Dissociative-electron-attachment dynamics near the 8-eV Feshbach resonance of CO2

Abstract

We present experimental results for dissociative electron attachment to carbon dioxide near the 8-eV Feshbach resonance. In particular, the dissociation channel leading to O${}^{\ensuremath{-}}$ production has been investigated with a momentum imaging technique that utilizes a supersonic gas jet to form a low-temperature, confined molecular target. Angular fragmentation and kinetic energy release distributions are compared to recent results by Slaughter et al. [J. Phys. B 44, 205203 (2012)] and Wu et al. [Phys. Rev. A 85, 052709 (2012)] using similar techniques. We show that careful attention to weighting of the O${}^{\ensuremath{-}}$ fragmentation momentum space is required to interpret the kinetic energy release observations and that there is no appreciable change in the angular distribution of O${}^{\ensuremath{-}}$ fragments at different energies around the resonance peak, as previously reported by Wu et al. The present O${}^{\ensuremath{-}}$ momentum distribution and kinetic energy release differ from previous results and provide alternative guidance for the theoretical consideration of potential energy surface dynamics that takes place during attachment.