节点文献
合肥光源束流不稳定性测量和横向模拟反馈
【作者】 杨永良；
【作者基本信息】 中国科学技术大学 ， 核技术及应用， 2009， 博士
【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。
【Abstract】 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.