COLLISIONAL ELECTRONIC QUENCHING OF NO A 2-SIGMA+ BY N2 FROM 300 TO 4500-K

We report rate coefficients for electronic quenching of NO A 2SIGMA+ upsilon'=0 by N2 measured at room temperature and at high temperatures behind reproducible shock waves. The quenching cross section increases from 0.007 angstrom2 at 300 K to 7 angstrom2 at 4500 K, and the temperature dependence in the range 300-2300 K is best understood using a charge-transfer (harpoon) collision model. We also record dispersed fluorescence spectra and time-resolved fluorescence from both the directly pumped level (upsilon'=0) and a collisionally populated level (upsilon'=1); from these results we obtain rate coefficients for vibrational energy transfer in NO (A) and electronic quenching of upsilon'=1 at 1900 K.