Thermal nonequilibrium in partially ionized atomic oxygen

Abstract

A stationary, nonlinear collisional-radiative model for high-temperature atomic oxygen is presented. Populations of electrons, ions, and excited atoms and intensities of spectral, continuum, and dielectronic recombination lines are calculated in a wide range of conditions (11 000 K\ensuremath{\le}${T}_{e}$\ensuremath{\le}15000 K, ${10}^{10}$\ensuremath{\le}${N}_{t}$\ensuremath{\le}${10}^{18}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$). Transport of radiation is included by coupling the rate equations for production of the electrons, ions, and excited atoms with the concept of the escape factors that are not constant but dependent upon plasma conditions. The calculated total continuum emission is in good agreement with existing measurements.