阳极层霍尔推进器磁极刻蚀的实验研究

Experimental Research of Magnetic Pole Erosion

关键词:  霍尔推进器  磁极刻蚀  影响因子  实验研究

Key words:  Hall thruster  Magnetic pole erosion  Influencing factor  Experimental research

摘要:

为了提出降低阳极层霍尔推进器运行过程中的磁极刻蚀程度的方案，记录磁极刻蚀程度在相关参数影响下的变化，针对阳极层霍尔推进器的放电电流、电压、工质输送速率等工作参数开展实验研究，定量分析了这些影响因子对推进器磁极刻蚀程度的影响。通过测量磁极被溅射出的粒子在样品表面不同位置上的沉积速率，计算出了推进器在不同运行条件下，由于磁极刻蚀而产生的溅射粒子数量和密度。实验结果表明，该推进器在运行过程中，溅射粒子主要集中在羽流中心线附近区域；随着放电电压和电流的增加，溅射粒子的密度显著上升，并且在以羽流中心线为中心，半径为4cm的圆面区域内，溅射粒子密度上升明显；降低工质输送速率，在低气压、高电压和小电流的运行条件下能够有效降低推进器磁极刻蚀程度，实验所采用的霍尔推进器合适的工作气压为0.02～0.025Pa。

Abstract:

In order to propose an optimization scheme to reduce the degree of magnetic pole erosion and record the effects of relevant factors on pole erosion degree，Hall Thruster operating parameters such as discharge voltage，discharge current and delivering rate of propellant and so on have been adjusted to quantitatively analyze the effects of these influencing factors on the degree of magnetic pole erosion. By measuring the deposition rate of the sputtered particles from the magnetic poles on different positions of sample surface，the number and density of sputtered particles in different thruster operation conditions have been acquired. The results indicate that most sputtered particles distribute in the area which is close to the central axis of the plume. And the density of sputtered particles observably increases with the increase of discharge voltage and discharge current. In addition，it is worth mentioning that the sputtered particle density increases much faster in a circular area with a radius of 4cm. The magnetic pole erosion degree can be effectively decreased by decreasing propellant delivering rate. Therefore，the operation condition of low gas pressure，low current and high voltage is beneficial for decreasing the magnetic pole erosion degree and a proper gas pressure condition of this thruster is 0.02～0.025Pa.