The EAST distributed data system

In this year, Experimental Advanced Superconducting Tokamak (EAST) has undergone the first tests successfully, and the EAST distributed data system has been reliably operated in the EAST experimental campaigns. This paper gives an overview of this system.The EAST distributed data system is based on the design of, and the experiences with the HT-7 data system; it is aimed to be a distributed, real-time and scalable system. The EAST distributed data system includes control subsystem, data acquisition subsystem and data service subsystem. Control subsystem provides remote control of the all data acquisition units, full information management and state monitoring; data acquisition subsystem that provide real-time and quasi-real-time data support for long-pulse operation consists of a set of autonomous data acquisition units which support autonomous operating and remote control. Data service subsystem is responsible for storing and publishing data.     

A new long-pulse data system for EAST experiments

A long pulse discharge requires high throughput data acquisition. As more physics diagnostics with high sampling rate are applied and the pulse length becomes longer, the original EAST (Experimental Advanced Superconducting Tokamak) data system no longer satisfies the requirements of real-time data storage and quick data access. A new system was established to integrate various data acquisition hardware and software for easy expansion and management of the system. Slice storage mechanism in MDSplus is now being used for the continuous and quasi real-time data storage. For every data acquisition thread and process, sufficient network bandwidth is ensured. Moreover, temporal digitized data is cached in computer memory in doubly linked circular lists to avoid the possible data loss by the occasional temporal storage or transfer jam. These data are in turn archived in MDSplus format by using slice storage mechanism called “segments”. For the quick access of the archived data to the users, multiple data servers are used. These data servers are linked using LVS (Linux Virtual server) load balance technology to provide a safe, highly scalable and available data service.     

The implementation of virtualization technology in EAST data system

The virtualization technology is very popular in many fields at present which has many advantages such as reducing costs, unified management, mobile applications, cross platform, etc. We have also implemented the virtualization technology in EAST control and data system. There are primarily four kinds of technology providers in virtualization technology including VMware, Citrix, Microsoft Hyper-V as well as open source solutions. We have chosen the Citrix solution to implement our virtualization system which mainly includes three aspects. Firstly, we adopt the XenServer technology to realize virtual server for EAST data management and service system. Secondly, we use XenApp technology to realize cross platform system for unify data access. Thirdly, in order to simplify the management of the client computers, we adopt the XenDesktop technology to realize virtual desktops for new central control room. The details of the implementation are described in this paper.     

A web based MDSplus data analysis and visualization system for EAST

In an EAST (Experimental Advanced Superconducting Tokamak) experiment, the convenient data analysis and visualization tools are very important for physicists and engineering experts to view the operational status of the device. Along with the increasing data sampling rate and pulse length, it will be increasingly challenging for the end user to view the data conveniently under limited Internet bandwidth. We propose a software based on jScope [1] called WebScope for data visualization. By applying java applet techniques, this software can be accessed directly over the Internet via a variety of web browsers without installing client software. Using this data viewer the frequency will be effectively adjusted according to the computer displaying resolution, which saves the total amount of data to be transferred across the Internet and enables the user to view the data quickly. When the signals are zoomed or unzoomed, the data frequency will be re-adjusted to the displaying resolution. With WebScope, data of various experiments in different servers can be viewed in either a single panel or multiple frames, which makes it easier for cross comparison among different data sources. The system was successfully applied to EAST experiment and achieved excellent performance. Its design, function and implementation details will be introduced in this paper.     

EAST装置的连续数据采集与服务系统的设计与实现

介绍了应用于EAST超导托卡马克装置的连续数据采集与数据服务系统的设计思路与具体实现过程,该系统能使实验人员了解EAST装置在降温以及实验过程中各系统与重要设备的运行状态,以保证系统的正常运转与安全.该系统经测试与实验表明,整个系统稳定、灵活、有效.     

Basic thermodynamic data in nuclear technology: New developments,old problems

Current trends in the determination of the basic thermodynamic data in nuclear technology are reviewed. Examples are given to illustrate the need for accurate and precise measurements of energy and entropy in the calculation of chemical equilibria and phase diagrams.     

基于嵌入式系统的离子回旋数据采集交换系统的开发和实现

为提高现有EAST离子回旋共振加热监测系统的性能,为EAST物理实验提供稳定可靠的加热手段,针对目前监控系统的多卡数据采集和交换过程中出现的实时问题及多卡采集出现的问题,文章提出了在EAST装置高功率离子回旋共振加热监控系统的设计的总体基本解决方案和实现过程,设计了双操作系统下多卡数据采集交换可行的实现模型,使用Visual C＋＋及Tornado for Windows开发相应的驱动及应用程序,对在嵌入式系统VxWorks和Windows操作系统下的通讯方式及系统性能进行了重点分析和讨论,使用嵌入式系统的软件逻辑分析仪对嵌入式系统的任务调度、信号量使用、内存使用情况、系统空闲时间等作了分析,为多操作系统多卡采集交互式系统提供了参考,测试结果表明该系统基本满足要求。     

The cryogenic control system of EAST

A large scale helium cryogenic system is one of the key components for the EAST tokamak device for the cooling of PF and TF coils, structures, thermal shields, buslines, current leads and cryopumps. Since the cooling scheme of the EAST cryogenic system is fairly complicated, a reliable and flexible control system is required for cryogenic system. The cryogenic control system is based on DeltaV DCS which is the process control software developed by Emerson Company. The EAST cryogenic system has been in operation for four years and has been proved to be safe, stable and energy saving by the past 7 experiments. This paper describes the redundant control network, hardware configuration, software structure, auxiliary system and the new development in the future.     

New developments in French transient monitoring system: SYSFAC from the experiments to the industrial process

After more than 15 years of experience with regulatory transient data collection, Electricité de France decided to design a new concept of fatigue monitoring system called SYSFAC. This new system is the result of seven years of successful experimentation with fatigue meters. This system will be connected to the on-site data acquisition system without any complementary instrumentation. The SYSFAC system has a modular structure: the mechanical transient module, the functional transient module, the fatigue meters module and the global damage computing module all have a high level of flexibility to be applied to various types of circuits. After the preliminary studies had been achieved, it was decided to undertake the industrial phase of the SYSFAC project. Specific codes on PC computers have been used to validate the basic concepts and the operator interface. Real-size coding will last one year and the first SYSFAC system will be delivered to the pilot power plant by the end of 1995.     

Calorimetric power measurements in the EAST ECRH system

In this paper,the measurement method of calorimetric power for an electron cyclotron resonance heating (ECRH) system for EAST is presented.This method requires measurements of the water flow through the cooling circuits and the input and output water temperatures in each cooling circuit.Usually,the inlet water temperature stability is controlled to obtain more accurate results.The influence of the inlet water temperature change on the measurement results is analyzed for the first time in this paper.Also,a novel temperature calibration method is proposed.This kind of calibration method is accurate and effective,and can be easily implemented.     

Design of the New SC Bus-Line System for the EAST

A new external superconducting (SC) bus-line system consisting of 13 pairs of bus-lines has been designed for the upgrade project of the experimental advanced SC tokamak. The old system integrated into two vacuum ducts will be extended approx. 23 m with new cable in conduit conductors (CICCs) connecting by twin-box lap joints. The leakage currents of the CICCs electrically insulated with four layers of polyimide films and pre-impregnation fiberglass tapes are <10 μA under a 10 kV electrical potential at 77 K, 0.1–100 Pa in helium atmosphere. Each bus-line pair is bound together by 50 % overwrapped with three layers of Kevlar polyester tapes to eliminate its adverse effects of electromagnetic forces with a maximum of 2.44 kN/m. The bus-lines designed with at least four bends are flexible to absorb the thermal shrinkage which is approx. 90 mm in total. The maximum shift of the CICCs is 26.1 mm when cooled down. The total thermal loads to 5 K components in bus-line group 1 and 2 are <0.3 W/m as required.     

Data monitoring system of technical diagnosis system for EAST

<正>Technical diagnosis system(TDS)is an important subsystem to monitor status parameters of EAST (experimental advanced superconducting tokamak).The upgraded TDS data monitoring system is comprised of management floor,monitoring floor and field floor.Security protection,malfunction record and analysis are designed to make the system stable,robust and friendly.During the past EAST campaigns,the data monitoring system has been operated reliably and stably.The signal conditioning system and software architecture are described.     

EAST托卡马克中央定时系统的实现

中央定时系统是EAST托卡马克装置总控系统的重要组成部分,是总控系统对各子系统进行时序和触发控制的基础.本工作建立的EAST中央定时系统采用分布式的系统结构,可对32 MHz的系统时钟信号进行0-65535的任意整数分频;能对系统触发进行延迟输出,最大的延迟时间为4294s、延迟的分辨率为1 μs.该系统性能稳定,并已成功地投入到2006年9月EAST托卡马克装置的首轮正式物理放电实验中.     

EAST托卡马克装置的核辐射监测系统

EAST(Experimental Advanced Superconducting Tokamak)现阶段D-D运行产生2.45 Me V聚变中子及次级核反应γ射线,为了解EAST运行期间辐射场的分布及强度,确保运行期间人员及环境的核辐射安全。针对EAST运行期间装置大厅内部存在较强的中子、伽马瞬变辐射场的特征,结合环境低本底辐射监测的需要,采用宽动态范围、快时间响应的场所辐射监测探测器,与高灵敏度、稳定性好的环境辐射监测探测器相结合的方式,围绕EAST装置布置13个辐射监测点,每点分别安装一台中子、伽马监测器。采用自行编写的Lab VIEW辐射监测软件进行数据采集,组建了一套EAST托卡马克装置的中子、伽马辐射剂量监测系统。该系统在2015年春季EAST实验中连续稳定运行了三个月,可靠性较高,获取了大量实验数据。监测系统满足EAST核辐射监测的要求,同时为后续开展聚变堆辐射安全与防护研究提供实验平台。     

Technical diagnosis system for EAST tokamak

Technical diagnosis system (TDS) is one of the important subsystems of EAST (experimental advanced superconducting tokamak) device, main function of which is to monitor status parameters in EAST device. Those status parameters include temperature of different positions of main components, resistance of each superconducting (SC) coils, joint resistance of SC coils and high-temperature superconducting (HTS) current leads, strain of cold-quality components endured force, and displacement and current of toroidal field (TF) coils in EAST device, which are analog input signals. In addition there are still some analog and digital output signals. The TDS monitors all of those signals in the period of EAST experiments. TDS data monitoring is described in detail for it plays important role during EAST campaign. And how to protect the SC magnet system during each plasma discharging is presented with data of temperature of coolant inlet and outlet of SC coils and feeders and cases of the TF coils and temperature in the upper and middle and bottom of the TF coil case.During construction of the TDS primary difficulties come from installation of Lakeshore Cernox temperature sensors, strain measurement of central solenoid coils support legs and installation of co-wound voltage sensors for quench detection. While during operation since the first commissioning big challenges are from temperature measurement changes in current leads and quench detection of PF coils. Those difficulties in both stages are introduced which are key to make the TDS reliable. Meanwhile analysis of experimental data like temperature as a back up to testify quench occurrence and stress on vacuum vessel thermal shield and vacuum vessel have also been discussed.     

Study of load balancing technology for EAST data management

With the continuous renewal and increasing number of diagnostics, the EAST tokamak routinely generates ∼3 GB of raw data per pulse of the experiment, which is transferred to a centralized data management system. In order to strengthen international cooperation, all the acquired data has been converted and stored in the MDSplus servers. During the data system operation, there are some problems when a lot of client machines connect to a single MDSplus data server. Because the server process keeps the connection until the client closes its connection, a lot of server processes use a lot of network ports and consume a large amount of memory, so that the speed of access to data is very slow, but the CPU resource is not fully utilized. To improve data management system performance, many MDSplus servers will be installed on the blade server and form a server cluster to realize load balancing and high availability by using LVS and heartbeat technology. This paper will describe the details of the design and the test results.     

EAST低温系统的故障树分析

EAST是世界上进行聚变研究的先进超导托卡马克实验装置.低温冷却系统是EAST的主要子系统之一,担负着纵向和极向场线圈、纵场线圈盒、冷屏和电流引线的冷却功能,需保证其能长期稳定运行.本文运用故障树分析法来评价低温系统的可靠性,使用自主开发的软件RiskA建立低温系统的故障树模型并进行定量计算,得到系统的失效概率和部件的重要度,并提出改进建议,为系统的优化设计和提高可靠性提供参考.     

Real-time virtual EAST physical experiment system

As a large fusion reaction device, experimental advanced superconducting tokamak (EAST)’s internal structure is complicated and not easily accessible. Moreover, various diagnostic systems and complicated configuration bring about the inconveniency to the scientists who are unfamiliar with the system but interested in the data. We propose a virtual system to display the 3D model of EAST facility and enable people to view its inner structure and get access to the information of its components in various view sights. We would also provide most of the diagnostic configuration details together with their signal names and physical properties. Compared to the previous ways of viewing information by reference to collected drawings and videos, virtual EAST system is more interactive and immersive. We constructed the browser-oriented virtual EAST physical experiment system, integrated real-time experiment data acquisition, plasma shape visualization and experiment result simulation in order to reproduce physical experiments in a web browser. This system used B/S (Browser/Server) structure in combination with the technology of virtual reality – VRML (Virtual Reality Modeling Language) and Java 3D. In order to avoid the bandwidth limit across internet, we balanced the rendering speed and the precision of the virtual model components. Any registered user can view the experimental information visually and efficiently by logining the system through a web browser. The establishment of the system provides the framework basis for a comprehensive virtual EAST cooperative physical experimental environment.     

EAST托卡马克新型积分器系统控制器的研制

为了满足EAST托卡马克的实验需求,提升积分器系统的可维护性和可测试性,研制了新型积分器系统控制器。该控制器采用ARM微控制器和轻量级IP协议栈,实现了积分器系统的网络化控制。所提供的参数设置指令可远程设置和读取积分器板卡上放大器的放大倍数,而控制指令则提供了初始化、标准信号积分、脉冲积分、积分保持、标定和探针测试功能。经实验和EAST现场测试,该积分器系统控制器可满足EAST装置的实验要求。