一维阵列电子注平面聚焦系统磁场分布特性

Magnetic field distribution characteristics of one-dimensional electron beam array planar focusing system

摘要:

针对平面集成行波管对一维阵列电子注聚焦的应用需求，设计了4通道电子注平面磁聚焦系统。将各通道磁场轴向和横向分量沿轴分布特征计算结果与测试结果进行对比，确认了Opera软件计算磁场分布特征的准确性。为与轴对称周期永磁(PPM)聚焦系统电子注通道内磁场分布特性进行对比，建立了轴对称PPM聚焦系统模型，测试结果与计算结果一致性较好。通过平面聚焦系统与轴对称PPM聚焦系统电子注通道内的磁场纵向和横向分布特性对比表明，两种聚焦系统电子注通道内纵向和横向磁场具有相同的分布特征，在离轴相同位置的圆周上横向磁场分量与轴向分量的比值均为B_x/B_z≈0.11，该平面聚焦系统可实现一维阵列圆形电子注的良好聚焦。

Abstract:

A four-channel electron beam planar focusing system is designed to meet the application requirements of the planar integrated traveling wave tube for one-dimensional electron beam array focusing. The calculated results of the axial and transverse components of the magnetic field along the axis are compared with the measured results, which confirms the accuracy of Opera software in calculating the magnetic field distribution. In order to compare with the magnetic field distribution in the electron beam channel of the axisymmetric Periodic Permanent Magnet(PPM) focusing system, a model of the PPM focusing system is established, and the tested results are in good agreement with the calculated results. By comparing the longitudinal and transverse distribution characteristics of the magnetic field in the electron beam channel of the planar focusing system and the axisymmetric PPM focusing system, it is shown that the two focusing systems share the same magnetic field distribution characteristics in the electron beam channel, the ratios of transverse magnetic field component to the axial component are both about 0.11 on the circumference at the same off-axis position, and it is expected that the planar focusing system can achieve good focusing of the one-dimensional array electron beam.