UV and visible emission spectra from the photodissociation of carbonyl sulfide using synchrotron radiation at 15-30 eV

The photofragmentation of OCS at photon energies of 15-30 eV has been studi ed by dispersed fluorescence spectroscopy. The primary photon beam was mono chromatized undulator radiation supplied from the UVSOR facility. The follo wing emission-band systems have been identified: OCS+[A(2)Pi (Omega)(0,0,0) --> X(2)Pi (Omega)(0,0,v(3)")], CO+(A(2)Pi (Omega) --> X(2)Sigma (+)), CS(B(2)Sigma (+) -->A(2)Pi (Omega)), and CO(d(3)Delta --> a(3)Pi). All of the transitions, except for OCS+[A(2)Pi (Omega) --> X(2)Pi (Omega)], were firs t observed in the vacuum UV photodissociation of OCS. The fluorescence exci tation spectra for the OCS+[A(2)Pi (Omega)(0,0,0) --> X(2)Pi (Omega)(0,0,v( 3)")] and CS+(B(2)Sigma (+) --> A(2)Pi (Omega)) transitions were measured i n the photon energy range of 15.1-15.75 and 21.8-26 eV, respectively. The e mission spectra obtained at 20.85 and 22.9 eV exhibit atomic transitions of S[nd(3)D(0) --> 4p(3)p(e) (n = 6-9)], which result from the neutral dissoc iation of superexcited Rydberg states of OCS into S(nd(3)D(0)) + CO. Possib le excited states of the counterpart CO are discussed on the basis of the d ifference in the n distribution between the two spectra.