Premium
Application of the rotational diffusion model to the CARS spectra of high‐temperature, high‐pressure water vapour
Author(s) -
Greenhalgh Douglas A.,
Hall Robert J.,
Porter Fiona M.,
England William A.
Publication year - 1984
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1250150202
Subject(s) - dephasing , chemistry , raman spectroscopy , spectral line , diffusion , bar (unit) , rotational diffusion , relaxation (psychology) , water vapor , analytical chemistry (journal) , thermodynamics , condensed matter physics , physics , meteorology , molecule , optics , organic chemistry , psychology , social psychology , astronomy
CARS spectra of water vapour at elevated pressures (1–16 bar) and temperatures (300–800 K) have been investigated experimentally and theoretically. A theoretical model of the CARS spectrum of water vapour based on Gordon's rotational diffusion model was tested. The model was adapted to include the effects of vibrational relaxation and dephasing processes. Good agreement was found between experiment and theory for all conditions investigated. Rotational inelastic collisions are dominant and contribute approximately 65% to the overall individual molecular linewidths. As part of the data analysis a new measurement of dσ/dω (H 2 O)=1.10 × 10 −34 ± 20% m 2 sr −1 has been made.