Phase control system for SSRF linac

The design of phase control system in Shanghai Synchrotron Radiation Facility (SSRF) linac is presented in this paper. And digital phase detecting algorithm, the key for phase control system, is fully described. The testing results for phase control system in 100MeV linac are discussed in detail.     

基于162.5 MHz HWR超导腔的氦压调谐器的设计与测试

162.5 MHz(?=0.10)半波长谐振型(Half Wave Resonance,HWR)超导腔被用于CIADS(China Initiative Accelerator Driven System)项目注入器II的低能段。氦气压力驱动式调谐器基于上述腔体的调谐范围及机械性能要求进行设计制造。为确保调谐器运行良好,进行了常温测试。铜制模型腔测试中调谐范围达到640 k Hz,满足频率调节范围要求。铌腔测试中得到腔体频率与气体压力关系,调谐敏感度为0.272 k Hz·h Pa-1。采用气体质量流量控制方案并搭建气体驱动控制平台进行分辨率测试,在测试结果显示调谐器满足调谐分辨率要求,分辨率精度达到4.4–15 Hz。计算了超导腔与调谐器间的传热量,其值不超过0.002 W,小于低温恒温器与调谐器之间的热辐射量,表明此调谐器可用于HWR腔体。     

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.     

Frequency control and pre-tuning of a large aperture 500 MHz 5-cell superconducting RF cavity

The 500 MHz 5-cell superconducting RF(SRF) cavity was designed aiming to be a candidate cavity for high current accelerators. A copper prototype cavity and a niobium cavity were fabricated at SINAP in 2012. In order to ensure these cavities get the desired frequency and a good field flatness higher than 98%, frequency control was implemented in the manufacturing process and pre-tuning has been done using a simple pre-tuning frame based on the bead-pull pre-tuning method. Then, TM010-π mode frequency within 5 kHz from the target frequency was achieved and the field flatness reached 98.9% on the copper prototype cavity. Finally, the same procedure was applied to the niobium cavity to obtain a field flatness better than 98% which benefited the cavity performance in the vertical testing.     

Design of large aperture 500 MHz 5-cell superconducting cavity

With the potential application of Energy Recovery Linac (ERL), the superconducting (SC) cavities were developed to deliver much higher current than before. Nowadays, the current of the international SC accelerator designed has already exceeded 100 mA. This paper presents the design of a new 500 MHz 5-cell SC cavity (SINAP 5-cell cavity), in which the parameters r/Q= 515.5 of the fundamental mode and the geometry factor G=275.8 are under an acceptable Radio Frequency (RF) field level (B peak /E acc =4.31 mT/MV/m and E peak /E acc =2.48). This design employs a larger beam pipe to propagate the Higher Order Modes (HOMs) out of the cavity and increases the damping efficiently for the dangerous HOMs. By simulation technique, it has been found that almost all the dangerous HOMs (including TE 111 , TM 110 , and TM 011 ) can be propagated into the beam pipe and are absorbed by ferrite absorbers, when the beam pile is enlarged. Finally, the loss factor for the new 5-cell cavity is also calculated.     

1500MHz 5-cell超导腔的仿真优化

能量回收直线加速器技术是近年来一项重要技术。针对能量回收直线加速器的主直线加速器,本文使用多种射频软件优化设计了一种新型的1 500 MHz 5-cell超导腔。该腔加速模TM010的R/Q值达到550Ω,可以有效降低低温损耗。该腔的端cell采用扩大束管传输有害高次模方案将高次模传输出超导腔,良好地抑制了高次模。新腔型保持了较低的表面峰值场强与平均加速梯度的比值:Epk/Eacc=2.06,Bpk/Eacc=4.22 m T/(MV·m-1),避免了场致发射的风险,并且在中等加速梯度区域(15-20 MV·m-1)无二次电子倍增现象。模拟结果显示,该超导腔能够满足连续波、准连续波或高重复频率稳定运行的要求。     

DeviceNet in SSRF control system

In the process of making preliminary design for the Shanghai Synchrotron Radiation Facility(SSRF) control system,we designed and implemented the fieldbus DeviceNet for communication between IOCs(I/O Controller)and device controllers,DeviceNet,as an open network standard,provides application layer protocol(IOS/OSI layer 7) and thus can transparently connect devices and IOCs without any need for network programming.The application of the DeviceNet to the EPICS(Experimental Physics and Industrial Control System) based control system are described.     

SSRF定时系统的温漂补偿系统设计

上海同步辐射装置(SSRF)的定时信号通过光纤由事件发生器EVG发送到事件接收器EVR,为各个分系统和设备提供精确时序信号,但光纤因SSRF复杂的局部环境而产生温度变化,从而引起EVR的输出信号与高频信号的相位漂移.因此需设计-套温漂补偿系统来补偿这种因光纤的温度变化而产生的相位漂移,本文详细阐述了温漂补偿系统的硬件架构及相位测量算法,最后给出了温漂补偿系统的测试结果.     

上海同步辐射装置电源控制系统

上海同步辐射装置电源控制系统是基于EPICS系统开发运行的分布式控制系统。系统中~65 K实时数据库记录分布运行于27个VME总线的IOC控制器中,实现了对600多台各类磁铁电源的访问控制。本文介绍了电源控制系统基于Ethernet的层次式结构与工作原理,分别描述了针对PSI与SINAP电源控制器的控制解决方案,同时介绍了系统的硬件设备、IOC和控制台软件及系统中采用的通讯技术。     

An on-line data acquisition system of oscilloscope-embedded input/output controller for cavity BPM measurement

Cavity beam position monitor(BPM) is widely used in a precise electron beam position measurement. Based on high performance oscilloscope-embedded EPICS input/output controller,we developed an on-line cavity BPM signal processing system for fast data acquisition solution when designing a cavity BPM.Also,methods for extracting the position information from cavity pickup signals and calibration algorithm are included in this solution.     

上海光源2998 MHz加速管波导耦合器的设计

上海同步辐射光源(SSRF, Shanghai Synchrotron Radiation Facility)直线加速器采用2998 MHz的加速管,这种加速管在结构形式上虽然与SLAC型2856 MHz加速管相似,但在尺寸上略有差异,需要重新计算.本文采用与实际调试加速管时相同的三频法、有限差分分析软件Superfish和HFSS对2998 MHz加速管耦合器进行物理设计,为实际工程设计提供指导.物理设计与实验测试结果非常吻合.     

一种γ辐照装置安全联锁系统的设计

为了改进一座γ辐照装置的安全性能,使之符合相关标准的要求,设计了一种基于可编程控制器的联锁系统.通过梯形图编程设计实现了顺序巡视、延时、异常报警等功能.结果表明:可编程柔性设计有利于完善系统的安全性.     

SSRF高频低电平系统预制研究

上海同步辐射装置(SSRF)预研阶段完成了一套500MHz高频系统的低电平控制系统,它主要由信号源、速调管的激励控制、三个反馈控制环路和连锁保护构成。本文重点介绍三个反馈环路的设计、测量和调试结果。     

SSRF电子枪控制系统的设计与实现

电子枪是上海光源SSRF(Shanghai Synchrotron Radiation Facility)中的直线加速器的关键部件,上海光源的束流品质很大程度上取决于电子枪的束流指标,因此电子枪需要一个稳定的控制系统来保证其可靠运行.本文介绍了上海光源电子枪控制系统的设计与实现过程.该系统底层采用可编程控制器PLC(Programmable Logic Controller)作为设备控制器,上层监控软件使用加速器控制系统通用软件EPICS (Experimental Physical and Industrial Control System),整个控制系统基于以太网连接.PLC和以太网技术的应用,使该系统具有可靠性好、易于维护等特点.     

Measurement system for SSRF pulsed magnets

This paper describes the magnetic field measurement system for pulsed magnets in SSRF.The system consists of magnetic probes,analog active integrator,oscilloscope,stepper motor and a controller.An application pro- gram based on LabVIEW has been developed as main control unit.After the magnetic field mapping of a septum magnet prototype,it is verified that the test results accord with the results of theoretical calculation and computer simulation.     

腔式束流位置探测器的设计与实验研究

束流位置探测器对自由电子激光装置的研制和运行具有重要的意义。其中,腔式束流位置探测器(腔式BPM)又以其高精度、高分辨率的特点而得到广泛的应用。本文对应用于上海深紫外自由电子激光装置上的腔式BPM进行了理论分析、模拟计算和BPM腔的测量等方面的研究。     

工频倍加型电子束辐照装置的调压控制

改进了调压控制系统以实现工频倍加型电子加速器的高压稳定调节。该系统采用伺服电机驱动柱式调压器进行调压,可编程控制器作为逻辑控制单元,工控机实现人机交互,采用闭环和开环方式实现高压调节控制。实验证明,该控制系统的响应速度、稳定度及调压精度较传统调压系统均有较大改进,能满足性能要求更高的电子加速器的控制要求。     

上海光源X射线针孔相机控制系统设计

采用美国NI公司的PXI-7344运动控制卡对衰减片进行控制;通过RS232协议控制小孔四维移动平台和相机二维移动平台的运动,实现对小孔位置、倾角和相机位置的调节;NI公司的PXI-8252板卡用于1394相机的图像采集.所有控制功能均有机地集成于LabVIEW界面中,实现各部件的协调配合运动,并通过EPICSShar...     

Simulation of higher order modes and loss factor of a new type of 500-MHz single cell superconducting cavity at SSRF

In this paper,higher order modes(HOMs) and loss factor of a new type of 500-MHz superconducting cavity is studied,by simulating its broadband HOMs damping at different positions of the ferrite HOM-absorber and different lengths of the ferrite.The results show that the impedance and Q value of the HOMs in transverse and longitudinal modes could be greatly reduced.The HOM longitudinal impedance could be damped to meet the requirement of SSRF beam instability threshold.The calculated loss factor of the new SC cavity was compared with cavities at SSRF.It was estimated that the HOM absorber could absorb a total power of 3.16 kW at 4-mm beam bunch length.     

可编程逻辑控制系统在北京自由电子激光装置的实验物理和工业控制系统中的应用

在北京自由电子激光(BFEL)装置的搬迁改造工程中,开关机系统的控制采用基于实验物理和工业控制系统(EPICS)的可编程逻辑控制(PLC)控制系统,它具有安全可靠、操作简单、易于扩展、便于通讯等优点.本文介绍了该控制系统的设计和开发,包括系统软硬件的结构设计以及系统的EtherNet/IP网络通讯.