合肥光源(Hefei Light Source,HLS)200 MeV直线加速器的束流横向位置是一个重要的运行参数,直接决定注入的效率,为此新开发了一种非拦截型、高精度、易于将测量结果数字化的条带电极束流位置测量系统(beam position monitor, BPM),该系统由条带电极和信号处理系统组成.信号处理系统选用对数比的信号处理方法,由带通滤波器(BPF)、对数检波模块、信号放大器、模数转换模块和上位机组成.带通滤波器选用中心频率为2.856 GHz、带宽为10 MHz的腔体滤波器,对数检波模块采用对数放大器AD8313芯片,模数转换模块采用NI公司的PXI-5102,上位机的数据采集程序采用Labview编写.本系统有效地采用了虚拟仪器(VI)的技术,具有模块化、开放性、易于交互、可扩展的特点,测试结果表明,其分辨率达到0.1 mm,符合设计要求.

The parameter of beam positions at HLS 200 MeV LINAC is very important to injection efficiency.A new strip-line beam position monitor system was designed recently,which is not interceptive to beam,qualified in precision and easy to digitalize the results.The system consists of a stripline structure and a signal processing system.The signal processing system consists of a band pass filter(BPF) with center frequency of 2.856 GHz and bandwidth of 10 MHz,a logarithmic detector,a analog digital converting module,and a data acquisition program based on Labview.The signal processing system takes advantage of the virtual instrument(VI) technique,which is open,modularized,interactive and expandable.The signal processing system has a resolution of 0.1 mm and meets the design requirement.