Spectral shapes of rovibrational lines of CO broadened by He, Ar, Kr and SF ₆ : A test case of the Hartmann-Tran profile

H. Ngo (1) , H. Lin (2, 3) , J.T. Hodges (2) , H. Tran (4)

1 HNUE - Hanoi National University of Education
2 NIST - National Institute of Standards and Technology [Gaithersburg]
3 National Institute of Metrology [Beijing]
4 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)

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.

Mots clés: Hartmann-Tran profile; cavity ring-down spectroscopy 2; CO; line shape

Domaines: Physique [physics]

H. Ngo, H. Lin, J.T. Hodges, H. Tran. Spectral shapes of rovibrational lines of CO broadened by He, Ar, Kr and SF ₆ : A test case of the Hartmann-Tran profile. Journal of Quantitative Spectroscopy and Radiative Transfer, 2017, ⟨10.1016/j.jqsrt.2017.03.001⟩. ⟨hal-01484556⟩