[LIF spectroscopic study of OH radical].

Hydroxyl radical molecular beam was generated by DC pulsed high voltage discharge. The rotational resolution excitation fluorescence spectra of the OH A 2sigma+ -X 2pi (1, 0) band were observed by using second harmonious output of a nanosecond dye laser (around 282 nm). The rotational temperature of the (1, 0) band was determined to be (30 +/- 1) K based on the analysis of the intensity distribution of the OH spectra. Moreover, the fluorescence decay curves of the (1, 1) band and the (0, 0) band and were obtained and the fluorescence lifetimes of A 2sigma+ (v' = 1) state and the X 2pi (v" = 0) state were fitted to be (637 +/- 16) and (675 +/- 13) ns, respectively.