Resonant vibrational-excitation cross sections and rate constants for electron scattering by molecular oxygen are presented. Transitions between all 42 vibrational levels of ${\rm O}_2({X}\, ^3\Sigma_{\rm g}^{-})$ are considered. Molecular rotations are parametrized by the rotational quantum number J, which is considered in the range 1-151. The lowest four resonant states of ${\rm O}_2^-$ , 2?g, 2?u, $^4\Sigma_{\rm u}^-$ and $^2\Sigma_{\rm u}^-$ are taken into account. The calculations are performed using the fixed-nuclei R-matrix approach to determine the resonance positions and widths, and the boomerang model to characterize the nuclei motion. Two energy regions below and above 4 eV are investigated: the first one is characterized by sharp structures in the cross section and the second by a broad resonance peaked at 10 eV. The computed cross sections are compared with theoretical and experimental results available in the literature for both energy regions, and are made available for use by modelers. The effect of including rotational motion is found to be non-negligible.
Resonant vibrational-excitation cross sections and rate constants for low-energy electron scattering by molecular oxygen
Laporta Vincenzo;Celiberto Roberto;
2013
Abstract
Resonant vibrational-excitation cross sections and rate constants for electron scattering by molecular oxygen are presented. Transitions between all 42 vibrational levels of ${\rm O}_2({X}\, ^3\Sigma_{\rm g}^{-})$ are considered. Molecular rotations are parametrized by the rotational quantum number J, which is considered in the range 1-151. The lowest four resonant states of ${\rm O}_2^-$ , 2?g, 2?u, $^4\Sigma_{\rm u}^-$ and $^2\Sigma_{\rm u}^-$ are taken into account. The calculations are performed using the fixed-nuclei R-matrix approach to determine the resonance positions and widths, and the boomerang model to characterize the nuclei motion. Two energy regions below and above 4 eV are investigated: the first one is characterized by sharp structures in the cross section and the second by a broad resonance peaked at 10 eV. The computed cross sections are compared with theoretical and experimental results available in the literature for both energy regions, and are made available for use by modelers. The effect of including rotational motion is found to be non-negligible.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.