Stabilization of operation during coupling tests between electron source and propulsion system

• Project/Area Number: 19H02337
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 24010:Aerospace engineering-related
• Research Institution: University of Tsukuba
• Principal Investigator: Yokota Shigeru 筑波大学, システム情報系, 准教授 (30545778)
• Co-Investigator(Kenkyū-buntansha): 嶋村 耕平 筑波大学, システム情報系, 助教 (90736183)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000); Fiscal Year 2021: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2020: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000); Fiscal Year 2019: ¥8,840,000 (Direct Cost: ¥6,800,000、Indirect Cost: ¥2,040,000)
• Keywords: 宇宙推進 / 電気推進 / ホローカソード / 電子源 / カップリング / ホールスラスタ / 作動モード / カップリング試験

Outline of Research at the Start

現在，宇宙大量物資輸送用として，燃費が良い電気推進機の大出力化が進められている．その放電に使用される電子源の大電流化も必要であり，研究代表者らは国内初100Aの電子源を開発し，その作動安定化指針も明らかにしてきた．一方，電子源と推進機とのカップリング試験では，電子源単体試験でみられた安定な作動を維持できず，安定・不安定な作動モードが頻繁に遷移し，系全体としての作動が不安定になることがわかった．そこで本研究の目的は，電子源と推進機のカップリング時の不安定放電の原因を追求し，この回避策を見出すことである．

Outline of Final Research Achievements

The problem is that the electron source of an electric propulsion system for space applications sometimes fails to maintain a stable state during coupling tests with the propulsion system, even under conditions of stable operation in stand-alone tests. First, the discharge state during the coupling test was observed, and it was clarified that this unstable phenomenon was a state in which the multiple operation modes seen in the stand-alone test appeared alternately. Experimental observations and theoretical considerations of the plasma state inside the electron source revealed that the mode change is caused by the plasma state between the propulsor and the electron source, i.e., the external environment of the electron source influences the plasma inside the source. Sufficient transport by diffusion inside the electron source is necessary for operational stabilization.

Academic Significance and Societal Importance of the Research Achievements

現在，宇宙開発は大量物資輸送時代を迎えつつある．従って，輸送コスト削減が重要課題であり，高い比推力（燃費の指標）を有する電気推進機（プラズマ排気型エンジン）の搭載が不可欠である．この宇宙での大量の物資輸送に使うべく，この電気推進機の大電力化が一つのトレンドとなっている．本研究対象の電子源は，その大電力電気推進機に必要なものであり，本研究成果は，推進機と電子源の噛み合わせの際の放電安定化の指針を示すものであり，将来の宇宙における物資輸送へ貢献するものであると言える．

Research Products

• [Journal Article] Development of Hall Thruster for Observing Rotating Spoke to Examine Anomalous Electron Transport (2021)
  • Author(s): M. Nonaka, J. Yamasaki, H. Ito, T. Kobayashi, E. Maruyama, Y. Murayama, K. Shimamaura, S. Yokota
  • Journal Title: Frontier of Applied Plasma Technolog Volume: 14 Pages: 7-13
  • Peer Reviewed
• [Journal Article] Characteristics of LaB6 Hollow Cathode Using Argon Propellant (2021)
  • Author(s): J. Yamasaki, S. Yokota, et.al
  • Journal Title: Plasma Application and Hybrid Functionally Materials Volume: 30 Pages: 52-52
• [Journal Article] 電気推進の電子源 (2020)
  • Author(s): 横田茂
  • Journal Title: 日本航空宇宙学会誌 Volume: 68 Pages: 257-257
  • NAID: 130007884672
  • Peer Reviewed
• [Journal Article] Plasma Diagnostics in High Current Hollow Cathode (2019)
  • Author(s): Kohei KOJIMA, Shigeru YOKOTA, Junko YAMASAKI, Moyuru YONAHA, Tatsuya KIMURA, Yoshihiro KAWAMATA, Masaaki YASUI
  • Journal Title: TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN Volume: 17 Issue: 1 Pages: 90-95
  • DOI: 10.2322/tastj.17.90
  • NAID: 130007542875
  • Peer Reviewed / Open Access
• [Presentation] TAL型ホールスラスタにおけるRotating Spoke および電子異常輸送に関する研究 (2022)
  • Author(s): 野中 正潤，山崎 純子，村山 侑太郎，小林 哲 也、丸山 映美，栗原 世羽，森田 虎頼，横田 茂，嶋村耕平
  • Organizer: 第61回航空原動機・宇宙推進講演会
• [Presentation] Rotating Spoke Behaviour and Anomalous Electron Transport in Hall thruster (2021)
  • Author(s): Masahiro Nonaka1, Junko Yamasaki, Yutaro Murayama, Tetsuya Kobayashi, Emi Maruyama, Hiroki Ito, Tsubasa Kurihara, Toramu Morita, Shigeru Yokota, Kohei Shimamura
  • Organizer: 33rd International Symposium on Space Technology and Science
  • Int'l Joint Research
• [Presentation] Effects of electron sources on propulsion performance in Hall thrusters (2021)
  • Author(s): Yutaro Murayama, Junko Yamasaki, Emi Maruyama, Tetsuya Kobayashi, Hiroki Ito, Tsubasa Kurihara, Toramu Morita, Shigeru Yokota, Kohei Shimamura
  • Organizer: 33rd International Symposium on Space Technology and Science
  • Int'l Joint Research
• [Presentation] Research about Rotating Spoke and Electron Anomalous Transport in TAL (2021)
  • Author(s): M. Nonaka, H. Ito, T. Kobayashi, E. Maruyama, Y. Murayama, J. Yamasaki, S. Yokota and K. Shimamur
  • Organizer: AIAA Propulsion and Energy 2021 Forum
  • Int'l Joint Research
• [Presentation] Characteristics of LaB6 Hollow Cathode Using Argon Propellant (2021)
  • Author(s): J. Yamasaki, S. Yokota, et.al
  • Organizer: The 14th International Workshop on Plasma Application and Hybrid Functionally Materials
  • Int'l Joint Research
• [Presentation] Plasma Structure in the High Current Hollow Cathode (2019)
  • Author(s): Junko Yamasaki, Kenshiro Nasu, Shigeru Yokota, Kohei Shimamura
  • Organizer: The 12th International Symposium on Applied Plasma Science
  • Int'l Joint Research
• [Presentation] Hollow Cathode Position Effect on Hall Thruster Performance (2019)
  • Author(s): Junko Yamasaki, Takeshi Nakatani, Shigeru Yokota and Kohei Shimamura
  • Organizer: The 11st International Workshop on Plasma Application and Hybrid Functionally Material
  • Int'l Joint Research
• [Presentation] Plasma Structure In and Out A Hollow Cathode (2019)
  • Author(s): Kenshiro Nasu, Junko Yamasaki, Shigeru Yokota, Kohei Shimamura
  • Organizer: The 32nd International Symposium on Space Technology and Science
  • Int'l Joint Research