碩士生: 張博傑
畢業年分: 2025年7月
論文名稱: 應用於離子推進器的電漿羽流診測之旋轉量測系統設計(中文) / Design of a rotating diagnostic system applied for plasma plume characteristics of ion thrusters (英文)
中文摘要:
法拉第探針（Faraday probe）為電漿推進系統常用的診測工具，廣泛應用於射頻離子推進器與霍爾推進器羽流特性量測，特別用於獲取電流密度角度分佈。其結構簡單、操作穩定且具方向選擇性，使其在羽流分析中佔有重要地位。然而，多數研究著重於探針本體設計與操作參數的影響，對於量測系統（如旋轉機構、角度控制與資料擷取流程）可能帶來的誤差卻著墨甚少。
本研究針對此問題設計並建構一套具旋轉功能之羽流角度量測系統，並以射頻離子推進器為穩定電漿來源進行驗證。該系統整合旋轉平台、法拉第探針與資料擷取模組，旨在評估其操作穩定性與量測準確性，並探討系統對不同取樣筆數與探針位置的敏感性。
實驗結果顯示，在羽流主體區，各角度電流密度量測具有良好一致性，變異係數（CV）低於20%，其中±10°範圍內更可控制於10%以下，顯示平台定位與訊號讀取具良好再現性。分析亦指出單次量測至少需擷取15筆以上資料以確保結果穩定。最後，系統成功於不同探針–推進器間距（200、250、300 mm）下觀察羽流分佈變化，證實其具高重複性、可擴展性與良好應用彈性。
英文摘要:
The Faraday probe is one of the most widely used diagnostic tools in electric propulsion systems, commonly applied to plume characterization of radio-frequency ion thrusters and Hall thrusters, particularly for obtaining angular distributions of current density. Due to its simple structure, operational stability, and directional selectivity, it plays a crucial role in plume diagnostics. However, most prior studies have focused on probe geometry and operating parameters, while potential errors introduced by the overall measurement system—such as rotation mechanisms, angular control precision, and data acquisition procedures—have been less explored.
To address this issue, a plume angular measurement system with rotational capability was designed and constructed in this study. Using an RF ion thruster as a stable plasma source, the system integrated a rotary stage, a Faraday probe, and a data acquisition module, aiming to systematically evaluate operational stability and measurement accuracy. The sensitivity of the system to variations in sampling size and probe position was also investigated.
Results show that within the plume core region, current density measurements at different angles exhibit good consistency, with coefficients of variation (CV) below 20%, and within ±10° further reduced to below 10%, confirming reliable angular positioning and reproducibility. Sampling analysis indicates that at least 15 data points per measurement are required to ensure stability and accuracy. Moreover, successful measurements at probe–thruster distances of 200, 250, and 300 mm demonstrated the system’s flexibility, repeatability, and applicability to plume diagnostics of other thruster types.
