Total removal rate constants from the NH(A3IIi) electronic state have been obtained in low pressure (~14-Torr) N2O flames. The fluorescence decay constants and quantum yields Φ depend on the temperature and composition at each position interrogated in the flame. In similar conditions, Φ for NH(A3IIu) is significantly greater than that for other radicals CH(A2Δ and B2Σ-) and OH(A2Σ+). A small decrease (~5%) in the electronic removal is observed with rotational excitation increasing from N′ = 2 to 12 in the A state. Estimates of collisional quenching cross sections at flame temperatures are made for the important combustion species, H2O, C3H8, C2H4, and C2H2.
© 1989 Optical Society of America
Richard A. Copeland, Michael L. Wise, Karen J. Rensberger, and David R. Crosley, "Time resolved laser induced fluorescence of the NH radical in low pressure N2O flames," Appl. Opt. 28, 3199-3205 (1989)