La-Mo阴极发射性能及机理研究  

A Study of the Emission Property and Mechanism of La-Mo Cathode

作　　者：王金淑[1] 李保真 周美玲[1] 

机构地区：[1]北京工业大学材料学院,北京100022 [2]京东方科技集团有限公司,北京100016

出　　处：《真空电子技术》2007年第6期5-7,11,共4页Vacuum Electronics

基　　金：国家863资助课题(2006AA03Z524)

摘　　要：研究了实用型La-Mo电子管的发射性能,并采用热力学计算、原位XPS等方法对La-Mo阴极中La的价态进行了研究,探讨了该阴极的发射机理。实验结果表明,实用型FU6051 La-Mo电子管的阴极饱和脉冲电流密度为同型号钍钨管的2.32倍,而所需加热功率仅为钍钨阴极的47%。高温下La2O3可以被Mo2C还原成单质La。在阴极工作过程中,还原得到的La覆盖在Mo基体表面,降低了基体Mo的逸出功,促进了阴极的发射。The emission property of La-Mo commercial tube and the emission mechanism of this kind of cathode have been studied. The valence of element lanthanum of cathode material has been studied by using thermodynamic calculation, in-situ high temperature X-ray photoelectron spectrum. On the basis of experiment results, the emission mechanism of La-Mo cathode has been discussed. Experimental results show that the saturated pulse emission current of La-Mo FU6051 electronic tube is about 2.32 times higher than that of Th-W tube, and the heating power is only 47 % of Th-W tube. It has been proved that molybdenum carbide can reduce lanthanum oxide to metallic lanthanum. It is shown that it is the formation of a monatomic layer of metallic lanthanum at the surface of a filament that is the cause of the emissivity of the cathode since the monatomic active surface layer has a lower work function than clean molybdenum.

关 键 词：La—Mo 热阴极 发射性能 发射机理 

分 类 号：O462[理学—电子物理学]