S− formation by dissociative attachment in OCS and CS2

Abstract

The electron energy dependence and magnitude of the cross section for formation of S− from OCS and CS2 are studied using monoenergetic electron beams. The dissociative attachment cross sections exhibit a near−vertical onset followed by structure at higher energies. In the case of S−/OCS, this structure probably arises from the production of the CS fragment in a vibrationally excited state (v = 1), but this explanation may not apply to the case of S− from CS2. The peak cross section in OCS is 2.9×10−17 cm2 at 1.35 eV; in CS2 it is 3.7×10−19 cm2 at 3.35 eV.