Line-by-line measurements of interference parameters for the 0–1 and 0–2 bands of CO in He, and comparison with coupled-states calculations
- 1 October 1992
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 97 (7) , 4623-4632
- https://doi.org/10.1063/1.463865
Abstract
Here we present the first line-by-line measurements of interference parameters Y(k)0 describing line-mixing effects in the weak overlapping regime for He-broadened CO lines in the 0-1 and 0-2 bands at 296 K. A detailed analysis of the line shape at intermediate perturber pressures (up to about 10 atm) has been performed, starting from previous theoretical calculations, which has demonstrated the possibility of an individual measurement of Y(k) parameters. The method is based on the existence of a component of the line shift, quadratic with the perturber pressure (density) and proportional to Y(k)0. Comparison of our measurements with results predicted from coupled-states calculations shows good overall agreement. Linear pressure shifts have also been simultaneously measured. The uncertainty on the data is important since linear shifts are very small; however, some features can be considered as significant although we have no clear understanding of them. Possible explanations are discussed.Keywords
This publication has 42 references indexed in Scilit:
- Heterodyne spectroscopy of carbon monoxide lines perturbed by hydrogen and heliumThe Journal of Chemical Physics, 1991
- The high energy asymptotic behavior of line shape cross sections and detailed balanceThe Journal of Chemical Physics, 1991
- Study of collisional effects on band shapes of the ν1/2ν2 Fermi dyad in CO2 gas with stimulated Raman spectroscopy. I. Rotational and vibrational relaxation in the 2ν2 bandThe Journal of Chemical Physics, 1990
- Collisionally induced population transfer effect in infrared absorption spectra. I. A line-by-line coupling theory from resonances to the far wingsThe Journal of Chemical Physics, 1988
- Line coupling in the temperature and frequency dependences of absorption in the microwindows of the 4.3 μm CO2 bandJournal of Quantitative Spectroscopy and Radiative Transfer, 1986
- Effect of the potential well on low temperature pressure broadening in CO–HeThe Journal of Chemical Physics, 1986
- Calculation of pressure broadening parameters for the CO–He system at low temperaturesThe Journal of Chemical Physics, 1985
- Finite duration of collisions and vibrational dephasing effects on the Ar broadened HF infrared line shapes: Asymmetric profilesThe Journal of Chemical Physics, 1984
- Overlapping effects and motional narrowing in molecular band shapes: Application to the Q branch of HDa)The Journal of Chemical Physics, 1977
- Application of pressure broadening theory to the calculation of atmospheric oxygen and water vapor microwave absorptionJournal of Quantitative Spectroscopy and Radiative Transfer, 1977