AIR-AND $N_{2}$ – BROADENING COEFFICIENTS AND PRESSURE SHIFT COEFFICIENTS IN THE $^{12}C^{16}O_{2}$ LASER BANDS
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Date
1997
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Publisher
Ohio State University
Abstract
This study reports both the pressure broadening and the pressure-induced shit coefficients for 46 rovibrational lines with J values ranging from P(46) to R(44) inn the ${^{12}}C^{16}O_{2} 00^{0} 1-(10^{0}0-02^{0}0)$, and $00^{0} 1-(10^{0}0-02^{0}0)_{H}$ laser bands (Laser band I centered at $960.969 cm^{-1}$ and Laser band II centered at $1063.735 cm^{-1})$. The measurements used spectra recorded with the McMath Pierce Fourier Transform Spectrometer. The results were obtained from analysis of 10 long path laboratory absorption spectra recorded at room temperature and at $0.0027 cm^{-1}$ resolution using a multispectrum nonlinear least-squares technique pressure effects caused by both air and nitrogen were investigated. The air broadening coefficients determined in this study agree well with the values in the recent HITRAN compilation. Broadening by nitrogen was 3 to 4% larger than that of air The individual shift coefficients were all negative or within two standard deviations of zero. The mean value for each broadening gas for each band was about $-1.5 \times 10^{-3} cm^{-1}$ $atm^{-1}$ at 296 K with a typical scatter among the shift coefficients of the various rotational quantum numbers of about $8 \times 10^{-1} cm^{-1}$ $atm^{-1}$ at 296 K. Similar to broadening coefficients, the pressure-induced line shift coefficients were also found to be transition dependent, but were different for the P and R- branch lines with the same value. No significant differences in the shift coefficients caused by air and nitrogen were found. The results obtained were compared with values reported in the literature.
Description
$^{h}$D. Chris Benner, C.P. Rinsland, V. Malathy Devi, M.A.H. Smith and D. Atkins, JQSRT 53, 705-721 (1995). $^{i}$L.S. Rothman, R.R. Gamache, R.H. Tipping, C.P. Rinsland, M.A.H. Smith D.C. Benner, V. Malathy Devi J.-M. Flaud, C. Camy-Peyret. A Perrin , A Goldman, S. T. Massie, L.R. Brown, and R. A. Toth, JQSRT 48, 469-507 (1992); L.S. Rothman et at. in preparation, (1997).
Author Institution: Department of Physics, The college of William and Mary; Atmospheric Sciences Division, NASA Langley Research Center
Author Institution: Department of Physics, The college of William and Mary; Atmospheric Sciences Division, NASA Langley Research Center