Measurement of line strengths in the à 2A’ ← X˜ 2A” transition of HO2 and DO2

0506626 - ÚFCH JH 2020 RIV GB eng J - Článek v odborném periodiku
Assaf, E. - Asvany, O. - Votava, Ondřej - Batut, S. - Schoemaecker, C. - Fittschen, Ch.
Measurement of line strengths in the à 2A’ ← X˜ 2A” transition of HO2 and DO2.
Journal of Quantitative Spectroscopy and Radiative Transfer. Roč. 201, NOV 2017 (2017), s. 161-170. ISSN 0022-4073. E-ISSN 1879-1352
Institucionální podpora: RVO:61388955
Klíčová slova: cw-CRDS * DO2 radicals * HO2 radicals * Near infrared spectroscopy
Obor OECD: Physical chemistry
Impakt faktor: 2.600, rok: 2017
Způsob publikování: Omezený přístup

The absorption spectrum of the à 2A’ ← X˜ 2A” 000–000 band of HO2 and DO2 radicals has been measured in the range 6941–7077 cm−1 with a resolution of around 0.005 cm−1. HO2 and DO2 radicals were generated from the reaction of Cl-atoms with CH3OH and CD3OD, respectively, whereby Cl-atoms were generated by pulsed photolysis of (COCl)2 at 248 nm. One time-resolved absorption curve was measured by cw-Cavity Ring Down Spectroscopy (cw-CRDS) for each wavelength. The relative absorption coefficient for each wavelength was then obtained from the ring down time τ, extrapolated to t = 0 s with respect to the photolysis pulse, and the ring down time τ0 before the photolysis pulse. Absolute absorption coefficients were quantified for several selected lines relative to a well characterized absorption line of HO2 at 6638.21 cm−1 by a second cw-CRDS absorption path. The maximum absorption cross section at 50 Torr Helium was for HO2 the transition N Ka Kc J = 11 0 11 11.5 ← 11 1 11 11.5 with σ7000.28 cm−1 = 2.12 × 10−19 cm2 and for DO2 the doublet transition N Ka Kc J = 18 1 18 18.5 ← 18 0 18 18.5 and 18 1 18 17.5 ← 18 0 18 17.5 with σ7019.83 cm−1 = 2.97 × 10−19 cm2. The full spectrum has been very well reproduced by employing spectroscopic data from earlier works.
Trvalý link: http://hdl.handle.net/11104/0297835