HDO and D2O long path spectroscopy: Ongoing work of the Brussels-Reims Team

Laboratory absorption spectra of H2O-D2O mixtures have been recorded in the spectral region 8800-1500 cm-1 by Fourier transform spectroscopy at high resolution (0.03 cm-1 ). The 50 m base long cell from Reims was used to record spectra with total pressure £ absorption path products of about 6000 torr m. In the continuation of our previous work concerning water vapor 1 ; 2 ; 3 ; 4 ; 5 ; 6 ; 7 ; 8 ; 9 ; 10 , the present study deals with the Deuterium enriched spectra. Two spectra with diÆerent mixing ratios for H 2 O, HDO and D 2 O species were recorded. The identiØcation of the HDO and D 2 O lines has been made by comparison of ratios between pure and enriched spectra. Partial pressures were carefully determined using (i) H2 ^16O previously determined line intensities, (ii) HDO and D 2 O line intensity ratios, and (iii) total pressures. The lines identiØcation was checked through the evolution of the integrated absorption coe±cients with the partial pressures. The observed lines have been Øtted to Voigt line proØles from which line positions (cali- brated afterwards), integrated absorption cross-sections and self-broadening coe±cients have been determined. For the two deuterated species the integrated absorption cross sections could be measured down to 5 10-27 cm/molecule. Comparisons with the most recent experimental data and calculations are presented.