关键词: 霍尔推力器;通道宽度;电离特性;粒子模拟;光谱诊断

Abstract: The ionization characteristics in Hall thrusters with different discharge channel width were investigated by both numerical and experimental methods. Two-dimensional particle-in-cell method based on Monte Carlo collision was utilized for simulation, while no-contact spectrum diagnosis was introduced in the experiment. Both of the calculated and measured results show that with the increasing of channel width, the ionization rate of propulsion increased, the ionization becomes more effective and the ionization area tenas to be more concentrated. Further calculation results indicate that the striking difference of ionization characteristic is closely related to the phenomenon that with the increase of channel width. The collision frequency is reduces between the electron and wall while the electron temperature raises. However, the rising electron temperature not only promotes the neutral ionized but also increases the loss of electron energy. Since the electron temperature in steady state was determined by the electron energy balance mechanism, through analyzing electron energy balance equation, we have found the wall loss is dominant factor affecting the electron temperature when the channel width changes, while the ionization loss was just a subordination factor. The increase of channel width is in favor of improving ionization characteristics. 

Key words: Hall effect thruster; Channel width; Ionization characteristic; Particle-in-cell; Spectrum diagnosis