Ne-LIKE Ge X-RAY LASER EXPERIMENTS

We report here an x-ray laser experiment in Ne-like Ge plasmas. This experiment was performed with Ge slab targets on the LF-12 laser facility. When the pumping laser wavelength, pulse width and energy were 1.053μm, 1.1-1.4ns and 550-650J and the focus line length and width were 20mm and 185μm respectively, we obtained the gain coefficients of 3.06, 3.99, 3.72, 2.36 and 4.59cm^-1 for five lasing lines of 19.61, 23.22, 23.63, 24.73 and 28.65nm respectively. We also report the data of the lasing plasma thickness, the divergence angle of the x-ray laser beams, and the dependence of the x-ray laser intensity on pumping laser power densities. At last we point out the causes why we didn't get the gain in the experiments for Ge foil targets.