Characterization of a hard X-ray telescope at a synchrotron facility

This paper presents characterization of hard X-ray telescope using synchrotron facility, mainly on experimental setup, benefits of such experiment, and measurement results only available by means of bright synchrotron light. We have developed hard X-ray telescope consisting of Wolter-I grazing incidence optics with platinum-carbon multilayer supermirror surfaces. Telescopes have been fabricated for InFOCuS balloon experiment, and we achieved first scientific flight in 2004. The hard X-ray telescope on board InFOCuS has been characterized at synchrotron facility SPring-8/BL20B2, Japan. Measurement at BL20B2 has great advantages such as extremely high flux, large sized and less divergent beam, and monochromatic beam covering entire hard X-ray region from 8 to over 100keV. A 16m-long experiment hutch is another feature suitable for measurements of hard X-ray telescopes. The telescope was illuminated by monochromatic hard X-rays, and focused image was measured by high resolution hard X-ray imager. Whole telescope aperture was mapped by small beam, and effective area and point spread function are obtained as well as local optical properties for further diagnostics of telescope characteristics.