NEW DATA AND ANALYSIS FOR SF6 ABSORPTION MODELLING IN THE 10 MICRON ATMOSPHERIC WINDOW

Modelling correctly the SF$_{6}$ atmospheric absorption requires the knowledge of the spectroscopic parameters of all states involved in the many hot bands in the 10 $\mu$m atmospheric window used for remote sensing. Since a direct analysis of the hot bands near the \nub{3} absorption of SF$_{6}$ in this atmospheric window is not possible, due to their overlapping, we use another strategy, gathering information in the far and mid infrared regions on initial and final states to compute the relevant total absorption. In this talk, we present new results of an analysis of spectra recorded at the AILES beam line at the SOLEIL Synchrotron facility. For these measurements, we used an IFS125HR interferometer in the 100 to 3200 \wn range, coupled to a cryogenic multiple pass cell. The optical path length was varied from 45 to 141 m with 223 and 153 K temperatures. New information has been obtained on the \nub{3} + \nub{5} band which, combined with improved parameters for \nub{5}, is used to model the important \nub{3}+\nub{5} - \nub{5} hot band contribution [1]. Also, data have been obtained on the \nub{3} band of the $^{36}$SF$_{6}$ isotopic species present in very low abundance (0.0002) [2]. These new parameters will be included in the XTDS model [3] and VAMDC/SheCaSDa database [4], thus improving the previous SF$_{6}$ parameters. [1] M. Faye, L. Manceron, P. Roy, V. Boudon, M. Loete, “First analysis of the \nub{3}+\nub{5} combination band of SF$_{6}$ observed at Doppler-limited resolution and effective model for the \nub{3}+\nub{5}-\nub{5} hot band” J. Mol. Spectrosc., in press. [2] M. Faye, L. Manceron, P. Roy, V. Boudon, M. Loete, “First high resolution analysis of the \nub{3} band of the $^{36}$SF$_{6}$ isotopologue”, J. Mol. Spectrosc., in press. [3] C. Wenger, V. Boudon, M. Rotger, M. Sanzharov, and J.-P. Champion,”XTDS and SPVIEW: Graphical tools for Analysis and Simlation of High Resolution Molecular Spectra”, J. Mol. Spectrosc. 251, 102 (2008). [4] http://vamdc.icb.cnrs.fr/PHP/shecasda.ph