Decay reactions of rare gas cluster ions: Kinetic energy release distributions and binding energies

We have carried out measurements on metastable fragmentation of mass selected argon cluster ions which are produced by electron impact ionization of a neutral argon cluster beam. From the shape of the fragment ion peaks (MIKE scan technique) one can deduce information about the distribution of kinetic energy that is released in the decay reaction. In this study, for Ar+5 to Ar + 15, it is Gaussian and thus we can calculate from the peak width the mean kinetic energy release 〈KER〉 of the corresponding decay reactions. Using finite heat bath theory we calculate from these data the binding energies of the decaying cluster ions. PACS. 36.40.Qv Stability and fragmentation of clusters – 33.15.Fm Bond strengths, dissociation energies – 34.30.+h Intramolecular energy transfer; intramolecular dynamics; dynamics of van der Waals molecules