Development of compact X-ray laser pumped by pulse-train laser and coherent X-ray optical System for its application

Abstract
We have been developing a tabletop x-ray laser with cavity based on the recombination plasma scheme where plasmas are pumped by a pulse-train laser. Advanced experiments have been performed with the double-target configuration. The spatial coherence of output x-ray beam were measured by using a dispersing coherent diagnostic System consisted of a Young s double-slit, a transmission grating and an x-ray CCD camera. The fringe pattern has been observed for the Al XI 3d-4f fine (15.47 nm), for which some gain was observed, for.double-slits of 24  m and 50 m separations placed 37 cm distance from the source. On the other hand, there has not been observed a clear fringe visibility for the other non-lasing lines. We propose a new soft x-ray interferometer with transmission gratings as a beam splitter and a beam deflector, for applications of coherent x-ray beam.