Contribution of different electron-capture mechanisms in the fragmentation of CO 2 3 + upon slow ion-molecule collisions

Abstract

Abstract We present a recoil ion—projectile ion coincidence study on the three body fragmentation of CO 2 3 + ion into C + + O + + O + fragments upon impact with Ar 3 + ,   Ar 6 +   and   Ar 8 + projectile ions having the same velocity of v p = 0.49 a.u. (atomic units) using the recoil ion momentum imaging technique. The kinetic energy release (KER) distributions are presented and the effect of different electron-capture associated processes such as pure capture, electron capture followed by target-ionization or projectile auto-ionization is discussed based on the analysis of KER corresponding to different final projectile charge states post-collision. As the capture stabilization increased, the relative yields in the KER distribution are found to decrease in the high KER side for low charged Ar 3 + impact, while an increase is observed for Ar 6 +   and   Ar 8 + impacts. We discuss the interplay between electron-capture, projectile auto-ionization, and target ionization for the dominance of a particular process. We also observe a low-KER feature around 15 eV which was observed for electron and proton impacts, that has not yet been observed for highly charged ion impacts.