GaAs真空电子源衰减模型研究  

Degradation model of GaAs vacuum electron sources

作　　者：邹继军[1,2] 张益军[1] 杨智[1] 常本康[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院,南京210094 [2]核技术应用教育部工程研究中心(东华理工大学),南昌330013

出　　处：《物理学报》2011年第1期722-727,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60801036;61067001);江西省青年科学家(井冈之星)培养对象计划(批准号:2009DQ01700);中国博士后科学基金(批准号:200904501098;201003589589);江苏省博士后科研资助计划(批准号:0901040C);江苏省普通高校研究生科研创新计划(批准号:CX09B_096Z)资助的课题~~

摘　　要：利用X射线光电子能谱(XPS)仪对激活后的GaAs真空电子源进行了随时间衰减变化的XPS分析,分析发现了电子源阴极表面各元素百分含量随时间的变化,揭示了杂质气体吸附造成的偶极矩方向的改变是电子源灵敏度显著下降的主要原因.基于上述结论,通过分析真空系统中杂质气体的吸附过程,推导并得到了GaAs电子源衰减模型.该模型从理论上揭示了GaAs电子源的指数衰减规律以及寿命与真空度的反比关系,与实验现象完全一致.The degradation of activated GaAs vacuum electron source as a function of time has been investigated by using X-ray photoelectron spectroscopy （ XPS）. We found that the cathode surface element content changes with time and the significant decrease in sensitivity of electron source is mainly due to the change of dipole direction caused by the adsorption of harmful gases on the cathode surface. Based on the above results,we deduced the degradation model of GaAs electron source through analyzing the adsorption process of harmful gases on the surface in vacuum system. The model reveals the exponential degradation rule of GaAs electron sources and the inverse relationship between lifetime and pressure. The theoretical results are in full agreement with the experimental fact.

关 键 词：电子源 X射线光电子能谱 衰减模型 真空度 

分 类 号：O472.4[理学—半导体物理]