用于合肥光源200MeV直线加速器束流位置测量的信号处理系统

Signal processing system for beam position monitor at HLS 200 MeV LINAC

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 stripline 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.