Fragmentation dynamics of carbonyl sulfide in collision with 500 eV electron

The fragmentation dynamics of OCS^q+ (q = 2, 3, 4) induced by electron collision at an impact energy of 500 eV is studied. By using the momentum imaging technique, the three dimensional momentum vectors of all the fragments are obtained, which enables us to analyse both the kinetic energy release and the momentum correlations for a certain fragmentation channel. Up to fifteen dissociation channels are analyzed including six, five, and four channels for two-body, and incomplete and complete three-body Coulomb fragmentations. For three-body dissociation, the fragmentation mechanisms are investigated with the help of Dalitz plot and Newton diagram. It is found that the sequential fragmentation involves in OCS²⁺→O+C⁺+S⁺ with S⁺ emitted first and in OCS³⁺→O⁺+C⁺+S⁺ with O-C and C-S bonds breaking first. The remaining channels, however, always dissociate through a concerted mechanism. The relative intensities of the channels are also presented in this work.