热电子发射密度
The density of state of valence electron of La and O ions increase during activation processes. The 6s higher energy valence electrons of La ions with unsaturated coordination number is easy to emit. It is clear that the processes is beneficial to thermionic emission.
激活过程促使La,O离子的价电子态密度增加,配位不饱和的La离子外层6s高能价电子易形成电子发射,即这一变化过程对热电子发射具有积极作用。
Among them, a better quality beam can be easily obtained from the thermionic cathode, but the emission current density of the electron is relatively low, the cathode is short life due to an easily cathode poisoning, and the cost is expensive.
其中,热阴极获得的电子束的束流品质较好,但发射电流密度相对较低,阴极容易中毒,寿命较短,而且成本高。
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