BEPCⅡ直线定时系统光信号收发器的研制

定时系统为BEPCⅡ直线电子枪、调制器和正电子源等设备提供精确的同步触发信号.因光纤介质的传输损耗低,使用光纤收发器传输同步触发脉冲信号,不但可以实现信号的远距离传输,同时保障了信号的电气隔离,增强了系统抗噪声能力.目前,自主研发的OTB插件已经投入了BEPCⅡ的直线定时系统的运行,结果表明系统性能达到并优于定时系统的设计指标.     

BEPCII基于数字采样的鉴相器设计

在北京正负电子对撞机重大改造项目(BEPCII)中,定时系统承担的任务是对储存环以及直线的各部分设备提供同步信号,从而协调整个对撞机系统的正常运行。描述了BEPCII定时系统鉴相器的设计原理和误差分析。该鉴相器用于对BEPCII不同途径传输的两路499.8MHz信号的相位进行鉴别。采用纯数字电路,不受温度以及湿度影响。且鉴相精度在1o以内。     

上海光源线站ps精度定时系统设计

为满足上海光源线站工程ps时间分辨科学研究需求,设计了ps精度定时系统。定时系统采用事件定时原理产生与射频时钟信号共相位的时钟信号、光纤传输网络用于时钟信号传输,并在EPICS软件控制架构下,产生高精度可控时钟同步信号序列,根据不同的同步控制需求,为激光器、探测器等被同步设备提供触发信号。研究结果表明:定时系统的硬件同步触发抖动为3.360 ps、延迟步长精度为3.703 ps,可实现10 ps时间分辨实验的同步控制。     

BEPCII直线加速器定时系统

北京正负电子对撞机升级改造工程BEPCII的重要组成部分--直线加速器于2006年7月通过了所内预验收,其中定时系统是全新建造的基于EVG/EVR的事件定时系统[1],于2006年3月起投入运行,为直线加速器的电子枪、微波激励源、能量倍增器、正电子源、调制器、BPM等设备提供精确的时序触发信号.本文介绍直线加速器定时系统的研制、安装调试、运行和改进等工作情况.     

光纤在合肥同步辐射装置新时序系统定时信号传输中的应用

本文讨论一种利用高速光纤传输定时精度，低重复率触发信号的方法，此方法在两相邻定地脉冲的时间间隔加入周期脉冲，在接收端剔除叠加的周期脉冲，检出定时脉冲，解决了由于光接收器低端截止频率高于定时脉冲频率的矛盾。     

EAST分布式定时同步系统的实现

分布式定时同步系统在国家大科学工程EAST中有重要作用,它用于同步EAST各子系统精准投入实验的时序。分布式定时同步系统利用PXI工业级设备并结合虚拟仪器技术实现定时同步系统,可提供1 Hz～80 MHz频率的参考时钟信号,产生1 ms～6 872 s延迟触发信号（精度达10 ns）。该系统能采集信号,并能根据检测的信号实时触发相应处理机制。分布式定时同步系统精度高且运行稳定可靠,已成功应用于2010年秋季EAST放电实验。     

BES Ⅲ触发系统与TOF读出电子学系统控制信号的远距离传输

介绍了BESⅢ改造工程中主触发系统与飞行时间计数器电子学系统之间的控制命令以及状态信号的远距离同步传输问题的解决方案。该电路基于高速光纤传输,采用现场可编程门阵列芯片和专用芯片,具备自动纠错和从错误中自动恢复的能力,设计可靠、灵活,通过测试证明符合北京谱仪的需求。     

BES III触发系统与TOF读出电子学系统控制信号的远距离传输

介绍了BES Ⅲ改造工程中主触发系统与飞行时间计数器电子学系统之间的控制命令以及状态信号的远距离同步传输问题的解决方案。该电路基于高速光纤传输,采用现场可编程门阵列芯片和专用芯片,具备自动纠错和从错误中自动恢复的能力,设计可靠、灵活,通过测试证明符合北京谱仪的需求。     

BEPCⅡ基于数字采样的鉴相器设计

在北京正负电子对撞机重大改造项目(BEPCⅡ)中,定时系统承担的任务是对储存环以及直线的各部分设备提供同步信号,从而协调整个对撞机系统的正常运行.描述了BEPCⅡ定时系统鉴相器的设计原理和误差分析.该鉴相器用于对BEPCⅡ不同途径传输的两路499.8MHz信号的相位进行鉴别.采用纯数字电路,不受温度以及湿度影响.且鉴相精度在1°以内.     

新型定时系统设计

大型加速器系统中,事件定时系统广播确定性数据,即事件发生器(EVG)传递定时信号给事件接收器(EVR).如EVR能彼此通讯,定时和实时数据传输两个功能就集成在一个系统中.新型定时系统是一种实时同步数据总线,可实现上述功能.本文描述了新型定时系统的系统结构、硬件设计和规格,包括定时脉冲的精度、定时脉冲相对于高频时钟的时间晃动及实时数据的传输速率进行了说明.另外,系统还特别考虑了拓扑结构的冗余性和对光纤长度的补偿.新型定时系统的硬件初步设计和实验室测试已完成.     

合肥光源谐波法束团长度测量系统研制

同步辐射光与束流信号具有相同的时间结构,测量同步辐射光并基于频域的信号处理方法可得到束团的长度。基于该原理,研制了采用谐波法测量束团长度的系统。该系统用高速光电接收器将同步光转换为电信号,然后采集该信号的四路频率分量,计算得到束团长度。阐述了该系统的软硬件设计,并应用该系统测量了束团长度随流强的变化规律,与条纹相机的测量结果相吻合。     

一台微秒级脉冲辐解装置

本文介绍了一台自行研制的微秒级脉冲辐解实验装置。该装置利用一台5MeV辐照用电子直线加速器作脉冲辐射源,电子束脉宽2μs,流强200mA。采用动力学分光光度法探测瞬态产物的光吸收。利用单板机和瞬态信号记录仪进行数据采集和实施时序同步控制。整个装置的时间分辨率为2μs,探测的光谱范围为200—800nm,探测灵敏度为5×10~(-4)OD值。     

A MCM-D-type module for the ATLAS pixel detector

For the ATLAS experiment at the planned Large Hadron Collider (LHC) at CERN hybrid pixel detectors are being built as innermost layers of the inner tracking detector system. Modules are the basic building blocks of the ATLAS pixel detector. A module consists of a sensor tile with an active area of 16.4 mm×60.4 mm, 16 read out ICs, each serving 24×160 pixel unit cells, a module controller chip, an optical transceiver and the local signal interconnection and power distribution busses. The dies are attached by flip-chip assembly to the sensor diodes and the local busses. In the following a module based on MCM-D technology will be discussed and prototype results will be presented     

Time structure measurement of the SSRF storage ring using TRXEOL method

In order to do alignment between the timing signal and the synchrotron X-ray pulse on the sample spot in the time domain,measuring time structure of the storage ring on the sample spot inside the experimental hutch is a foundational step during the time-resolved experiments using the pulsed synchrotron X-rays with the time structure defined by the storage ring.In this work,the method of time-resolved X-ray excited optical luminescence(TRXEOL)was designed and implemented to do the measurement.It is based on the principle of time-correlated single photon counting techniques.The measurement system consists of a spectrometer with a detector of photomultiplier tube,a timing system,a set of nuclear instrument modules and a luminescent material of zinc oxide.The measurement was performed on the X-ray absorbed fine structure spectrum beamline at Shanghai Synchrotron Radiation Facility.The results show that this method can be used to measure the time structure of the storage ring with a precision of less than 1 ns.The measurement system can also be used for the time-resolved research for the optical luminescent materials.     

Analysis of electro-optical intensity modulator for bunch arrival-time monitor at SXFEL

A bunch arrival-time monitor(BAM) based on an electro-optical intensity modulation scheme is currently under development at Shanghai Soft X-ray Free-Electron Laser to meet the high-resolution requirements for bunch stability. The BAM uses a radio frequency signal generated by a pickup cavity to modulate the reference laser pulses in an electro-optical intensity modulator(EOM), and the bunch arrival-time information is derived from the amplitude change of the laser pulse after laser pulse modulation.EOM is a key optical component in the BAM system.Through the basic principle analysis of BAM, many parameters of the EOM are observed to affect the measurement resolution of the BAM system. Therefore, a systematic analysis of the EOM is crucial. In this paper, we present two schemes to compare and analyze an EOM and provide a reference for selecting a new version of the EOM.     

基于软核的数字化多道脉冲幅度分析器

介绍了一种数字化多道脉冲幅度分析器(DMCA),该系统采用数字梯形滤波成形等数字信号处理方法进行核脉冲信号处理,采用NOISII软核处理器进行数据处理,所有数字功能均在单片FPGA中实现。测试表明,该系统转换增益可达4 096道,最大脉冲通过率可达200 kcps以上。     

高分辨小型伽玛相机的数据采集触发电路

本文设计了一个数据采集触发电路,把伽玛相机位置读出信号的峰位检测转化为精度高的过零定时测量.该采集触发电路将输入信号全通滤波成形为一个有过零点的双极性信号,检测其过零点的位置检测峰位,产生触发脉冲,由单稳态触发器调节脉冲的脉宽和延时,用于后端数据采集系统的启动信号.实验证明:该触发电路性能稳定,对信号峰位的定时精度高,适用于高分辨小型伽玛相机的模块化开发.     

TDC-GPX-based synchronization scheme for QKD system

To meet the needs of signal alignment between the transmitter and receiver in a quantum key distribution(QKD) system, we put forward a TDC-GPX-based synchronization scheme, which is based on high-precision time measurement. We send a low-frequency repeat optical pulse synchronized with associated quantum signals on the receiver's side by using a time-to-digital converter(TDC)module, the time intervals between quantum signals, and synchronization signals measured and converted to corresponding temporal orders to complete the synchronization.We state the principle of the synchronization scheme in detail and then verify it in an actual QKD test bed. The test results show that our TDC-GPX-based synchronization can obtain a time resolution better than 100 ps, and the proposed scheme shows full feasibility for an actual QKD system.     

A new digital Gaussian pulse shaping algorithm based on bilinear transformation

Nuclear pulse signal needs to be transformed to a suitable pulse shape to remove noise and improve energy resolution of a nuclear spectrometry system. In this paper, a new digital Gaussian shaping method is proposed.According to Sallen-Key analog Gaussian shaping filter circuits, the system function of Sallen-Key analog Gaussian shaping filter is deduced on the basis of Kirchhoff laws. The system function of the digital Gaussian shaping filter based on bilinear transformation is deduced too. The expression of unit impulse response of the digital Gaussian shaping filter is obtained by inverse z-transform. The response of digital Gaussian shaping filter is deduced from convolution sum of the unit impulse response and the digital nuclear pulse signal. The simulation and experimental results show that the digital nuclear pulse has been transformed to a pulse with a pseudo-Gaussian, which confirms the feasibility of the new digital Gaussian pulse shaping algorithm based on bilinear transformation.     

新型超快光电辐射探测器研制

针对超快脉冲辐射测量的需求,开发了一种具有超快时间响应、大线性电流输出的新型光电探测器件——超快大电流光电管。利用脉冲氙灯、飞秒激光器对该光电探测器件的最大线性电流输出、时间响应等特性参数进行了实验测量。同时,利用该探测器件与超快闪烁体耦合构成的超快脉冲辐射探测器对亚纳秒脉冲X射线源时间谱进行了测量。结果表明,该光电探测器件对脉冲的响应前沿为251ps、半高宽小于500ps,在其典型电压下具有3A以上线性电流输出,对于亚纳秒脉冲X射线束等脉冲辐射场的测量是一较为理想的探测器件。