XRPIX is the monolithic X-ray SOI (silicon-on-insulator) pixel detector, which has a time resolution better than 10 μs as well as a high detection efficiency for X-rays above 10 keV. XRPIX is planned to be installed on future X-ray satellites. To mount on satellites, it is essential that the ADC (analog-to-digital converter) be implemented on the detector because such peripheral circuits must be as compact as possible to achieve a large imaging area in the limited space in satellites. Thus, we developed a new XRPIX device with the on-chip ADC, and evaluated its performances. As the results, the integral non-linearity was evaluated to be 6 LSB (least significant bit), equivalent to 36 eV. The differential non-linearity was less than 0.7 LSB, and input noise from the on-chip ADC was 5~e−. Also, we evaluated end-to-end performance including the sensor part as well as the on-chip ADC. As the results, energy resolution at 5.9 keV was 294 ± 4 eV in full-width at half maximum for the best pixel.
@article{arxiv.2405.05649,
title = {Evaluation of the X-ray SOI pixel detector with the on-chip ADC},
author = {Hiroumi Matsuhashi and Kouichi Hagino and Aya Bamba and Ayaki Takeda and Masataka Yukumoto and Koji Mori and Yusuke Nishioka and Takeshi Go Tsuru and Mizuki Uenomachi and Tomonori Ikeda and Masamune Matsuda and Takuto Narita and Hiromasa Suzuki and Takaaki Tanaka and Ikuo Kurachi and Takayoshi Kohmura and Yusuke Uchida and Yasuo Arai and Shoji Kawahito},
journal= {arXiv preprint arXiv:2405.05649},
year = {2024}
}