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

TL;DR

This study investigates the fragmentation pathways of CO23+ ions produced by electron capture in collisions with highly charged argon ions, revealing control over decay mechanisms through energy deposition and distinguishing them via momentum analysis.

Contribution

It introduces a method to differentiate fragmentation pathways of CO23+ ions using momentum measurements and Dalitz plots, highlighting the role of energy in pathway selection.

Findings

Identified three distinct fragmentation pathways: sequential, Coulomb explosion, and asynchronous dissociation.

Demonstrated that energy deposition controls the transition between these pathways.

Used momentum analysis to distinguish decay mechanisms in molecular ion fragmentation.

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.