Numerical simulation of a recombination x-ray laser

A numerical model of a recombination x-ray laser has been developed. A calculation on the gasdynamics of a plasma with nonequilibrium diffusion of thermal radiation includes the stage of laser irradiation of the target. A model for the kinetics of the level populations of hydrogen-like ions incorporates reabsorption of Lyman lines through an exact solution of the transport equation in a cylindrical inhomogeneous plasma.The dynamic Doppler effect is taken into account. Experiments carried out at the Rutherford Appleton Laboratory to observe a gain on the 3–2 transition of the C VI ion in the expanding plasma of a carbon fiber are analyzed numerically. A satisfactory description of the experimental results is found when account is taken of the fine splitting of the working levels and of the distortion of the signal by the measurement apparatus.