脉冲金属离子等离子体推进器的等离子体生成和传播特性

综述了不同阳极结构脉冲金属离子等离子体推进器的放电特性、等离子体生成及传播特性。首先，讨论了一种带有绝缘套筒的裸阳极推进器结构。对比分析了无、有绝缘套筒的裸阳极推进器的等离子体生成及传播特性的区别。结果表明，绝缘套筒阻碍了阴极近旁带电粒子的径向运动，提高了沿绝缘套筒轴向喷射出去的等离子体的喷射性能。此外，发现采用裸阳极推进器结构放电过程中会有大量带电粒子进入阳极。其次，讨论了一种绝缘阳极推进器结构。结果表明，采用绝缘阳极结构进一步提高了沿绝缘套筒轴向喷射出去的等离子体密度。但是，与裸阳极推进器结构相比，等离子体的生成量减少。再次，讨论了一种微孔绝缘阳极推进器结构。结果表明，与裸阳极推进器结构相比，采用微孔绝缘阳极推进器结构生成的等离子体的密度峰值和传播速度峰值分别提高了12.6倍、3.9倍。最后，分别讨论了一种螺旋阳极推进器结构和一种多阳极推进器结构。结果表明，这两种推进器结构分别利用放电过程中形成的自磁场及电场有效提高了等离子体羽流的定向喷射性能。本研究可以为金属等离子体喷射性能的提高以及脉冲金属离子等离子体推进器的设计提供支持。

Generation and propagation characteristics of plasma applied to pulsed metal ion plasma thruster

In this paper, discharge characteristics, plasma generation and propagation characteristics of pulsed?metal?ion?plasma?thruster (PMIPT) using different anode structures are reviewed. First of all, a PMIPT using an exposed anode structure with an insulating sleeve (EASIS) is discussed. Differences in plasma generation and propagation characteristics between the EASIS-PMIPT and the PMIPT using an exposed anode structure without an insulating sleeve (EAS-PMIPT) are analyzed. Results show that the insulating sleeve blocks radial diffusion of generated charged particles near cathode, and improves the ejection performance of plasma. In addition, it is found that a large number of charged particles enters anode during discharge with an exposed anode (EA). Then, a PMIPT using an insulated anode structure (IAS) is discussed. Results indicate that peak density of plasma ejected along axial direction of insulating sleeve is further increased by using an IAS. However, compared with the PMIPT with an EA, production of plasma is reduced. Furthermore, a PMIPT using an IAS with a micropore (IASM) is discussed. It is revealed that, compared with the PMIPT with an EA, plasma peak density and propagation velocity when adopting an IASM increase by 12.6 times and 3.9 times respectively. Eventually, PMIPT structures with a spiral anode structure (SpAS) and a multi-anode structure (MAS) are discussed respectively. Results show that for the two thrusters, directional ejection performance of plasma plumes are effectively improved by using the self-magnetic field and electric field during discharge respectively. This study will provide support for improvement of metal plasma ejection performance and the design of a PMIPT.