Calculated X-radiation from optically thin plasmas. IV - Atomic data and rate coefficients for spectra in the range 1-270 A.

Rate coefficients of ionization, recombination, and excitation, used in recent computations of the soft X-ray (1-270 A) spectra of transient optically thin plasmas are discussed in detail. A total of 870 spectral lines containing about 100 satellites to resonance lines in hydrogen- and helium-like ions is considered. These satellite lines are produced by innershell excitation, dielectronic recombination, and innershell ionization, processes that can be extremely sensitive to nonequilibrium effects in the ionization balance. The elements that are included in the calculations are H, He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, and Ni. Some resulting spectra are shown graphically, and the intensities of the emission lines of a stationary plasma are tabulated over the temperature range 10 to the 5th - 10 to the 8th K. The effects on the emergent X-ray spectrum and on the satellite line formation processes deriving from deviations from the ionization equilibrium are illustrated for the model of a transient plasma in which the electron temperature strongly increases with a jump.