Recent results from hard x-ray telescope characterization at SPring-8

Abstract

We have been developing a hard X-ray imaging telescope with Pt/C multilayers for balloon experiments and for ASTRO-H. Calibration of the hard X-ray telescope has been performed at the synchrotron radiation facility, SPring-8, to obtain point spread function and effective area for the InFOCuS and SUMIT experiments. Hard X-ray characterization at the SPring-8 beamline BL20B2 has great advantages over those with conventional sources, such as an extremely high flux, a larger beam with less divergence, and a selectable, narrow bandwidth covering the hard X-ray region from 20 to over 100 keV. We have been successful not only in characterizing the telescope but also in establishing the tuning procedure to improve its image quality. The 16m-long experimental hutch has sufficient capability for characterization of the telescope with a long focal length up to 12 m as well as reflectivity and diffraction measurements of multilayer reflectors. Recently we have measured 87 pairs of multilayer mirrors and obtained an angular resolution of 1.5 arcmin (HPD), and reflectivity of Pt/C multilayers designed for ASTRO-H. In this paper, we report recent results of X-ray measurements of our hard X-ray telescope and multilayer mirrors.