Dissociative attachment and vibrational excitation of F2 by slow electrons

Abstract

Self‐consistent dissociative attachment and vibrational excitation cross sections for F₂ have been calculated using Herzenberg’s theory of resonant electron scattering. It has been found that the observed electron–F₂ attachment data can be explained by a low energy shape resonance. Potential parameters for the ²Σ⁺_u negative ion were varied in order to fit predicted attachment cross sections to measured rate constant data. The best fit was obtained for a negative ion curve which crosses the F₂ ground state in the vicinity of the equilibrium internuclear separation, in good agreement with an ab initio calculation for this state. The associated total vibrational cross section has a peak of about 2.0×10⁻¹⁶ cm² at an incident electron energy of 0.45 eV. A strong dependence of attachment rate on F₂ vibrational state is predicted.