湿热环境对改进型钡钨发射体空心阴极放电特性的影响

电推力器用传统钡钨空心阴极具有工作温度低、发射效率高的优点，但其抗中毒能力却较差。电推力器的寿命受到空心阴极寿命的制约，为保证推力器长期在轨工作，研制了一种具备强抗中毒能力的改进型钡钨阴极，将其暴露在90%湿度、60℃的湿热环境中累计240h，试验前后触持电压的变化量小于1V，满足判据要求。随后对改进型钡钨阴极分别进行了组件级和推力器级性能测试，测试结果表明，改进型钡钨阴极的稳态工作温度为1050℃，比六硼化镧型阴极低250℃,组件级阳极电压为21V，比六硼化镧型低4~5V；推力器级阳极电压为35V，比六硼化镧型低8~10V。试验结论表明，改进型钡钨阴极具有强抗中毒能力及优异的工作性能，采用该类阴极可以有效地满足推力器的长寿命要求。

Influence of hygrothermal environment on discharge characteristics of modified barium tungsten emitter hollow cathode

The traditional barium tungsten hollow cathode has the advantages of low working temperature and high emission efficiency, but its anti poisoning ability is poor. The life of electric thruster is mainly limited by hollow cathode. To ensure the long term on orbit working of thruster, a new kind of modified barium tungsten cathode with a strong anti poisoning ability was developed. The cathode was exposed to environment of 90% humidity, 60℃ and accumulated 240h.The discharge voltage variation before and after test was less than 1V, satisfing the requirement of criterion. The test results also show that the steady working temperature of the modified barium tungsten cathode is 1050℃, 250℃ lower than that of lanthanum hexaboride type cathode. The component level anode voltage is 21V, 4~5V lower than the lanthanum hexaboride hollow cathode. The thruster level anode voltage is 35V, 8~10V lower than the lanthanum hexaboride hollow cathode. The experimental results show that the modified barium tungsten cathode has strong anti poisoning ability and excellent performance, and the application of the cathode can effectively meet the long life requirement of the thruster.