Supermirror design for Hard X-Ray Telescopes on-board Hitomi (ASTRO-H)
Abstract
We designed depth-graded multilayers, so-called supermirrors, with platinum/carbon (Pt/C) layer pairs for the Hard X-Ray Telescope (HXT) that was on-board the sixth Japanese X-Ray Astronomy Satellite Hitomi (ASTRO-H). The HXT has multinested thin foil optics, and the grazing angles of the x-ray mirrors are 0.07 to 0.27 deg. Supermirrors for HXTs are designed to provide a broad energy response (up to 80 keV) for astronomical requests. Under practical boundary conditions, we establish a block method applying empirical rules to maximize the integrated reflectivity. We fabricated Pt/C supermirrors using a DC magnetron sputtering system. The reflectivity of the mirrors was measured in a synchrotron radiation facility, SPring-8. We describe the design method for the supermirrors and our results.
- Publication:
-
Journal of Astronomical Telescopes, Instruments, and Systems
- Pub Date:
- January 2018
- DOI:
- 10.1117/1.JATIS.4.1.011209
- Bibcode:
- 2018JATIS...4a1209T