Research into the sampling methods of digital beam position measurement

• Published in: 核技术（英文版） 2015-06, Vol.26 (3), p.71-76
• Main Author: 邬维浩 赵雷 陈二雷 刘树彬 安琪
• Format: Article
• Language: English
• Subjects: 上海同步辐射装置; 位置分辨率; 位置测量; 抽样方法; 数字波束; 束流位置监测系统; 试验比较; 采样方法
• ISSN: 1001-8042; 2210-3147
• DOI: 10.13538/j.1001-8042/nst.26.030402

A fully digital beam position monitoring system（DBPM） has been designed for SSRF（Shanghai Synchrotron Radiation Facility）. As analog-to-digital converter（ADC） is a crucial part in the DBPM system, the sampling methods should be studied to achieve optimum performance. Different sampling modes were used and compared through tests. Long term variation among four sampling channels, which would introduce errors in beam position measurement, is investigated. An interleaved distribution scheme was designed to address this issue. To evaluate the sampling methods, in-beam tests were conducted in SSRF. Test results indicate that with proper sampling methods, a turn-by-turn（TBT） position resolution better than 1 μm is achieved, and the slow-acquisition（SA） position resolution is improved from 4.28 μm to 0.17 μm.