The S21 lines of the OH radical for the A2Σ+ (v′ = 1)←X2Π (v″ = 0) transition have been observed in the 278-280 nm region from the laser-excitation spectrum. The OH radical was generated from either the H + NO2 or the H + O3 reaction in a flow system and the fluorescence passing through a 309.6 nm interference filter was detected with a photomultiplier-boxcar integrator arrangement. The weak S21 lines were observed at laser energies above 0.2 mJ. The observed peak wavenumbers are in excellent agreement with those predicted for the S21 bands of the A (v>′ = 1)←X (v″ = 0) transition from the known spectroscopic parameters. Observation of the corresponding S21 system for OD in the 286.0-286.9 nm region further confirms this assignment. The relative absorption cross-sections of about one-tenth those of the P1 lines are in good agreement with theoretical considerations.
|Number of pages||4|
|Journal||Journal of Quantitative Spectroscopy and Radiative Transfer|
|State||Published - Sep 1987|