磁屏蔽霍尔推力器加速区电子传导特性研究

Active development on Hall thruster is a significant strategy of our country to promote the level of power system for future space platform and show the world our advance. A newly discovered magnetic shielding technology completely eliminates the most critical lifetime constraint of Hall thruster – channel wall erosion due to ion sputtering, which enhances the thruster application ability greatly, represents the inevitable trend of future development and has important research value..Applicant of this project has grasped and verified in experiments the essentials for achieving magnetic shielding effect in Hall thrusters. However, as the use of magnetic shielding technology will inevitably move the thruster acceleration zone from channel interior to channel exterior, the traditional electron transport theory, dominated by near-wall conduction in the acceleration zone, is no longer valid. Based on this, this project will carry out related research to obtain a correct understanding on the characteristics of electron transport in the acceleration zone of this kind of Hall thruster..This project will take a systematic and in-depth study on the macroscopic behavior and microscopic mechanism of electron transport in the acceleration zone under the condition of wall absence. Experimental diagnostics, with a supplementary numerical simulation, will be used. The goal is to establish a new electron transport theory suitable for the magnetically shielded Hall thruster, obtain the design criteria of magnetic field topology in the acceleration zone in view of optimal control of electron conduction behavior, and finally settle the foundation for our country to master the key technology of a long-lifetime and high-performance Hall thruster.

大力发展霍尔推力器是我国提升未来空间平台动力系统水平、展现国际先进性的重要战略。最新发现的磁屏蔽技术消除了推力器中离子对通道壁面的溅射侵蚀这一最关键的寿命制约因素，极大地增强了推力器的应用能力，代表了未来发展的方向，具有重要的科学研究价值。.本课题申请人已掌握了磁屏蔽技术的实现要点，并通过了实验的验证。然而，由于磁屏蔽技术的使用会不可避免地使得推力器的加速区从通道内移动到通道外，因此传统的以近壁传导为主的加速区电导理论不再成立。基于此，本课题拟开展相关研究，形成对这类推力器加速区电子传导特性的正确认识。.本课题拟采用以实验诊断为主、数值模拟为辅的手段对加速区无壁面条件下电子传导的宏观行为和微观机制进行系统深入的研究，建立适用于磁屏蔽式霍尔推力器的电子传导新理论，获得优化控制电子传导行为的加速区磁场位型设计准则，为我国掌握长寿命高性能霍尔推力器的关键技术奠定基础。

未来航天任务的发展趋势是执行周期长、目标任务多以及距离远，这些都对霍尔推力器提出了大总冲和长寿命的需求。为了满足这些需求，本项目提出了对能极大拓展现有霍尔推力器寿命的磁屏蔽技术开展相关研究工作；并在过去的三年重点开展了磁屏蔽霍尔推力器的放电机理、电子传导特性以及放电性能的优化研究工作。.通过本项目的研究，掌握了磁屏蔽放电条件下霍尔推力器的电离特性、电子能量转换特性以及近场区电子能量分布特性，搞清楚了通道出口壁面形貌影响电子传导及放电特性的规律和机理，以及会切磁场位形下电子传导的特性及机理，提出了一种可以优化磁屏蔽霍尔推力器放电性能的磁场强度与通道长度匹配的方法。这些研究收获使我们形成了对磁屏蔽技术的系统性认识，找到了即保证放电性能又保证工作寿命的有效方法，为我国长寿命高性能霍尔推力器的应用奠定了坚实的理论与技术基础。.在本项目的资助下，共发表SCI论文13篇，授权发明专利2项，培养硕博士生5名。