TRANSITION ELECTRON-DENSITY BETWEEN THE CORONAL AND THE THERMAL-EQUILIBRIUM IN HYDROGEN PLASMAS

Non-equilibrium ionization in a hydrogen plasma was considered on the basis of the collisional-radiative model of Bates et al. The ionizatio n ratio was calculated for a wide range of electron density and temper ature, and the electron density, at which the transition between the t hermal equilibrium and the coronal equilibrium takes place, was calcul ated. It was found that the transition occurs at the electron density (1 similar to 3) x 10(23) m(-3) for the temperature from 5 x 10(3) to 10(5) K and that the transition electron density is almost independent of the temperature.