Space-charge-limited current of vacuum arc thruster |
| |
| Authors: | Tianping Zhang Lei Chang Xinyue Hu Runlong Wang Huijie Zhang Xianming Wu Xinfeng Sun Ning Hu |
| |
| Institution: | 1. Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou, China;2. College of Aerospace Engineering, Chongqing University, Chongqing, China;3. School of Aeronautics and Astronautics, Sichuan University, Chengdu, China;4. Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing, China |
| |
| Abstract: | To optimize thrust performance, the expression of space-charge-limited current for vacuum arc thruster is derived from Poisson's equation. The commonly used ring-type and coaxial-type vacuum arc thrusters are simplified to the equivalent current sheet in planar geometry and cylindrical capacitor, respectively, for this calculation. Both the spatial distribution and peak magnitude of space-charge-limited current are given explicitly, together with their dependences on gap distance, applied voltage, charge number, and ion mass. For typical experimental parameters of the vacuum arc thruster, it is shown that the maximum current density drops significantly when the gap distance becomes large and grows when the applied voltage increases; moreover, a cathode material of lower atomic weight yields a higher current density. The expressions of total current for these two types of vacuum arc thruster are also presented. This work, to our best knowledge, is the first application of space-charge-limited current to the vacuum arc thruster and practically very interesting for engineering design. |
| |
| Keywords: | plasma thruster space-charge-limited current vacuum arc |
|
|
