Emissivity and radiative cooling of weakly non-ideal high-temperature Flibe gas

A theoretical model is developed to predict "rough estimates" of the isochors of the radiative cooling time of the high-temperature partially ionized Flibe gas at conditions relevant to the inertial fusion energy (IFE) chamber conditions. The model embodies the calculation of the occupational densities of all plasma species, calculation of the gas specific heat at constant volume, c_v along with the gas opacity/emissivity and radiative cooling surface based on the National Institute of Standards and Technology (NIST) extensive compilation of atomic and spectroscopic data. Although the problem of calculating radiative cooling in IFE environment is a very complicated multi-physics and multi-scale problem, which includes self-consistent solution of the magneto-hydrodynamics, radiation transport (possibly in time-dependent formulation), plasma kinetic, and atomic systems of equations, the rough estimates presented herein will be beneficial for benchmarking and engineering purposes with some carefulness.