Study of Robinson instabilities with a higher-harmonic cavity for the HLS phase Ⅱ project  

作　　者：赵宇宁 李为民 吴丛凤 王琳 

机构地区：[1]National Synchrotron Radiation Lab.,University of Science and Technology of China

出　　处：《Chinese Physics C》2012年第11期1136-1139,共4页中国物理C（英文版）

基　　金：Supported by National Natural Science Foundation of China(10979045,11175180,11175182)

摘　　要：In the Phase Ⅱ Project at the Hefei Light Source, a fourth-harmonic ＂Landau＂ cavity will be operated in order to suppress the coupled-bunch instabilities and increase the beam lifetime of the Hefei storage ring. Instabilities limit the utility of the higher-harmonic cavity when the storage ring is operated with a small momentum compaction. Analytical modeling and simulations show that the instabilities result from Robinson mode coupling. In the analytic modeling, we operate an algorithm to consider the Robinson instabilities. To study the evolution of unstable behavior, simulations have been performed in which macroparticles are distributed among the buckets. Both the analytic modeling and simulations agree for passive operation of the harmonic cavity.In the Phase Ⅱ Project at the Hefei Light Source, a fourth-harmonic ＂Landau＂ cavity will be operated in order to suppress the coupled-bunch instabilities and increase the beam lifetime of the Hefei storage ring. Instabilities limit the utility of the higher-harmonic cavity when the storage ring is operated with a small momentum compaction. Analytical modeling and simulations show that the instabilities result from Robinson mode coupling. In the analytic modeling, we operate an algorithm to consider the Robinson instabilities. To study the evolution of unstable behavior, simulations have been performed in which macroparticles are distributed among the buckets. Both the analytic modeling and simulations agree for passive operation of the harmonic cavity.

关 键 词：Robinson instability higher-harmonic cavity analytic modeling Landau damping rate simulation energy spread 

分 类 号：TL501[核科学技术—核技术及应用]