La soutenance de thèse de cotutelle de TENANGUENA NONGNI Fresnelle aura lieu le Mardi 18 juin à 13h30 à VSB-Technical University of Ostrava en République Tchèque.
Title: Modeling of molecular ions formation in cold rare-gas plasma
Contact : Malika Benhenni
Abstract
Molecular ions, in particular, dimeric rare-gas ions have a very important influence on the behavior of rare gas plasmas used in multiple fields. Therefore, the analysis and understanding of their formation are of great importance for the macroscopic modeling of these plasmas. The main objective of this work is to perform calculations of the rate constants of dimers ionformation in cold plasmas using rare gases as carriers over a wide range of reduced electric fields. To do so we have used mesoscopic data (cross sections) obtained from microscopic data (interaction potentials) for argon to provide reaction rate constants of the formation of Ar2+. Further, to perform our calculations we have considered all six lowest-lying electronic states of the Ar2+ ions. These six electronic states are classified in two fine structure states of the atomic ion, the ground state 2P(3/2) and the excited state 2P(1/2). A quasi-classical trajectory approach based on the nonadiabatic mean-field dynamics approach and Diatomics In Molecules (DIM) model of the interactions in collision complexes used in preceding studies to calculate the collision cross sections that we will use in the present work. These collision cross sections will feed a Monte Carlo code adapted and optimized for the calculation of auxiliary data such as collision energy distributions which are important to provide averaged, thermal ternary recombination rate constants of ground and excited states of the dimer ion. The ternary recombination rate constants calculated in this way are compared with the experimental measurements and theoretical available in the literature. The results we have obtained, are close to these experimental and theoretical values for selected values of reduced electric fields, E/N = 1, 50, and 100 Td, with standard conditions of temperature T = 300 K and pressure P =10^5 Pa. Thus, these results are expected to be helpful in tuning cold plasma generators for specific applications.
Composition du jury:
Nelly Bonifaci: INP-Grenoble (rapporteur)
Malika Benhenni: LAPLACE UT3-Toulouse (co-directrice de thèse)
Ciprian Dalibor: VSB Technical University of Ostrava (rapporteur)
Florent Xavier Gadea: IRSAMC UT3-Toulouse (examinateur)
Tomas Gonzales-Lezana: CSIC-Madrid (rapporteur)
Pascal Parneix: Université Paris-Saclay (examinateur)
Rene Kalus: VSB Technical University of Ostrava (co-directeur de thèse)
Ivan Janecek: Institute of Geonics of the Czeck Academy of Sciences Sciences (examinateur)
