Self and N2 broadening coefficients of H2S probed by submillimeter spectroscopy: Comparison with IR measurements and semi-classical calculations. (May 2020)

• Record Type: Journal Article
• Authors: Mouelhi, M.; Cuisset, A.; Hindle, F.; Jellali, C.; Galalou, S.; Aroui, H.; Bocquet, R.; Mouret, G.; Rohart, F.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 247(2020)
• Publication Date: 2020-05
• Subjects: Broadening coefficients -- H2S -- Submillimeter-wave spectroscopy -- Speed-dependence effects -- Semi-classical calculation -- Rotational dependencies; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2020.106955
• Languages: English
• ISSNs: 0022-4073

Abstract

Highlights: High-resolution lines of H2 S self-perturbed and perturbed by N2 have been recorded at room temperature using a frequency modulated THz spectrometer. The self- and N2 -broadening coefficients of H2 S of pure rotational transitions have been retrieved in the submillimeter region. The lineshapes are well reproduced by the Speed-Dependent Voigt profile accounting for the speed dependence of relaxation rates. The broadening coefficients were calculated with the Robert and Bonamy formalism. The observed J″ and Ka ″ rotational dependences have been analyzed using an empirical model and compared to previous rovibrational studies. Abstract: High-resolution lines of H2 S self-perturbed and perturbed by N2 have been recorded at room temperature using a frequency modulated THz spectrometer at pressures of H2 S ranging from 0.1 to 1.0 mbar. A non-linear least squares fitting of these spectra has been performed to retrieve self- and N2 -broadening coefficients of pure rotational transitions (mainly in the R Q sub-branch) of H2 S in the submillimeter region. We show that the lineshapes are well reproduced by the Speed-Dependent Voigt profile accounting for the speed dependence of relaxation rates which display linear pressure dependencies. Using the Robert and Bonamy formalism, these coefficients were calculated, showing the need to account for all contributions of the intermolecular interaction for N2 -broadening. The calculated coefficients are consistent with the measured data and the average accuracy of the line parameters has been estimated to be about 5%. The observed J″ and Ka ″ rotational dependences have been analyzed using an empirical model and compared to previous rovibrational studies in the ν2 fundamental band. In our study the self- and the N2 -broadening coefficients decreases monotonically with Ka ″ and J″, respectively.