三维射频加速腔程序包MAFIA的开发和应用

DEVELOPMENT AND APPLICATION OF 3D RF CAVITY CODE MAFIA

介绍了三维射频加速器计算机辅助设计(CAD)程序包MAFIA的特点、功能及其应用。用CAD的方法实现了射频加速器特别是非轴对称带耦合腔的加速器的三维腔形设计。同时介绍了节省内存、节约机时的模型方法,使得在中小型机器上运行大程序(八万条)成为可能。文章主要对L波段的加速腔进行了数值模拟,并和实验进行了比较,结果符合较好;通过三维数值模拟及图形模拟的方法比较了各种形状谐振腔的性能;计算分析了输入耦合腔及高阶模耦合器对加速腔电磁场分布等参量的影响;提出了加耦合器后谐振频率改变的补偿方法。

The design of a asymmetric RF cavity requires a code that can treat 3D structure . This paper describes the characteristics , functions and applications of the 3D RF cavity computer - aided design ( CAD ) program MAFIA . The 3D geometry design of non - axial symmetric RF cavity with a coupler is realized by CAD method . A kind of data input is presented that can save not only machine memory ,but also the CPU time , and large programs can be run on a medium -small size machine . The numerical simulation of a L - band RF cavity is presented and the modeling results agree well with its experimental values . We have also compared electric properties of the RF cavity with variant geometry by applying 3D numerical and graphic simulations .The influence on electric and magnetic fieldsby adding a input coupler or HOM coupler at the side of a RF cavity is analysed . Adding a coupler to a RF cavity can cause the change of resonatancefrequency . A method that can compensate the variation of frequency is also presented .