RH07		15min3:12

K. A. COWEN, K. T. LORENZ, P. E. FLEMING, M. F. HERMAN AND B. KOPLITZ, Department of Chemistry, Tulane University, New Orleans, LA 70118.

A variation on the technique of velocity-aligned Doppler spectroscopy has been used to measure the relative populations in the F=0 and F=1 nuclear hyperfine levels in the ground electronic state of atomic hydrogen produced in the 193 nm photolysis of HBr. This technique provides an unambiguous correlation between the H atom state distributions and the spin-orbit states of the counter fragment, i.e. Br(²P_3/2) and Br(²P_1/2). H atom state distributions are monitored by observing the (1+1) two-color multiphoton ionization spectrum exciting through the Lyman-\alpha transition. Effects of small Stark fields on the observed spectra will be discussed.