PHOTOFRAGMENT SPECTROSCOPY OF SO-514.5 NM( IN THE WAVELENGTH RANGE FROM 308)

The direct photodissociation process SO+ + hv --> S+ + O has been stud ied using the technique of ion photofragment spectroscopy. The kinetic energy distribution of the S+ photofragments has been measured for se lected wavelengths in the range lambda = 308-514.5 nm. Transitions fro m the metastable a4(PI) state to the dissociative 1 (4)SIGMA+ state as well as from the X(2)PI ground state to a higher-lying (2)PI state ha ve been observed. From the vibrationally resolved kinetic energy spect ra, the potential curve of the repulsive 1 (4)SIGMA+ state has been de termined for the range of internuclear distances R = 3.0-4.5 a0. In ad dition, the analysis gives the vibrational population of the SO+ (a (4 )PI) ions after dissociative electron-impact ionization of SO2 in the low-pressure monoplasmatron ion source.