X-ray laser development and applications of coherent X-ray

Compact x-ray lasers are developed by the transient collisional excitation method using a CPA (chirped pulse amplification) laser system as a pumping driver. The pumping laser beam is focused in a line shape and is irradiated in solid metal targets (Ti, Ag, Sn and La). The saturated amplification was obtained at wavelengths of 13.9 nm (Ni-like Ag) and 11.9 nm (Ni-like Sn). Recently, the lasing was obtained at a shorter wavelength of 8.8 nm (Ni-like La). The several application experiments were tried by using the x-ray laser of 13.9 nm, where x-ray optics with high reflectance could be used. In addition, two experiments are now being carried out using seeding light amplification for generating highly coherent x-ray lasers. (author)