Hard x-ray imager onboard Hitomi (ASTRO-H)

• DOI: 10.1117/1.jatis.4.2.021410
• Publication Date: 2018-04-09T06:14:00Z
• Authors: Kazuhiro Nakazawa; Goro Sato; Motohide Kokubun; Teruaki Enoto; Yasushi Fukazawa; Kouichi Hagino; Katsuhiro Hayashi; Jun Kataoka; Junichiro Katsuta; Shogo B. Kobayashi; Philippe Laurent; Francois Lebrun; Olivier Limousin; Daniel Maier; Kazuo Makishima; Tsunefumi Mizuno; Kunishiro Mori; Takeshi Nakamori
• Keywords: X-ray detector

The hard x-ray imaging spectroscopy system of "Hitomi" observatory is composed two sets imagers (HXI) coupled with telescopes (HXT). With a 12-m focal length, the provides fine (1 ′ . 7 half-power diameter) covering about 5 to 80 keV. HXI sensor consists camera, which four layers Si and one layer CdTe semiconductor imagers, an active shield nine Bi4Ge3O12 scintillators provide low background. HXIs started observation on March 8 14, 2016 were operational until 26 March. Using Crab observation, keV energy coverage good detection efficiency confirmed. detector background level 1 3 × 10 − 4 counts s cm 2 (in geometrical area) at was achieved, by cutting high-background time-intervals, adopting sophisticated energy-dependent imager selection, baffling cosmic active-shielding. This among lowest detectors working in this band. By comparing effective area background, it shown that had sensitivity same NuSTAR for point sources times better largely extended diffuse sources.