Dissociative electron attachment and electron-impact resonant dissociation of vibrationally excited O2 molecules

TL;DR

This paper calculates state-specific cross sections for dissociative electron attachment and dissociation of vibrationally excited O2 molecules using ab initio resonance curves, providing key data for plasma modeling.

Contribution

It introduces detailed ab initio calculations of resonance states and cross sections for vibrationally excited O2, advancing understanding of electron-molecule interactions in plasmas.

Findings

Main contribution from $^2\Pi_u$ resonance in ground state

Vibrational excitation increases cross sections and lowers thresholds

Significant role of $^4\Sigma$ and $^2\Pi_g$ resonances

Abstract

State-by-state cross sections for dissociative electron attachment and electron-impact dissociation for molecular oxygen are computed using ab initio resonance curves calculated with the R-matrix method. When O2 is in its vibrational ground state, the main contribution for both processes comes from the $^2\Pi_u$ resonance state of $O_2^-$ but with a significant contribution from the $^4\Sigma$ resonant state. Vibrational excitation leads to an increased contribution from the low-lying $^2\Pi_{g}$ resonance, greatly increased cross sections for both processes, and the threshold moving to lower energies. These results provide important input for models of O2-containing plasmas in nonequilibrium conditions.