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, 2Π32, spin orbit component. Greater than 75% of the O atoms are produced in the O1D state. an HO2 detection sensitivity of 2 × 1011 cm−3 was achieved in 300 Torr of N2, indicating that this approach has the sensitivity and temporal resolution to be useful for kinetic studies of HO2 under realistic atmospheric conditions.