双频法束长测量关键技术研究

发布时间：2018-04-26 04:27

本文选题：X光源 + 双频法　；参考：《中国科学院研究生院(上海应用物理研究所)》2017年博士论文

【摘要】：X射线光源技术的发展已经经历了了四代,安装大量插入件的同步辐射加速器和高增益的自由电子激光装置是现今主流的X光源方案。本文以上海同步辐射光源和在建的上海软X射线自由电子激光装置为应用背景,开展了双频法束长测量的关键技术研究。论文通过对国内外现有的各类束长测量方法展开调研,分析各种方法的测量能力、优缺点,结合实际应用装置的情况,选取双频法束长测量作为研究对象。完成双频法束长测量系统设计,实现储存环上逐束团的长度测量,且测量误差相对较小。高斯型束团推导出的双频法束长计算原理、逐束团测量需求分析,构成了系统设计的理论基础。结合纽扣电极输出信号的频谱分布和测试的经验,我们选取500MHz和3GHz作为双频法的工作频率。加上对实际信号的大小和射频电路设计主要参数的综合考虑,完成了双频法束长测量系统的设计。束团长度与电荷量的关系的实验,我们采用条纹相机来进行。同时利用条纹相机的测量值与双频法系统作对比,完成对单束团和多束团两种情况下束长计算公式的验证以及系统参数K的标定。束长同步振荡过程的数学仿真,详细地阐释了注入事件发生前后束长变化的规律和时频域的特征。单束团和多束团的注入过程束流实验的结果与仿真工作相符合,两种情况下都成功地记录了束长的同步振荡过程。利用Hybrid器件对500MHz和3GHz信号在中频进行求差得到的差信号,更加明显地看到束长的同步振荡过程。双频法束长测量系统单束团下的随机测量误差小于0.2ps,逐束团的随机测量误差小于0.5ps,系统的动态范围满足5nC电荷量以下的测量要求。选择高输入功率限制的模拟器件,可以增大系统的动态范围,使系统能够应用于质子以及其他重离子的加速器。腔式探头共模信号TM010具有很高的信号精度,设计两个不同工作频率的腔式探头,可以用于FEL装置进行超短束长的测量,且能满足装置设计的测量要求。由于工程进度的问题,双频双腔法的研究我们只完成了系统设计和模拟前端电路的设计。整体线性度的实验室测试以及各器件的测试,保证了前端电路的可用性。
[Abstract]:The development of X-ray light source technology has gone through four generations. A large number of inserts of synchrotron radiation accelerator and a high gain free electron laser device are the mainstream X-ray light source schemes. Based on the application background of Shanghai synchrotron radiation light source and the Shanghai soft X-ray free electron laser facility under construction, the key techniques of dual-frequency beam length measurement have been studied in this paper. Based on the investigation of all kinds of beam length measurement methods at home and abroad, this paper analyzes the measuring ability, advantages and disadvantages of these methods, and selects dual-frequency beam length measurement as the object of study combined with the actual application of the device. The dual frequency beam length measurement system is designed to measure the length of the bundles on the storage ring, and the measurement error is relatively small. The principle of calculating beam length of double frequency method derived by Gao Si cluster, and the analysis of requirement of beam by cluster measurement, constitute the theoretical basis of system design. Combined with the spectrum distribution of button electrode output signal and the experience of measurement, we select 500MHz and 3GHz as the working frequency of dual-frequency method. Considering the actual signal size and the main parameters of RF circuit design, the design of dual-frequency beam length measurement system is completed. In the experiment of the relationship between the beam length and the charge quantity, we use the stripe camera to carry out the experiment. At the same time, the calculation formula of beam length and the calibration of system parameter K under the condition of single beam cluster and multiple beam cluster are verified by comparing the measured values of the fringe camera with the dual frequency method. The mathematical simulation of beam length synchronous oscillation process explains in detail the variation of beam length before and after injection events and the characteristics of time-frequency domain. The beam experiment results of single and multi-beam injection are in agreement with the simulation work. In both cases, the synchronous oscillation of beam length is successfully recorded. The synchronous oscillation process of beam length can be seen more obviously by using Hybrid device to obtain the difference signal of 500MHz and 3GHz signal in intermediate frequency. The random measurement error is less than 0.2psunder the single beam cluster and the random measurement error is less than 0.5ps. the dynamic range of the system can meet the requirement of 5nC charge measurement. The dynamic range of the system can be enlarged by selecting the analog device with high input power limit, and the system can be applied to the accelerator of proton and other heavy ions. The common mode signal TM010 of cavity probe has high signal precision. The design of two cavity probe with different working frequency can be used to measure the length of ultrashort beam in FEL device, and it can meet the requirements of the design of the device. Due to the progress of the project, we have only completed the design of the system and the design of the analog front-end circuit. The laboratory test of the overall linearity and the testing of each device ensure the availability of the front-end circuit.
【学位授予单位】：中国科学院研究生院(上海应用物理研究所)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TL594

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