ICLAS of HDO between 13020 and 14115 cm-1

O. V. Naumenko (1, 2) , Serge Béguier (2, 3) , Olga Leshchishina (2, 4) , Alain Campargue (2, 3)

1 IAO - V.E. Zuev Institute of Atmospheric Optics
2 LSP - Laboratoire de Spectrométrie Physique
3 LAME-LIPhy - LAsers, Molécules et Environnement
4 LTS - Laboratory of Theoretical Spectroscopy [Tomsk]

The high resolution absorption spectrum of monodeuterated water, HDO, has been recorded by Intracavity Laser Absorption Spectroscopy (ICLAS) in the 13020-14115 cm-1 region dominated by the 43 band. The achieved noise equivalent absorption (min~ 10-9 cm-1) allowed detecting transitions with line strengths as small as 2×10-27 cm/molecule which is about 10 times lower than the smallest line intensities previously detected in the region. The rovibrational assignment of the spectrum was based on the results of the variational calculations of Schwenke and Partridge (SP) as well as recent calculations using a new potential energy surface performed by Voronin, Tolchenov and Tennyson (VTT). 2157 transitions involving 21 upper vibrational states were assigned to HD16O while only four bands were previously reported in the region. A set of 157 new energy levels could be derived. It includes rotational levels of several highly excited bending states, in particular the (0 11 0) pure bending state. For some states like the (103) and (023) Fermi dyad, effective Hamiltonian modelling was needed to establish the vibrational assignments of some rotational levels. VTT calculations were found to significantly improve SP results, the rms deviation of the calculated and observed energies being decreased from 0.23 to 0.06 cm-1. Finally, 79 transitions of the 43 band of the HD18O isotopologue were assigned, leading to the derivation of 48 levels which are the most excited energy levels reported so far for this isotopologue.

Domaines: Physique Atomique [physics.atom-ph]; Optique [physics.optics]

O. V. Naumenko, Serge Béguier, Olga Leshchishina, Alain Campargue. ICLAS of HDO between 13020 and 14115 cm-1. Journal of Quantitative Spectroscopy and Radiative Transfer, 2010, 111, pp.36. ⟨10.1016/j.jqsrt.2009.06.016⟩. ⟨hal-00563131⟩