飞行时间质谱法研究新型氧化物阴极的蒸发

Study on Evaporation of New Oxide Cathode with Time of Flight Mass Spectroscopy

阴极的蒸发是评价阴极性能的一个重要指标,它直接关系到微波管的稳定性和寿命。采用飞行时间质谱法(ToFMS),分析气-液相合成碳酸盐制备贮存式氧化物阴极在分解、激活过程中及激活后的蒸发物。结果表明:新型碳酸盐阴极纯净无杂质,在常规分解工艺过程中能够充分分解和激活;激活时阴极涂层内产生盈余Ba,此时检测到Ba的蒸发;在微波管最高工作温度时没有检测到活性物质,不会因为Ba蒸发过快而造成阴极寿命和发射电流快速降低。

Cathode Evaporation is an important index to evaluate the capability of cathodes.It relates to the stability and lifetime of cathodes.In this paper,time of flight mass spectroscopy is used to analyze the evaporation of cathodes in different states.The results show that the new cathode is clean.It can be decomposed and activated by the normal technics.After being decomposed,there is Ba in the surface of the cathode.The lifetime and stability would not be affected by the cathode evaporation.