Spectroscopie diode laser : étude des élargissements collisionnels de raies d’absorption des molécules CS2 et CO2

Student thesis: Doc typesDoctor of Sciences

Abstract

The aim of this thesis was to study the collisional broadening coefficients of absorption lines of carbon disulfide and carbon dioxide molecules in the presence of perturber gases. The measurements have been realized using a high resolution tunable diode laser spectrometer. We have measured and analyzed the collisional broadening coefficients of absorption lines in the nu3 vibrational band of 12C32S2 and in the nu3-nu1 vibrational band of 12C16O2 diluted in helium, neon and krypton. The collisional broadening coefficients of the absorption lines of the nu2 vibrational band of 13C16O2 have been also studied in the presence of nitrogen and oxygen. The collisional widths have been determined by fitting the Voigt, the Rautian and the Galatry profiles. The latter models take into account the effect of narrowing of the Doppler profile by molecular confinement (Dicke effect). The consideration of the interaction of collisions on the Doppler effect substantially improves the quality of fits. The spectral parameters derived from these fits are thus more precise. From the collisional widths obtained for each line studied at 4 or 5 pressures, collisional broadening coefficients have been determined by linear regression. As the measurements have been realized at different temperatures (from 173 to 576 K), the temperature dependence of collisional broadening coefficients has been determined for each line understudy. Our results have both fundamental and applied interests. They will allow a better understanding of the intermolecular interactions in the gas phase and the determination of the molecular interaction potentials involved in the process of collisions. The collisional parameters are also important to complete the atmospheric databases as HITRAN, GEISA or CDSD.
Date of Award30 Aug 2012
Original languageFrench
Awarding Institution
  • University of Namur
SupervisorMuriel Lepere (Supervisor), Ghislain Blanquet (Jury), Luc Henrard (Jury), Laurent Houssiau (President), Pierre Defrance (Jury), Michel Herman (Jury) & Thérèse HUET (Jury)

Cite this

Spectroscopie diode laser : étude des élargissements collisionnels de raies d’absorption des molécules CS2 et CO2
Kongolo Tshikala, P. (Author). 30 Aug 2012

Student thesis: Doc typesDoctor of Sciences