论文部分内容阅读
在磁场不变的情况下,随着霍尔(Hall)推力器放电电压的提高,其通道内的最大电子温度会在一定的电压区间内出现“饱和”现象。为进一步理解这一现象,在完成了变电压不变磁场PIC(Particle in cell)模拟的基础上,首先分析了电子能量的平衡机制的构成要素和最大电子温度的影响因素,进而对各个影响因素在变电压下的变化趋势进行了研究。结果显示:最大电子温度点上游区域的电场加热效应是最大电子温度变化的主导因素,而上游区域的电子与壁面碰撞效应对最大电子温度的变化起到一定的调节作用。在高电压下,由于磁场无法有效束缚电子,上游区域的电子数密度急剧降低,导致电子壁面碰撞能量损失大幅降低,使得碰撞损失对最大电子温度的影响变得较为微弱。进一步指出了磁场在霍尔推力器变电压运行中的核心地位,并提出了高电压放电优化的2个方向:增大放电磁场以及更换二次电子发射系数更高的陶瓷壁面。
With the constant magnetic field, the maximum electron temperature in the channel increases “saturation” within a certain voltage range as the Hall thruster discharge voltage increases. To further understand this phenomenon, after completing the simulation of PIC (Particle in Cell), the components of the electronic energy balance mechanism and the influencing factors of the maximum electron temperature are first analyzed, and then the influences of various influencing factors The changing trend under varying voltage was studied. The results show that the electric field heating effect in the upstream region of the maximum electron temperature is the dominant factor of the maximum electron temperature change, while the collision between the electron and the wall in the upstream region plays a regulatory role on the change of the maximum electron temperature. Under the high voltage, the electron density in the upstream region is drastically reduced due to the inability of the magnetic field to bind the electrons effectively. As a result, the energy loss of the electron wall collision greatly decreases, making the influence of the collision loss on the maximum electron temperature relatively weak. Further pointed out the magnetic field in Hall thruster variable voltage operation of the core position and proposed high voltage discharge optimization in two directions: increase the discharge magnetic field and replace the secondary electron emission coefficient higher ceramic wall.