Laser photofragmention laser induced fluorescence detection of the hydroperoxyl radical: Photofragment energy distributions, detection sensitivity and kinetics

A laser photofragment-laser induced fluorescence technique has been developed for the detection of the hydroperoxyl radical, HO2. The OH photofragment rotational distribution peaks at low temperature with a preference for population of the lower energy, (II3/2)-I-2, spin orbit component. Greater than 75% of the O atoms are produced in the O D-1 state. An HO2 detection sensitivity of 2 x 10(11) cm(-3) was achieved in 300 Torr of N-2, indicating that this approach has the sensitivity and temporal resolution to be useful for kinetic studies of HO2 under realistic atmospheric conditions.