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.