电子枪加速极对空间电场影响的解析研究  

Analytic research on accelerating electrodes' influence on the space electric field of electron gun

作　　者：赵伟霞[1] 董全林[1] 丁莹[1] 孙茂多[1] 杨娅姣 党玉杰 

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100191

出　　处：《云南大学学报（自然科学版）》2015年第1期62-72,共11页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家科技支撑计划项目重大科研仪器设备研制专项(2006BAK03A24)

摘　　要：推导了电子枪中各电极之间的类平行板电容公式,根据电场叠加原理和点电荷场强公式推导了加入加速极前后电子枪的电场分布解析式,并针对轴上关键区域的电场用Matlab进行了仿真分析,结果显示对于阴极半径0.5 mm,阳极内半径5 mm、外半径30 mm,两极间距110 mm的结构,在无加速极时只会在阴极表面1.9mm范围内产生大于1 V/mm的强电场,其他位置几乎都为零;加入加速极后轴上电场会急剧增大到原来的几百倍,且加速极数目越多,轴上电场越大,并且加入3个电极时可以形成相对最均匀的电场,说明了电子枪设计加速极的原因和必要性,为电子枪结构的设计提供了一定理论依据.Similar to the parallel plate capacitor, the capacitance formulas between cathode and anode, anode and accelerating electrode in electron gun （EGUN） have been derived, and the analytical expression of electric field distribution between the two poles has been derived according to the superposition principle, and the electric field of the extremely critical axis area has been simulated by Matlab before and after the accelerating electrode is added.The simulation results show that for the structure 0.5 mm and the anode whose inner radius is 5 mm and of a 110 mm-space between the another whose radius is outer radius is 30 mm, before adding accelerating elec- trodes the EGUN generates a strong electric field which is larger than 1 V/mm only in an area about 1.9 mm which approaches the surface of the cathode and on other position almost zero which can not be guaranteed to work properly.After adding accelerating electrodes, the electric field on the axis will dramatically increase to sev- eral hundred times of the original, and the more the number of accelerating poles are, the larger the axis electric field is, and form a uniform electric field when adding three accelerating electrodes, illustrating the reason and ne- cessity of the EGUN gun design of adding accelerating electrodes, and this can provide a theoretical basis for the EGUN design.

关 键 词：电子光学 电子枪 电极电容 加速极 电场 MATLAB 

分 类 号：O463[机械工程—光学工程]