Spectral shapes of rovibrational lines of CO broadened by He, Ar, Kr and SF6: A test case of the Hartmann-Tran profile. (December 2017)

• Record Type: Journal Article
• Authors: Ngo, N.H.; Lin, H.; Hodges, J.T.; Tran, H.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 203(2017)
• Page Start: 325
• Page End: 333
• Publication Date: 2017-12
• Subjects: CO -- Line shape -- Hartmann-Tran profile -- Cavity ring-down spectroscopy; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2017.03.001
• Languages: English
• ISSNs: 0022-4073

Abstract

Abstract: High signal-to-noise ratio spectra of the (3-0) band P(1) and P(17) lines of CO broadened by He, Ar, Kr and SF6 were measured with a frequency-stabilized cavity ring-down spectroscopy system. For each collision-partner and both lines, multiple spectra were measured over pressures spanning nearly three decades up to 130 kPa. These data were analyzed with a multispectrum fitting procedure. Line shapes were modeled using the Hartmann-Tran (HT) profile with first-order line mixing as well as several other simplified profiles. The results show that for all considered collision partners (with the exception of SF6 ), the HT profile captures the measured line shapes with maximum absolute residuals that are within 0.1% of the peak absorption. In the case of SF6, which is the heaviest perturber investigated here, the maximum residuals for the HT profile are twice as large as for the other collision partners. Highlights: The Hartmann-Tran profile was compared to measured spectra of CO in various perturbers. High resolution and high S/N of two lines of CO were measured with a FS-CRDS system. Spectra measured over a large pressure range were simultaneously analyzed. The HTp is capable to represent the measurements within 0.1% of the peak absorption.