合肥光源交错刀片型光位置检测器的研制

为了减小同步光尺寸对同步光位置检测器灵敏度的影响,合肥光源新研制了一种交错刀片型光位置检测器,并使用成熟的商业化产品Libera Photon进行后续的数据处理和输出。基于传统计算光位置信号的差比和方法,提出了比值和对数比两种新的计算方法,理论模拟了3种计算方法下交错刀片型光位置检测器的性能。在线标定结果与理论计算结果相符,并在机器研究光束线进行了初步的应用研究。     

HLS Ⅱ储存环条带束流位置检测器的离线标定

针对合肥光源二期改造工程设计了一条带束流位置检测器(BPM), 用于储存环中束流参数在线测量。对条带BPM进行了位置信号的离线标定,采用差比和法和对数比法进行计算,获得了灵敏度系数、映射图和拟合经验多项式,发现采用对数比法得到的灵敏度大小和线性范围好于差比和法。对和信号进行离线标定,发现和信号相对中心位置处的归一化值在(-5 mm, -5 mm)到(5 mm, 5 mm)范围内变化不超过6%。该条带BPM也用来测量合肥光源储存环上束团横向四极振荡,所以需对横向四极分量进行标定。采用二维网格结构高斯加权法模拟高斯束团,使用差比和法进行计算,并将测量结果与模拟结果比较,发现横向四极分量随 (x2-y2)线性变化的灵敏度与模拟结果相同,均为0.001 1 mm-2。得到的拟合经验公式用于在线测量。     

HLS-Ⅱ储存环工作点测量系统的开发（英）

介绍了在合肥光源重大维修改造工程期间,开发的一套基于扫频激励法的工作点测量系统。测量系统硬件包括基于条带BPM的信号拾取电极、前端信号调理模块、一台带跟踪输出的信号分析仪N9000AEP、功率放大器以及用于激励束流的条带激励器。系统控制软件采用EPICS开发,基于EPICS Stream Device设计的输入输出控制器(soft IOC)运行在服务器虚拟机中,通过VXI11协议进行通信实现对信号分析仪的控制和数据获取;用户操作界面采用EPICS平台下的EDM开发,通过Channel Access与IOC通信。在HLS-II储存环上对工作点测量系统进行了在线的调试。调试结果说明,在扫频范围为2.1 MHz到4.1 MHz时,工作点测量系统的统计分辨率在水平方向上好于0.000 3,在垂直方向上好于0.000 2。     

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。     

HLSⅡ新的注入器束流强度测量系统

合肥光源升级改造任务已基本完成,注入器实现满能量注入。为适应新的注入器束流强度的测量需求,设计了新的注入器束流强度测量系统,该系统利用安装在真空腔上的3个快速束流变压器(FCT)和2个积分束流变压器(ICT),能够实现束流流强和电荷量的非拦截实时测量。为了准确获取束流参数,首先对束流变压器(CT)传输电缆进行了在线和离线标定;由于ICT输出信号信号幅度较小,噪声大,设计了低噪声前置放大器以改善信噪比;考虑低频谐波噪声和Kicker噪声的干扰,软件中通过适当的算法对噪声进行了处理;最后给出了部分在线实验结果。实验结果表明,束流传输效率约为27.4%,注入效率约为44.3%。     

A study of pickup and signal processing for HLS-Ⅱ bunch current measurement system

For the HLS-Ⅱ bunch current measurement system, in order to obtain the absolute value of bunch current, the calibration factor should be determined by using DCCT. At the HLS storage ring, the stretch effect of bunch length is observed and the change rate is about 19% when the bunch current decays over time and this will affect the performance of bunch current detection. To overcome the bunch stretch influence in the HLS-Ⅱ bunch current measurement, an evaluation about pickup type and signal processing is carried out. Strip-line pickup and button pickup are selectable, and the theoretical analysis and demonstration experiment are performed to find out an acceptable solution for the bunch current measurement system at HLS-Ⅱ. The experimental data analysis shows that the normalized calibration factor will change by about 27% when the bunch length changes by about 19% if using the button pickup and processing by peak value of bunch signal; the influence will be reduced to 2% less if adopting the strip-line pickup and integral.     

A study of pickup and signal processing for HLS- bunch current measurement system

For the HLS-bunch current measurement system,in order to obtain the absolute value of bunch current,the calibration factor should be determined by using DCCT.At the HLS storage ring,the stretch efect of bunch length is observed and the change rate is about 19% when the bunch current decays over time and this will afect the performance of bunch current detection.To overcome the bunch stretch influence in the HLS-bunch current measurement,an evaluation about pickup type and signal processing is carried out.Strip-line pickup and button pickup are selectable,and the theoretical analysis and demonstration experiment are performed to find out an acceptable solution for the bunch current measurement system at HLS-.The experimental data analysis shows that the normalized calibration factor will change by about 27% when the bunch length changes by about 19% if using the button pickup and processing by peak value of bunch signal;the influence will be reduced to 2% less if adopting the strip-line pickup and integral.