In low earth orbit, there are many cosmic rays composed primarily of high energy protons. These cosmic rays cause surface and bulk radiation effects, resulting in degradation of detector performance. Quantitative evaluation of radiation hardness is essential in development of X-ray detectors for astronomical satellites. We performed proton irradiation experiments on newly developed X-ray detectors called XRPIX based on silicon-on-insulator technology at HIMAC in National Institute of Radiological Sciences. We irradiated 6 MeV protons with a total dose of 0.5 krad, equivalent to 6 years irradiation in orbit. As a result, the gain increases by 0.2% and the energy resolution degrades by 0.5%. Finally we irradiated protons up to 20 krad and found that detector performance degraded significantly at 5 krad. With 5 krad irradiation corresponding to 60 years in orbit, the gain increases by 0.7% and the energy resolution worsens by 10%. By decomposing into noise components, we found that the increase of the circuit noise is dominant in the degradation of the energy resolution.
@article{arxiv.1810.09193,
title = {Proton Radiation Damage Experiment for X-Ray SOI Pixel Detectors},
author = {Keigo Yarita and Takayoshi Kohmura and Kouichi Hagino and Taku Kogiso and Kenji Oono and Kousuke Negishi and Koki Tamasawa and Akinori Sasaki and Satoshi Yoshiki and Takeshi Go Tsuru and Takaaki Tanaka and Hideaki Matsumura and Katsuhiro Tachibana and Hideki Hayashi and Sodai Harada and Ayaki Takeda and Koji Mori and Yusuke Nishioka and Nobuaki Takebayashi and Shoma Yokoyama and Kohei Fukuda and Yasuo Arai and Toshinobu Miyoshi and Ikuo Kurachi and Tsuyoshi Hamano and the SOIPIX group},
journal= {arXiv preprint arXiv:1810.09193},
year = {2019}
}
Comments
6 pages, 11figures, accepted for Nuclear Instruments and Methods in Physics Research Section A (NIMA)