Wave-front evaluation of the Ni-like Ag laser

Coherent x-ray lasers are desired for various applications such as holography of biological samples and diagnostics of laser-produced plasmas. However, the shape of the x-ray laser had not been examined. Information about its wave-front shape is also important for future application of x-ray lasers in research and industry. In this paper, we report the evaluation of the shape of the wave-front of the x-ray laser. Ni-like Ag lasers at 13.9 nm were examined in IV-01-GXII experiment at GEKKO XII glass laser facility at ILE, Osaka Univ. The fringe patterns generated using crossed wires located in the beam were recorded on the x-ray CCD. Our experimental results indicate that x-ray laser emitted from an end of a plasma column has a property of a point light source.