“Development of Hard X-ray Telescope to be onboard ASTRO-H” Takuya Miyazawa

Speaker:
Dr. Takuya Miyazawa
Researcher
Department of Graduate School of Science
Nagoya University

Abstract:
ASTRO-H is Japan’s sixth x-ray astronomical satellite mission. It will be launched in 2016 and dedicated to investigate the physics of the high-energy universe by the hard x-ray imaging, high-resolution spectroscopy and broad-band coverage. The scientific objectives are revealing the large-scale structure and its evolution of the Universe, understanding the extreme condition in the Universe, exploring the diverse phenomena of non-thermal Universe, and elucidating dark matter and dark energy. 

ASTRO-H is designed to carry four science instruments to cover the wide energy range between 0.3 to 600 keV. One of the key instruments of ASTRO-H is a Hard X-ray Telescope (HXT), which cover the energy range of 5 to 80 keV. The HXT mirror employs tightly nested, conically approximated thin-foil Wolter-I optics, and the mirror surface are coated with Platinum (Pt) and Carbon (C) depth-graded multilayers to enhance the hard x-ray effective area by means of Bragg reflection. The HXT comprises foils 120-450 mm in diameter and 200 mm in length, with a focal length of 12 m. To obtain a large effective area, 213 aluminum foils 0.2 mm in thickness are tightly nested confocally. All of the reflector fabrication and the mirror assembly of two HXTs are performed in a production facility at Nagoya University. The x-ray performance of each HXT was measured at a synchrotron radiation facility, SPring-8 BL20B2 in Japan. Angular resolutions (half-power diameter; HPD) of 1.9’ and 1.8’ at 30 keV were obtained for the full telescopes of HXT-1 and HXT-2, respectively. The total effective are of the two HXTs at 30 keV is 349 cm^2. The x-ray performance of HXTs meets the requirements of HXTs. In this seminar, I will talk about the development of X-ray telescope through ASTRO-H HXT.