射频离子推力器多元工质束流调节试验研究

Experimental Study on Beam Current Regulation of Diverse Propellant Types for RF Ion Thruster

关键词:  离子推力器  多元工质  性能调节  离子束流  试验研究

Key words:  Ion thruster  Diverse propellant type  Performance turning  Beam current  Experimental study

摘要:

为了获得射频离子推力器离子束流随放电参数的变化规律，采用试验研究的方法，就推力器引出束流与射频功率强度、工质种类、工质流量之间的调节规律开展了研究，搭建了射频离子推力器束流调节试验系统。研究结果表明：屏栅电压1200V，加速电压-250V，射频功率200W~700W，工质流量0.2mg/s ~4.76mg/s，Xe，Ar，O₂，N₂四种工质下能够可靠放电并稳定引出，实现束流从54mA~467mA的调节，电离效率Xe>Ar>O₂>N₂，离子束流随射频功率和工质流量线性增加，在1.01mg/s的氙工质下，推力、比冲随射频功率从100W~400W线性增加实现推力7.35mN~27.5mN，比冲1191s~3696s大范围连续可调，工质利用率为21.1%~78.8%，并在射频功率为276W时工质利用率和功耗之间存在明显拐点，在应用中要根据任务选择最佳工作区间,合理控制工作参数可以提高推力器工作性能和效率。

Abstract:

In order to obtain the variation of the ion beam current with the discharge parameters of the RF ion thruster, the regulation between beam current and RF power, propellant type, propellant flow rate was studied by the experiment. The RF ion thruster beam current regulation test system was presented. The results show that stable operation of the RF ion thruster in the Xe， Ar， O₂， N₂ propellants and the beam current ranging from 54mA to 467mA can be achieved with the RF power from 200W to 700W and flow rate from 0.2mg/s to 4.76mg/s, at the screen grid voltage 1200V, acceleration voltage -250V. Ionization efficiency is Xe>Ar>O₂>N₂, ion beam current increases linearly with RF power and propellant flow rate. The ranges of thrust from 7.35mN to 27.5mN and the specific impulse from 1191s to 3696s can be achieved with the RF power from 100W to 400W in the Xe 1.01mg/s. In addition， the propellant utilization rate is 21.1%~78.8%. Meanwhile，there was an adjusted turning between the propellant utilization rate and the power consumption at RF power 276W. The best adjustment interval should be selected according to the task in the practice application. Controlling these parameters reasonably can improve the stability of characteristics and efficiency of the thruster.