Development of wide-band high-speed compact digital camera for cosmic hard X-ray observation

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01256
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: Kanto Gakuin University
• Principal Investigator: Nakajima Hiroshi 関東学院大学, 理工学部, 准教授 (70570670)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: Ｘ線イメージング / CMOS / 放射線耐性

Outline of Final Research Achievements

We have developed complementary MOS (CMOS) sensors originally fabricated for the sensitive visible light imaging. We irradiate the sensors with monochromatic X-rays from 109Cd (22.1keV). The energy resolution of 0.94 keV (FWHM) is better than that of conventional CCD camera. Radiation tolerance was evaluated with proton and heavy ion beams. We tested the device with the total dose of 100krad, which is much higher than the dose expected in the lifetime of the ordinary astronomical satellite. The Ka and Kb from 55Fe could be resolved after the irradiation. Furthermore, there was no critical malfunction in the heavy ion test, which ensures the radiation tolerance in space.

Free Research Field

X線天文学

Academic Significance and Societal Importance of the Research Achievements

将来の高感度硬X線望遠鏡と従来のCCDを用いて観測したとすると、硬X線は検出器を透過してしまい検出できず、軟X線にしても検出器面上で光子密度が高くなりすぎて重なり合い(パイルアップ)、各光子の正確なエネルギーが測定できなくなるが、本研究で開発したCMOSを用いることで、パイルアップのない、連続的な観測を広帯域で行う見込みが得られた。