基于PXI Express的托卡马克同步数据采集系统设计

随着J-TEXT装置的发展,原有的数据采集系统在稳定性、模块化、采样率等方面已不能满足装置运行的需要,所以需建立一套新的数据采集系统来满足实验需求。本文介绍了基于PXI Express的托卡马克分布式高速同步数据采集系统的设计与实现。系统的采集单元由PXIe机箱NI PXIe-1062Q、PXIe控制器NI PXIe-8133和高速同步数据采集卡NI PXIe-6368组成,兼容ITER CODAC最新标准,具有良好的机械封装性、模块化程度高和高采样率等优点。系统采用同步差分采集方式采集实验数据,并将数据存储于核聚变领域通用的MDSplus数据库中。测试和使用结果表明,系统能在2 MSps采样率下连续稳定工作,可较好地满足装置运行的需要。     

Upgraded data service system for HT-7 Tokamak

A data service system plays an indispensable role in HT-7 Tokamak experiment. Since the former system doesn＇t provide the function of timely data procession and analysis, and all client software are based on Windows, it can＇t fulfill virtual fusion laboratory for remote researchers. Therefore, a new system which is simplified by three kinds of data servers and one data analysis and visualization software tool has been developed. The data servers include a data acquisition server based on file system, an MDSplus server used as the central repository for analysis data, and a web server. Users who prefer the convenience of application that can be run in a Web Browser can easily access the experiment data without knowing X-Windows. In order to adjust instruments to control experiment the operators need to plot data duly as soon as they are gathered. To satisfy their requirement, an upgraded data analysis and visualization software GT-7 is developed. It not only makes 2D data visualization more efficient, but also it can be capable of processing, analyzing and displaying interactive 2D and 3D graph of raw. analyzed data by the format of ASCII, LZO and MDSplus.     

MDSplus automated build and distribution system

Support of the MDSplus data handling system has been enhanced by the addition of an automated build system which does nightly builds of MDSplus for many computer platforms producing software packages which can now be downloaded using a web browser or via package repositories suitable for automatic updating. The build system was implemented using an extensible continuous integration server product called Hudson which schedules software builds on a collection of VMware based virtual machines. New releases are created based on updates via the MDSplus cvs code repository and versioning are managed using cvs tags and branches. Currently stable, beta and alpha releases of MDSplus are maintained for eleven different platforms including Windows, MacOSX, RedHat Enterprise Linux, Fedora, Ubuntu and Solaris. For some of these platforms, MDSplus packaging has been broken into functional modules so users can pick and choose which MDSplus features they want to install. An added feature to the latest Linux based platforms is the use of package dependencies. When installing MDSplus from the package repositories, any additional required packages used by MDSplus will be installed automatically greatly simplifying the installation of MDSplus. This paper will describe the MDSplus package automated build and distribution system.     

基于MDSplus分段技术的Web数据显示系统

先进托卡马克装置需要长脉冲放电实验运行,针对装置长脉冲放电实验的数据存储和交互技术是重要的研究内容之一。本工作设计了一种Web数据显示系统,系统采用ASP.NET架构和数据分段技术从MDSplus数据库读取分段数据,利用NI Measurement Studio控件库将数据显示在Web页面中。数据分段技术将长脉冲实验数据划分为多个较小的数据单元--数据段,用户可按需读取长脉冲实验数据中的部分数据段。同时系统制定了高效的分段读取策略,可准确、快速地显示用户所需的数据波形。Web数据显示系统在J-TEXT托卡马克上进行了测试,运行性能稳定,达到了系统的设计目标。     

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.     

Application of MDSplus on EAST Tokamak

EAST is a fully superconducting Tokamak in China used for controlled fusion research. MDSplus, a special software package for fusion research, has been used successfully as a central repository for analysed data and PCS （Plasma Control System） data since the debugging experiment in the spring of 2006 [1]. In this paper, the reasons for choosing MDSplus as the analysis database and the way to use it are presented in detail, along with the solution to the problem that part of the MDSplus library does not work in the multithread mode. The experiment showed that the data system based on MDSplus operated stably and it could provide a better performance especially for remote users.     

Future directions in fusion research: Super high-field tokamaks

Recent experimental results and advances in magnet engineering suggest that super high-field, high-aspect ratio tokamak devices could be a very efficient way to achieve burning plasma conditions and could open up a new area of research. Copper magnet devices with fields of 13 to 25 T at the plasma are considered. The super high-field approach could also provide advantages for ETR and demonstration/commercial reactor concepts (magnetic fields at the plasma in the 8–13 T range).Presented at the American Vacuum Society Meeting, October 30, 1986, Baltimore, Maryland.     

Tokamak research at University of São Paulo

The main results obtained in the small tokamak TBR-1 of University of São Paulo (USP) are reviewed. The main effort has been concentrated on the characterization and external control of MHD activity, plasma edge phenomena and diagnostic development. The design of a small-aspectratio tokamak, TBR-E, and the research program to be carried out in TCA, to be transferred from Lausanne to São Paulo, are also briefly described.     

High performance plasma vertical position control system for upgraded MAST

A plasma vertical control system able to control high elongation (～2.5) plasmas at moderate internal inductance (～0.9) is analysed, including both active and passive components in a closed loop system. The analysis is based on the RZIp rigid plasma model and this is extensively validated using present day MAST discharges, especially at the limits of controllability. Special consideration is given to the unusual MAST geometry (coils inside the main vacuum vessel) and general conclusions regarding system design are drawn wherever possible.     

Conceptual design of the FAST load assembly

Fusion advanced studies torus (FAST) is a proposal for a satellite facility which can contribute the rapid exploitation of ITER and prepare ITER and DEMO regimes of operation, as well as exploiting innovative DEMO technology. FAST is a compact (R₀ = 1.82 m, a = 0.64 m, triangularity δ = 0.4) machine able to investigate non-linear dynamics effects of alpha particle behaviours in burning plasmas [1], [2] and [5]. The project is based on a dominant 30 MW of ion cyclotron resonance heating (ICRH), 6 MW of lower hybrid (LH) and 4 MW of electron cyclotron resonance heating (ECRH). FAST operates at a wide range [3] and [4] of parameters, e.g., in high performance H-mode (B_T up to 8.5 T; I_P up to 8 MA) as well as in advanced Tokamak operation (I_P = 3 MA), and full non-inductive current scenario (I_P = 2 MA). Helium gas at 30 K is used for cooling the resistive copper magnets [6]. That allows for a pulse duration up to 170 s. To limit the TF magnet ripple ferromagnetic insert have been introduced inside the vacuum vessel (VV). Ports have been designed to also accommodate up to 10 MW of negative neutral beam injection (NNBI). Tungsten (W) or liquid lithium (L-Li) have been chosen as the divertor plates material, and argon or neon as the injected impurities to mitigate the thermal loads.     

托卡马克装置中氢同位素滞留研究现状

当前托卡马克装置中氢同位素滞留研究通常用原位测量分析与事后样品评价两种方法,主要滞留机制为注入-捕获与共沉积。JT-60U、DIII-D、JET、ASDEX-U、C-MOD、TEXTOR和TORE SUPRA等装置的研究结果表明材料种类、偏滤器位形、瓦块结构及排列、温度等均会对氢同位素滞留产生影响。本文介绍了以上装置的研究现状,并说明了EAST氢同位素滞留的事后样品评价研究计划。