Origin of the in-orbit instrumental background of the Hard X-ray Imager onboard Hitomi

Kouichi Hagino; Hirokazu Odaka; Goro Sato; Tamotsu Sato; Hiromasa Suzuki; Tsunefumi Mizuno; Madoka Kawaharada; Masanori Ohno; Kazuhiro Nakazawa; Shogo B. Kobayashi; Hiroaki Murakami; Katsuma Miyake; Makoto Asai; Tatsumi Koi; Greg Madejski; Shinya Saito; Dennis H. Wright; Teruaki Enoto; Yasushi Fukazawa; Katsuhiro Hayashi; Jun Kataoka; Junichiro Katsuta; Motohide Kokubun; Philippe Laurent; François Lebrun; Olivier Limousin; Daniel Maier; Kazuo Makishima; Kunishiro Mori; Takeshi Nakamori; Toshio Nakano; Hirofumi Noda; Masayuki Ohta; Rie Sato; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'Ichiro Takeda; Takaaki Tanaka; Yukikatsu Terada; Hideki Uchiyama; Yasunobu Uchiyama; Shin Watanabe; Kazutaka Yamaoka; Yoichi Yatsu; Takayuki Yuasa

doi:10.1117/1.JATIS.6.4.046003

Origin of the in-orbit instrumental background of the Hard X-ray Imager onboard Hitomi

Kouichi Hagino, Hirokazu Odaka, Goro Sato, Tamotsu Sato, Hiromasa Suzuki, Tsunefumi Mizuno, Madoka Kawaharada, Masanori Ohno, Kazuhiro Nakazawa, Shogo B. Kobayashi, Hiroaki Murakami, Katsuma Miyake, Makoto Asai, Tatsumi Koi, Greg Madejski, Shinya Saito, Dennis H. Wright, Teruaki Enoto, Yasushi Fukazawa, Katsuhiro HayashiJun Kataoka, Junichiro Katsuta, Motohide Kokubun, Philippe Laurent, François Lebrun, Olivier Limousin, Daniel Maier, Kazuo Makishima, Kunishiro Mori, Takeshi Nakamori, Toshio Nakano, Hirofumi Noda, Masayuki Ohta, Rie Sato, Hiroyasu Tajima, Hiromitsu Takahashi, Tadayuki Takahashi, Shin'Ichiro Takeda, Takaaki Tanaka, Yukikatsu Terada, Hideki Uchiyama, Yasunobu Uchiyama, Shin Watanabe, Kazutaka Yamaoka, Yoichi Yatsu, Takayuki Yuasa

Research output: Contribution to journal › Article › peer-review

2 Citations (Scopus)

Abstract

Understanding and reducing in-orbit instrumental backgrounds are essential to achieving high sensitivity in hard x-ray astronomical observations. The observational data of the Hard X-ray Imager (HXI) onboard the Hitomi satellite provide useful information on the background components due to its multilayer configuration with different atomic numbers: The HXI consists of a stack of four layers of Si (Z = 14) detectors and one layer of cadmium telluride (CdTe) (Z = 48, 52) detector surrounded by well-Type Bi4Ge3O12 active shields. Based on the observational data, the backgrounds of the top Si layer, the three underlying Si layers, and the CdTe layer are inferred to be dominated by different components, namely, low-energy electrons, albedo neutrons, and proton-induced radioactivation, respectively. Monte Carlo simulations of the in-orbit background of the HXI reproduce the observed background spectrum of each layer well, thereby quantitatively verifying the above hypothesis. In addition, we suggest the inclusion of an electron shield to reduce the background.

Original language	English
Article number	046003
Journal	Journal of Astronomical Telescopes, Instruments, and Systems
Volume	6
Issue number	4
DOIs	https://doi.org/10.1117/1.JATIS.6.4.046003
Publication status	Published - 2020 Oct 1
Externally published	Yes

Keywords

ASTRO-H
Hitomi
background
hard x-ray imager
hard x-rays
simulation

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Control and Systems Engineering
Instrumentation
Astronomy and Astrophysics
Mechanical Engineering
Space and Planetary Science

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10.1117/1.JATIS.6.4.046003

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Hagino, K., Odaka, H., Sato, G., Sato, T., Suzuki, H., Mizuno, T., Kawaharada, M., Ohno, M., Nakazawa, K., Kobayashi, S. B., Murakami, H., Miyake, K., Asai, M., Koi, T., Madejski, G., Saito, S., Wright, D. H., Enoto, T., Fukazawa, Y., ... Yuasa, T. (2020). Origin of the in-orbit instrumental background of the Hard X-ray Imager onboard Hitomi. Journal of Astronomical Telescopes, Instruments, and Systems, 6(4), Article 046003. https://doi.org/10.1117/1.JATIS.6.4.046003

Hagino, K, Odaka, H, Sato, G, Sato, T, Suzuki, H, Mizuno, T, Kawaharada, M, Ohno, M, Nakazawa, K, Kobayashi, SB, Murakami, H, Miyake, K, Asai, M, Koi, T, Madejski, G, Saito, S, Wright, DH, Enoto, T, Fukazawa, Y, Hayashi, K, Kataoka, J, Katsuta, J, Kokubun, M, Laurent, P, Lebrun, F, Limousin, O, Maier, D, Makishima, K, Mori, K, Nakamori, T, Nakano, T, Noda, H, Ohta, M, Sato, R, Tajima, H, Takahashi, H, Takahashi, T, Takeda, SI, Tanaka, T, Terada, Y, Uchiyama, H, Uchiyama, Y, Watanabe, S, Yamaoka, K, Yatsu, Y & Yuasa, T 2020, 'Origin of the in-orbit instrumental background of the Hard X-ray Imager onboard Hitomi', Journal of Astronomical Telescopes, Instruments, and Systems, vol. 6, no. 4, 046003. https://doi.org/10.1117/1.JATIS.6.4.046003

@article{7f0003f9e5c34315b34a06379f74532b,

title = "Origin of the in-orbit instrumental background of the Hard X-ray Imager onboard Hitomi",

abstract = "Understanding and reducing in-orbit instrumental backgrounds are essential to achieving high sensitivity in hard x-ray astronomical observations. The observational data of the Hard X-ray Imager (HXI) onboard the Hitomi satellite provide useful information on the background components due to its multilayer configuration with different atomic numbers: The HXI consists of a stack of four layers of Si (Z = 14) detectors and one layer of cadmium telluride (CdTe) (Z = 48, 52) detector surrounded by well-Type Bi4Ge3O12 active shields. Based on the observational data, the backgrounds of the top Si layer, the three underlying Si layers, and the CdTe layer are inferred to be dominated by different components, namely, low-energy electrons, albedo neutrons, and proton-induced radioactivation, respectively. Monte Carlo simulations of the in-orbit background of the HXI reproduce the observed background spectrum of each layer well, thereby quantitatively verifying the above hypothesis. In addition, we suggest the inclusion of an electron shield to reduce the background.",

keywords = "ASTRO-H, Hitomi, background, hard x-ray imager, hard x-rays, simulation",

author = "Kouichi Hagino and Hirokazu Odaka and Goro Sato and Tamotsu Sato and Hiromasa Suzuki and Tsunefumi Mizuno and Madoka Kawaharada and Masanori Ohno and Kazuhiro Nakazawa and Kobayashi, {Shogo B.} and Hiroaki Murakami and Katsuma Miyake and Makoto Asai and Tatsumi Koi and Greg Madejski and Shinya Saito and Wright, {Dennis H.} and Teruaki Enoto and Yasushi Fukazawa and Katsuhiro Hayashi and Jun Kataoka and Junichiro Katsuta and Motohide Kokubun and Philippe Laurent and Fran{\c c}ois Lebrun and Olivier Limousin and Daniel Maier and Kazuo Makishima and Kunishiro Mori and Takeshi Nakamori and Toshio Nakano and Hirofumi Noda and Masayuki Ohta and Rie Sato and Hiroyasu Tajima and Hiromitsu Takahashi and Tadayuki Takahashi and Shin'Ichiro Takeda and Takaaki Tanaka and Yukikatsu Terada and Hideki Uchiyama and Yasunobu Uchiyama and Shin Watanabe and Kazutaka Yamaoka and Yoichi Yatsu and Takayuki Yuasa",

note = "Funding Information: We acknowledge all the Hitomi team members, including many graduate students, for their great contributions to the HXI and the Hitomi project. We acknowledge the support of Ministry of Education, Culture, Sports, Science, and Technology/Japan Society for the Promotion of Science (JSPS)/ KAKENHI under Grant Nos. 24105007, 15H03639, 25287059, 24244014, and 16H02170, and the JSPS Core-to-Core Program. All the members from the U.S. acknowledge support received from the NASA Science Mission Directorate. Stanford and Stanford Linear Accelerator Center (SLAC) members acknowledge support via Department of Energy contract to SLAC National Accelerator Laboratory DE-AC3-76SF00515 and NASA under Grant No. NNX15AM19G. French members acknowledge support from the Centre National d{\textquoteright}Etudes Spatiales. Publisher Copyright: {\textcopyright} The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.",

year = "2020",

month = oct,

day = "1",

doi = "10.1117/1.JATIS.6.4.046003",

language = "English",

volume = "6",

journal = "Journal of Astronomical Telescopes, Instruments, and Systems",

issn = "2329-4124",

publisher = "SPIE",

number = "4",

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TY - JOUR

T1 - Origin of the in-orbit instrumental background of the Hard X-ray Imager onboard Hitomi

AU - Hagino, Kouichi

AU - Odaka, Hirokazu

AU - Sato, Goro

AU - Sato, Tamotsu

AU - Suzuki, Hiromasa

AU - Mizuno, Tsunefumi

AU - Kawaharada, Madoka

AU - Ohno, Masanori

AU - Nakazawa, Kazuhiro

AU - Kobayashi, Shogo B.

AU - Murakami, Hiroaki

AU - Miyake, Katsuma

AU - Asai, Makoto

AU - Koi, Tatsumi

AU - Madejski, Greg

AU - Saito, Shinya

AU - Wright, Dennis H.

AU - Enoto, Teruaki

AU - Fukazawa, Yasushi

AU - Hayashi, Katsuhiro

AU - Kataoka, Jun

AU - Katsuta, Junichiro

AU - Kokubun, Motohide

AU - Laurent, Philippe

AU - Lebrun, François

AU - Limousin, Olivier

AU - Maier, Daniel

AU - Makishima, Kazuo

AU - Mori, Kunishiro

AU - Nakamori, Takeshi

AU - Nakano, Toshio

AU - Noda, Hirofumi

AU - Ohta, Masayuki

AU - Sato, Rie

AU - Tajima, Hiroyasu

AU - Takahashi, Hiromitsu

AU - Takahashi, Tadayuki

AU - Takeda, Shin'Ichiro

AU - Tanaka, Takaaki

AU - Terada, Yukikatsu

AU - Uchiyama, Hideki

AU - Uchiyama, Yasunobu

AU - Watanabe, Shin

AU - Yamaoka, Kazutaka

AU - Yatsu, Yoichi

AU - Yuasa, Takayuki

N1 - Funding Information: We acknowledge all the Hitomi team members, including many graduate students, for their great contributions to the HXI and the Hitomi project. We acknowledge the support of Ministry of Education, Culture, Sports, Science, and Technology/Japan Society for the Promotion of Science (JSPS)/ KAKENHI under Grant Nos. 24105007, 15H03639, 25287059, 24244014, and 16H02170, and the JSPS Core-to-Core Program. All the members from the U.S. acknowledge support received from the NASA Science Mission Directorate. Stanford and Stanford Linear Accelerator Center (SLAC) members acknowledge support via Department of Energy contract to SLAC National Accelerator Laboratory DE-AC3-76SF00515 and NASA under Grant No. NNX15AM19G. French members acknowledge support from the Centre National d’Etudes Spatiales. Publisher Copyright: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

PY - 2020/10/1

Y1 - 2020/10/1

N2 - Understanding and reducing in-orbit instrumental backgrounds are essential to achieving high sensitivity in hard x-ray astronomical observations. The observational data of the Hard X-ray Imager (HXI) onboard the Hitomi satellite provide useful information on the background components due to its multilayer configuration with different atomic numbers: The HXI consists of a stack of four layers of Si (Z = 14) detectors and one layer of cadmium telluride (CdTe) (Z = 48, 52) detector surrounded by well-Type Bi4Ge3O12 active shields. Based on the observational data, the backgrounds of the top Si layer, the three underlying Si layers, and the CdTe layer are inferred to be dominated by different components, namely, low-energy electrons, albedo neutrons, and proton-induced radioactivation, respectively. Monte Carlo simulations of the in-orbit background of the HXI reproduce the observed background spectrum of each layer well, thereby quantitatively verifying the above hypothesis. In addition, we suggest the inclusion of an electron shield to reduce the background.

AB - Understanding and reducing in-orbit instrumental backgrounds are essential to achieving high sensitivity in hard x-ray astronomical observations. The observational data of the Hard X-ray Imager (HXI) onboard the Hitomi satellite provide useful information on the background components due to its multilayer configuration with different atomic numbers: The HXI consists of a stack of four layers of Si (Z = 14) detectors and one layer of cadmium telluride (CdTe) (Z = 48, 52) detector surrounded by well-Type Bi4Ge3O12 active shields. Based on the observational data, the backgrounds of the top Si layer, the three underlying Si layers, and the CdTe layer are inferred to be dominated by different components, namely, low-energy electrons, albedo neutrons, and proton-induced radioactivation, respectively. Monte Carlo simulations of the in-orbit background of the HXI reproduce the observed background spectrum of each layer well, thereby quantitatively verifying the above hypothesis. In addition, we suggest the inclusion of an electron shield to reduce the background.

KW - ASTRO-H

KW - Hitomi

KW - background

KW - hard x-ray imager

KW - hard x-rays

KW - simulation

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U2 - 10.1117/1.JATIS.6.4.046003

DO - 10.1117/1.JATIS.6.4.046003

M3 - Article

AN - SCOPUS:85098732976

SN - 2329-4124

VL - 6

JO - Journal of Astronomical Telescopes, Instruments, and Systems

JF - Journal of Astronomical Telescopes, Instruments, and Systems

IS - 4

M1 - 046003

ER -

Origin of the in-orbit instrumental background of the Hard X-ray Imager onboard Hitomi

Abstract

Keywords

ASJC Scopus subject areas

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