Determining nuclear hyperfine populations in the ground electronic state of atomic hydrogen produced by the 193 nm photolysis of HBr

A variation of velocity-aligned Doppler spectroscopy is used to study F=0 and F=1 nuclear hyperfine populations in the ground electronic state of atomic hydrogen as the result of a chemical reaction. In this case, the reaction is the 193 nm photolysis of HBr. Not only can the nuclear hyperfine states be studied, but the method allows unequivocal correlation with the spin--orbit states of the bromine atom, i.e., Br(2P1/2) and Br(2P3/2). For H atoms correlated with Br(2P3/2), the F=0/F=1 is 1.2±0.2. Future directions involving the study of this fundamental chemical product state distribution are also discussed. copyright 1995 American Institute of Physics