Steady and oscillatory plasma properties in the near-field plume of a hollow cathode

• Published in: Plasma science & technology Vol. 20; no. 2; pp. 67 - 75
• Main Author: 张尊;谢侃;欧阳吉庭;郭宁;秦宇;夏启蒙;白松;吴先明;谷增杰
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.02.2018
• Subjects: emissive probe; hollow cathode; Langmuir probe; PIC simulation; plasma potential oscillation; 阴极;离子推进器;稳定;羽毛;性质;血浆;摆动;模拟分析
• ISSN: 1009-0630; 1009-0630
• DOI: 10.1088/2058-6272/aa9d7d

Hollow cathodes serve as electron sources in Hall thrusters,ion thrusters and other electric propulsion systems.One of the vital problems in their application is the cathode erosion.However,the basic erosion mechanism and the source of high-energy ions cause of erosion are not fully understood.In this paper,both potential measurements and simulation analyses were performed to explain the formation of high-energy ions.A high-speed camera,a single Langmuir probe and a floating emissive probe were used to determine the steady and oscillatory plasma properties in the near-field plume of a hollow cathode.The temporal structure,electron temperature,electron density,and both static and oscillation of plasma potentials of the plume have been obtained by the diagnostics mentioned above.The experimental results show that there exists a potential hill（about 30 V） and also severe potential oscillations in the near-plume region.Moreover,a simple 2 D particle-in-cell model was used to analyze the energy transition between the potential hill and/or its oscillations and the ions.The simulation results show that the energy of ions gained from the static potential background is about 20 e V,but it could reach to 60 e V when the plasma oscillates.