We have been developing P-channel Charge-Coupled Devices (CCDs) for the upcoming X-ray Astronomy Satellite XRISM, planned to be launched in 2021. While the basic design of the CCD camera (Soft X-ray Imager: SXI) is almost the same as that of the lost Hitomi (ASTRO-H) observatory, we are planning to reduce the "light leakages" that is one of the largest problems recognized in Hitomi data. We adopted a double-layer optical blocking layer on the XRISM CCDs and also added an extra aluminum layer on the backside of them. We develop a newly designed test sample CCD and irradiate it with optical light to evaluate the optical blocking performance. As a result, light leakages are effectively reduced compared with that of the Hitomi CCDs. We thus conclude that the issue is solved by the new design and that the XRISM CCDs satisfy the mission requirement for the SXI.
@article{arxiv.2007.07608,
title = {Optical Blocking Performance of CCDs Developed for the X-ray Astronomy Satellite XRISM},
author = {Hiroyuki Uchida and Takaaki Tanaka and Yuki Amano and Hiromichi Okon and Takeshi G. Tsuru and Hirofumi Noda and Kiyoshi Hayashida and Hironori Matsumoto and Maho Hanaoka and Tomokage Yoneyama and Koki Okazaki and Kazunori Asakura and Shotaro Sakuma and Kengo Hattori and Ayami Ishikura and Hiroshi Nakajima and Mariko Saito and Kumiko K. Nobukawa and Hiroshi Tomida and Yoshiaki Kanemaru and Jin Sato and Toshiyuki Takaki and Yuta Terada and Koji Mori and Hikari Kashimura and Takayoshi Kohmura and Kouichi Hagino and Hiroshi Murakami and Shogo B. Kobayashi and Yusuke Nishioka and Makoto Yamauchi and Isamu Hatsukade and Takashi Sako and Masayoshi Nobukawa and Yukino Urabe and Junko S. Hiraga and Hideki Uchiyama and Kazutaka Yamaoka and Masanobu Ozaki and Tadayasu Dotani and Hiroshi Tsunemi and Hisanori Suzuki and Shin-ichiro Takagi and Kenichi Sugimoto and Sho Atsumi and Fumiya Tanaka},
journal= {arXiv preprint arXiv:2007.07608},
year = {2020}
}
Comments
6 pages, 4 figures, accepted for publication in NIMA, proceedings of the 12th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detector (HSTD12)