The No Vibrational Fundamental Band: Temperature Dependence of N2-Broadening Coefficients

Rovibrational spectra of the vibrational fundamental of nitric oxide have been recorded under N2-broadening conditions at 0.0056 cm(exp-1) resolution using the Solar McMath FTS at the Kitt Peak National Observatory. The temperature range for the experiments was 296 K to 183 K. The 30 cm absorption cell used for the measurements is cooled with a helium compressor and can operate at temperatures down to 60 K; vibration isolation of the cell allows its use with high performance Fourier Transform Spectrometers. From these spectra, N2-broadened line widths have been determined thru m = 16.5. Qualitative as well as quantitative discrepancies are observed between our experimental determinations of the temperature dependence of the broadening and theoretical calculations.