Thermionic properties of Mo-La2O3
cathode wires
cathode wires
(The Key Laboratory of Advanced Functional Materials for
Ministry of Education, Beijing Polytechnic University,
Beijing 100022, China)
Ministry of Education, Beijing Polytechnic University,
Beijing 100022, China)
Abstract: The recent advances in Mo-La2O3 thermionic cathode materials were presented.It is shown that Mo-La2O3 cathode has better ductility,radioactive pollut ion-free,excellent thermionic electron-emission properties and lower operating temperature compared with W-ThO2 cathode. At operating temperature 1350～1400℃,the average saturation current of the Mo-La2O3 cathode is 118mA,the corresponding average current density is 367mA/cm2,and the average emission efficiency is 11.8mA/W.The lifetime of diode is more than 2000h when the stable emission current is 80mA.More over,the lifetime of practical 6T51-type triode is more than 1000h.These advances show that the Mo-La2O3 cathode electron tube is closer to industry application.
Key words: molybdenum;rare earth oxide;cathode;thermionic emission