脈衝電漿推進器 (PPT) 係為電力推進系統之一，主要通過系統的脈衝電場和自感應磁場之間的相互作用，加速所誘發的電漿並產生推力。由於 PPT的設計簡單、體積小、成本低，以及功耗低，因此 PPT 是最具有潛力的電力推進器，應用於維持衛星高度和軌道控制等任務。然而， 針對 PPT 的主要研究著重於推進劑的進料方式和電極形狀之優化。
主要影響 PPT 的推力效率為後期燒蝕 (Late Time Ablation, 簡稱 LTA) 的損耗。實際消耗的推進劑中只有大約 40% ~ 60% 用於電漿加速。在 2019 至 2021 年，本實驗室進行雙階段脈衝電漿推進器 (DSPPT) 的性能優化。DSPPT 的設計目的在於克服 LTA 現象。在優化部分，使用田口法對 PPT 的性能進行優化，討論主要影響參數以及進行系統優化。
在高真空條件下（10^(-5) Torr），針對五個參數進行討論，分別為第一級電極的電壓、第二級電極的電壓、電極組之間的距離、電極的長度以及脈衝的頻率。放電電流測量以及使用朗繆爾三探針用於估計推進器脈衝位、電漿密度，和電漿速度。在 16 次的實驗組，獲得脈衝位、電漿密度和電漿速度的最大值分別為：1.36 μN∙s、5.88×10^22 m^(-3) 和 18 506 m∙s^(-1)。並且發現第一階段電壓是影響脈衝位和電漿度最大的參數，然而電漿速度主要取決於電極的長度。此外，使用田口法獲得實驗參數的最佳參數值。

Pulsed Plasma Thruster (PPT) is a type of electric propulsion producing thrust through the acceleration of a self-created plasma thanks to the interaction between a pulsed electric field supplied to the system and a self-induced magnetic field. Due to its simple design, smallness, low cost, and low power consumption, PPT is one of the most promising electric thrusters for missions such as satellites' altitude and motion control. Nowadays, research on PPTs is centred on optimisation in two main ways: the feeding method and the shape of the electrodes.
One of the main issues in pulsed plasma thruster is the Late Time Ablation (LTA). Indeed, only around 40% ~ 60% of the consumed propellant contributes to be accelerated as a plasma. This work, carried out from 2019 to 2021 in ZAP LAB, NCKU, is based on optimising a Dual Stage Pulsed Plasma Thruster (DSPPT), DSPPT being one way to overcome this LTA phenomenon. This optimisation, performed using the Taguchi method, consists of finding out which parameter has the most significant impact on the thruster performance and how to improve it.
Five parameters were investigated under high vacuum condition (10^(-5) Torr): the voltage supplied on the first stage, the voltage supplied on the second stage, the distance between the sets of electrodes, the length of the electrodes, and the frequency of the pulse. Discharge current measurement and triple Langmuir probe are used to estimate the thruster impulse bit, plasma density and plasma velocity. From the sixteen experiments carried out, the maximum value in impulse bit, plasma density, and plasma velocity achieved were respectively: 1.36 μN∙s, 5.88×10^22 m^(-3) and 18 506 m∙s^(-1). It found that the first stage voltage was the parameter impacting the most the impulse bit and plasma density, while the plasma velocity mainly depends on the length of the electrodes. Additionally, the Taguchi method conduct us to obtain the optimal parameter values of the aforesaid experimental parameters.

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