Molecular Dynamics in Dissociative Electron Attachment to CO probed by Velocity Slice Imaging

TL;DR

This study investigates the kinetic energy and angular distributions of O$^-$ ions produced by dissociative electron attachment to CO, revealing two distinct reaction pathways and their underlying resonant states using velocity slice imaging.

Contribution

The paper provides detailed experimental analysis of DEA to CO, identifying separate reaction channels and their associated resonant states through velocity slice imaging.

Findings

Two separate DEA pathways to O$^-$ ions identified

Distinct resonant states involved in each pathway

Forward-backward asymmetry explained by partial wave interference

Abstract

Kinetic energy and angular distributions of O$^-$ ions formed by dissociative electron attachment to CO molecule have been studied for 9, 9.5, 10, 10.5, 11, 11.5 eV incident electron energies around the resonance using time sliced velocity map imaging spectrometer. Detailed observations clearly show two separate DEA reactions lead to the formation of O$^{-}$ ions in the ground $^{2}P$ state along with the neutral C atoms in ground $^{3}P$ state and first excited $^{1}D$ state, respectively. Within the axial recoil approximation and involving four partial waves, our angular distribution results clearly indicate that the two reactions leading to O$^{-}$ formation proceed through the distinct resonant state(s). For the first process, more than one intermediate states are involved. Whereas, for the second process, only one state is involved. The observed forward-backward asymmetry is explained due to the interference between the different partial waves that are involved in the processes.