Service de Chimie Quantique et Photophysique
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Experimental Spectroscopy Atmospheric
Spectroscopy
J. Vander Auwera
M. Herman
T. Földes
T. Vanfleteren

High-resolution laser and Fourier transform spectroscopy of gas-phase molecules

High-resolution spectroscopy of prototypical species

High-resolution spectra of polyatomic molecules in various spectral ranges are recorded and/or analyzed. The target species are selected based on their relevance for various environments, in particular planetary atmospheres. The behavior of prototypical species in their vibrational overtones is investigated, aiming at the understanding of intramolecular vibrational redistribution from homemade global effective Hamiltonians. Thermodynamical and dynamical issues are considered. The emphasis is set on acetylene. We contribute developing model-Hamiltonians (rotation-vibration-torsion) and related computer codes. A significant effort is devoted to developing new absorption techniques and constantly and originally improving on technological performances to support all experimental research activities

Accurate measurements of vibration-rotation line parameters

Absorption line parameters (positions, absolute intensities, pressure-induced widths and shifts) are measured with state-of-the-art accuracy in the infrared range using high resolution Fourier transform spectroscopy and home-made software implementing multi-spectra analysis methods. Target species include polyatomic molecules relevant for planetary atmospheres, reactive compounds or species involved in chemical equilibria.

High-resolution overtone spectroscopy of dimers containing small polyatomic molecules

Ultrasensitive absorption laser techniques are developed and used to record high-resolution overtone spectra of van der Waals species containing small polyatomic molecules, under jet-cooled conditions. Acetylene, ammonia and water complexes are mainly investigated. Vibration-rotation constants are produced from line positions and excited vibrational predissociation lifetimes are deduced from linewidths. A global description of all vibration-rotation levels is searched for dedicated species.

Technological applications

A portable and patented homemade laser spectrometer is being developed and used for high-sensitivity online and on-site detection of some important contaminants, pollutants and disinfection-by-products in water.

Contracts

  • Research credit (CDR) F.R.S.-FNRS entitled "Methane spectrometry for atmospheres" (2016-2017).
  • ACME ("Ammonia Collisions MEchanisms"), collaboration with the Oxford University, funded by the Wiener-Anspach Foundation (2013-2016).
  • COST Action MOLIM ("MOLecules In Motion"), PI A. Csaszar, funded by the European Cooperation in Science and Technology (-2019).
  • LAUNCH (Brussels spin-off) project SPIP ("ultra-Sensitive sPectroscopy for In situ exploration") funded by the Bruxelles Région Capitale (INNOVIRIS) (2016-2019).

Full list of publications.


Université Libre de Bruxelles – Faculté des Sciences