W波段扩展互作用器件均匀磁聚焦电子光学系统

扩展互作用器件，采用三个线圈和一个磁极实现均匀磁场分布。根据理论计算采用有限元法磁学（FEMM）仿真软件对所求磁场进行了建模分析，依据FEMM计算的磁场结合静电电子枪，采用CST仿真软件对高电流密度、高压缩比的电子注在均匀聚焦磁场的作用下传输进行优化。经过计算得出，在工作电压为17 kV、阴极发射电流密度小于10 A/cm2的条件下，由皮尔斯电子枪发射的电子注在均匀磁场的聚焦作用下传输良好，通过率为100%，得到了导流系数为0.175 P的电子枪，在均匀磁场区形成了高电流密度、高压缩比的电子注，平均电流密度达到343.17 A/cm2，压缩比为32，电子注横纵速度比为7.2%。

W-band extended interaction device uniform magnetic focusing electronic optical system

Uniform magnetic focusing system adopts three coil and a pureironto realize gradient uniform magnetic field distribution. The model of magnetic field is built and analyzed by utilizing FEMM (Finite Element Method Magnetics) simulation software, according to the theoretical calculation of the electrostatic gun with uniform focusing magnetic field. CST simulation of the electron gun shows that the perveance of the electron gun is 0.175 P and the cathode emission current density is less than 10 A/cm2 and the anode voltage is 17 kV, under conditions of the magnetic field 0.7 T. CST simulation software optimizes the transmission of electron beam to get the results. The results shows that gun parameter compression ratio is about 32, the beam current density is 343.17 A/cm2, and the electronic beam transverse longitudinal velocity ratio is 7.2%.