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.     

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.     

Assessment of Radiation Damage to the Structural Material of EAST Tokamak

Radiation damage to structural material of fusion facilities is of high concern for safety. The superconducting tokamak EAST will conduct D-D plasma experiments with the neutron production of 1015 neutrons per second. To evaluate the material radiation damage a programme system has been devised with the Monte Carlo transport code MCNP-4C, the inventory code FISPACT99, a specific interface, and the fusion evaluated nuclear data library FENDL-2. The key nuclear responses, i.e. fast neutron flux, displacement per atom, and the helium and hydrogen production, are calculated for the structural material SS-316L of the first wall, and the vacuum vessel, using this programme. The results demonstrate that the radiation damage to the structural material is so little that it will not lead to any significant change of material properties according to the reference design. This indicates that there is a large potential space for EAST to test advanced operation regime from the viewpoint of structural material safety.     

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.     

Static and Dynamic Mechanical Analyses for the Vacuum Vessel of EAST Superconducting Tokamak Device

EAST （experimental advanced superconducting tokamak） is an advanced steadystate plasma physics experimental device, which is being constructed as the Chinese National Nuclear Fusion Research Project. During the plasma operation the vacuum vessel as one of the key component will withstand the electromagnetic force due to the plasma disruption, the Halo current and the toroidal field coil quench, the pressure of boride water and the thermal load due to 250℃ baking by pressurized nitrogen gas. In this paper a report of the static and dynamic mechanical analyses of the vacuum vessel is made. Firstly the applied loads on the vacuum vessel were given and the static stress distribution under the gravitational loads, the pressure loads, the electromagnetic loads and thermal loads were investigated. Then a series of primary dynamic, buckling and fatigue life analyses were performed to predict the structure＇s dynamic behavior. A seismic analysis was also conducted.     

EAST等离子体电子密度测量与处理算法设计

介绍EAST托卡马克中HCN 激光干涉仪测量等离子电子密度基本原理,给出了等离子体电子密度HCN信号处理算法,该算法能准确地去零漂并有效的进行信号翻转处理,并利用小波分析的方法对信号进行去噪处理,获得了高精度低噪音的HCN信号.该算法同样可用于HT7托卡马克五道HCN信号处理中,利用好的HCN信号可以更加准确地反演等离子体密度空间分布,这种密度处理算法是行之有效的.     

First Engineering Commissioning of EAST Tokamak

Experimental Advanced Superconducting Tokamak （EAST） is the first fully superconducting tokamak. The first commissioning started on Feb. 1st of 2006 and finished on March 30TM of 2006 at the Institute of Plasma Physics, Chinese Academy of Sciences. It consists of leakage testing at both room temperature and low temperature, pumping down, cooling down all coils, current leads, bus bar and the thermal shielding, exciting all the coils, measuring magnetic configuration and warming up the magnets. The electromagnetic, thermal hydraulic and mechanical performance of EAST Toroidal Field （TF） and Poloidal Field （PF） magnets have also been tested. All sub-systems, including pumping system, cryogenic system, PF＆ TF power supply systems, magnet instrumentation system, quench detection and protection system, water cooling system, data acquisition system, main control system, plasma control system （PCS）, interlock and safety system have been successfully tested.     

EAST全超导托卡马克装置失超保护检测技术的现状及发展

EAST装置是九五国家重大科学工程项目之一,做为世界上第一个全超导托卡马克装置,其纵场和极向场线圈全部由超导磁体组成,进行安全,准确,有效的失超保护是装置安全运行的首要环节。如何在全超导托卡马克装置这样复杂的电磁环境进行失超检测在世界上也无先例可寻。EAST上失超检测系统经过几十轮单饼超导线圈实验及两轮装置正式放电实验后逐步建立和完善起来,并已通过工程验收达到装置实验运行要求。主要介绍了EAST超导装置失超检测系统的基本结构和检测原理,同时还简述失超检测技术的发展并给出了实验结果。     

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.     

Bench Test of the Vibration Compensation Interferometer for EAST Tokamak

A visible laser-based vibration compensation interferometer has recently been designed for the EAST tokamak and the bench test has been finished.The system was optimized for its installation on EAST.The value of the final optical power before the detectors without plasma has been calculated from the component bench test result,which is quite close to the measured value.A nanometer level displacement(of the order of the laser's wavelength) has been clearly measured by a modulation of piezoelectric ceramic unit,proving the system's capability.     

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.     

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.     

Structural design of cryogenic component support for EAST （HT-7U）

EAST is a full superconducting tokamak with an elongated plasma cross-section. It consists of superconducting poloidal field (PF) magnet system, toroidal field (TF) magnet system, vacuum vessel with inner parts, thermal shields and cryostat vessel. The mission of the project is to widely investigate both physics and technologies of advanced tokamak operations, especially the mechanism of power and particle handling for steady-state operations. The cryogenic component is mainly composed of superconducting TF and superconducting PF coils that ensure the ability of sustaining magnetic field for plasma confinement, control and shaping in steady-state. This report describes the process of the structure design of cryogenic component support for EAST.     

The Application and Improvement of Helium Turbines in the EAST Cryogenic System

The helium cryogenic system supplies supercritical helium cooling capacity at 4.5 K for the superconducting magnets in the EAST superconducting tokamak.Four low-temperature helium turbines are used in the 2 kW helium refrigeration system,and their performance and reliability are critical for the continuous operation of the tokamak.The turbines were made by the Helium Mechanics Company in Russia.The start-up process is very unstable,easily broken,and thus testing and improvements are needed.In this paper,we analyze the structure of the helium turbine,make improvements,and describe the testing process and results of the improved helium turbines.Some of the operational experiences during the start-up process and tests are also presented.     

Eddy Calculation and Vacuum Field Reconstruction on EAST

A new method, by using eigenmodes to reduce the fitting parameters and pre-calculated eddy current based on a lump parameter circuit equation, is applied to reconstruct the vacuum field for EAST plasma startup.     

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.     

EAST托卡马克绝缘子低温力学性能理论及实验分析

复合材料绝缘子是EAST托卡马克磁体系统的关键部件，担负着整个磁体系统低温冷却回路与高压部件的对地绝缘作用。运行中，绝缘子在低温下要承受较高的内压及电压，保持绝缘子在低温状态下的机械整体性是运行安全的必要保证。从整个装置的使用安全考虑，有必要对绝缘子低温力学性能作全面分析。本工作首先对绝缘子的机械低温力学性能进行理论分析，然后通过设计的低温力学实验验证理论分析结果。以此为基础，对装置中的损坏绝缘子进行分析，确定损坏原因。     

Simulation Analysis of Divertor Performance in EAST

A detailed study of the divertor performance in the EAST has been conducted for both its double null and single null configurations. The results of the application of the SOLPS （B2/Eirene） code package to the analysis of the EAST divertor are summarized. Here we concentrate on the effects of the increased geometrical closure and variation in the magnetic topology on the behavior of divertor plasmas. The results of numerical predictions for the EAST divertor＇s operational window are also described in this paper.     

Design and Analysis of the Thermal Shield of EAST Tokamak

EAST （Experimental Advanced Superconducting Tokamak） is a tokamak with su- perconducting toroidal and poloidal magnets operated at 4.5 K. In order to reduce the thermal load applied on the surfaces of all cryogenically cooled components and keep the heat load of the cryogenic system at a minimum, a continuous radiation shield system located between the magnet system and warm components is adopted. The main loads to which the thermal shield system is subjected are gravity, seismic, electromagnetic and thermal gradients. This study employed NASTRAN and ANSYS finite element codes to analyze the stress under a spectrum of loading conditions and combinations, providing a theoretical basis for an optimization design of the structure.