[P-EM10] Space Weather and Space Climate

[PEM10-P14] Development status of the geostationary orbit high energy proton flux measurement instrument (RMS-p) IV

*Kenichi Otsuji¹, Kaori Sakaguchi^1,2, Shinji Saito¹, Taku Namekawa¹, Park Inchun¹, Takefumi Mitani³, Shin-ichiro Meigo⁴, Yuji Yamaguchi⁴ (1.National Institute of Information and Communications Technology, 2.Ministry of Internal Affairs and Communications, 3.Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 4.Japan Atomic Energy Agency, J-PARC)

Keywords:space weather, high energy proton, silicon semiconductor detector, Cherenkov photodetector

National Institute of Information and Communications Technology (NICT) has developed the EM (engineering model) of a space environment measurement instrument (RMS: Radiation Monitors for Space weather) that will be mounted on the next generation meteorological observation satellite. Within RMS, the RMS-p instrument measures the energy and flux of protons in geostationary orbit. The energy range covered by RMS-p ranges from 10 MeV to over 1 GeV. RMS-p is equipped with two detectors capable of measuring both high-energy (RMS-p(hi)) and low-energy (RMS-p(lo)) protons. The energy range of protons which can be measured by RMS-p(lo) is from 10 to about 500 MeV, and the energy of incident protons is measured by stacking of eight silicon semiconductor detectors (SSDs). RMS-p(hi) combines a single silicon semiconductor detector with a Cherenkov light radiator for energy measurement between 400 MeV and over 1 GeV. In January 2025, the RMS-p was installed at the J-PARC Center of the Japan Atomic Energy Agency, and a proton beam irradiation test from 400 MeV to 3 GeV was conducted. As a result, it was confirmed that the proton beam energy can be measured by RMS-p(hi) in the case where the energy of the irradiated proton is 450 MeV or more. The response of the RMS-p(lo) to protons with energies of 400 MeV to 500 MeV was also confirmed. In addition, the results of muon detection using RMS-p and environmental test will be reported.