Strain Measurement on the Toroidal Field （TF） Coil Cases

The stress-strain state of the structure is a matter of interest to designer. The strain measurement of superconducting magnets at cryogenic temperature is a specific technique. Based on strain measurement of TF coil case for EAST, this paper presents a measuring technique at cryogenic temperature and on intense magnetic field. The compensation methods for both temperature and magnetic field effects of the gauges, together with the measured results are involved, and the discussions of the measured results are given in the paper.     

Coupling Effect between Equilibrium Field and Heating Field and Modification of the Power Supply System on SUNIST Spherical Tokamak

Strong inductive coupling between the heating field and equilibrium field is confirmed to be responsible for the poor plasma equilibrium in initial discharges on the SUNIST spherical tokamak. A modification project for the power supply system of equilibrium field coils is successfully performed to increase the duration time of plasma current flattop from nmch less than 1ms to about 2 ms.     

The Power Supply System for HL-2A Tokamak＇s Magnetic Field

The highpower pulsed power supply system for the magnetic field of the HL-2A Tokamak is described in this paper. The total output power of its eight magnetic field power supply units of nearly 250 MW. Their highest DC output voltage and current are 3510 V and 45 kA, respectively. All the units are operated in a pulsed mode. The pulse duration is 5 s, and the cyclic period is 15 min. The power supply system consists mainly of pulsed flywheel motor generators, rectifying transformers, thyristor converters, diode rectifiers and switches. The system incorporates many key technologies-supply equalization with two generators and four diode bridges, constant-angle phase triggers with a wide frequency range, current equalization, a status detector for the high current 6-phase converter, and advanced monitoring based on a programmable logic computer and engineering parameter measurement. The experimental results show that the performance of the power supply system satisfies the requirements of HL-2A experiments very well.     

The Development of a Framework for Target Diagnostic Centralized Control System （TDCCS） in ICF Experiments

A framework for target diagnostic centralized control system （TDCCS） in inertial confinement fusion （ICF） experiment has been developed. The developed framework is based on the common object request broker architecture （CORBA） standard and part of the concept from the ICFRoot （a framework based on ROOT for ICF experiments） framework design. This framework is of a component architecture, including a message bus, command executer, status processor, parser and proxy. To test the function of the framework, a simplified prototype of the TDCCS has been developed as well.     

New Current Control Method of DC Power Supply for Magnetic Perturbation Coils on J-TEXT

In order to advance the research on suppressing tearing modes and driving plasma rotation, a DC power supply （PS） system has been developed for dynamic resonant magnetic perturbation （DRMP） coils and applied in the J-TEXT experiment. To enrich experimental phe- nomena in the J-TEXT tokamak, applying the circulating current four-quadrant operation mode in the DRMP DC PS system is proposed. By using the circulating current four-quadrant oper- ation, DRMP coils can be smoothly controlled without the dead-time when the current polarity reverses. Essential circuit analysis, control optimization and simulation of desired scenarios have been performed for normal current. Relevant simulation and test results are also presented.     

Design and Analysis of the Poloidal Field Grid Power Supply System for the HT-7 Tokamak

This paper reports a new project - the poloidal field （PF） grid power supply system to replace the ac flywheel generator power supply system on the basis of the present running parameters of the HT-7 poloidal field and the short-circuit capacity of our transformer substation. The designed parameters of the PF grid power supply system have been verified to meet the requirements of the heating field （HF） and the vertical field （VF）. In the meantime, in order to reduce the disturbance to the local power grid, the device of reactive power and harmonic current compensation has been added. Experimental results have confirmed the feasibility of the PF grid power supply system. Compared with the ac flywheel generator, the PF grid power supply system has the advantages of lower noise, precise control, convenient maintenance, simple operation and cost savings.     

Implementation of Automatic Process of Edge Rotation Diagnostic System on J-TEXT Tokamak

A spectral diagnostic control system （SDCS） is developed to implement automatic process of the edge rotation diagnostic system on the J-TEXT tokamak. The SDCS contains a control module, data operation module, data analysis module, and data upload module. The core of this system is a newly developed software ＂Spectra Assist＂, which completes the whole process by coupling all related subroutines and servers. The results of data correction and calculated rotation are presented. In the daily discharge of J-TEXT, SDCS is proved to have a stable performance and high efficiency in completing the process of data acquisition, operation and results output.     

Kicker磁铁电源控制系统设计

兰州重离子加速器冷却储存环包含多个注入和引出环节,其中较为关键的是CSRm的引出和CSRe的注入系统,其时间控制精度直接影响束流的注入引出效率。本文采用先进的ARM+FPGA技术实现对踢轨电源系统的精确控制,其时间控制精度达ns量级。ARM主要实现控制数据的下载与上传,踢轨系统的控制时序主要通过FPGA编程完成。远程时序控制信号均通过光纤传输,同时对踢轨电源的电压给定采用数字电位器技术实现,给定精度达0.1%。     

CSNS引出脉冲电源控制系统设计

基于EPICS框架设计开发的CSNS引出KICKER脉冲电源控制系统,采用ZTEC数字化示波器对脉冲电源输出信号进行实时采集,通过运行在上位计算机的EPICS soft IOC实现对电源远程开/关操作和基准电压设定。性能测试的结果表明,该系统能够满足物理设计对引出KICKER脉冲电源的控制要求。     

Study on the Current-Sharing Control System of the TF Power Supply for a Superconducting Tokamak

The superconducting toroidal field (TF) plays an important role in a superconduct-ing tokamak,whose power supply was developed based on the feedback control principle.In this paper,superconducting tokamaks in different countries are described,and the TF power sup-ply of the International Thermonuclear Experimental Reactor (ITER) is taken as an example to study the current-sharing characteristics in the current-stabilized stage.Firstly,the math-ematical model of the TF power supply is established,and then the 3-loop control method is put forward for achieving the stability and reliability of current-stabilization and current-sharing.Furthermore,further studies indicate that the current-sharing controller has no influence on the current-stabilized control,and current-stabilizing and current-sharing can be realized at the same time.All the work done provides valuable references for the current-sharing design of the TF power supply for a superconducting tokamak,and all these studies lay a solid foundation for developing superconducting tokamaks.     

托卡马克程控积分器系统的研制

为满足J-TEXT托卡马克装置电磁诊断的需求,研制了程控积分器系统。积分器系统采用模块化方式设计,由积分器板卡、控制器板卡、线性电源板卡和BNC接口板卡组成,并由上位机控制程序进行网络化控制。一套积分器系统可提供32路积分器通道,所有积分器通道均具有4种可供程控选择的积分时间常数,同时提供3种积分器运行控制方式。实验室和J-TEXT现场测试结果为：每路积分器通道的输出电压范围为-10～10 V;输出噪声≤5 mV;在4种积分时间常数条件下,积分器累计积分100 s的输出漂移均小于5 mV。     

Introduction to resonant magnetic perturbation coils of the J-TEXT Tokamak

To investigate the interactions between both the static and rotating resonant magnetic perturbations (RMP) and the tokamak plasma, two sets of coils, namely static RMP (SRMP) and dynamic RMP (DRMP), are constructed on the J-TEXT tokamak. SRMP is reconstructed from TEXT-U and mainly produces static m/n = 1/1, 2/1 and 3/1 resonant perturbation field, where m and n are the poloidal and toroidal mode numbers, respectively. DRMP, newly designed and installed inside the vacuum vessel, can generate pure 2/1 RMP. DRMP is also designed to operate in the AC mode and can produce rotating 2/1 RMP which will be used to study the tearing mode control. Due to the effect of the eddy current in the vacuum vessel wall, the amplitudes of the 2/1 component will be attenuated to about 1/3.6 of the DC value when the operation frequency is larger than 500 Hz. However, DRMP can still provide sufficient large rotating 2/1 perturbation for tearing mode related studies.