Ionization and fragmentation of cold clusters of PAH molecules: collisions with keV ions

Abstract

We report on collisions between atomic ions and pure, loosely bound, clusters of Polycyclic Aromatic Hydrocarbon (PAH) molecules. We find that charge and excitation energy is distributed on the cluster constituents before break-up which mostly leads to emissions of intact, excited, singly charged monomers. Surprisingly, collisions with highly charged ions lead to hotter monomers than collisions with ions in low charge states. Small PAH clusters fragment promptly when singly ionized while clusters of more than 13 or 5 molecules may remain intact for anthracene or coronene clusters, respectively.