阐述了2-cell Telsa腔的设计.用3维程序HFSS分析了其高阶模的特点,给出了高阶模的主要参数频率、品质因数、分路阻抗以及模式的电场分布,并且π模的电场分布与Superfish的模拟结果相比较,两者是一致的.最后,简要分析了各高阶模对电子加速的影响,分析表明高阶模降低了电子加速效率和束流的稳定性.

This paper presents the design of 2-cell Tesla type cavity and the properties of higher order modes(HOMs) of 2-cell cavity simulated by HFSS process,including the tuning frequency,the quality factor,the shunt impedance and the distribution of the electronic fields. The simulation results of π mode using HFSS is the same as that using Superfish.The effect of HOMs on electron acceleration is analyzed.The analysis result shows that the efficiency of acceleration is decreased and the electron beam becomes unstable because of the HOMs.