Dissociative attachment of electrons to CS₂

Abstract

The formation of various negative ions from CS₂ by electron impact up to 50 eV is studied using a crossed beam geometry. A pulsed electron beam-pulsed ion extraction technique has been coupled with a specially designed time-of-flight mass spectrometer to make complete detection of all the ions irrespective of their kinetic energies and mass-to-charge ratios. The cross sections for the formation of different ions are put on an absolute scale using the relative flow technique. The formation of S^-₂ through dissociative attachment is confirmed and is explained as arising from the presence of small number of CS₂ molecules with bending mode excitations in the neutral molecular beam. From the various thresholds the dissociation energy and electron affinity of CS are determined to be 6.5 and 0.8 eV respectively.