Thermally assisted fluorescence of laser-excited OH A 2 Σ + as a flame diagnostic tool

摘要: A simple laser-induced-fluorescence measurement technique for turbulent flame temperature and OH concentration is proposed successfully tested. The main idea that a narrow-band tunable excimer laser beam (λ = 308 nm) focused into atmospheric-pressure nonpremixed flame. molecule Q(1)(3) (X(2)II υ″ 0, A(2)Σ+υ″ 0) transition excited. By subsequent vibrational energy transfer, the distribution in molecules' upper electronic level (excited Σ(+) state) redistributed. evaluating spectrum of broadband emission from υ' 1 ? 0 2 bands with full spectral fit, we were able to evaluate density. concurrent processes quenching, rotational transfer taken account evaluation process. results compared numerical calculations revealed good agreement. One problem this new application laser-induced fluorescence self-absorption emitted light. This, however, shown not be serious, but it has checked carefully. advantages are experimental setup procedure, high signal intensity, straightforward data method. Thus suitable measurement, an alternative other well-established techniques much more complicated.