Development and application of bunch-by-bunch measurement system for BEPCⅡ storage ring

Abunch-by-bunch beam measurement system is 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 m for bunch-by-bunch measurement is reached. Bunch-by-bunch tunes and oscillation amplitudes are provided by the system. The system has become a powerful tool for BEPCⅡ machine study.