tune调制对储存环横向稳定性影响的模拟研究

对包含非线性六极场储存环的线性tune(Qx,Qy)加以余弦调制,通过计算粒子轨道沿相角畸变的动力学孔径,研究了tune调制对储存环中粒子运动横向稳定性的影响.从模拟结果可以看出,tune调制对粒子稳定性的影响是一种长期效应.当调制振幅很小、调制tune远离共振岛tune值时,对粒子稳定性的影响很小,随着调制振幅增大,调制tune接近共振岛tune,影响越来越明显.     

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

引入基于Hilbert变换的相空间重建手段, 对合肥光源(HLS)逐束团测量系统采集的数据进行了全面的分析, 其中包括单个束流位置监测器(BPM)数据的相空间重建, 逐圈逐束团振荡相位信息、束团振荡模式信息、逐束团横向工作点(tune值)变换. 提出了新的分析束团tune值的手段, 提供传统方法无可比拟的更高的时间和频率分辨率. 还对不同模式的阻尼率进行了计算, 这为衡量逐束团反馈系统的效果提供了确实可靠的方法.     

HLS逐束团跟踪监测系统

介绍了合肥光源(HLS)逐束团跟踪监测系统, 并且展示了相关的实验、数据分析 结果. 通过同相的门电路信号和RF的分频信号控制ADC的外触发, 对该测量系统的可靠性、稳定性进行了验证. 并且利用该系统, 跟踪记录了完整的注入, 慢加速, 降频, 校正轨道, 扭摆磁铁充电, 加斜四极铁以及正常供光运行的全过程. 最后展示了该过程的横向工作点(tune值)漂移, 多束团耦合不稳定性的研究结果.     

束流逐圈位置测量在BEPC储存环上的初步应用

介绍了利用合肥同步辐射光源(HLS)的逐束团位置测量系统在北京正负电子对撞机(BEPC)上进行的逐圈位置测量实验. 在不同条件下对束流进行逐圈位置测量, 得到束流的相运动图像并观测了阻尼效应. 利用基频数值分析(NAFF)方法对逐圈位置数据分析得到高精度的束流频谱, 可以由此研究各种效应引起的工作点漂移. 实验中观测到特定工作点下由色品校正六极子引起的束流共振现象, 并对此作了合理解释.     

合肥光源储存环聚焦模型标定

 描述了利用轨道响应矩阵拟合技术标定合肥光源储存环聚焦模型的过程及实验结果。通过响应矩阵分析,得到了合肥光源储存环弯铁边缘聚焦强度约为0.1 mrad/A,场积分为0.62~0.63,考虑了四极铁聚焦强度的修正系数的影响,发现了原四极铁磁测数据中较大的系统偏差,分析结果和备用磁铁的磁场测量数据吻合良好。在此基础上建立的合肥光源储存环理论模型可以准确地描述实际储存环线性光学特性。     

Libera数字束流位置处理器在工作点测量中的应用

 数字信号处理技术在现代束流诊断中有成熟的应用,特别是在束流位置检测器信号分析和工作点测量时有优越的性能。在合肥光源工作点测量中,采用高斯白噪声激励起束流横向振荡,再利用Libera数字束流位置处理器采集激励后的束流位置信号,并进行幅度解调得到束流横向振荡频率,再利用Matlab进行快速傅里叶分析处理,得到工作点的小数部分,从而实现工作点测量。在合肥光源上进行实验,测量得到其水平工作点是3.535 2,垂直工作点是2.629 9。     

基于嵌入式EPICS的中子监测仪研制

针对合肥光源（HLS-Ⅱ）辐射防护与安全需求,且合肥光源的控制系统是基于EPICS架构,为减少辐射监测系统中间的环节,提高合肥光源人身安全联锁可靠性,研制了基于嵌入式EPICS控制系统的中子监测仪。中子监测仪的关键部件-探测器选用BF₃针对合肥光源（HLS-Ⅱ）辐射防护与安全需求,研制了基于嵌入式EPICS的中子监测仪,用于场所与环境辐射场中子的监测。合肥光源的控制系统是基于EPICS架构,为减少辐射监测系统中间的环节,提高合肥光源人身安全联锁可靠性,研制了基于嵌入式EPICS控制系统的中子监测仪。中子监测仪的关键部件-探测器选用BF₃正比计数管,通过对正比计数管产生的微弱电信号加2 kV的正高压偏置,交流耦合介入前置放大器放大,后输出固定宽度的脉冲信号。信号由CORTEX-M3电路计数,后经CORTEX-A8电路处理后将数据发布到局域网。利用镅铍中子源和合肥光源现场辐射环境对所研制的监测仪性能进行了初步测试,结果表明,该监测仪达到设计要求,可用于中子监测。     

合肥光源的衍射光栅制备技术

正衍射光栅是合肥光源光束线中重要的分光元件。本文介绍伴随合肥光源而发展起来的衍射光学元件精密加工实验室衍射光栅制备技术及相关工作进展。一、引言合肥同步辐射装置是工作在真空紫外-软X射线波段的连续光源。在真空紫外-软X射线波段通常使用光栅单色器分光,将所需的单色光从同步辐射光源中分离出来。衍射光栅是合肥光源重要的色散元件。国家同步辐射实验室成立了光学组,并逐步发展成现在的衍射光学元件精密加工实验室,     

基于MATLAB的HLS束流轨道慢反馈控制系统

束流轨道稳定性是同步辐射光源的重要性能指标,直接影响实验线站光通量的稳定性.介绍了在合肥光源储存环上实现束流轨道慢反馈校正的研究与实验工作,目前合肥光源的全环垂直轨道的稳定性为Ay<±30μM,从而使轨道的稳定性达到了国际同类机器先进水平.     

合肥光源数字横向逐束团反馈系统

为了克服横向耦合束团不稳定性对合肥光源的不利影响,在合肥光源(HLS)研制了一套数字横向逐束团反馈系统。该系统使用直接采样前端,同时针对合肥光源水平方向工作点和垂直方向工作点太过接近的情况,修改了数字处理器的FPGA程序,使得单个处理器能够实现独立的双通道反馈。束流试验验证了反馈系统能有效抑制横向不稳定性,并可以提高注入流强。     

Lattice optimization for the HLS-Ⅱ storage ring

The upgrade project of the Hefei Light Source (HLS), named HLS-Ⅱ, is under way, whose storage ring will be reconstructed. The HLS-Ⅱ storage ring has lower emittance and more straight sections available for insertion devices compared with the present HLS storage ring. The scan method is applied to the linear lattice optimization for the HLS-Ⅱ storage ring to get thorough information about the lattice. To reduce the computation amount, several scans with different grid spacing values are conducted. And, the calculation of the chromatic sextupole strength for the achromatic mode is included in the scan, which is useful for nonlinear lattice optimization. To better analyze the obtained solutions in the scan, the lattice properties and the variables of quadrupole strengths are statistically analyzed. And, the process of selecting solutions is described in detail, including the choice of the working point, the settings for the emittance and optical functions, and the restriction of maximum magnet strength. Two obtained lattices, one for the achromatic mode and the other for the non-achromatic mode, are presented, including their optical functions and optimized dynamic apertures.     

HLS横向反馈系统研制中的关键技术

较为全面地介绍了合肥光源横向模拟反馈系统研制过程中, 所涉及的部分关键问题, 如矢量运算模块的开发, Notch滤波器研制, 基于Hilbert变换进行相空间重建、模式分析, 反馈Kicker腔的研制.     

合肥光源储存环注入凸轨系统满能量注入可行性研究

 合肥同步辐射光源现有的注入系统采用1/4能量注入。二期工程改造后,注入系统采用集中布局方案。以改造后的机器为基础,针对合肥同步辐射光源的两组运行模式,探讨实现满能量注入的可行性和实施方案。     

Identification of nonlinear multi-degree-of freedom structures based on Hilbert transformation

The modeling method and identified method adapted to multi-degree-of-freedom structures with strucrural nonlinearities are established. The component mode synthesis method is used to establish the nonlinear governing equations by extending the connected relationships. Based on the modeling method, the Hilbert transform method is applied to identify the nonlinear stiffness of multi-degree-of-freedom structures. Nonlinear analysis and identification of a typical folding wing configuration with three freeplay hinges are investigated. The nonlinear governing equation is established based on present methods and the computing results of different stiffness are checked by finite element programming. In order to illustrate the influence of the nonlinearities, the frequency response characteristics of the structure are analyzed and Hilbert transform is performed. The Hilbert transform identification method is utilized to identify the nonlinear stiffness of nonlinear hinges in the time domain and several parametric studies are performed. In addition, the comparison of response is made to illustrate the feasibility of the methods. The results show that the extending component mode synthesis method in the present work can be used to establish the governing equation with structural nonlinearities. Based on the modeling method, the Hilbert transform identified method can be extended to multi-degree-of-freedom structures accurately.     

静力水准系统用于基准高差测量的研究

为了拓展静力水准系统（HLS）在粒子加速器准直测量工作中的应用,开展了针对HLS系统用于多点间基于水平面的基准高差测量的实现方法的研究。基于传感器工作原理,设计并搭建了一套由双频激光干涉仪、高精度位移平台、HLS传感器等组成的比对系统,利用该系统控制多传感器在同一坐标系下观测同一液位。通过比对获得多传感器间基于底部坐标系的零位高度差,实现了多个传感器坐标系间相对于水平面的高差值测量,并验证了高差测量精度优于5 μm。除此之外,通过在HLS传感器上方安装靶座,使用三坐标测量机(CMM)严格标定各传感器电极板至靶球球心的距离,实现了多靶球球心位置基于水平面的高差值测量,并验证了其测量精度优于30 μm。     

HLSⅡ干涉法测量储存环横向尺寸与发射度

为了满足合肥光源升级改造后测量小束流尺寸的需求,设计了干涉法测量束团尺寸与发射度系统。简要介绍了在可见光波段利用干涉法测量束团横向尺寸的原理,详细介绍了该系统的光路与软硬件系统和图像处理算法。为了消除CCD的本底噪声对测量的影响,建立了本底噪声图像与束流流强的查找表,最终得到了多束团模式下的在线实验结果。测量得到的水平尺寸为265μm,测量误差为5.78μm;垂直尺寸为114μm,测量误差为4.89μm。     

合肥储存环电子束流寿命分析

 电子束流寿命是个很重要的指标,直接影响合肥光源的正常运行,为此研究了影响束流寿命的因素,测量了高频腔压、耦合度以及束团长度对电子束流寿命的影响,研究显示合肥储存环的电子束流真空寿命和托歇克寿命相当;并且利用束损系统测量了因托歇克寿命的变化而造成束流损失的相对变化;通过增加耦合度增加束流的垂直发射度,有效地提高了束流的寿命,保证了合肥光源的正常运行。     

Theoretical analysis of BLM system for HLS Ⅱ

Hefei Light Source (HLS) is being upgraded to HLS Ⅱ. Its emittance will be much lower than before, therefore the Touschek scattering will increase significantly and become the dominant factor of beam loss. So it is necessary to build a new beam loss monitoring (BLM) system that, in contrast to the old one, is able to obtain the quantity and position information of lost electrons. This information is useful in the commissioning, troubleshooting, and beam lifetime studying for HLS Ⅱ. This paper analyzes the distribution features of different kinds of lost electrons, introduces the operation parameters of the new machine and discusses how to choose proper monitoring positions. Based on these comprehensive analyses, a new BLM system for HLS Ⅱ is proposed.     

合肥光源储存环束流软慢加速控制

 合肥光源储存环为非满能量注入,束流以200MeV的能量注入到储存环后慢加速到800MeV。介绍了慢加速的理论依据及储存环主电源控制系统的硬件结构,详细描述了束流软慢加速方法中的慢加速表计算及慢加速过程控制。机器运行结果表明:软慢加速方法控制灵活,慢加速过程运行平稳,束流损失很少,能很好地满足合肥光源机器运行和研究的需要。     

Lattice study for the HLS-Ⅱ storage ring

The Hefei Light Source (HLS) is undergoing a major upgrade project, named HLS-Ⅱ, in order to obtain lower emittance and more insertion device straight sections. Undulators are the main insertion devices in the HLS-Ⅱ storage ring. In this paper, based on the database of lattice parameters built for the HLS-Ⅱ storage ring obtained by the global scan method, we use the quantity related to the undulator radiation brightness to more directly search for high brightness lattices. Lattice solutions for achromatic and non-achromatic modes are easily found with lower emittance, smaller beta functions at the center of the insertion device straight sections and lower dispersion in non-zero dispersion straight sections compared with the previous lattice solutions. In this paper, the superperiod lattice with alternating high and low horizontal beta functions in long straight sections for the achromatic mode is studied using the multiobjective particle swarm optimization algorithm.