Size and temporal dependence of the average kinetic-energy release during the evaporation of sputtered Cs(CsI)ₙ⁺ clusters

The average kinetic-energy release is measured for the evaporation of CsI and (CsI)₂ molecules from sputtered Cs(CsI)ₙ⁺ clusters (n=2--17) in two different time windows. Size and temporal (temperature) dependence of the average kinetic-energy release (KER) is found to be in reasonable agreement with the predictions of the evaporative ensemble model, except for evaporation processes involving the cluster with magic number n=13. Agreement can be obtained for the latter if the assumption of the independence of the heat of evaporation on the cluster size in the model is removed.