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微波放电中和器作为微波离子推力器系统的重要组成部分,在维持航天器电位平衡、中和羽流方面发挥着重要作用,其电子引出性能直接关系到电推力器系统的工作状态。在磁阵列微波放电中和器的磁场结构定型实验中,发现调转磁阵列朝向后引出电流的伏安特性曲线差异极大。由于磁阵列微波放电中和器的放电室直径仅10 mm,介入式探针诊断对等离子体干扰大,本文采用了一体化PIC方法对中和器的工作过程进行仿真,仿真结果与实验现象相吻合。通过对比不同磁场结构、工作电压下的等离子体参数分布,发现引出孔附近的电势分布决定着中和器的电子引出能力;并进一步揭示了离子在中和器电子引出过程中发挥的关键作用,阐明了磁场结构对中和器电子引出能力的影响机制。最后,本文总结了微波放电中和器有效引出电子的两个必要条件:(1)磁场梯度指向引出孔,引导等离子体迁移;(2)引出孔附近有足够的离子抬升电势,降低或打破电势阱。Microwave discharge neutralizer is an important part of microwave discharge ion thruster system, which plays a vital role on maintaining potential balance of spacecraft and neutralizing ion beam. Its electron extraction property directly affects the operation condition of ion thruster system. In order to break through the power limit of miniature microwave discharge ion thruster, a magnet array microwave discharge ion thruster system was designed and tested. During the magnetic field structure testing experiments of magnet array microwave discharge neutralizer, an interesting phenomenon was found. When turning around the magnet array, the I-V curves of electron current show a notable difference. Defining forward direction of magnet array can normally extract electrons, then backward direction of that can hardly extract electrons. Because the diameter of discharge chamber is only 10 mm, it is too tiny to use Langmuir probe diagnosis. And thus, an integrative particle-in-cell method was used to simulate the neutralizer operation processes of two different magnetic field structures, in which the real vacuum permittivity was applied for accuracy. The simulation results show great agreement with experiment phenomenon. In initial discharge process, it is found that the magnetic field gradient leads to different plasma distributions; in electron extraction process, it is found that the potential distribution near the orifice determines the electron extraction property of the neutralizer. Through comparing the plasma parameter distributions under different magnetic field structures and operating voltages, an assumption that the ion is an important factor in electron extraction process was proposed. Then, a simulation that ions disappear artificially outside the orifice was conducted, and the simulation results show that electrons cannot be effectively extracted without ions near the orifice. According to the simulation and experiment results, two necessary conditions are summarized for electron extraction of the neutralizer. The first one is magnetic field structure: the magnetic field gradient should point towards the orifice to lead plasma migrate towards the orifice. The second one is potential distribution: there should be enough ions to lift the potential near the orifice for decreasing or breaking the potential well. These two conditions can help understand the electron extraction mechanism of microwave discharge neutralizer and provide theoretical reference for performance optimization of the neutralizer in future.
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Keywords:
- Electron cyclotron resonance /
- Neutralizer /
- Electron extraction
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[1] Nono A, Morishita T, Hosoda S, Tsukizaki R, Nishiyama K 2023 Acta Astronaut. 212 130-138
[2] Yang J, Mou H, Geng H, Wu X M 2023 J. Propuls. Tech. 44 2208095 (in Chinese) [杨涓, 牟浩, 耿海, 吴先明 2023 推进技术 44 2208095]
[3] Koizumi H, Komurasaki K, Aoyama J, Yamaguchi K 2018 J. Propuls. Power. 34 960-968.
[4] Koizumi H, Komurasaki K, Aoyama J, Yamaguchi K 2014 Trans. JSASS Aerospace Tech. 12 1884-0485
[5] Tsukizaki R, Ise T, Koizumi H, Togo H, Nishiyama K, Kuninaka H 2014 J. Propuls. Power. 30 91-96
[6] Barquero S, Tabata K, Tsukizaki R, Merino M, Navarro-Cavallé J, Nishiyama K 2023 Acta Astronaut. 211 750-754
[7] Sekine H, Minematsu R, Ataka Y, Ominetti P, Koizumi H, Komurasaki K 2022 J. Appl. Phys. 131 093302
[8] Motoki T, Takasaki D, Koizumi H, Ataka Y, Komurasaki K, Takao Y 2022 Acta Astronaut. 196 231-237
[9] Sato Y, Koizumi H, Nakano M, Takao Y 2020 Phys. Plasmas. 27 063505
[10] Tsuru T, Kondo S, Yamamoto N, Nakashima H 2009 Trans. JSASS Aerospace Tech. 7 163-167
[11] Yamamoto N, Maeda Y, Nakashima H, Watanabe H, Funaki I 2016 Trans. JSASS Aerospace Tech. 59 100-103
[12] Foster J E, Patterson M J 2005 J. Propuls. Power. 21 862-869
[13] Xia X, Yang J, Geng H, Wu X M, Fu Y L, Mou H, Tan R W 2022 Acta Phys. Sin. 71 045201 (in Chinese) [夏旭, 杨涓, 耿海, 吴先明, 付瑜亮, 牟浩, 谈人玮 2022 物理学报 71 045201]
[14] Masui H, Tashiro Y, Yamamoto N, Nakashima H, Funaki I 2006 Trans. JSASS Aerospace Tech. 49 87-93
[15] Kubota K, Watanabe H, Yamamoto N, Nakashima H, Miyasaka T, Funaki I 2014 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference Cleveland, OH, July 28-30, 2014 1-12
[16] Meng H B, Yang J, Huang W B, Xia X, Fu Y L, Hu Z 2019 J. Astronaut. 40 1478-1484 (in Chinese) [孟海波, 杨涓, 黄文斌, 夏旭, 付瑜亮, 胡展 2019 宇航学报 40 1478-1484]
[17] Hiramoto K, Nakagawa Y, Koizumi H, Takao Y 2017 Phys. Plasmas. 24 064504
[18] Sato Y, Koizumi H, Nakano M, Takao Y 2019 J. Appl. Phys. 126 243302
[19] Fu Y L, Yang J, Geng H, Wu X M, Hu Z, Xia X 2021 Vacuum 184 109932
[20] Fu Y L 2022 Ph. D. Dissertation (Xian: Northwestern Polytechnical University) (in Chinese) [付瑜亮 2022 博士学位论文(西安:西北工业大学)]
[21] Fu Y L, Yang J, Mou H, Tan R W, Xia X, Gao Z Y 2022 Comput. Phys. Commun. 278 8395
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