Radiative power and electron cooling rates for oxygen in steady-state and transient plasmas at densities beyond the coronal limit

We have developed a time-dependent, collisional-radiative model to calculate radiative power and electron cooling rates for oxygen at intermediate densities (1016 cm-3 less than or equal to n/sub e/ less than or equal to 1020 cm-3) where the usual coronal approximation is not valid. Large differences from coronal values are predicted. The behavior of the steady-state radiative power loss coefficient, L/sub Z, is investigated as the electron density is increased. Generalized power loss coefficients applicable to transient plasmas are derived and applied to ionizing and recombining oxygen plasmas. Time-dependent effects are found to play a large role both in terms of the total radiated power and the net electron energy loss rate. 41 refs., 11 figs