Diagnostics laser ultrarapides d'écoulements réactifs et hors équilibre à l'interface gaz-liquide

In this PhD thesis, we propose to apply unique non-linear ultrafast laser techniques (fs-TALIF, fs/ps-CARS) to investigate the same plasma device, namely a microwave plasma jet, which can be driven in continuous or pulsed mode at atmospheric or intermediate pressures. The plasma non-equilibrium degree (vibration, rotation, translation), its reactivity (radical fluxes) and its interaction with a water liquid surface will be controlled spatially or temporarily. Mapping of the vibrational non-equilibrium distribution (non-Boltzmann) in electronic ground states of N₂, O2 and H₂ molecules is essential for example for understanding vibration-dependent kinetics in applications such as plasma-assisted nitrogen fixation, where vibrational ladder is a key dissociation mechanism. Radical density (e.g. O, N, H) and temperature mappings at the plasma-liquid interface provide access to gradients and thus to species and heat transfer fluxes. This knowledge is important for understanding fundamental processes in non-equilibrium reactive flows, such as plasma kinetics under various degrees of humidity, evaporation, or radical diffusion in liquid phase, for applications such as plasma water depollution (e.g. PFAS abatement) or plasma-assisted two-phase combustion. École doctorale : Sciences Mécaniques Energétiques et MAtériaux pour l'InGénierie Direction : Gabi-Daniel STANCU Financement : Autre type de financement - Autre type de financement,