LOW-TEMPERATURE COLLISIONAL BROADENING IN THE FAR-INFRARED CENTRIFUGAL DISTORTION SPECTRUM OF CH4

Boudon, Vincent

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https://hdl.handle.net/2142/79395 Copy

Description

Title

LOW-TEMPERATURE COLLISIONAL BROADENING IN THE FAR-INFRARED CENTRIFUGAL DISTORTION SPECTRUM OF CH4

Author(s)

Boudon, Vincent

Contributor(s)

• Faye, Mbaye
• Amyay, Badr
• Gabard, Tony
• Kwabia Tchana, F.
• Manceron, Laurent
• Vander Auwera, Jean

Issue Date

23-Jun-15

Keyword(s)

Mini-symposium: Accelerator-Based Spectroscopy

Abstract

Previously, we could record on the AILES Beamline at the SOLEIL Synchrotron facility the first resolved centrifugal distorsion spectrum of methane (CH$_4$) in the THz region, which led to a precise determination of line intensities footnote{V. Boudon, O. Pirali, P. Roy, J.-B. Brubach, L. Manceron and J. Vander Auwera, {em J. Quant. Spectrosc. Radiate. Transfer}, {bf 111}, 1117--1129 (2010).}. Later, we could measure collisional self- and N$_2$-broadening coefficients at room temperaturefootnote{M. Sanzharov, J. Vander Auwera, O. Pirali, P. Roy, J.-B. Brubach, L. Manceron, T. Gabard and V. Boudon, {em J. Quant. Spectrosc. Radiate. Transfer}, {bf 113}, 1874--1886 (2012).}. This time, we reinvestigated this topic by measuring these broadening coefficients at low temperature (between 120~K and 160~K) for $J=5$ to $12$, thanks to a cryogenic multipass cellfootnote{F. Kwabia Tchana, F. Willaert, X. Landshere, J.-M. Flaud, L. Lago, M. Chapuis, C. Herbeaux, P. Roy and L. Manceron, {em Rev. Sci. Instrum./}, {bf 84}, 093101 (2013).}. We used a 93~m total optical path length. Five pure methane pressures (from 10 to 100 mbar) and four CH$_4$/N$_2$ mixtures (20~% of methane with a total pressure from 100 to 800 mbar) were used. These measurements allow us to obtain data for physical conditions approaching those of Titan's atmosphere and to estimate temperature exponents.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

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http://hdl.handle.net/2142/79395

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