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, 60t and accumulated 240 h.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 1 050t , 250 degrees C lower than that of lanthanum hexaboride type cathode. The component-level anode voltage is 21 V, 4 similar to 5 V lower than the lanthanum hexaboride hollow cathode. The thruster-level anode voltage is 35 V, 8 similar to 10 V 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.