Gigantic mirror for X-radiation in outer space
It is to become the largest X-ray telescope ever: The International X-Ray Observatory (IXO), which has been planned in a cooperation between NASA, ESA and Japan's Aerospace Exploration Agency JAXA, will be launched into space in 2021 and provide the world with brand new information about black holes and, thus, about the origin of the universe. Its dimensions are gigantic: The surface of the mirror alone, which is to capture, for example, the cosmic X-radiation of black holes, will be 1300 m2 in size. It will consist of commercially available silicon wafers with pores of a few millimetres underneath. The quality of these "hidden" surfaces will be tested at the Physikalisch-Technische Bundesanstalt (PTB) with a monochromatic X-ray pencil beam. The new measuring device has been installed at PTB's synchrotron radiation laboratory at BESSY II in Berlin-Adlershof.