ABSTRACT
The radiation generated in the soft-x-ray domain by spontaneous emission, and amplified while propagating in a plasma column, is investigated in recombination lasers in the framework of the small-signal theory, and in the saturation regime of collisionally-pumped lasers with the help of the Maxwell-Bloch formalism. We have analyzed the effect of accurate line shapes on gain numbers and integrated intensities. Our calculations are applied to the 3d-4f and 3d-5f radiations in Li-like Al, where the Stark interaction due to neighbouring ions is important, and to the 0-1 and 2-1 radiations in Ne-like Ge. In the second case the Stark broadening is negligible. We define an effective gain in the same way as in experiments.
