Silver and tin slab targets were irradiated by line-focused chirped pulse amplification glass laser light. In this experiment, the laser pulses consisted of two pulses with 4 ps duration, separated by 1.2 ns. Strong amplification in the nickel-like silver and tin x-ray lasers at the wavelengths of 13.9 and 12.0 nm was demonstrated with pumping energy of 12 and 14 J, respectively, and gain-saturation behavior could be seen. A hydrodynamics simulation coupled with a collisional-radiative model was performed under the present experimental conditions, and the calculated result was compared with the experimental results.
