Low-energy electron collisions with CH3Br: the dependence of elastic scattering, vibrational excitation, and dissociative attachment on the initial vibrational energy

M Braun, I I Fabrikant, M-W Ruf, H Hotop
2007 Journal of Physics B: Atomic, Molecular and Optical Physics  
Follow this and additional works at: http://digitalcommons.unl.edu/physicsfacpub Part of the Physics Commons This Article is brought to you for free and open access by the Research Papers in Physics and Astronomy at DigitalCommons@University of Nebraska -Lincoln. It has been accepted for inclusion in Faculty Publications, Department of Physics and Astronomy by an authorized administrator of DigitalCommons@University of Nebraska -Lincoln. Braun, M.; Fabrikant, Ilya I.; Ruf, M-W.; and Hotop, H.,
more » ... W.; and Hotop, H., "Low-energy electron collisions with CH 3 Br: the dependence of elastic scattering, vibrational excitation, and dissociative attachment on the initial vibrational energy" (2007). Faculty Publications, Department of Physics and Astronomy. 66. Abstract Using the laser photoelectron attachment (LPA) method at an energy width of 1-2 meV, the Br − yield due to dissociative electron attachment to the molecule CH 3 Br has been measured over the energy range 1-180 meV at a gas temperature of 600 K. The data clearly exhibit the vibrational Feshbach resonance predicted by Wilde et al. (2000 J. Phys. B: At. Mol. Opt. Phys. 33 5479) and associated with the v 3 = 4 vibrational level of the C-Br stretch mode in the neutral molecule. We also report the dependence of the rate coeffi cient for Rydberg electron attachment (measured at high principal quantum numbers n ≈ 150) on gas temperature and fi nd an Arrhenius-type behavior compatible with the results of R-matrix calculations and with earlier fi ndings of electron swarm experiments. With the aim to stimulate experiments, we report absolute cross sections for elastic scattering and vibrationally inelastic scattering involving the C-Br stretch mode v 3 of CH 3 Br for several initial vibrational levels in the range v 3 = 0-4; they were obtained with R-matrix calculations based on the same potential input as that involved in the computations of the cross sections for dissociative attachment.
doi:10.1088/0953-4075/40/4/002 fatcat:xvcc2kjcyvcvpcnpodbjsuuca4