[19a-D61-1~11] 2.1 Detection Devices

9:15 AM - 9:30 AM JST(12:15 AM - 12:30 AM UTC)

[19a-D61-2] Investigation of the lower energy measurement limit of the Cherenkov detector Lunar-RICheS

〇Naoyuki Ota^1,3, Toru Tamgawa¹, Riichiro Nakamura¹, Keisuke Uchiyama^1,3, Tomoshi Takeda^1,3, Aiko Nagamatsu², Takayoshi Kohmura⁴, Yuusuke Uchida⁴, Kaito Fujisawa⁴, Jo Sato⁴, Kazuki Toyama⁴, Masayuki Fujii5⁵, Kouichi Hagino⁶, Hisashi Kitamura⁷ (1.RIKEN, 2.JAXA, 3.Tokyo Univ. of Scinece Graduate School of Science, 4.Tokyo Univ. of Scinece Graduate School of Science and Technology, 5.FAM Science, 6.The Univ. of Tokyo, 7.QST)

Keywords:

Cherenkov detector,charged particle,spectrometer

After 2025, the construction of a Lunar gateway and lunar exploration are being considered. Manned exploration outside the magnetosphere poses a problem due to high-energy particles falling on the human body. We are developing a ring-imaging Cherenkov spectrometer, Lunar-RICheS, to measure the energy of charged particles around GeV/n, which harm human health. When the energy of the incident particle is near the Cherenkov emission threshold, the number of Cherenkov photons decreases, and scintillation photons are generated in proportion to the energy deposit, resulting in contamination. We develop a Cherenkov detector using a glass with a refractive index of 1.6 as the radiator. We measured the detector response around the Cherenkov emission threshold of 260 MeV/n by carbon ion irradiation to investigate the lower limit of energy measurement. As a result, the lower limit of energy measurement was between 329 MeV/n and 308 MeV/n.