title: INNER-SHELL IONIZATION X-RAY LASER DRIVEN BY HIGH INTENSITY LASER Authors: Kengo Moribayashi$^1$, Akira Sasaki$^1$, Yutaka Ueshima$^1$, and T. Tajima$^{1,2}$ Affiliation: $^1 $ Advanced Photon Research Center,Japan Atomic Energy Research Institute, 25-1, Mii-minami-cho, Neyagawa-shi, Osaka, 572-0019, Japan $^2$ Department of Physics and Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA summary: Physical processes of an inner-shell ionization x-ray laser by using high intensity laser are considered. We employ the high brightness x-rays driven by the high-intensity short-pulse laser as a x-ray pumping source. We will show some examples of detailed requirements for an experiment for the initiating laser power, geometry and conditions at the presentation.