Spin-orbit branching in Cl(P-2) atoms produced by ultraviolet photodissociation of HCl

The ultraviolet photodissociation of jet-cooled HCl molecules at 5 waveleng ths in the range 201-210 nm has been investigated. Ground state hydrogen ph otofragments, H(S-2), were detected using the H Rydberg atom time-of-flight (HRTOF) technique to obtain directly the relative yields of the available product channels: H(S-2) + Cl(P-2(3/2)) and H(S-2) + Cl(P-2(1/2)). The prod uct branching fractions are reported and compared with recent experimental measurements and theoretical calculations. In addition, the two spin-orbit components of ground state chlorine photofragments formed by photolysis of HCl at 205.5 nm were monitored using (2 + 1) resonance enhanced multiphoton ionization (REMPI). The relative sensitivity of this detection method for Cl(P-2(3/2)) and Cl(P-2(1/2)) atoms is found by comparing the relative REMP I signal intensities with the product branching fraction determined by the HRTOF technique.