Measurements of line strengths in the 2nu1 band of the HO2 radical using laser photolysis/continuous wave cavity ring-down spectroscopy (cw-CRDS).

J Phys Chem A

Physico-Chimie des Processus de Combustion et de l'Atmosphère (PC2A), CNRS UMR 8522, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France.

Published: August 2007

Absolute absorption cross sections of the absorption spectrum of the 2nu1 band of the HO2 radical in the near-IR region were measured by continuous wave cavity ring-down spectroscopy (cw-CRDS) coupled to laser photolysis in the wavelength range 6604-6696 cm(-1) with a resolution better than 0.003 cm(-1). Absolute absorption cross sections were obtained by measuring the decay of the HO2 self-reaction, and they are given for the 100 most intense lines. The most important absorption feature in this wavelength range was found at 6638.20 cm(-1), exhibiting an absorption cross section of sigma = 2.72 x 10(-19) cm2 at 50 Torr He. Using this absorption line, we obtain a detection limit for the HO2 radical at 50 Torr of 6.5 x 10(10) cm(-3).

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http://dx.doi.org/10.1021/jp0703307DOI Listing

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