Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5415885 | Journal of Molecular Spectroscopy | 2007 | 28 Pages |
Intensity and line shape parameters which predict spectral lines with absolute accuracies better than 0.3% have been determined for transitions of the 30012 â 00001 band of 16O12C16O centered near 6348 cmâ1 from 26 high resolution, high signal-to-noise ratio spectra recorded at room temperature with the McMath-Pierce Fourier transform spectrometer. To maximize the accuracies of the retrieved parameters, the multispectrum non-linear least squares retrieval technique was modified to adjust the rovibrational constants (G, B, D, etc.) and intensity parameters, including Herman-Wallis terms, rather than retrieving the individual positions and intensities. Speed-dependent Voigt line shapes with line mixing were required to remove systematic errors in the fit residuals. Self- and air-broadening (widths and pressure-induced shifts, speed dependence parameters) and line mixing (off-diagonal relaxation matrix elements) coefficients were thus obtained in the multispectrum fit. Remaining errors were minimized by fitting the weak 30011 â 00001 band of 16O13C16O as well as the weak hot bands 31112 â 01101, 32212 â 02201, 40012 â 10001, and 40013 â 10002 of 16O12C16O that contribute interfering absorptions in this spectral window. This study presents the most extensive set of measurements to date for self- and air-broadening and self- and air-shift coefficients of a near infrared band of CO2. This is also the first study where line mixing parameters have been experimentally determined for any parallel CO2 band.