong dependence of the evaporation rate on the activation energy for the process. In particular, the abundances in an ensemble of hot clusters will reflect the relative stabilities of the indiv idual species. We derive the relation between evaporative activation energi es and relative abundances for large clusters. Quantitative criteria for th e applicability of the theory are derived and the analytical results an com pared with numerical simulations. [S1050-2947(99)05208-7].