多道微波干涉仪在HL-1装置上的等离子体电子密度测量

由两道8mm波段,一道4mm和一道2mm波段组成的四道微波干涉仪已经用在HL-1装置的等离子体电子密度测量上。2mm微波干涉仪测到了接近5×10~(13)(cm~(-3))的平均电子密度。在多道微波干涉仪的可测密度范围内,我们测得了HL-1装置等离子体小圆截面上的电子密度分布。利用微机进行数据处理的工作也取得了可喜的进展。     

多道微波干涉仪在HL-1装置上的等离子体电子密度测量

由两道8mm波段,一道4mm和一道2mm波段组成的四道微波干涉仪已经用在HL-1装置的等离子体电子密度测量上。2mm微波干涉仪测到了接近5×10~(13)(cm~(-3))的平均电子密度。在多道微波干涉仪的可测密度范围内,我们测得了HL-1装置等离子体小圆截面上的电子密度分布。利用微机进行数据处理的工作也取得了可喜的进展。     

EAST等离子体图像边界提取算法的改进

本文采用快速CCD相机采集托卡马克装置的等离子体放电图像,根据等离子体放电的位置特点,采用基于Otsu阙值改良的Canny算法对等离子体图像进行等离子体边界位置的提取,并通过最小二乘法进行边界拟合,从而得到准确的等离子体位置。     

基于小波变换的核磁共振FID信号的去噪方法研究

以医用核磁共振自由感应衰减(FID)信号的去噪处理为研究目标,基于小波变换技术,分析了有效信号和噪声的小波变换特性,针对三种去噪方法--模极大值、阈值收缩和平移不变,提出了改进方案,并以阈值收缩去噪方法为例,对临床获取的神经胶质瘤病例的大量数据样本进行了去噪、分析实验,探讨了适用于本类FID信号去噪处理的小波基函数、分解参数、分解层次和阈值策略的选取方法,通过实验建立了最优选取方案.实验结果有效地验证了新方案良好的去噪性能.本研究对于医用磁共振数据的高效处理具有很好的参考价值.     

EAST等离子体图像采集与位置识别技术

本工作采用快速CCD相机采集并保存托卡马克等离子体放电时的图像。根据放电时等离子体图像的位置特点,采用改进的主动轮廓模型算法实时获得等离子体边界位置,并通过最小二乘法对其边界进行拟合,以此获得等离子体的中心位置,为进一步进行等离子体的实时控制提供了基础。该方法已成功应用于EAST装置的放电实验中,并取得了良好的效果。     

小波变换及其在γ能谱去噪处理中的应用

为了利用小波变换对HPGeγ谱仪测量的γ能谱进行消噪处理,首先论述了小波变换基本原理以及一维信号消噪过程中小波函数、分解层数、阈值函数以及阈值规则选取方法,然后结合已测的137Cs、140Laγ能谱所固有的噪声特性,采用小波工具箱对其进行了消噪处理.消噪结果与MCNP仿真计算结果进行了比对,计算了两者之间绝对误差的2范数,对比曲线图表明两者相当一致.     

特种废物等离子体处理技术的应用与研究

简单介绍了等离子体的基本概念及其热等离子体废物处理技术的基本原理,从几个方面总结介绍了固体废物等离子体处理技术的应用与研究。与常规处理方法相比较,采用热等离子体特种废物处理技术其先进性和优越性得到进一步显现,成为特种废物处理领域最有发展前途,最引人关注的高科技处理技术之一。文章还简单介绍了作者在实验室热等离子体技术工作中的一些实验结果以及核工业西南物理研究院在引进、吸收、消化、发展国外等离子体炬和在研制等离子体炬新型电源方面所做的一些工作。     

核磁共振癌症诊断数据处理技术的研究与实现

分析了癌症临床诊断领域中MRI、MRS、PACS和小波变换技术的应用研究现状,针对目前主流核磁共振设备的特点,利用医疗图像存档与通信系统(PACS),提出了基于FTP/Telnet网络通讯技术从不同核磁共振设备获取NMR数据的方法.研究了FID信号的存储格式,以Philips Intera1.5T系统产生的FID信号向Windows标准格式的转换为例,给出了适用于目前主流核磁共振设备的核磁共振底层数据格式转换的方法,并给出了具体的程序实现.基于小波变换阈值去噪技术进行了FID信号的去噪研究,利用自行构造的小波滤波器组取得了较好的去噪实验效果.     

模拟不可燃放射性废物等离子体熔融处理试验研究

在自制的等离子体熔融试验台架上对玻璃纤维、混凝土、土壤的单体玻璃固化配方及三元混合废物玻璃固化配方开展等离子体熔融处理和同位素示踪实验。四种样品在1 100~1 300 ℃条件下熔融1 h均可得到玻璃固化体,经检测,玻璃固化体的密度、抗浸出性能以及机械性能均满足放射性废物玻璃固化体性能要求。示踪实验结果表明,等离子体熔融系统对示踪元素Co、Cs和Sr有较高截留率,且玻璃固化体对Co和Sr的固化能力较高、对Cs固化能力相对较低。在工程应用中,建议在熔融炉系统前端增设造粒等预处理系统,减少物料直接进入烟气净化系统的比例,以提高物料固化效率。     

小波算法在非介入式医用X光机管电流信号处理中的应用研究

医用诊断X光机在各级医院中被大量使用,为了保障医用X光机安全可靠运行,管电流参数作为质量监督控制对象在国家检定规程JJG 744 - 2004《医用诊断X射线辐射源》中已被明确提出.同时,由于小波算法具有良好的时频局部特性,在信号处理领域中被广泛采用,故采用小波算法实现对医用X光机管电流信号的多层次分解,提取有用特征信...     

Electron Cyclotron Emission Imaging on the EAST Tokamak

An upgraded electron cyclotron emission imaging (ECEI) system consisting of new optics lenses with necessary electronics for receiving and processing signals for two dimension (2D) ECEI diagnostics was installed on EAST. Hyperboloid lens were adopted in the new system to optimize the spatial resolutions. The mixers array of sixteen elements measured the plasma electron cyclotron emission at eight frequencies simultaneously, and the profiles of the electron temperature and its fluctuation in an area of 20 cm (vertical) × 6 cm (horizontal) could then be analyzed. Eevolution of sawtooth precursor and crash in EAST was observed.     

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.     

EAST装置通用数据分析软件的设计与实现

介绍了EAST 装置聚变实验数据分析与可视化集成软件EastScope的设计与实现.该软件采用ActiveX技术实现了多种格式数据访问方式的统一,调用了MATLAB引擎进行信号表达式运算,使用OpenGL技术完成了阵列信号的三维显示等.只需操作鼠标就可以完成信号的处理、分析、对比以及二维、三维显示,并能用交互式方式实现二维图形的任意轴缩放,三维图形的旋转、平移与缩放.     

The Procedure for Assembling the EAST Tokamak

Due to the complicated constitution and high precision requirements of the EAST superconducting tokamak, a meticulous assembling procedure and measurement scheme must be established. The big size and mass of the EAST machine＇s components and complicated configuration with tight installation tolerances call for a highly careful assembling procedure. The assembling procedure consists of three main sub-procedures for the assembling of the base, of the tori of the VV, the vacuum vessel TS and the TF, and of the peripheral parts respectively. Before the assembly, a reference framework has been set up by means of an industrial measurement system with reference fiducial targets fixed on the wall of the test hall. In this paper, the assembling procedure is described in detail, the survey control system of the assembly is discussed, and progress in the assembly work is also reported.     

The Alignment and Assembly for EAST Tokamak Device

EAST （HT-7U） is a large fusion experimental device. It is a full superconducting tokamak with 1 MA of plasma current, 1000 s of plasma duration, high elongation and triangularity. It mainly consists of superconducting magnets of poloidal and toroidal field （PF ＆ TF）, vacuum vessel （VV）, thermal radiation shield （TRS） and cryostat vessel （CV）. The significant difficulty for assembly of EAST is tight installation tolerances, which are in the order of several tenth of a millimeter. In particular, the alignment of plasma facing components to the magnetic axis of the device is less than ±0.5 mm. At present, a reasonable assembly process of EAST has been defined, and based on it, the alignment method for EAST, including the survey control network, the location of the main components in different directions, the magnetic axis determination and the accurate positioning of the plasma facing components inside of the vacuum vessel and so on, has been defined by using the sophisticated optical metrology system （SOMS）. This paper describes the assembly procedure of EAST and the installation tolerances associated with the main components. Meanwhile, how to establish the assembly survey control network, magnetic axis determination methods, are introduced in detail.     

EAST托卡马克的中性束注入方案

高能中性束注入(Neutral beam injection,NBI)是核聚变装置托卡马克采用的芯部辅助加热和非感应电流驱动主要手段之一.本文介绍了国家大科学工程全超导托卡马克实验装置(Experimental advanced super-conductingtokamak,EAST)上的高能NBI加热方案及注入器的工程要求,并讨论了中性束在EAST等离子体中的传输等相关问题.     

Modelling of First Discharge in EAST Tokamak

An 1.5D equilibrium evolution code was used to model the time evolution of the first ohmic discharges in the EAST experiment. Good agreement between the simulation and the experimental results was obtained in the plasma current, major radius, electron temperature, loop voltage and poloidal field （PF） current for the entire duration of the discharge, which indicates that the code is highly reliable and will allow to further study the EAST discharge. At the same time, the code also simulates some important plasma parameters without experimental measured data yet, such as the plasma minor radius, central and edge safety factors, elongation and triangilarity, which are important in the analysis of EAST data.     

Numerical Study of Tokamak Equilibrium with Toroidal Flow on EAST

The effect of the toroidal flow on the equilibrium of tokamak plasmas is a sensitive point for high performance plasma and its precise control. In this paper the effect is studied numerically using the EFIT （Equilibrium Fitting） code on EAST （Experimental Advanced Superconducting Tokamak）. Firstly, the numerical calculation exhibits a clear outward shift of pressure contour from the magnetic surfaces in the plasma core and the shift grows with the increase of the toroidal velocity. The peak shift of 8% is observed when the ratio between the plasma velocity and the Alfvdn speed equals to 0.15. Secondly, it is shown that the magnetic surfaces shift outwards from those without flow. With a certain plasma current the safety factor on the magnetic axis decreases as the plasma flow velocity increases. The magnetic shear increases about 10% on the plasma boundary compared with the case without flow.     

SN方法自动建模程序SNAM在EAST纵场线圈核热计算中的应用

在核领域的中子学计算中,离散纵标(SN)方法三维粒子输运计算程序得到了广泛应用.SNAM作为离散纵标法粒子输运自动建模程序系统,其主要功能是CAD模型与SN计算模型之间的相互转换.一方面,SNAM可以将通用格式的CAD模型转换成SN计算模型,另一方面可以以CAD模型的方式显示SN计算模型中几何及材料等相关信息.本文主要介绍使用SNAM程序对EAST三维模型进行中子学建模,并计算分析了EAST装置纵场线圈的中子注量率与核热沉积.