合肥光源束流不稳定性测量和横向模拟反馈
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摘要
追求光源高亮度和高稳定性是加速器装置建造者的主要目标。对同步辐射光源而言,有着各种因素影响着光源流强的提高和光源稳定性,其中影响最大的是各种束流不稳定性,尤其是耦合束团不稳定性。对储存环中束流运行时存在的各种不稳定性现象进行研宄,建立有效的观测手段,采取有针对性的措施来抑制不稳定性的发生,从而保证光源的稳定运行和提高光源亮度是重要的课题之一。在此背景下作者所在的课题组进行了合肥光源逐圈测量、逐束团测量和横向反馈系统的研制。本文的重点是介绍逐圈测量系统的集成和应用,以及逐束团横向模拟反馈系统的改进及相关应用研宄。
本文首先介绍了合肥光源逐圈测量系统的集成和应用。开发了系统配套控制软件和数据处理程序。对逐圈测量系统的应用进行了研究,引入了基于NAFF算法的瞬时工作点提取和基于数字锁相的阻尼时间计算方法,总结并发展了相空间的测量和计算,还进行了横向耦合度测量的计算。
其次,对合肥光源横向模拟反馈系统样机进行了改进。在很多实验研究分析的基础上,提出并进行了如下改进:前端束流位置信号处理模块的重建;加入了直流成分剔除单元;改进了信号矢量合成模块并增加了四路高频相位控制模块;加入了XY反馈增益独立控制模块;全面优化了信号传输线路,有效解决了信号传输中的反射问题。本文还开发了基于EPICS的反馈系统控制软件。
最后,使用逐圈测量系统和改进后的横向模拟反馈系统对合肥光源电子储存环进行了不稳定性研究。本文分析了纵向振荡对横向模拟反馈系统的影响。对800MeV运行状态下合肥光源电子储存环不稳定性进行了初步研究,给出了Beta振荡的增长和阻尼时间,计算了瞬时工作点变化和对应的相空间变化规律。本文还介绍了改进的横向模拟反馈系统在注入状态下的调试实验,对200MeV注入状态的不稳定性现象进行了测量和分析。
Brightness and stability are key specifications of synchrotron radiation light sources.Continual endeavor is directed to acquire high current,high brightness and favorable stability.Whereas the knowledge of coupling impedance(by which we mean the interaction between a beam and the surrounding vacuum chamber) indicates that the probability of improving performance of storage ring is limited by complicated beam surroundings.What caused the beam unstable,and how to cure the beam instabilities are the key questions,which all the accelerator researchers around the world need to face.
Firstly,the HLS turn by turn measurement(TBT) system integration and application are introduced.A couple of system control software and data processing procedures are developed.The transient tune extraction based on NAFF algorithm and damping time calculating based on digital phased-locked amplifier are introduced. The measurement and calculation of the phase space are summed up and development, also,the x y coupling.
Secondly,the HLS analog transverse feedback prototype has been improved. Analysis the existing problems of feedback prototype and proposed the following improvements:front-end signal processing module reconstruction;joined the DC component removed units;improved the signal vector resultant modules and added four high-frequency phase control modules;joined the XY feedback gain independent control module;fully optimize the signal transmission line,effectively solute the issue of signal reflection.This article has also developed a system based on the EPICS control software.
Finally,a couple of experiments for HLS electron storage ring are conducted based on turn-by-turn measurement systems and improved analog transverse feedback system.This article also analyzed the influence of longitude oscillation to the transverse feedback system.For HLS electron storage ring,the growth and damping rate of Beta oscillation are given,the transient tune changed with time and corresponding changes in phase space are showed.This paper has also introduced the debugging of improved analog transverse feedback system at 200MeV injection status, and the injection beam instabilities phenomenon have been measured and analyzed.
本文首先介绍了合肥光源逐圈测量系统的集成和应用。开发了系统配套控制软件和数据处理程序。对逐圈测量系统的应用进行了研究,引入了基于NAFF算法的瞬时工作点提取和基于数字锁相的阻尼时间计算方法,总结并发展了相空间的测量和计算,还进行了横向耦合度测量的计算。
其次,对合肥光源横向模拟反馈系统样机进行了改进。在很多实验研究分析的基础上,提出并进行了如下改进:前端束流位置信号处理模块的重建;加入了直流成分剔除单元;改进了信号矢量合成模块并增加了四路高频相位控制模块;加入了XY反馈增益独立控制模块;全面优化了信号传输线路,有效解决了信号传输中的反射问题。本文还开发了基于EPICS的反馈系统控制软件。
最后,使用逐圈测量系统和改进后的横向模拟反馈系统对合肥光源电子储存环进行了不稳定性研究。本文分析了纵向振荡对横向模拟反馈系统的影响。对800MeV运行状态下合肥光源电子储存环不稳定性进行了初步研究,给出了Beta振荡的增长和阻尼时间,计算了瞬时工作点变化和对应的相空间变化规律。本文还介绍了改进的横向模拟反馈系统在注入状态下的调试实验,对200MeV注入状态的不稳定性现象进行了测量和分析。
Brightness and stability are key specifications of synchrotron radiation light sources.Continual endeavor is directed to acquire high current,high brightness and favorable stability.Whereas the knowledge of coupling impedance(by which we mean the interaction between a beam and the surrounding vacuum chamber) indicates that the probability of improving performance of storage ring is limited by complicated beam surroundings.What caused the beam unstable,and how to cure the beam instabilities are the key questions,which all the accelerator researchers around the world need to face.
Firstly,the HLS turn by turn measurement(TBT) system integration and application are introduced.A couple of system control software and data processing procedures are developed.The transient tune extraction based on NAFF algorithm and damping time calculating based on digital phased-locked amplifier are introduced. The measurement and calculation of the phase space are summed up and development, also,the x y coupling.
Secondly,the HLS analog transverse feedback prototype has been improved. Analysis the existing problems of feedback prototype and proposed the following improvements:front-end signal processing module reconstruction;joined the DC component removed units;improved the signal vector resultant modules and added four high-frequency phase control modules;joined the XY feedback gain independent control module;fully optimize the signal transmission line,effectively solute the issue of signal reflection.This article has also developed a system based on the EPICS control software.
Finally,a couple of experiments for HLS electron storage ring are conducted based on turn-by-turn measurement systems and improved analog transverse feedback system.This article also analyzed the influence of longitude oscillation to the transverse feedback system.For HLS electron storage ring,the growth and damping rate of Beta oscillation are given,the transient tune changed with time and corresponding changes in phase space are showed.This paper has also introduced the debugging of improved analog transverse feedback system at 200MeV injection status, and the injection beam instabilities phenomenon have been measured and analyzed.
引文
[1]King-Yuen Ng,PHYSICS OF COLLECTIIVE BEAM INSTABILITIES,US Particle Accelerator School,2000.
[2]孙葆根,“合肥光源新的束流测量系统研制及其应用研究”,博士论文,中国科学技术大学,2000.
[3]王筠华,刘建宏,孙葆根,李为民,刘祖平,王琳,杨永良,郑凯,逐圈测量系统定标和新近测量结果,《强激光与粒子束》,2004年16卷,第5期。
[4]王筠华,李为民,刘祖平,孙葆根,刘建宏,郑凯,杨永良等,合肥光源逐圈测量系统试验结果及其在注入调试中的应用,《强激光与粒子束》,2004年16卷,第1期。
[5]王筠华,李为民,孙葆根,等,基于对数比电路的HLS turn-by-turn系统,《强激光与粒子束》,2002年14卷,第4期。
[6]刘建宏,HLS Bunch-by-Bunch测量系统研制及束流不稳定性的初步研究。博士论文,中国科学技术大学,2005
[7]王筠华,刘建宏,郑凯等,合肥光源逐束团测量和横向束流反馈系统设计,《强激光与粒子束》,18(2),2006
[8]郑凯,合肥光源逐束团测量和模拟反馈系统。博士论文,中国科学技术大学,2007
[9]郑凯,王筠华,刘祖平等,HLS逐束团跟踪监测系统,《高能物理与核物理》,30(6),2006年6月
[10]郑凯,王筠华,刘祖平等,改进的合肥光源数团流强测量方案,《强激光与粒子束》,18(7),2006年7月
[11]郑凯,王筠华,刘祖平等,基于Hilbert变换的相空间重建方法在HLS逐束团测量系统中的应用,《高能物理与核物理》31(3),2007。
[12]金玉明,“电子储存环物理”,中国科学技术大学出版社,2001
[13]J.D.Fox,E.Kikutani,Bunch Feedback System and Signal Processing
[14]孙葆根,束流测量与诊断讲义,NSRL
[15]国智元,加速器中的聚束束流不稳定性,2000.7
[16]W.Barry,J.Byrd,J.Corlett,etc.COMMISSIONING OF THE ALS TRANSVERSE COUPLED-BUNCH FEEDBACK SYSTEM,1995(PAC95),USA
[17]Log-ratio Beam Position Monitor User's Manual
[18]CompuScope 1250 User's Manual,GAGE APPLIED,INC
[19]D.D.Caussyn,M.Ball,Experimental studies of nonlinear beam dynamics,PHYSICAL REVIEW A,December 1992,Volume46,Number 12.
[20]R.Bartolini et al,Tune Evaluation in Simulations and Experiments,Particle Accelerators,1996,Vol.52.p147-177.
[21]刘祖平,束流光学,中国科学技术大学出版社
[22]P.Kromer,R.Robinett,R.Bengtson,etc."PC-Based Digital Lock-In Detection of Small Signals in the Presence of Noise",Department of Physics,University of Texas at Austin
[23]徐守时,信号与系统:理论、方法和应用,中国科学技术大学出版社,1999
[24]曹涌,基于束流的准直系统研制及相关研究,博士论文,中国科学技术大学,2007
[25]Y.Ohnishi,Y.Funakoshi,K.Mori,etc.MEASUREMENT OF XY COUPLING USING TURN-BY-TURN BPM AT KEKB,Proceedings of EPAC 2000,Vienna,Austria
[26]P.Cameron,A.Fedotov,N.Malitsky,Tune Measurement In The SNS Ring,Proceedings of EPAC,Paris,2002
[27]M.Serio,Tune Measurements,Cem Accelerator School
[28]D.Still,I.Kourbanis,D.Capista,“Tune Measurement Methods in the Fermilab Main Ring”,17th Particle Accelerator Conference Vancouver,Canada,1997,P2061-2063
[29]C.Simopoulos,R.L.Holtzapple,“Damping Rate Measurements in the SLC Damping Rings”,Proceedings of PAC,1995,P3073-3075
[30]张磊,焦毅,王九庆等,BEPC横向阻尼时间的测量,强激光与粒子束,Vol.18
[31]S.Prabhakar,New Diagnostics and Cures for Coupled-Bunch Instability,SLAC,2001
[32]S.Prabhakar et al,Phase space tracking of coupled-bunch instabilities,Physical Review Special Topics-Accelerators and Beams,,1999,Vol.2:084411
[33]R.Claus,J.Fox,H.Hindi,I.Linscott etc.Observation,Control and Modal Analysis of Coupled-Bunch Longitudinal Instabilities
[34]Tobiyama M,Kikutani E,Flanagan J W,et al.Beam diagnostic using Bunch-by-Bunch feedback system in the KEKB rings[A].Asian Particle Accelerator Conference 2001[C].Beijing:2001.752-754
[35]J.Y.Huang,M.K.Park,M.Kwon,M.Yoon and I.S.Ko,TRANSVERSE BEAM FEEDBACK SYSTEM IN THE PLS,APAC98,P2350-2352
[36]M.Tobiyama,E.Kikutani,Bunch-by-bunch feedback systems for KEKB rings
[37]T.Nakamura,S.Date,K.Kobayashi,T.Ohshima,Transverse Bunch-by-bunch Feedback System for the SPring-8 Storage Ring,EPAC'04,Lucerne,June 2005,p.2649
[38]http://www.aps.anl.gov/epics/,Experimental Physics and Industrial Control System
[39]李为民,加速器控制系统,讲义,中国科学技术大学
[40]李为民,戴益民等,在NSRL上利用RFKO实现部分填充,核技术,第25卷,第1期,2002年
[2]孙葆根,“合肥光源新的束流测量系统研制及其应用研究”,博士论文,中国科学技术大学,2000.
[3]王筠华,刘建宏,孙葆根,李为民,刘祖平,王琳,杨永良,郑凯,逐圈测量系统定标和新近测量结果,《强激光与粒子束》,2004年16卷,第5期。
[4]王筠华,李为民,刘祖平,孙葆根,刘建宏,郑凯,杨永良等,合肥光源逐圈测量系统试验结果及其在注入调试中的应用,《强激光与粒子束》,2004年16卷,第1期。
[5]王筠华,李为民,孙葆根,等,基于对数比电路的HLS turn-by-turn系统,《强激光与粒子束》,2002年14卷,第4期。
[6]刘建宏,HLS Bunch-by-Bunch测量系统研制及束流不稳定性的初步研究。博士论文,中国科学技术大学,2005
[7]王筠华,刘建宏,郑凯等,合肥光源逐束团测量和横向束流反馈系统设计,《强激光与粒子束》,18(2),2006
[8]郑凯,合肥光源逐束团测量和模拟反馈系统。博士论文,中国科学技术大学,2007
[9]郑凯,王筠华,刘祖平等,HLS逐束团跟踪监测系统,《高能物理与核物理》,30(6),2006年6月
[10]郑凯,王筠华,刘祖平等,改进的合肥光源数团流强测量方案,《强激光与粒子束》,18(7),2006年7月
[11]郑凯,王筠华,刘祖平等,基于Hilbert变换的相空间重建方法在HLS逐束团测量系统中的应用,《高能物理与核物理》31(3),2007。
[12]金玉明,“电子储存环物理”,中国科学技术大学出版社,2001
[13]J.D.Fox,E.Kikutani,Bunch Feedback System and Signal Processing
[14]孙葆根,束流测量与诊断讲义,NSRL
[15]国智元,加速器中的聚束束流不稳定性,2000.7
[16]W.Barry,J.Byrd,J.Corlett,etc.COMMISSIONING OF THE ALS TRANSVERSE COUPLED-BUNCH FEEDBACK SYSTEM,1995(PAC95),USA
[17]Log-ratio Beam Position Monitor User's Manual
[18]CompuScope 1250 User's Manual,GAGE APPLIED,INC
[19]D.D.Caussyn,M.Ball,Experimental studies of nonlinear beam dynamics,PHYSICAL REVIEW A,December 1992,Volume46,Number 12.
[20]R.Bartolini et al,Tune Evaluation in Simulations and Experiments,Particle Accelerators,1996,Vol.52.p147-177.
[21]刘祖平,束流光学,中国科学技术大学出版社
[22]P.Kromer,R.Robinett,R.Bengtson,etc."PC-Based Digital Lock-In Detection of Small Signals in the Presence of Noise",Department of Physics,University of Texas at Austin
[23]徐守时,信号与系统:理论、方法和应用,中国科学技术大学出版社,1999
[24]曹涌,基于束流的准直系统研制及相关研究,博士论文,中国科学技术大学,2007
[25]Y.Ohnishi,Y.Funakoshi,K.Mori,etc.MEASUREMENT OF XY COUPLING USING TURN-BY-TURN BPM AT KEKB,Proceedings of EPAC 2000,Vienna,Austria
[26]P.Cameron,A.Fedotov,N.Malitsky,Tune Measurement In The SNS Ring,Proceedings of EPAC,Paris,2002
[27]M.Serio,Tune Measurements,Cem Accelerator School
[28]D.Still,I.Kourbanis,D.Capista,“Tune Measurement Methods in the Fermilab Main Ring”,17th Particle Accelerator Conference Vancouver,Canada,1997,P2061-2063
[29]C.Simopoulos,R.L.Holtzapple,“Damping Rate Measurements in the SLC Damping Rings”,Proceedings of PAC,1995,P3073-3075
[30]张磊,焦毅,王九庆等,BEPC横向阻尼时间的测量,强激光与粒子束,Vol.18
[31]S.Prabhakar,New Diagnostics and Cures for Coupled-Bunch Instability,SLAC,2001
[32]S.Prabhakar et al,Phase space tracking of coupled-bunch instabilities,Physical Review Special Topics-Accelerators and Beams,,1999,Vol.2:084411
[33]R.Claus,J.Fox,H.Hindi,I.Linscott etc.Observation,Control and Modal Analysis of Coupled-Bunch Longitudinal Instabilities
[34]Tobiyama M,Kikutani E,Flanagan J W,et al.Beam diagnostic using Bunch-by-Bunch feedback system in the KEKB rings[A].Asian Particle Accelerator Conference 2001[C].Beijing:2001.752-754
[35]J.Y.Huang,M.K.Park,M.Kwon,M.Yoon and I.S.Ko,TRANSVERSE BEAM FEEDBACK SYSTEM IN THE PLS,APAC98,P2350-2352
[36]M.Tobiyama,E.Kikutani,Bunch-by-bunch feedback systems for KEKB rings
[37]T.Nakamura,S.Date,K.Kobayashi,T.Ohshima,Transverse Bunch-by-bunch Feedback System for the SPring-8 Storage Ring,EPAC'04,Lucerne,June 2005,p.2649
[38]http://www.aps.anl.gov/epics/,Experimental Physics and Industrial Control System
[39]李为民,加速器控制系统,讲义,中国科学技术大学
[40]李为民,戴益民等,在NSRL上利用RFKO实现部分填充,核技术,第25卷,第1期,2002年