11:00 AM - 1:00 PM
[PEM09-P10] Development status of the geostationary orbit high energy proton flux measurement instrument (CHARMS-p)
Keywords:space weather, high energy proton, silicon semiconductor detectors, cherenkov photodetectors
When a solar flare or coronal mass ejection (CME) occurs, protons, electrons, and heavy ions are accelerated and can come to Earth as particles with energies ranging from a few MeV to several GeV. From the perspective of high-energy protons, this phenomenon is called a Solar Energetic Particle Event (SEP event), and it has a variety of effects, including exposure of astronauts and passengers and crew on board aircraft flying at high altitudes and high latitudes, and satellite failure as typified by a single event. Therefore, it is necessary to monitor the high-energy protons that cause these space weather damages. The National Institute of Information and Communications Technology (NICT) is currently developing a space environment monitoring system (CHARMS: charging and radiation monitors for space weather) that can be installed on geostationary orbit satellites. As a part of this project, a conceptual design of the proton flux measurement system (CHARMS-p) was carried out to obtain the energy spectrum of high-energy protons in geostationary orbit.
In the development of CHARMS-p, we are planning to expand the measurement energy range (20 MeV-80 MeV) of the Space Environment Monitor (SEDA) onboard the Himawari satellite, which is currently in operation, to the lower limit of 10 MeV and the upper limit of 1 GeV. This enables the complementary measurement of the geostationary orbit high-energy proton environment with an energy range similar to that of the Solar and Galactic Proton Sensor (SGPS) onboard NOAA's GOES. In addition, the monitoring of high-energy proton flux values above 10 MeV, which is being performed by NICT in its space weather forecasting operations, can be performed using observation data from Japanese satellite, contributing to stable space weather monitoring.
High-energy protons have very large flux fluctuations, exceeding 104 [cm-2 sr-1 s-1] when a SEP event occurs, but falling below 1 when the solar proton is quiet, requiring a large dynamic range (~106). On the other hand, since there is an upper limit to the signal processing speed, if a single measurement device is designed for low flux conditions, the signal processing will be saturated when an event occurs. In addition, as mentioned above, the measurement energy range is wide, and the number of layers of conventional silicon semiconductor detectors increases unrealistically in order to detect protons in the high energy range (~1 GeV). In order to solve these problems, the conceptual design adopts a hybrid system in which silicon semiconductor detectors and a Cherenkov photon detectors are combined in parallel, with the silicon semiconductor detectors for the low-energy band (10 MeV to 250 MeV) and the Cherenkov photon detector for the high-energy band (250 MeV to 1 GeV). In this poster presentation, we will introduce the outline of the high-energy proton measurement system and report the elemental test results of high-energy particle detection by Cherenkov photon detector.
In the development of CHARMS-p, we are planning to expand the measurement energy range (20 MeV-80 MeV) of the Space Environment Monitor (SEDA) onboard the Himawari satellite, which is currently in operation, to the lower limit of 10 MeV and the upper limit of 1 GeV. This enables the complementary measurement of the geostationary orbit high-energy proton environment with an energy range similar to that of the Solar and Galactic Proton Sensor (SGPS) onboard NOAA's GOES. In addition, the monitoring of high-energy proton flux values above 10 MeV, which is being performed by NICT in its space weather forecasting operations, can be performed using observation data from Japanese satellite, contributing to stable space weather monitoring.
High-energy protons have very large flux fluctuations, exceeding 104 [cm-2 sr-1 s-1] when a SEP event occurs, but falling below 1 when the solar proton is quiet, requiring a large dynamic range (~106). On the other hand, since there is an upper limit to the signal processing speed, if a single measurement device is designed for low flux conditions, the signal processing will be saturated when an event occurs. In addition, as mentioned above, the measurement energy range is wide, and the number of layers of conventional silicon semiconductor detectors increases unrealistically in order to detect protons in the high energy range (~1 GeV). In order to solve these problems, the conceptual design adopts a hybrid system in which silicon semiconductor detectors and a Cherenkov photon detectors are combined in parallel, with the silicon semiconductor detectors for the low-energy band (10 MeV to 250 MeV) and the Cherenkov photon detector for the high-energy band (250 MeV to 1 GeV). In this poster presentation, we will introduce the outline of the high-energy proton measurement system and report the elemental test results of high-energy particle detection by Cherenkov photon detector.