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Dicke-narrowed spectral line shapes of CO in Ar: Experimental results and a revised interpretation
- Source :
- Journal of Molecular Spectroscopy. 235:54-68
- Publication Year :
- 2006
- Publisher :
- Elsevier BV, 2006.
-
Abstract
- The shapes of Dicke-narrowed spectral lines in the fundamental P -branch of CO in Ar are studied by comparing high-resolution measurements and theoretical calculations. The measured spectra were recorded at temperatures between 214 and 324 K, and at pressures between 0.025 and 1 atm. The calculations are based on solving a transport/relaxation equation for the appropriate off-diagonal element of the density matrix; they use a realistic intermolecular potential to determine the speed-dependent collisional broadening, and a rigid sphere potential to determine the Dicke narrowing. It is found that the calculations can reproduce the measured spectra within the experimental noise under all conditions, but that the magnitude of the Dicke narrowing in the measured spectra is 70–90% less than predicted from the mass diffusion constant. A revised view of the collision operator resolves the discrepancy in principle, and leads to a better understanding of the line shape problem in general.
- Subjects :
- Physics
Density matrix
business.industry
Inelastic collision
Magnitude (mathematics)
Noise (electronics)
Atomic and Molecular Physics, and Optics
Spectral line
Spectral line shape
Computational physics
Optics
Physical and Theoretical Chemistry
business
Constant (mathematics)
Spectroscopy
Line (formation)
Subjects
Details
- ISSN :
- 00222852
- Volume :
- 235
- Database :
- OpenAIRE
- Journal :
- Journal of Molecular Spectroscopy
- Accession number :
- edsair.doi...........6a86a9f23184fd0e7bc74559d357752e