Bunch current measurement system for BEPCⅡ storage ring

The BCM (Bunch Current Measurement) system was developed at BEPCⅡ (Beijing Electron-Positron Collider Ⅱ) for solving the instability. In order to measure the bunch current in accelerator storage rings, the signal of beam position monitor (BPM) was sampled by the high-speed ADC, and the digital signal was processed in field-programmable gate array (FPGA). Based on the reflective memory network, the system realized sharing of the results in high-speed and displayed the results in real-time. The system achieved higher precision, the accuracy of real-time display was 0.1 mA/bucket, and the best measurement resolution reached 10 A/bucket. Since the trigger and the algorithm structure for system were adjusted, the system realized stably work for a long time, the positron and the negative electron storage ring could control the uniformity of the bunch current, which improved the luminance of accelerator collisions.