Fragmentation dynamics of CO23+ investigated by multiple electron capture in collisions with slow highly charged ions

Abstract

Fragmentation of highly charged molecular ions or clusters consisting of more than two atoms can proceed in an onestep synchronous manner where all bonds break simultaneously or sequentially by emitting one ion after the other. We separated these decay channels for the fragmentation of CO23+ ions by measuring the momenta of the ionic fragments. We show that the total energy deposited in the molecular ion is a control parameter which switches between three distinct fragmentation pathways: the sequential fragmentation in which the emission of an O+ ion leaves a rotating CO2+ ion behind that fragments after a time delay, the Coulomb explosion and an in-between fragmentation - the asynchronous dissociation. These mechanisms are directly distinguishable in Dalitz plots and Newton diagrams of the fragment momenta. The CO23+ ions are produced by multiple electron capture in collisions with 3.2 keV/u Ar8+ ions.