Electron induced processes in CH: an R-matrix study of electronic excitation, dissociation and dissociative attachment

Abstract

The CH radical is of considerable interest in both low temperature astrophysical plasmas as well as high temperature fusion plasmas. Although collision cross section data for different collision processes are required for modeling the relevant plasma, there are very few studies of electron collision with CH. To this end, we have used the R-matrix method to study electron collision with the CH molecule at low energies. CH target state energies, dipole and quadrupole moments were first determined at its equilibrium geometry R e = 2.116a 0. Scattering calculations were then performed for elastic scattering and electron impact excitation from the ground state to some of the low lying excited states of CH. The excitation cross sections were then used to estimate the cross section for the dissociation of CH under electron impact. An approximate calculation of the cross section for dissociative electron attachment of CH in the energetically lowest channel C−(4So) + H(2S), was also done via the lowest 5Σ− Feshbach resonance at R e = 2.116a 0.