Line Intensities, $N_{2}^{-},$ and He-Broadening in the $\nu_{2}$ Bending Mode of $N_{2}O$
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Date
1995
Journal Title
Journal ISSN
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Publisher
Ohio State University
Abstract
Abstract-Spectra of nitrous oxide at $0.005cm^{-1}$ spectral resolution have been recorded with the 1m FTIR spectrometer at the National Solar Observatory in Kitt Peak, AZ. From a least-squares fit of individual transitions to a general Voigt profile, line intensities, band strengths, and Herman-Wallis factors have been derived for the $\nu_{2}$ fundamental and the three strongest hotbands (PR-transitions)of $2{\nu_{2}}^{2e} \leftarrow {\nu_{2}}^{1e}, 2{\nu_{2}}^{2f}\leftarrow {\nu_{2}}^{1f}$, and $2{\nu_{2}}^{1e} \leftarrow {\nu^{1e}}_{2}$. The major contribution to the Herman Wallis factors is due to a Coriolis-type interaction with $\nu_{3}$, but part of the measured Herman-Wallis factors in the hotbands can be attributed to $\ell$-resonance mixing effects in the $2\nu_{2}$ $manifold.^{3}$ These measurements are the first reported to be obtained under high resolution. From $N_{2}^{-}$ and $He-$ foreign gas broadened data, broadening coefficients and pressure shifts have been derived and fitted to an energy-gap sealing law. $N_{2}O$ is an important tropospheric molecule and the intensity information provided should also prove useful for Direct Numerical Diagonalization (DND) $calculations.^{4}$
Description
$^{1}$ NAS/NRC Resident Research Associate $^{2}$ USRA Research Scientist. $^{3}$ M. Weber, W.E. Blass, G.W. Halsey, and J.J. Hillman, J. Mol. Spectrosc, 165, 194 (1994). $^{4}$ R.B. Wattson and L.S. Rothman, J. Mol. Spectrosc., 119, 83 (1988); J. Quant. Spectrosc. Rad Transfer, 48, 763 (1992).
Author Institution: Lab. for Extraterrestrial Physics, Code 693, Greenbelt, MD 20771
Author Institution: Lab. for Extraterrestrial Physics, Code 693, Greenbelt, MD 20771