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第17回宇宙環境シンポジウム (2020年10月7日-8日. 宇宙航空研究開発機構(JAXA)オンライン会議), The 17th Spacecraft Environment Symposium (October 7-8, 2020. Japan Aerospace Exploration Agency (JAXA), Online meeting), Recently, the operating voltage of electronic devices on spacecrafts tends to be weakly, and even a little electric potential fluctuation may cause malfunctions. Therefore, it is necessary to evaluate the electrical properties of insulating materials by focusing on electronic properties. In this study, we focus on the generation of electron-hole pairs, and we measured the amount of charges when the irradiated by electron beam at each flux using a new voltage application method with a vacuum capacitor., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA2030009010, レポート番号: JAXA-SP-20-007

第17回宇宙環境シンポジウム (2020年10月7日-8日. 宇宙航空研究開発機構(JAXA)オンライン会議), The 17th Spacecraft Environment Symposium (October 7-8, 2020. Japan Aerospace Exploration Agency (JAXA), Online meeting), Spacecrafts operated the outside of geo magnetosphere are irradiated solar protons directly. Therefore, it is important to investigate the charging phenomenon of insulation materials under a proton beam irradiation. In this study, we focused on the internal charge accumulation during proton beam irradiation of insulation materials. We developed the electrode system to measure the charge distribution from the surface to the bulk of the sample. From the results, it observed that the amount of charge accumulation is larger 3.4 times than the results of using the general electrode system and the surface potential is 4.4 kV. These results suggest the possibility of discharge at the spacecraft operating environment., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA2030009008, レポート番号: JAXA-SP-20-007

第16回宇宙環境シンポジウム (2019年11月12日-13日. 東京都市大学横浜キャンパス), 横浜市, 神奈川県, The 16th Spacecraft Environment Symposium (November 12-13, 2019. Yokohama Campus, Tokyo City University), Yokohama, Kanagawa, Japan, It has been reported that the MLI and OSR of spacecraft and the insulation layer of the wire harness are charged by high-energy charged particles such as electrons and protons, resulting in operational abnormalities due to electrostatic discharge. In this study, we measured space charge distribution during proton beam irradiation in order to understand the charge accumulation characteristics of space insulating materials by proton beam irradiation. As a result, positive charge accumulation was observed in the sample, and different charge accumulation tendencies were obtained in the proton passage region and the unreachable region. This elephant is thought to be caused by radiation-induced conduction with different origin in each region and the increase in conductivity, and was examined from the accumulated charge amount and distribution., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1930014001, レポート番号: JAXA-SP-19-009

第16回宇宙環境シンポジウム (2019年11月12日-13日. 東京都市大学横浜キャンパス), 横浜市, 神奈川県, The 16th Spacecraft Environment Symposium (November 12-13, 2019. Yokohama Campus, Tokyo City University), Yokohama, Kanagawa, Japan, Spacecraft are covered with MLI and OSR for protecting from the hard temperature differential in space environment and keeping the temperature inside of spacecraft. As the satellite are operated in the Van-Allen belt, those insulating materials are exposed by radio-active rays, such as electron and proton. Those charged particles are injected and accumulate in the bulk of materials. And it will be origin of electric static discharge (ESD). There phenomenon may lead to the satellite operation anomaly. Therefore, it is necessary to understand charging phenomena in the bulks of materials for spacecraft based on electronic physics, for reliabilities of long-life operation. In this research, we try to understand the charging phenomena on fluorinated polymer which are used for wire harness. Space charge accumulations in the bulk of the sample irradiated by an electron under DC application were studied using the pulsed electroacoustic (PEA) method., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1930014002, レポート番号: JAXA-SP-19-009

第16回宇宙環境シンポジウム (2019年11月12日-13日. 東京都市大学横浜キャンパス), 横浜市, 神奈川県, The 16th Spacecraft Environment Symposium (November 12-13, 2019. Yokohama Campus, Tokyo City University), Yokohama, Kanagawa, Japan, Secondary electron emission yield, one of the physical property used for the electrification analysis of the surface materials of spacecraft, has little data in Japan. We create semi-empirical model to know secondary electron emission yield of unmeasured samples. We measured in the low energy band and examined the necessity of the peak., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1930014003, レポート番号: JAXA-SP-19-009

第16回宇宙環境シンポジウム (2019年11月12日-13日. 東京都市大学横浜キャンパス), 横浜市, 神奈川県, The 16th Spacecraft Environment Symposium (November 12-13, 2019. Yokohama Campus, Tokyo City University), Yokohama, Kanagawa, Japan, 宇宙機は軌道上の放射線による帯電・放電現象により運用異常を起こす可能性があり、設計段階から電気絶縁物性を考慮した材料設計が重要となる。移動度は絶縁材料の電気伝導や絶縁破壊機構を解明するための最も重要な物性値の一つで、本研究では移動度測定方法の考案を目的としている。本報告では特に、パルス静電応力法を用いたフッ素系絶縁材料のキャリア移動度測定法を提案した。測定の結果、ETFEの移動度を10(exp -12) [m2V(exp -1)S(exp -1)]オーダーと算出した。, 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1930014004, レポート番号: JAXA-SP-19-009