Spectroscopic study of self- and air-broadened methane in the 4100-4300 cm−1 region

Smith, Mary Ann H.

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https://hdl.handle.net/2142/100707 Copy

Description

Title

Spectroscopic study of self- and air-broadened methane in the 4100-4300 cm−1 region

Author(s)

Smith, Mary Ann H.

Contributor(s)

• Nikitin, Andrei V.
• Sung, Keeyoon
• Devi, V. Malathy
• Predoi-Cross, Adriana

Issue Date

2018-06-22

Keyword(s)

Atmospheric science

Abstract

The line parameters of self- and air-broadened methane in the ν1 + ν4 and ν3 + ν4 bands are determined using a nonlinear least-squares multispectrum fitting technique. We have analyzed a set of 14 laboratory spectra of pure methane and lean mixtures of methane in air which were recorded using a high-resolution Fourier Transform Spectrometer (FTS) at the Jet Propulsion Laboratory, California, employing a coolable sample cell with optical path length 20.38 cm. The line parameters determined in this analysis include line positions, intensities, self- and air-broadened line widths and pressureinduced shifts along with their temperature dependences, assuming a Speed-Dependent Voigt Profile (SDVP). The line mixing coefficients are quantified via the off-diagonal relaxation matrix element formalism. The broadening and shift parameters show good agreement with literature values and spectroscopic database entries. The observed line positions and intensities also agree fairly well with theoretically calculated results and values found in the spectroscopic databases. Spectroscopic parameters are also determined for some transitions of the ν2 + 2ν4, 2ν2 + ν4 and 3ν4 bands of methane in the spectral range 4100-4300 cm−1 . b

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100707

DOI

10.15278/isms.2018.FF02

Copyright and License Information

Copyright 2018 Mary Ann H. Smith

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