磁场梯度对Hall推力器放电特性影响的实验研究

为进一步探索Hall推力器通道内磁场优化设计理论,通过实验分析了强场区磁场梯度对推进剂的电离与加速等放电过程的影响. 研究发现,在本实验设计的磁场梯度范围内,磁场梯度大小对推进剂的电离过程影响较小,但是对离子流的加速特性会产生较为明显的影响.随着磁场梯度的增加,离子束的能量分布会趋于集中,推力器效率提高. 最后,对磁场轴向梯度进一步变大可能会引起的一系列物理问题如有限Larmor半径效应、电子传导机理转变规律和梯度漂移效应等进行了分析和思考.

On the effect of magnetic field gradient on the discharge characteristics of Hall thrusters

An experiment was performed to investigate how the magnetic field gradient in strong field zone affects the discharge processes of Hall thrusters, such as the ionization and acceleration of propellants, for further research on optimal design theory of magnetic field in discharge channels of Hall thrusters. The results show that magnetic field strength has little effect on the ionization of propellants within the designed range of magnetic field gradient, but has significant influence on the acceleration of ions.With the increase of magnetic field gradient, the ion-beam energy distribution tends to be concentrated, and the thrust efficiency tends to rise. Finally, further increase of magnetic field gradient may lead to a series of physical problems,among whith such as the finite Larmor radius effect, the changes in the law of electronic conduction mechanism, and the magnetic field gradient drift are analyzed.