稀土-钼次级发射体发射性能的研究

A Study on Emission Property of Rare Earth Doped Molybdenum Emitter

阐述了液 固掺杂法制备的稀土 钼烧结体的次级发射性能及其在磁控管中应用的可能性。实验结果表明 ,在钼中添加稀土氧化物可以提高发射体的次级发射性能。经过高温激活处理 (激活温度≥ 14 0 0℃ )的稀土 钼烧结体 ,最大次级发射系数δmax大于 3 0。随着稀土添加量的增加 ,材料的次级发射系数增大。该发射体在电子束轰击下经过数百小时的寿命实验后 ,其次级发射系数仍在 2 5以上 ,显示了良好的抗电子轰击性能。发射体也具有一定的热发射能力。暴露大气后再加热时 ,次级发射和热发射均可恢复。研究认为 ,该发射体已能满足磁控管的应用要求。

The secondary electron emission property of rare earth-molebdenum emitter made by aqueous solution-solid doping method as well as its possible application have been discussed.The experimental results show that adding rare earth oxide into molybdenum can improve the secondary emission coefficient of the emitter.After rare earth doped molybdenum is actived at high temperature(≥1400*!℃),the maximum secondary emission coefficient can be high to more than 3.0.The higher the content of rear earth,the higher the secondary emission coefficient.The secondary emission coefficient can keep higher than 2.5 after bombing by electrons for several hundreds hours.This life test result shows that the emitter has good stability under electron bombardment.This kind of emitter has proper thermionic emission property.Both secondary emission and thermionic emission of such emitters will get to the former level after atmosphere exposure as soon as they are re-actived.The characteristics of this emitter show its potential application in magnetron.