HIGH-TEMPERATURE QUENCHING CROSS-SECTIONS FOR NITRIC-OXIDE LASER-INDUCED FLUORESCENCE MEASUREMENTS

Collisional quenching cross sections for laser-induced fluorescence from NO A (upsilon'= 0) are measured for H2O, CO2, 02, NO, N2, H-2, Ar, C2H6, and CO as a function of temperature from 300 to 1750 K. Room temperature cross sections vary widely (<0.03 angstrom2 for N2, H-2, C2H6, and Ar to greater-than-or-equal-to 100 angstrom2 for H2O). As temperature increases, cross sections for H2O and CO2 decrease, cross sections for 02 and NO remain constant, and cross sections for N2, H-2, CO, and C2H6 increase. These data provide quantitative quenching corrections for laser-induced fluorescence measurements of NO concentrations in nonreacting and reacting flows. Physical quenching models (based upon NO-Q and NO+-Q- collision complexes) are reviewed and used for experimental data correlation and extrapolation. A new quenching