一种非正交对称条带束流位置监测器设计

Design of a non-orthogonal symmetrical strip beam position monitor

介绍了一种条带束流位置监测器(BPM)的设计与仿真方法。在国家同步辐射实验室"太赫兹近场高通量材料物性测试系统"工程项目中,针对波荡器出口处真空室非正交对称性的问题,设计了矩形真空室和跑道形真空室下的两种非正交对称性条带BPM,并与传统的圆形真空室下条带BPM进行对比。基于边界元法,利用MATLAB软件分别对三种真空室下的条带BPM进行建模和仿真。仿真结果表明:相对于传统的圆形真空室下条带BPM,矩形和跑道形真空室下条带BPM灵敏度提高了30%,阻抗匹配误差相对降低了20%,束流位置拟合误差降低了80%。考虑加工精度,矩形真空室下的条带BPM更适用于该工程。

This paper introduces the approach to design a stripline beam position monitor(BPM)for the project of"THz High-flux Material Physical Property Testing System",which is hosted by National Synchrotron Radiation Laboratory.Due to the non-orthogonal symmetric vacuum chamber at the exit of the undulator,two kinds of stripline BPMs with rectangular and racetrack vacuum chamber respectively are considered as an option,and compared with the traditional BPM with circular vacuum chamber.The modeling and simulation are based on the boundary element method via Matlab.The simulation results show that the sensitivities of BPMs with rectangular and racetrack vacuum chamber are improved by 30%,the impedance matching errors are reduced by 20%,and the beam position fitting errors are reduced by 80%,compared with the traditional BPM with circular vacuum chamber.Considering the accuracy of processing,the stripline BPM with rectangular vacuum chamber is more suitable for the project.