Lawrence Berkeley National Laboratory

The exciton energy deposited in an argon cluster, (Arn ,< n=20>) using VUV radiation is transferred to softly ionize doped water clusters, ((H2O)n, n=1-9) leading to the formation of non-fragmented clusters. Following the initial excitation, electronic energy is channeled to ionize the doped water cluster while evaporating the Ar shell, allowing identification of fragmented and complete water cluster ions. Examination of the photoionization efficiency curve shows that cluster evaporation from excitons located above 12.6 eV are not enough to cool the energized water cluster ion, and leads to their dissociation to (H2O)n-2H+ (protonated) clusters.