Anisotropic angular distribution of fragment ions in dissociative double photoionization of OCS

Angular distributions of fragment ions produced in the dissociative double photoionization of OCS have been studied in the photon energy region 37--100 eV with the use of synchrotron radiation and photoion-photoion coincidence. The asymmetry parameter {β} ranges from 0.01 to 0.48 for the three major dissociation channels OC⁺+S⁺, O⁺+S⁺+C, and C⁺+S⁺+O of OCS²⁺. The observation of an anisotropy in the direct double photoionization from valence orbitals is discussed in relation to the symmetry consideration involved in the transition and the dynamics of the dissociation.