Collimated-X-ray propagation in Ne-like and Ni-like media

We present results on the propagation of X-ray lasers where amplification occurs in a laser-produced plasma having a large proportion of either Ni-like silver or Ne-like iron ions. A ray-trace algorithm is used to model the refraction of the X-ray beam due to electron density gradients. The electron density profile used in the ray-trace calculations is provided by the hydro-code EHYBRID. Knowing the beam paths for various initial conditions the intensity and population densities are calculated in the saturation regime by using a Maxwell-Bloch approach. In the saturation regime, interaction between the pencil-shaped X-ray beam and the medium must be taken into account. In our modeling, the radiative transfer equation and the population rate equations are handled in a single calculation as the X-ray electric field affects the level populations and vice versa. (C) 2003 Elsevier Science Ltd. All rights reserved.