Electron scattering cross sections from NH₃: A comprehensive study based on R-matrix method

Abstract In this study, a comprehensive cross-sectional computation on the electron scattering from NH 3 was performed using the frame of the R -matrix method. Cross section sets for total elastic, differential, momentum transfer, total ionization, and electronic excitation are presented. The electron-impact dissociation of NH 3 to NH 2 + H and NH+H 2 was considered by summing up the cross sections for the molecular dissociative excitations to the correlated dissociation channels. The reported cross sections for vibrational excitation of NH 3 remain controversial and are unable to distinguish the N–H symmetric and asymmetric stretching modes of close frequencies. Here, the excitation cross section for each vibrational mode of NH 3 was computed by applying the theoretical approach combining the fixed-nuclei R -matrix method, normal mode approximation and the vibrational frame transformation. The uncertainties of the cross section sets computed in this study were estimated for convenience of use in the plasma modeling.