A hard-x-ray telescope is successfully produced for balloon observations by making use of depth-graded multilayers, or so-called supermirrors, with platinum-carbon (Pt/C) layer pairs. It consists of four quadrant units assembled in an optical configuration with a diameter of 40 cm and a focal length of 8 m. Each quadrant is made of 510 pieces of coaxially and confocally aligned supermirrors that significantly enhance the sensitivity in an energy range of 20–40 keV. The configuration of the telescope is similar to the x-ray telescope onboard Astro-E, but with a longer focal length. The reflectivity of supermirrors is of the order of 40% in the energy range concerned at a grazing angle of 0.2 deg. The effective area of a fully assembled telescope is 50 cm<sup>2</sup> at 30 keV. The angular resolution is 2.37 arc min at half-power diameter 8.0 keV. The field of view is 12.6 arc min in the hard-x-ray region, depending somewhat on x-ray energies. We discuss these characteristics, taking into account the figure errors of reflectors and their optical alignment in the telescope assembly. This hard-x-ray telescope is unanimously afforded in the International Focusing Optics Collaboration for μCrab Sensitivity balloon experiment.
© 2002 Optical Society of America
(110.6770) Imaging systems : Telescopes
(230.4170) Optical devices : Multilayers
(340.7440) X-ray optics : X-ray imaging
(340.7470) X-ray optics : X-ray mirrors
(340.7480) X-ray optics : X-rays, soft x-rays, extreme ultraviolet (EUV)
Takashi Okajima, Keisuke Tamura, Yasushi Ogasaka, Kazutoshi Haga, Seiji Takahashi, Satoshi Ichimaru, Hideo Kito, Shin’ichi Fukuda, Arifumi Goto, Kentaro Nomoto, Hiroyuki Satake, Seima Kato, Yuichi Kamata, Akihiro Furuzawa, Fumie Akimoto, Tsutomu Yoshioka, Kazumasa Kondo, Yoshito Haba, Takeshi Tanaka, Keiichi Wada, Noriyuki Hamada, Murat Hudaverdi, Yuzuru Tawara, Koujun Yamashita, Peter J. Serlemitsos, Yang Soong, Kai-Wing Chan, Scott M. Owens, Fred B. Berendse, Jack Tueller, Kazutami Misaki, Ryo Shibata, Hideyuki Mori, Kei Itoh, Hideyo Kunieda, and Yoshiharu Namba, "Characterization of the Supermirror Hard-X-Ray Telescope for the InFOCµS Balloon Experiment," Appl. Opt. 41, 5417-5426 (2002)