摘要
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,本文采用了一体化粒子模拟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符合.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 in maintaining potential balance between 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 is designed and tested.In the experiment on finalizing magnetic field structure of magnet array microwave discharge neutralizer,an interesting phenomenon is found that the I-V curves of electron current,after rotating the magnetic array orientation,are very different.Defining forward direction of magnet array can normally extract electrons,then backward direction of magnet array can hardly extract electrons.Because the diameter of discharge chamber is only 10 mm,it is too small to perform Langmuir probe diagnosis.And thus,an integrative particle-in-cell method is used to simulate the neutralizer operation processes of two different magnetic field structures,and for the sake of accuracy,real vacuum permittivity is used.The simulation results show good consistence with experimental phenomenon.In the 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 is proposed.Then,a simulation that ions disappear artificially outside the orifice is 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 neutrali
作者
付瑜亮
张思远
孙安邦
马祖福
王亚楠
Fu Yu-Liang;Zhang Si-Yuan;Sun An-Bang;Ma Zu-Fu;Wang Ya-Nan(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2024年第11期231-236,共6页
Acta Physica Sinica
基金
国家自然科学基金(批准号:52307183)资助的课题。
关键词
电子回旋共振
中和器
电子引出
electron cyclotron resonance
neutralizer
electron extraction
