15min:

D. CHRIS BENNER, V. MALATHY DEVI, Department of Physics, The College of William and Mary, Box 8795, Williamsburg, VA 23187-8795; M. A. H. SMITH, C. P. RINSLAND, Atmospheric Sciences, NASA Langley Research Center, Mail Stop 401A, Hampton, VA 23681-2199; L. R. BROWN, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109; AND M. DULICK, National Solar Observatory, P. O. Box 26732, Tucson, AZ 85726-6732.

In a previous study we had reported air- and N₂-broadening and pressure-induced shift coefficients for 46 rovibrational transitions in the ¹²C¹⁶O₂ 00⁰1-(10⁰0-02⁰1)_I and 00⁰1-(10⁰0-02⁰1)_II laser bands near 10 µm These parameters were determined from spectra recorded with the McMath-Pierce Fourier transform spectrometer (FTS) of the National Solar Observatory on Kitt Peak, Arizona. We now report similar measurements of air- and N₂-broadening and shifts for the two ¹³C¹⁶O₂ laser bands, plus new determinations of self-broadening and shifts in the ¹²C¹⁶O₂ laser bands. These results were obtained from simultaneous analysis of 30 long-path absorption spectra using a multispectrum nonlinear least-squares technique. In addition to the 10 spectra of air- and N₂-broadened natural CO₂ analyzed previously, we have included 20 new spectra recorded at room temperature and 0.005 cm^-1 resolution using the McMath-Pierce FTS. These additional spectra include two low pressure, four air-broadened and four N₂-broadened spectra obtained with a 90% ¹³C-enriched CO₂ sample and 10 self-broadened spectra obtained with a high purity natural CO₂ sample. The self-broadened spectra were recorded with pathlengths of 73, 97, 193 and 433 m and CO₂ pressures varying between 3 Torr and 400 Torr. The ¹³CO₂ spectra were obtained with a pathlength of 84 m with sample pressures < 4 Torr for the low-pressure spectra and from 100 to 500 Torr for the air- and N₂-broadened mixtures. By combining the spectra of ¹²CO₂ and ¹³CO₂ in the same fit we were able to obtain a consistent set of line parameters for both molecules. The results obtained for the ¹²CO₂ and ¹³CO₂ laser bands will be compared with each other, with the values in the HITRAN database, and with available values reported in the literature.