使用全三维电磁场粒子模拟程序MAFIA建立了行波管周期永磁聚焦系统模型,计算了磁系统中的磁场分布和静态电子注传输特性.分析了周期永磁系统聚焦电子注传输特性,并重点讨论了磁场强度、磁场端部效应和横向速度分布对电子注聚焦性能的影响.为周期永磁聚焦系统的工程设计和优化提供了有价值的模拟结果.

A fully three-dimensional (3-D) of an electron beam optical model focused by a periodic permanent magnet (PPM) stack has been developed using 3-D particle-in-cell (PIC) code of MAFIA, the static magnetic field and electron beam transmission characteristics were simulated using static solver and PIC module. The characteristics of the electron beam confined by the PPM stack are analyzed and the effects of the peak magnetic flux density, magnetic tapering, initial transversal velocity distribution are mainly discussed. Some useful data are obtained for the PPM stack engineering design and optimization.