基于BEPCⅡ数据的数字束流位置测量器算法离线分析

Offline research of digital beam position monitor algorithm based on BEPC Ⅱ

介绍了数字BPM算法的原理和架构,并基于高能物理研究所自制的数字BPM硬件平台获取了BEPCⅡ束流流强为600 m A条件下的ADC采样数据。然后在MATLAB环境中设计了NCO模块、CIC滤波器、FIR滤波器以及BEPCⅡ束流逐圈位置数据计算模块,并给出了各模块的具体设计参数。最后通过实际ADC数据对各算法模块进行检验,给出了各模块处理后的频域分析结果,并得到了实际束流下水平方向和垂直方向上的逐圈位置分辨率分别为4. 55μm和4. 28μm,为FPGA在线算法的实现与优化提供了可靠的理论依据。

The signal processing algorithm is one of the keys for digital beam position monitor(BPM)system.In order to optimize the digital BPM algorithm effectively,it is important and significant to research the BPM algorithm offline by using MATLAB.In this paper,the principle and framework of digital BPM algorithm are introduced firstly,the raw ADC data is subsequently obtained from BEPCⅡbased on the digital BPM hardware platform,which is domestically made by Institute of High Energy Physics,Chinese Academy of Sciences.Then NCO module,CIC filter,FIR filter and TBT position data calculation modules are designed with MATLAB,and the specific design parameters of each module are provided.Finally,each algorithm module is tested using raw ADC data and signal spectrograms are given.The turn-by-turn position resolution in horizontal and vertical directions under the actual beam are 4.55μm and 4.28μm.The offline research provides a reliable theoretical basis for the implementation and optimization of FPGA algorithm.