A method for calculating the radiation characteristics of nonequilibrium laboratory plasmas

Abstract

One of the fundamentally important issues in the characterization of a dense high-temperature plasma is the description of its self-radiation aimed at determining the radiation losses and their spectral composition. In this paper, a new method is proposed for calculating the radiation characteristics of a high-temperature nonequilibrium plasma. The method is based on a collisional radiative model, which makes it possible to calculate the charge-state distribution in the plasma and the excited-state distribution of the plasma ions. The transfer equations are solved separately for the radiation with a continuous spectrum, combining the bremsstrahlung and recombination radiation spectra, and for the spectral line radiation. A feature of the method is that, when calculating the mean line absorption coefficients, dimensionless weighting coefficients are used, which make it possible to take into account the contribution of the strongest lines. The use of weighting coefficients has the result that even a one-group approximation yields good agreement with the numerical solution of the complete spectral problem.