上海光源储存环直流流强监测系统设计

上海光源储存环调试运行需要一个分辨率达到微安量级的直流流强监测系统.为此设计完成的硬件系统包含一个Bergoz公司NPCT型探头、一个NI公司PXI总线数字电压表模块以及一个PXI总线的输入输出控制器.数据采集处理软件在LabVIEW平台上开发,与控制系统的接口通过EPICS Shated Memory IOCcore技术实现.实验室测试及仿真结果表明该系统直流流强测量分辨率可达2微安,束流寿命相对测量精度可望达到0.5%.     

单束团运行模式下影响直流流强检测器的机理分析及改进措施

分析了合肥８００ＭｅＶ电子储存环束团运行模式下影响直流流强检测器的机理,并提出了几种改进措施。采用了增加陶瓷狭缝电容的措施,保证了ＤＣＣＴ在单束团工作模式下的正常工作,并给出了测试结果。     

应用数据挖掘的束流流强预测

文章简要介绍数据挖掘技术。在详细分析束流流强曲线特点和束流流强曲线与历史曲线的相似性基础上，提出了1种基于数据挖掘中时间序列相似性研究的束流流强预测方法，并将其运用到合肥光源运行数据分析中。试验结果表明，该方法是有效的，能够满足运行要求。     

合肥光源200MeV直线加速器束流流强测量系统的改进

用ＰＣ机经扩展机箱完成对８路束流信号的采集,处理,并可同时显示,打印全部８路束流流强信号于一幅,也可任选其中一路帮单幅放大显示,此设备提高了直线加呸器束流流强信号的测量精度,并方便了直线加速器调机人员的操作。     

上海光源DCCT系统置信度算法

介绍上海光源直流流强监测系统数据可靠性指标评估方法。建立DCCT系统的卡尔曼(Kalman)滤波模型,预测DCCT系统实测数据的真值。通过对DCCT系统数据的统计分析,定义数据的置信度阈值,编程实现在线的数据置信度评估及置信度指标的发布,实时给出束流流强、寿命数据置信度因子,提高系统可用性。     

CYCIAE-100的直流流强监测器研制及实验验证

100 MeV强流质子回旋加速器（CYCIAE-100）加速H^-,引出质子束能量为75~100 MeV、最大束流强度为200 μA。为对束流输运线上的质子束流强度进行无阻挡实时监测,选择了直流流强监测器（DCCT）,其在设计上考虑了空间限制、杂散磁场和外部高频干扰信号等因素对探头的影响。探头外采用了三重磁屏蔽设计,磁屏蔽外为1层黄铜的电屏蔽。采用了绝缘垫圈隔断束流输运线的直流导电性,束流输运线管壁通有冷却水以保证探头温度稳定。在绝缘垫圈处增加电容以满足探头对电容值的要求。采用高精度PLC-AI模块对DCCT的输出电压进行了读取。通过模拟束流的实验验证表明,DCCT设计合理可行,测量结果的线性度、误差等指标符合设计要求。     

上海光源直线加速器的弱流强运行

上海光源(SSRF)直线加速器正常运行时,重复频率2 Hz,单束团脉宽1 ns,电荷量1 nC。近年来,国际同步辐射领域发展起来的恒流注入模式要求直线加速器以弱流强运行,在相同的重复频率和脉宽下,单脉冲电荷量越小越好,此方法重复性较好。本文在理论计算基础上,结合实验,给出了弱流强稳定运行的实现方法,确定了在Top-up模式下,直线加速器的脉冲电荷量为0.1 nC。     

^60Co集装箱检测系统直流模式下图像模糊问题的研究

对＾６０Ｃｏ集装箱检测系统直流工作模式和时间响应特性对系统输出的影响机制进行了理论分析,从理论上推导了＾６０Ｃｏ集装箱检测系统的冲击响应,并利用理论推导结果对集装箱图像进行了反卷积处理,该处理对改善图像质量有明显的效果。     

低能强流离子束装置计算机控制系统

为实现低能强流离子束装置自动化,提高抗干扰能力和稳定度,研究开发了低能强流离子束装置计算机控制系统。该控制系统采用西门子S7 300PLC,下位机使用STEP7V5组态软件进行编程,控制界面用LabWindows/CVI6.0编制,控制位于3个不同电位的离子束系统。文章描述了控制系统的总体结构、硬件选取和软件实现的功能,讨论了系统在调试过程中抑制干扰的方法。     

100MeV强流回旋加速器径向靶的研制

在100MeV强流回旋加速器调试过程中,需对束流在加速器内的轴向和径向参数进行测量。径向靶系统是束流诊断系统中用于获取上述参数的主要部件,本文研制了3套阻挡式径向靶系统,并安装到加速器主体,获得了束流在连续加速过程中的轴向和径向分布,为加速器运行提供了相应束流参数,并为后续加速器升级工作提供了必要的条件。     

A real-time beam loss monitoring system for storage ring of SSRF

In this paper we report the real-time beam loss monitoring (BLM) system at the storage ring of SSRF.The BLM-XS detectors and Ethernet data acquisition system are used in this system.Some applications and experiments of the BLM system are also presented.The BLM system provides dynamic information of beam loss for the storage ring,and is helpful to ensure the facility commissioning,investigate the problems of machine,optimize the machine parameters and further increase the beam lifetime.     

Baseline recovery method to measure bunch charge under low-current mode of SSRF

The top-up injection mode of Shanghai Synchrotron Radiation Facility(SSRF) needs precise measurement of the beam bunch charges.This is performed by an integration current transformer,but the beam current is too low to neglect the background noise.In order to wipe out the noise coming from the ground loops,the adaptable polynomial fitting method is used to extract the baseline,instead of using the constant background or the linear background model. Test results show that the system resolution can be improved to <3%.     

Development of the bunch-by-bunch beam current acquisition system at SSRF

In this paper, we report the development of a bunch-by-bunch beam current acquisition system. Through a waveform-reconstruction algorithm, the system realizes high equivalent sampling rate with a relatively low inherent rate. Based on the EPICS environment, information communication with other systems can be achieved. Preliminary test results in commissioning the SSRF storage ring show that the system can reconstruct the beam waveform of single bunch, providing a convenient and reliable method for the top-up operation in the future.     

基于软件无线电的新型数字束流位置处理器

研究了基于软件无线电架构的新型数字束流位置处理器,介绍了处理器样机的射频、模数转换和数字处理模块的硬件架构和主要参数。针对处理器多通道的不对称性,提出了校准方案。测试结果表明,处理器逐圈位置电子学分辨率在输入大于–30 dBm时,优于1.5μm;输入大于–27 dBm时,电子学分辨率达到亚微米量级。处理器在上海光源储存环流强为150 mA条件下测试,逐圈位置分辨率优于2μm,并能够准确获取包含束流实时信息的逐圈位置信号。     

A beam position measurement system of fully digital signal processing at SSRF

This fully digital beam position measurement instrument is designed for beam position monitoring and machine research in Shanghai Synchrotron Radiation Facility. The signals received from four position-sensitive detectors are narrow pulses with a repetition rate up to 499.654 MHz and a pulse width of around 100 ps, and their dynamic range could vary over more than 40 dB in machine research. By the employment of the under-sampling technique based on high-speed high-resolution A/D conversion, all the processing procedure is performed fully by the digital signal processing algorithms integrated in one single Field Programmable Gate Array. This system functions well in the laboratory and commissioning tests, demonstrating a position resolution (at the turn by turn rate of 694 kHz) better than 7 μm over the input amplitude range of -40 dBm to 10 dBm which is well beyond the requirement.     

磁调制DCCT调制噪声及测量方法研究

硬X射线自由电子激光装置要求电源输出电流分辨率优于2.5×10^-6,因此,直流电流互感器（DCCT）的分辨率也必须高于以上指标,而降低DCCT调制噪声是提高其分辨率的重要方法。为降低调制噪声,本文提出了一种调制噪声的数学模型,导出了磁调制噪声的近似表达式,分析了调制噪声与相关因素的关系。同时提出了一种调制噪声的评估方法,该方法利用Matlab的periodogram命令获得噪声功率谱。利用数学模型和评估方法分析了Sinap-DCCT产品的噪声特征,结果表明,调制噪声与相关因素的关系符合数学模型的推论。据此,给出了降低DCCT调制噪声的解决方向。     

Development of the bunch-by-bunch beam position acquisition system based on BEEcube

In this paper, we report the development of a bunch-by-bunch beam position acquisition system.Through a wideband synthesizer of PLL, the system realizes synchronous clock of bunch signal. Based on the highperformance FPGA hardware DAQ environment, fourchannel raw data of beam signal can be achieved. Test results in the SSRF storage ring show that the system can obtain beam position of single bunch with the resolution of10 lm and multi-bunch instability can be observed.