Vacuum ultraviolet photodissociation of SH radical at 121.6Â nm

Vacuum ultraviolet (VUV) photodissociation of jet-cooled SH radical is studied at the photolysis wavelength of 121.6 nm using high-n Rydberg atom time-of-flight (HRTOF) technique. Both the ground-state S(3PJ) and the excited-state S(1D2) and S(1S0) products are observed, with a branching fraction of S(3PJ):S(1D2):S(1S0) = 0.07 ± 0.01:0.82 ± 0.01:0.11 ± 0.01. The spin-orbit branching fraction of the minor S(3PJ) product is S(3P2):S(3P1):S(3P0) = 0.28 ± 0.12:0.54 ± 0.16:0.18 ± 0.09. The predominant production of S(1D2) is consistent with a direct dissociation from the repulsive 22Π state. The S(3PJ) product fine-structure state distribution from SH photodissociation at 121.6 nm is significantly different from that in the UV region.