电磁场对阳极层霍尔推力器电离效率的影响

Effect of Electromagnetic Field on Ionization Efficiency of Anode Layer Hall Thruster:A Simulation Study

推力器的电离效率直接影响到推力器的功率、比冲以及推力等重要工作参数,本文主要利用PIC模拟得到阳极层霍尔推力器放电等离子体的平均电子能量以及电子、离子数比率随电磁场变化规律,由此分析电磁场对推力器电离效率的影响情况。由结果可知,平均电子能量在放电电压750V之前逐渐增加,而后又降低;磁感应强度B小于170×10^-4T时,平均电子能量随磁场的增加而增加,之后随磁场的增加而降低。在放电等离子体中离子的比率随着放电电压的增加而增加,在800V之后略有降低,电子比率的变化和离子比率的变化是个相反的过程。随着磁场的增加离子数比率基本上是一个降低趋势,而电子比率是逐渐增加的。通过平均电子能量、电子和离子比率与E/B之间的关系,得到最佳E/B比值大约为1.6×10^6m/s。

Ionization of argon and particle interaction,in the anode layer Hall thruster,were mathematically modeled,theoretically analyzed and numerically simulated with PIC software.The influence of the electric(E) and magnetic(M) fields on the variables,including the ionization efficiency,average electron energy,power,number ratio of electron to ion,was investigated.The simulated results show that the E and M fields have a major Impact.To be specific,as the discharge voltage increases,the average e-energy changes in an increase-decrease manner,peaking at 750 V,the number ratio of electron to ion increases and slowly decrease above 800V;and as the magnetic field increases the average e-energy varies in an increase-decrease mode,maximizing at 170×10^-4 T,accompanied by increasing electron and decreasing ion numbers.We suggest that the optimized E/B ratio may be 1.6×10^6m/s,that is,a discharge voltage of 750V and a magnetic field strength of 170×10^-4T.