基于北京正负电子对撞机二期工程储存环,研制了一套逐束团束流测量系统.系统包括模拟前端、数据采集处理控制和显示软件三个部分.储存环束流位置探头的四路信号作为逐束团测量系统的输入,该系统宽带模拟前端完成信号幅度相位的调理,并保证束团间无干扰;四路500 MHz模数转换器对信号采样实现逐束团测量;基于现场可编程门阵列的数字信号处理逻辑计算得到每个束团的位置.系统在线实时束流位置测量分辨率优于4.5 μm,同时该测量系统可实现实时逐束团振荡幅度和工作点的测量.系统还拥有存储大容量逐束团原始数据的功能,为日常的机器研究提供了有力的测量手段.

A bunch-by-bunch beam measurement system has been developed for BEPCⅡ (Beijing Electron-Positron ColliderⅡ).In order to realize the bunch-by-bunch measurement,high isolation for signals of each bunch should be reached.The analogy signals are sampled bunch-by-bunch with high speed (500 MHz) ADCs,Bunch signals’ separation and digital processing are done in Field Programmable Gate Array (FPGA).A resolution of about 4.5 um for bunch-by-bunch measurement has been reached.Bunch-by-bunch tunes and oscillation amplitudes are also provided by the system. The system has become a powerful tool for BEPCⅡ machine study.