大幅度纳秒脉冲发生器

本文叙述一种大幅度纳秒脉冲发生器，脉冲上升时间为１．５ｎｓ，半高宽为３ｎｓ；幅度为３５０￣１００Ｖ，对应重复频率为１￣２ＭＨｚ，峰值电流为７￣２Ａ，输出阻抗为５０Ω。     

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.     

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。     

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 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.     

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.     

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。     

Analytical Description of Long-Pulse Tokamaks

It is shown that the condition for long-pulse tokamak is the synchronization between deterministic (H modes) and stochastic (ELMs) regimes. These regimes can be obtained analytically using the theory of semigroups and Kolmogorov–Arnold–Moser theorem via fuzzy neural techniques.     

断层屏蔽SPECT成像法探讨

本文以空间积分原理为基础,以逐渐逼近法为图像重建的核心,探讨了可实现断层屏蔽的SPECT成像的途径。与传统的SPECT成像方法比较,它具有高的灵敏度和数据获取速度快的特点。由于无须用机械装置将γ照相机旋转,消除了运动带来的误差,提高了成像的质量。本文用线性方程组的松弛解法对无散射和无噪音的二维空间的模拟数据进行了验算,证明逐渐逼近法能逐渐逼近到放射性分布区域,并能基本给出分布形式。     

压水堆乏燃料中间贮存技术研究

本文通过调研主要核电国家的压水堆核电站乏燃料中间贮存与处理现状,分析研究近年来在压水堆核电站乏燃料中间贮存方面的趋势,明确乏燃料干式贮存技术将是未来压水堆核电站乏燃料中间贮存的主流。结合我国压水堆核电站乏燃料的现状并对未来核电站乏燃料贮存与处理工作提出建议。     

CMS分布式网格存储统计和监控系统的研究和实现

为了方便CMS对分布式网格存储资源进行有效管理和利用,合理安排和分配物理数据到合适的网格站点,基于CMS网格传输系统Ph EDEx的分布式架构设计了网格存储统计和监控系统,实现了存储信息收集、加工、存储和查询等一系列功能,并通过可视化工具将统计结果以图形和表格等多种方式直观而清晰地显示,满足了不同层次的CMS用户对网格存储信息的需求。     

废放射源长期贮存现状

简单介绍了国际上对对废放射源的长期贮存方法一直接贮存、加外包装贮存和整备后贮存,分别介绍了英国、奥地利、白俄罗斯、捷克、比利时等国废放射源的贮存现状;介绍了我国对废放射源的贮存方法及北京城市放射性废物库、中国辐射防护研究院废放射源贮存库、核工业废放射源集中贮存库、国家废放射源集中贮存库对废放射源的贮存情况,以期对我国废放射源的长期贮存研究有所帮助。