Dissociative recombination, and vibrational excitation of CO$^{+}$: model calculations and comparison with experiment

TL;DR

This paper models the dissociative recombination and vibrational excitation of CO$^{+}$ using quantum defect theory, comparing theoretical cross sections with experimental data to validate the approach and identify areas for improvement.

Contribution

The study provides a detailed theoretical analysis of CO$^{+}$ dissociative recombination using molecular data and quantum defect theory, and compares results with experimental measurements.

Findings

Calculated cross sections match experimental resonance shapes.

Theoretical cross sections underestimate experimental values by a factor of 2.

The approach confirms the validity of the dynamics modeling despite discrepancies.

Abstract

The latest molecular data - potential energy curves and Rydberg$/$valence interactions - characterizing the super-excited electronic states of CO are reviewed, in order to provide inputs for the study of their fragmentation dynamics. Starting from this input, the main paths and mechanisms for CO$^+$ dissociative recombination are analyzed; its cross sections are computed using a method based on Multichannel Quantum Defect Theory. Convoluted cross sections, giving both isotropic and anisotropic Maxwellian rate-coefficients, are compared with merged-beam and storage-ring experimental results. The calculated cross sections underestimate the measured ones by a factor of $2$, but display a very similar resonant shape. These facts confirm the quality of our approach for the dynamics, and call for more accurate and more extensive molecular structure calculations.