Parameters of broadening of water molecule absorption lines by argon derived using different line profile models

Abstract

The water vapor absorption spectrum was measured in the spectral region 6700–7650 cm^–1 with argon as a buffer gas. The room-temperature spectrum was measured using a Bruker IFS 125-HR Fourier Transform Spectrometer with high signal-to-noise ratio, with a spectral resolution of 0.01 cm^–1, at argon pressures from 0 to 0.9 atm. The H₂O absorption spectral line parameters are derived by fitting two line shape profiles (Voigt and speed-dependent Voigt) to the experimental spectrum. It is shown that the use of speed-dependent Voigt profile provides the best agreement with experimental data.