He-broadening coefficients and line intensitiesin the 2ν1 band of carbonyl sulfide (OCS)

Abstract

Using Fourier transform spectrometer, He-broadening coefficients have been measured for the first time in the P and R branches of the 2ν1 parallel band of carbonyl sulfide (OCS). The measurements have been performed at room temperature for rotational quantum number up to J = 70. A total of 131 lines were measured using a nonlinear least squares multi-pressure spectrum fitting procedure. Since the measurements have been performed using different values of OCS pressures, we have also retrieved line intensities of the ro-vibrational lines of the same branches. The fits were performed using the Voigt profile which leads to a precise determination of these spectroscopic parameters.From line intensities, we have determined vibrational transition moment, band intensity as well as Herman-Wallis parameters for the 2ν1 band. The results have been discussed as a function of the rotational quantum number and compared to previous data.The line-mixing effect on broadening coefficients was also analyzed showing a negligible influence.