Irradiation of clusters with intense femtosecond laser pulses has been found to oftentimes produce highly charged ion fragments resulting from Coulomb explosion of the cluster under investigation. When a time-of-flight mass spectrometer is used for detection, double peaks can be observed for these multicharged species due to the different arrival times of backward and forward ejected ions. Kinetic energy release values can be calculated from these peaks splittings and also can be directly measured from cutoff potentials using a reflectron as an energy analyzer. The experimental values determined with both of these methods are surprisingly large, typically on the order of several hundred electronvolts. The purpose of the work reported herein is to model the temporal evolution of a cluster system after the ionization event, using MD simulations on a level of pure electrostatic interactions between the formed ion cores. The results give insight into how composition, size, structure, and charge distribution in the initially ionized cluster influence the kinetic energy distribution of the ejected ions.
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