真空背压对霍尔推力器放电特性影响的实验研究

真空背压的变化会改变进入霍尔推力器放电通道内的背景气体量,对工质的电离、电子的传导等物理过程产生影响,从而进一步影响到推力器的宏观放电特性.为分析真空背压对推力器放电的影响规律,通过向真空罐输入流量可控的氪气改变真空背压,在不同真空背压下测量通道内原子、离子的发光特性以及出口处离子流的伏安特性.分析结果表明:背景气体返流对通道内工质放电过程具有全局性的影响,提高背压会使通道内的电子温度降低、电离效率降低,并会在通道内形成一个新的电离区,且背压越高,该电离区距推力器阳极越近.

Experimental study of vacuum backpressure on the discharge characteristics of a Hall thruster

It is found that the vacuum backpressure affects the flow of background gas into a Hall thruster channel. The flow of background gas can affect the ionization of propellants and the conductivity of electrons, and thereby affect the physical process and discharge characteristic of Hall thrusters. In order to investigate these effects, the atomic and the ionic emission spectra in the discharge channel and the ions energy distribution are measured under different vacuum backpressures. The experimental results indicate that the increase of vacuum backpressure can reduce the electron temperature and ionization efficiency of propellants and a new ionization region appears near exit plane in the channel; and moreover, it is found that the new ionization region penetrates into the channel more deeply under the higher vacuum backpressure case.