ISSN:
1432-0649
Keywords:
33.00
;
42.65
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Polarization spectroscopy has been used to investigate the electronic bands of OH (A 2 Σ-X 2 Π) and NH (A 3 Π-X 3 Σ) radicals generated in atmospheric pressure flames. The pump-beam intensity dependence of the polarization-spectroscopy signals of isolated lines in theR branches has been studied. It was found that significant saturation is noticeable for pump-beam intensities as low as 0.1 MW/cm2. A detailed theoretical description inluding laser-bandwidth convolutions has been developed to model unsaturated polarization spectra of OH and NH. For OH, temperature evaluations have been performed in methane/air flames from fits to experimentalR 1 band head spectral structures. The results are critically dependent on the degree of saturation in experimental spectra, instrumental bandwidth and the assumed coupling cases in the calculation of line-strength parameters. It is shown that saturation leads to an error of more than 60% in the temperature evaluation when a pump-beam intensity of 1 MW/cm2 is used.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01081270
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