Isolated line shape of methane with various collision partners

Research output: Contribution to journalArticle

Abstract

In this work, the spectral profile of an isolated transition of methane broadened by Ar, N2, O2 and He was studied using different line-shape models, from the simple Voigt to the recently recommended Hartmann–Tran profiles. For each collision-partner, absorption spectra of the ν4 2A11-3A21 line of methane were measured at room temperature and pressures ranging from 28.26 to 95.50 mbar, with a high resolution tunable diode laser spectrometer. The spectroscopic parameters of each line-shape model used were then retrieved from measured spectra using a multispectrum fitting procedure. The obtained results show that the Voigt profile leads to large deviations with respect to the measured one and that non-Voigt effects are more important for CH4 diluted in Ar, N2 and O2 than in He. We also confirm that both the confinement narrowing and the speed dependence effects must be taken into account in order to correctly reproduce the experimental spectra. In addition, the determination of the instrumental distortions of the spectrometer is also presented and discussed as a main difficulty of this analysis.

Original languageEnglish
Pages (from-to)27-36
Number of pages10
JournalJournal of Quantitative Spectroscopy and Radiative Transfer
Volume185
DOIs
Publication statusPublished - 1 Dec 2016

Fingerprint

Methane
line shape
Spectrometers
methane
collisions
profiles
Semiconductor lasers
Absorption spectra
laser spectrometers
diodes
spectrometers
absorption spectra
deviation
high resolution
room temperature
Temperature

Keywords

  • Diode laser spectrometer
  • Hartmann–Tran profile
  • Line-shape
  • Methane

Cite this

@article{bcb7fa752fab4b5780167711c90fd131,
title = "Isolated line shape of methane with various collision partners",
abstract = "In this work, the spectral profile of an isolated transition of methane broadened by Ar, N2, O2 and He was studied using different line-shape models, from the simple Voigt to the recently recommended Hartmann–Tran profiles. For each collision-partner, absorption spectra of the ν4 2A11-3A21 line of methane were measured at room temperature and pressures ranging from 28.26 to 95.50 mbar, with a high resolution tunable diode laser spectrometer. The spectroscopic parameters of each line-shape model used were then retrieved from measured spectra using a multispectrum fitting procedure. The obtained results show that the Voigt profile leads to large deviations with respect to the measured one and that non-Voigt effects are more important for CH4 diluted in Ar, N2 and O2 than in He. We also confirm that both the confinement narrowing and the speed dependence effects must be taken into account in order to correctly reproduce the experimental spectra. In addition, the determination of the instrumental distortions of the spectrometer is also presented and discussed as a main difficulty of this analysis.",
keywords = "Diode laser spectrometer, Hartmann–Tran profile, Line-shape, Methane",
author = "{Le Cong}, Tuong and Laurent Fissiaux and Muriel Lep{\`e}re and Ha Tran",
year = "2016",
month = "12",
day = "1",
doi = "10.1016/j.jqsrt.2016.07.017",
language = "English",
volume = "185",
pages = "27--36",
journal = "Journal of Quantitative Spectroscopy and Radiative Transfer",
issn = "0022-4073",
publisher = "Elsevier Limited",

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TY - JOUR

T1 - Isolated line shape of methane with various collision partners

AU - Le Cong, Tuong

AU - Fissiaux, Laurent

AU - Lepère, Muriel

AU - Tran, Ha

PY - 2016/12/1

Y1 - 2016/12/1

N2 - In this work, the spectral profile of an isolated transition of methane broadened by Ar, N2, O2 and He was studied using different line-shape models, from the simple Voigt to the recently recommended Hartmann–Tran profiles. For each collision-partner, absorption spectra of the ν4 2A11-3A21 line of methane were measured at room temperature and pressures ranging from 28.26 to 95.50 mbar, with a high resolution tunable diode laser spectrometer. The spectroscopic parameters of each line-shape model used were then retrieved from measured spectra using a multispectrum fitting procedure. The obtained results show that the Voigt profile leads to large deviations with respect to the measured one and that non-Voigt effects are more important for CH4 diluted in Ar, N2 and O2 than in He. We also confirm that both the confinement narrowing and the speed dependence effects must be taken into account in order to correctly reproduce the experimental spectra. In addition, the determination of the instrumental distortions of the spectrometer is also presented and discussed as a main difficulty of this analysis.

AB - In this work, the spectral profile of an isolated transition of methane broadened by Ar, N2, O2 and He was studied using different line-shape models, from the simple Voigt to the recently recommended Hartmann–Tran profiles. For each collision-partner, absorption spectra of the ν4 2A11-3A21 line of methane were measured at room temperature and pressures ranging from 28.26 to 95.50 mbar, with a high resolution tunable diode laser spectrometer. The spectroscopic parameters of each line-shape model used were then retrieved from measured spectra using a multispectrum fitting procedure. The obtained results show that the Voigt profile leads to large deviations with respect to the measured one and that non-Voigt effects are more important for CH4 diluted in Ar, N2 and O2 than in He. We also confirm that both the confinement narrowing and the speed dependence effects must be taken into account in order to correctly reproduce the experimental spectra. In addition, the determination of the instrumental distortions of the spectrometer is also presented and discussed as a main difficulty of this analysis.

KW - Diode laser spectrometer

KW - Hartmann–Tran profile

KW - Line-shape

KW - Methane

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U2 - 10.1016/j.jqsrt.2016.07.017

DO - 10.1016/j.jqsrt.2016.07.017

M3 - Article

VL - 185

SP - 27

EP - 36

JO - Journal of Quantitative Spectroscopy and Radiative Transfer

JF - Journal of Quantitative Spectroscopy and Radiative Transfer

SN - 0022-4073

ER -