Low-pressure line shape study of acetylene transitions in the ν₁ + ν₂ + ν₄ + ν₅ band over a range of temperatures

Abstract

In this study we have retrieved the self-broadened widths, self-pressure-induced shifts, and Dicke narrowing coefficients for 20 R-branch transitions in the ν₁ + ν₂ + ν₄ + ν₅ band of acetylene. The spectra were recorded using a three-channel diode laser spectrometer, a temperature-controlled cell of fixed length and a second, room temperature cell. The soft collision (Galatry) and hard collision (Rautian) profiles with inclusion of line mixing effects were used to retrieve the line parameters. We determined the temperature dependencies for line broadening, shift, and Dicke narrowing coefficients. We performed comparisons between our retrieved line parameters and published line parameters for acetylene transitions.

Keywords:

• temperature variable cell
• absorption
• control software
• laser spectroscopy
• acetylene
• spectral line shapes
• intensities
• pressure broadening
• pressure-induced shifts
• infrared spectroscopy
• remote sensing
• spectral line parameters