High sensitivity CW-Cavity Ring Down Spectroscopy of N2O between 6950 and 7653 cm-1 (1.44-1.31 μm): II. Line intensities

The room temperature absorption spectra of nitrous oxide, N2O, have been recorded in the 6950-7653 cm(-1) spectral region at 2 and 10 Torr using a CW-CRDS spectrometer based on 24 fibered DFB lasers. The achieved sensitivity (noise equivalent absorption alpha(min) approximate to 5 x 10(-11) cm(-1)) allowed detecting lines with intensities as low as 1 x 10(-29) cm/molecule. In the preceding contribution (Lu Y, Mondelain D, Liu AW, Perevalov VI, Kassi S. Campargue A, J Quant Spectros and Radiat Transfer 2012;113:749-62), we reported the assignment of more than 7200 N2O lines in the region and the derivation of the corresponding spectroscopic parameters G(v), B-v, D-v, and H-v. In the present work; more than 1300 (N2O)-N-14-O-16 absolute line intensities of cold and hot bands belonging to the Delta P=12, 13 and 14 series of transitions have been measured (P=2V(1) + V-2+ 4V(3) is the polyad number). The uncertainty of the obtained line intensity values varies from 4 to 7% for the majority of the lines. The obtained dataset extends importantly the set of measurements available in the literature, in particular for the Delta P =13 series for which previous data were very limited. The Delta P=12-14 effective dipole moment parameters were fitted to the intensity values measured in this work and available in the literature. The obtained sets of the dipole moment parameters allow reproducing the observed line intensities within their experimental uncertainties. The calculated intensities of the Delta P=12, 13 and 14 bands of (N2O)-N-14-O-16 assigned by CRDS in the 6950-7653 cm(-1) region are provided as supplementary material. (C) 2012 Elsevier Ltd. All rights reserved.