High sensitivity Cavity Ring Down Spectroscopy of the 2ν1 + 3ν2 + ν3 band of NO2 near 1.57 µm. (October 2017)

• Record Type: Journal Article
• Authors: Lukashevskaya, A.A.; Kassi, S.; Campargue, A.; Perevalov, V.I.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 200(2017)
• Page Start: 17
• Page End: 24
• Publication Date: 2017-10
• Subjects: Nitrogen dioxide, NO2 -- Cavity Ring Down Spectroscopy -- Electron spin-rotation interaction -- Effective Hamiltonian; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2017.05.017
• Languages: English
• ISSNs: 0022-4073

Abstract

Highlights: First detection and analysis of the 2ν1 + 3ν2 + ν3 band of 14 N 16 O2 near 6351.4 cm -1 . 1069 assigned lines with rotational quantum numbers N and Ka up to 48 and 8. Line positions reproduced with an effective Hamiltonian ( rms of 2.35 × 10 -3 cm -1 ). Coriolis resonance coupling of (2, 3, 1) with the (2, 5, 0) and (2, 1, 2) dark states. Principal effective dipole moment parameter fitted to measured line intensities. Abstract: The weak 2ν1 + 3ν2 + ν3 absorption band of the nitrogen dioxide main isotopologue ( 14 N 16 O2 ) is investigated near 6350 cm −1 . The absorption spectrum was recorded by high sensitivity Cavity Ring Down Spectroscopy with a noise equivalent absorption of α min ≈ 1 × 10 −10 cm −1 . In total, 1069 lines of the 2ν1 + 3ν2 + ν3 band were assigned with rotational quantum numbers N and Ka up to 48 and 8, respectively, that corresponds to 1276 vibration-rotation transitions. The derived set of line positions is reproduced with an effective Hamiltonian with an rms of 2.35 × 10 −3 cm −1 for the (obs.-calc.) deviations. The effective Hamiltonian takes explicitly into account the Coriolis interactions between the spin rotational levels of the (2, 3, 1) upper vibrational state and those of two nearby dark states - (2, 5, 0) and (2, 1, 2) - together with the electron spin-rotation interactions. Using the corresponding eigenfunctions the principal effective dipole moment parameter responsible for the line intensities of the 2ν1 + 3ν2 + ν3 band is fitted to selected measured line intensities which are reproduced with an rms deviation of 6.2%.