Optimization of an in-vessel visible inspection system for a long-pulse operation in KSTAR

To monitor the global formation of shaped plasmas, motion, and damage to the internal structures of the vacuum vessel, an in-vessel visible inspection system has been developed and operated on the Korean superconducting tokamak advanced research (KSTAR) device. The system contributed much to research progress on KSTAR such as the plasma start-up, plasma wall interactions, edge-localized modes, and disruptions. Moreover the need to perform inspections became important with high plasma power operation because of the increased frequency of first wall damage following off-normal events. Therefore the system is being improved from its original concept, and its final goal is operation during steady-state operation of the tokamak. The system consists of three fast visible cameras and two light-emitting diode illuminators. They are designed to be controlled fully from the control room to provide inspection capability at any time during hostile operating conditions. In this paper, we describe the upgrade of the system and recent results of the visible inspection system with the images of the KSTAR discharges for the last four years. Finally, we discuss the technical issues for a long pulse steady-state operation.     

基于PCI接口的瞬态波形记录仪

阐述了一套基于PCI接口采样率达200M／s的瞬态波形记录仪的结构及其性能。该系统适用于对高速、宽带的瞬态信号进行数字化处理。     

BEPC试验束数据获取系统改进及离线数据分析

运行在BEPC电子直线加速器上的试验束,主要利用在线探测器和离线数据分析选择单粒子事例,满足多种单粒子束流试验.本文介绍了试验束改进后的数据获取系统,以及离线数据分析中的飞行时间谱分析,单粒子判选和粒子击中位置定位等.     

Design of FPGA based high-speed data acquisition and real-time data processing system on J-TEXT tokamak

Tokamak experiment requires high-speed data acquisition and processing systems. In traditional data acquisition system, the sampling rate, channel numbers and processing speed are limited by bus throughput and CPU speed. This paper presents a data acquisition and processing system based on FPGA. The data can be processed in real-time before it is passed to the CPU. It provides processing ability for more channels with higher sampling rates than the traditional data acquisition system while ensuring deterministic real-time performance. A working prototype is developed for the newly built polarimeter–interferometer diagnostic system on the Joint Texas Experimental Tokamak (J-TEXT). It provides 16 channels with 120 MHz maximum sampling rate and 16 bit resolution. The onboard FPGA is able to calculate the plasma electron density and Faraday rotation angel. A RAID 5 storage device is adopted providing 700 MB/s read–write speed to buffer the data to the hard disk continuously for better performance.     

Water-cooling effects on the high-voltage and long-pulse capabilities of the KSTAR ICRF antenna

A new ICRF antenna originating from the prototype antenna was constructed for the KSTAR tokamak in 2002. The performance of the antenna was experimentally estimated at the RF test stand without a plasma. Recently three series of RF tests were performed at a frequency of 30 MHz; without any cooling, with a water-cooling for only the antenna, and with a water-cooling of the antenna and the transmission line connected to the antenna. In the tests, a half of the current strap was connected to a RF source via a matching circuit with the other half one connected to an open terminated coaxial line, and the other three straps were shorted at the input ports. During the RF pulse, the temperatures at several positions of the antenna cavity wall were measured by embedded thermocouples and the temperature profile of the front face of the antenna was measured by an IR camera. The line voltage, forward and reflected powers, and the RFTC pressure were also measured. The water-cooled antenna showed several enhanced performances in a comparison with the non-cooled case, and the standoff voltage was significantly increased. By utilizing a water-cooling of the antenna and the transmission line, we achieved a standoff voltage of 41.3 kVp for a pulse length of 300 s, and we could extend the pulse length up to 600 s at a maximum voltage of 35.0 kVp without encountering any problems, which considerably exceeds the design requirements.     

The PAN-DA data acquisition system

The VAXONLINE data acquisition package has been extended to include a VME-based data path. The resulting environment, PAN-DA, provides a high throughput for logging, filtering, formatting, and selecting events. The authors describe the history and rationale of the system, the VME hardware modules, PAN-DA systems coordination, and system connectivity     

The Aleph data acquisition system

Aleph is one of the four large high-energy physics experiments being completed for the LEP (Large Electron Positron) accelerator at CERN. Several hundred thousand detector elements deliver some 500 Mbytes of raw data per second. The author briefly describes the accelerator and the Aleph detector. He then discusses the design and implementation of the multilevel real-time data reduction and acquisition system, covering the requirements, the readout architecture, its implementation, data reduction, aspects of the detector-specific front-end electronics, and Aleph's present status and performance     

工业CT数据采集系统

工业CT机中需要对数百通道微弱光信号同时进行数据采集传输,本文介绍的系统是为满足这一要求而设计;系统采用FPGA 20位积分转化芯片模式构建探测部分,采用FPGA AMCCS5335模式主控采集部分;运用多级缓存机制解决了实际应用中出现的数据阻塞、丢失问题;该设计已应用于重庆大学ICT中心的多台工业CT机中,取得了良好的效果.     

The upgrade of the J-TEXT experimental data access and management system

The experimental data of J-TEXT tokamak are stored in the MDSplus database. The old J-TEXT data access system is based on the tools provided by MDSplus. Since the number of signals is huge, the data retrieval for an experiment is difficult. To solve this problem, the J-TEXT experimental data access and management system (DAMS) based on MDSplus has been developed. The DAMS left the old MDSplus system unchanged providing new tools, which can help users to handle all signals as well as to retrieve signals they need thanks to the user information requirements. The DAMS also offers users a way to create their jScope configuration files which can be downloaded to the local computer. In addition, the DAMS provides a JWeb-Scope tool to visualize the signal in a browser. JWeb-Scope adopts segment strategy to read massive data efficiently. Users can plot one or more signals on their own choice and zoom-in, zoom-out smoothly. The whole system is based on B/S model, so that the users only need of the browsers to access the DAMS. The DAMS has been tested and it has a better user experience. It will be integrated into the J-TEXT remote participation system later.     

基于CAMAC总线的交替式数据采集及实时监控系统研究

进行了一种称为交替式数据采集及实时监控系统的研究。该系统不仅能实现以较高频率进行任意时间的数据采集,还能在放电过程中以图形方式实时显示等离子体的各种参数供实验人员在线分析及控制。     

Application of HDF5 in long-pulse quasi-steady state data acquisition at high sampling rate

A new high sampling rate quasi-steady state data-acquisition system has been designed for the microwave reflectometry diagnostic of EAST experiments. In order to meet the requirements of long-pulse discharge and high sampling rate, it is designed based on PXI Express technology. A high-performance digitizer National Instruments PXIe-5122 with two synchronous analog input channels in which the maximum sampling rate is 100 MHz has been adopted. Two PXIe-5122 boards at 60 MSPS and one PXIe-6368 board at 2 MSPS are used in the system and the total throughput is about 500 MB/s. To guarantee the large amounts of data being saved continuously in the long-pulse discharge, an external hard-disk data stream enclosure NI HDD-8265 in which the capacity of sustained speed of reading and writing is 700 MB/s. And in RAID-5 mode its storage capacity is 80% of the total.The obtained raw data firstly stream continuously into NI HDD-8265 during the discharge. Then it will be transferred to the data server automatically and converted into HDF5 file format. HDF5 is an open source file format for data storage and management which has been widely used in various fields, and suitable for long term case. The details of the system are described in the paper.     

Commissioning and initial operation of KSTAR superconducting tokamak

The commissioning and the initial operation for the first plasma in the KSTAR device have been accomplished successfully without any severe failure preventing the device operation and plasma experiments. The commissioning is classified into four steps: vacuum commissioning, cryogenic cool-down commissioning, magnet system commissioning, and plasma discharge.Vacuum commissioning commenced after completion of the tokamak and basic ancillary systems construction. Base pressure of the vacuum vessel was about 3 × 10^?6 Pa and that of the cryostat about 2.7 × 10^?4 Pa, and both levels meet the KSTAR requirements to start the cool-down operation. All the SC magnets were cooled down by a 9 kW rated cryogenic helium facility and reached the base temperature of 4.5 K in a month. The performance test of the superconducting magnet showed that the joint resistances were below 3 nΩ and the resistance to ground after cool-down was over 1 GΩ. An ac loss test of each PF coil made by applying a dc biased sinusoidal current showed that the coupling loss was within the KSTAR requirement with the coupling loss time constant less than 35 ms for both Nb₃Sn and NbTi magnets. All the superconducting magnets operated in stable without quench for long-time dc operation and with synchronized pulse operation by the plasma control system (PCS). By using an 84 GHz ECH system, second harmonic ECH assisted plasma discharges were produced successfully with loop voltage of less than 3 V. By the real-time feedback control, operation of 100 kA plasma current with pulse length up to 865 ms was achieved, which also meet the first plasma target of 100 kA and 100 ms. The KSTAR device will be operated to meet the missions of steady-state and high-beta achievement by system upgrades and collaborative researches.     

基于AVR单片机与USB接口的高速多道核数据采集系统

介绍了多个探测通道组成的多道核数据采集系统,对4 MeV静电加速器核辐射进行监测防护.各个通道采用AVR单片机ATmega128作为主控制器,通过基于CH375构成的USB接口实现数据传输.经实验测试,该系统采集速度快,死时间小,计数率高.其探头部分在更换相应的探测传感器和稍作参数调整后,便可同时探测分析γ、X和快中子等不同的放射性辐射,适用于作为大范围场地的辐射监测系统.     

Design and operation results of nitrogen gas baking system for KSTAR plasma facing components

A baking system for the Korea Superconducting Tokamak Advanced Research (KSTAR) plasma facing components (PFCs) is designed and operated to achieve vacuum pressure below 5 × 10^?7 mbar in vacuum vessel with removing impurities. The purpose of this research is to prevent the fracture of PFC because of thermal stress during baking the PFC, and to accomplish stable operation of the baking system with the minimum life cycle cost. The uniformity of PFC temperature in each sector was investigated, when the supply gas temperature was varied by 5 °C per hour using a heater and the three-way valve at the outlet of a compressor. The alternative of the pipe expansion owing to hot gas and the cage configuration of the three-way valve were also studied. During the fourth campaign of the KSTAR in 2011, nitrogen gas temperature rose up to 300 °C, PFC temperature reached at 250 °C, the temperature difference among PFCs was maintained at below 8.3 °C, and vacuum pressure of up to 7.24 × 10^?8 mbar was achieved inside the vacuum vessel.     

氡室数据采集系统的设计

介绍了氡室数据采集系统的整体设计方案,各部分硬件结构组成,系统软硬件之间的结构框架,数据采集系统的显示图谱,以及系统中α谱测量的部分主要性能。该方案设计的氡室数据采集系统具有微机化程度较高、计算机菜单显示操作方便,系统运行稳定可靠等特点。     

光束线站EPICS数据采集系统研究

上海光源光束线控制系统采用标准软硬件平台开发完成.为实现XBPM测量及电离室等探测器要求的运动控制与信号采集的联动集成,本文用Hytec公司的ADC/DAC模块建立一套VME/IOC的EPICS数据采集系统.经光束线在线测试,该系统完全可应用在XBPM同步光位置诊断、单色器能量控制与探测器信号同步采集等相关用户实验中.     

Architecture of SPIDER control and data acquisition system

The ITER Heating Neutral Beam injectors will be implemented in three steps: development of the ion source prototype, development of the full injector prototype, and, finally, construction of up to three ITER injectors. The first two steps will be carried out in the ITER neutral beam test facility under construction in Italy. The ion source prototype, referred to as SPIDER, which is currently in the development phase, is a complex experiment involving more than 20 plant units and operating with beam-on pulses lasting up to 1 h. As for control and data acquisition it requires fast and slow control (cycle time around 0.1 ms and 10 ms, respectively), synchronization (10 ns resolution), and data acquisition for about 1000 channels (analogue and images) with sampling frequencies up to tens of MS/s, data throughput up to 200 MB/s, and data storage volume of up to tens of TB/year. The paper describes the architecture of the SPIDER control and data acquisition system, discussing the SPIDER requirements and the ITER CODAC interfaces and specifications for plant system instrumentation and control.     

USB2.0通讯在数据采集系统中的应用

设计USB数据采集系统的难点在于:其一,对USB传输、事务、信息包以及握手信号等相关概念的正确理解和应用;其二,正确处理好数据采集与数据传输之间的时序关系。针对一种实际的数据采集系统的设计特点,对设计过程进行了较详细的阐述。     

Implementation of IEEE-1588 timing and synchronization for ATCA control and data acquisition systems

Control and data acquisition (C&DA) systems for Fusion experiments are required to provide accurate timing and synchronization (T&S) signals to all of its components. IPFN adopted PICMG's Advanced Telecommunications Computing Architecture (ATCA) industry standard to develop C&DA instrumentation. ATCA was chosen not only for its high throughput characteristics but also for its high availability (HA) features which become of greater importance in steady-state operation scenarios. However, the specified ATCA clock and synchronization interface may be too limited for the timing and synchronization needs in advanced Physics experiments. Upcoming specification extensions, developed by the “xTCA for Physics” workgroups, will contemplate, among others, a complementary timing specification, developed by the PICMG xTCA for Physics IO, Timing and Synchronization Technical Committee. The IEEE-1588 Precision Time Protocol (PTP) over Ethernet is one of the protocols, proposed by the Committee, aiming for precise synchronization of clocks in measurement and control systems, based on low jitter and slave-to-slave skew criteria.The paper presents an implementation of IEEE-1588 over Ethernet, in an ATCA hardware platform. The ATCA hardware consists of an Advanced Mezzanine Card (AMC) quad-carrier front board with PCI Express switching. IEEE-1588 is to be implemented on a Virtex-6 FPGA. Ethernet connectivity with the remote master clock is located on the rear transition module (RTM). The generated synchronized clock and absolute time in IRIG-B format are distributed to all systems endpoints by a cross-point switch which is also implemented on the FPGA.     

BESIII Slow Control计算机系统结构与数据获取方案

介绍了北京正负电子对撞机升级改进国家重点项目二期工程中,北京谱仪BESIII 慢控制系统的微机系统结构及数据获取方案及系统软件设计.