Progress in X-ray laser development at JAERI

By traveling wave irradiation with a compact, 2-beam, 1-ps, 20-J CPA Nd-glass laser dedicated to X-ray laser research, saturated amplification was demonstrated in Ni-like Ag at 13.9 nm and Ni-like Sn at 12.0 nm. High gain amplification was also obtained in Ni-like La at 8.8 nm and with gaseous targets in Ne-like Ar at 46.9 nm and Ni-like Xe at 9.98 nm. Generation of highly coherent X-ray laser is planned by injection seeding of the plasma amplifier. The newly developed 340-TW Ti-sapphire laser may make it possible to generate exceedingly high power X-ray radiation, which will be useful for pumping inner-shell ionization X-ray lasers.