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

2021 Fiscal Year Final Research Report

• 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
• 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

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.

Free Research Field

宇宙推進工学

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．