Kinetics of population of atom excited states with taking into account the resonance radiation transport in the transition region of plasma-gas

The collision-radiative model (CRM) for the optically thick stationary non-uniform nonequilibrium plasma including the excited atoms diffusion and the radiation transport is developed. The basic purpose of work is the elaboration of the adequate physical description of the excited states kinetics and radiation transport in the trapped lines in a transition layer plasma-gas for its application in the analysis of processes in divertor plasma of tokamak. The collision-radiating processes and processes of diffusion are considered on the fixed set of radial distributions for the electronic temperature and density having universal behavior for the cylindrical symmetry. The full enough set of elementary collision-radiative processes is included in the kinetic scheme which allows revealing the phenomenon of spatial change of kinetics regimes of population of the excited states in the non-uniform, nonequilibrium plasma. For the description of radiation transport the traditional approach of escape factor and the two special approaches of averaged radiation diffusion are used, differing by a technique and sequence of average procedure of radiation intensity over frequency in the region of spectral lines with the large value of optical thickness. The sense of these approaches correspond to an introduction in consideration an effective quantum of radiation. By consideration of the diffusion of such quanta a radiation transport problem is solved for the spatially non-uniform distribution of populations. The original computer code is created, allowing calculations of the spatial intensity distribution of the spectral lines and their integrated over volume intensity values for various regions of the discharge. The developed approach is used for the interpretation of the spectroscopic measurements carried out at the LENTA device (Institute of nuclear synthesis, RRC Kurchatov Institute) in the experiments on modeling divertor plasmas of tokamak