My research activities focus on the modeling and the measurement of the ionization and the radiative properties (opacity, emissivity) of hot plasmas at Local Thermodynamic Equilibrium (LTE) and out of equilibrium (non-LTE). The modeling involves domains like quantum mechanics (n-body problem, fine structure calculations, Racah algebra, Slater-Condon approach, configuration interaction, etc.), elaborate methods of statistical physics (superconfigurations), microscopic physics (master equations, collisional and radiative processes, Auger effect), atomic spectroscopy (lines accounting, Stark and Zeeman effects), radiative-hydrodynamic simulations, thermodynamics. I am also strongly involved in the design, participation and interpretation of LTE/non-LTE plasma atomic spectroscopy experiments carried out on laser (LULI, ELFIE) or Z-pinch (SNL) facilities.