Delayed photofission of dianionic tin clusters

Abstract

Dianionic tin clusters \(\textrm{Sn}_{34}^{2-}\) stored in a Penning trap are excited by nanosecond laser pulses with photon energies ranging from 2.0 to \(4.7\,\textrm{eV}\), resulting in delayed decays. Time-resolved measurements with varying delays between laser irradiation and fragment analysis from a few ten microseconds to a second reveal matching exponential appearance constants of several singly charged dissociation products. This indicates that the dianions undergo fission into competing pairs of \(\textrm{Sn}_{10}^{-}\) + \(\textrm{Sn}_{24}^{-}\) and \(\textrm{Sn}_{15}^{-}\) + \(\textrm{Sn}_{19}^{-}\). Furthermore, matching decay constants for high photon energies of twice the low-energy values indicate that the decay observed at the low energies results from two-photon excitation.The delayed photodecay of dianionic tin clusters shows competing dissociation pathways by fission into two singly charged product clusters. Further sequential decay processes are investigated.