摘要
根据热初速理论,分析了皮尔斯电子枪的电子注包络曲线,结果表明理论上采用的热电子径向分布σ曲线一直处于增长发散状态,导致理论包络曲线在注腰之后严重发散。本文提出一种新的修正计算方法,在电子注汇聚阶段考虑电子的热速度效应,在电子注发散阶段忽略σ的影响,只考虑起主导作用的空间电荷效应,综合得到新的电子注包络曲线。计算结果表明,与旧方法相比,新方法得到的电子注包络曲线与实验结果吻合性更好。
The impact of the transversal velocity of the thermal electrons and the anode aperture on the electron beam spreading in Pierce-type electron gun was mathematically modeled,theoretically analyzed and experimentally measured,to get a more realistic correction of the electron beam spread curve.The calculated results show that the widely-accepted normal deviation σ of the thermal electrons keeps on significandy widening the spreading in the formation of the electron beam,resulting in a fairly large discrepancy between the calculated and measured results.In the newly-formulated model,thermal velocity dominates in the beam convergence;whereas the space charge plays a dominant role in the beam divergence in ignorance of the normal deviation σ.Based on the new model,the beam spread curve was calculated.The results show that the new model outperforms the conventional one because of a better agreement between the predicted and measured beam spread curves.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2016年第2期234-237,共4页
Chinese Journal of Vacuum Science and Technology
关键词
电子枪
电子注
热初速
包络曲线
Electron gun
Electron beam
Thermal velocity
Beam spread curve
