Digital bunch-by-bunch transverse feedback system at SSRF

作     者：YUAN RenXian LENG YongBin YU LuYang HAN LiFeng YE KaiRong 

作者机构：Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2011年第54卷第S2期

页      面：305-308页

核心收录：

学科分类：07[理学] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 

主　　题：transverse feedback multi-bunch instability 

摘      要：In order to suppress multi-bunch couple instabilities caused by transverse impedance, a bunch-by-bunch transverse feedback system based on a FPGA digital processor is commissioned at SSRF storage ring. The RF front end has two COD pre-rejected attenuators for increasing the system arrangement and signal noise ratio, and the 3*RF Local signal comes from the BPM s sum signal using a FIR filter for avoiding the effect of longitudinal oscillation. The digital processor receives the coupled horizontal and vertical oscillation signals in the base band and transforms the coupled signals to the horizontal and vertical feedback signals with two series double-zeroes FIR filters. A matlab GUI is applied for producing the FIR coefficients when the tune is shifted. The horizontal and vertical Kickers have a special design for increasing the shunt impedance. Then the multi-bunch instabilities are suppressed respectively and the minimum damping time is about 0.4 ms.