3 GHz边耦合直线加速结构中桥式耦合器设计参数的优化

Design Parameter Optimization of the Bridge Coupler in 3 GHz Side-Coupled Linear Accelerator Structure

在保证部件电路参数与只含有加速腔和耦合腔的无限长周期结构电路参数相同的条件下,利用CST Microwave Studio软件对桥式耦合器2种腔体进行建模。通过控制桥式耦合器的耦合孔张角及宽度对周期参数进行优化。计算结果表明,中心腔体的谐振频率与加速腔的谐振频率相差约0.33%,桥式耦合器耦合腔谐振频率与加速链耦合腔谐振频率相差约0.01%,2个桥式耦合器连接的3个加速组元的峰值电场强度不平整度小于3.5%。

Under the condition that the circuit parameters of the components are the same as those of the infinite periodic structure with accelerating cavity and coupling cavity,two kinds of cavities of bridge coupler are modeled by CST Microwave Studio software.The periodic parameters are optimized by controlling the opening angle and width of the coupling slot of the bridge coupler.The results show that the difference between the resonant frequency of the central cavity and that of the accelerating cavity is about 0.33%,the difference between the resonant frequency of the coupling cavity of the bridge coupler and that of the acceleration chain coupling cavity is about 0.01%.The unevenness of the peak electric field strength in the three accelerating components linked by two bridge couplers is less than 3.5%.