Recombination laser in the exploding-type-pumping using a 30-nm thin membrane target

In order to increase the gain length product for the Ha line (13.4 mn) of h ydrogen-like Nitrogen in the "exploding type pumping" of irradiating a 30 n m thick SiN membrane target with a few ps pulse, the pumping laser system i s up-graded. For crucially important issue of suppressing a pre-pulse, the energy of the front-end of the pumping laser system was increased by one or der. Beam pattern of the pumping laser pulse on the vacuum chamber window w as improved with an image relay. In order to start experiments of a water-w indow laser, chirping pulse amplification in e-beam pumped KrF laser system is planned.