Differential cross sections and angular distributions of H-from dissociative electron attachment to H2between 3.75 eV and 13 eV

Abstract

An electron-impact spectrometer has been modified for the study of negative-ion fragments. This instrument has been used to observe differential cross sections and angular distributions of H^- ions produced by dissociative attachment to H₂ through the ² Sigma _u⁺ and ² Sigma _g⁺ resonances. The measured angular distributions are analysed using the pure resonant scattering with potential scattering theoretical model which is discussed. Vibrational structure observed in the differential cross section between 11.30 eV and 13.30 eV is interpreted as resulting from predissociation of the 'a' resonance bands by the H₂^{- 2} Sigma _g⁺ repulsive state.