Investigation of phase modulation and propagation-route effect from unmatched large-scale structures for Doppler reflectometry measurement through 2D full-wave modeling

To interpret the common symmetric peaks caused by the large-scale structure in the complex S(f) spectrum from the heterodyne Doppler reflectometry(DR) measurement in EAST, a 2D circular-shaped O-mode full-wave model based on the finite-difference time-domain method is built. The scattering characteristics and the influences on the DR signal from various scales are investigated. When the structure is located around the cutoff layer, a moving radial or poloidal large-scale structure k_θ■...     

智能化无线数字传输控制系统简介

一、概述智能化无线数字传输控制系统是基于无线数据通讯技术的民用水、电、气、暖等计量仪表的抄表收费管理系统。     

Design of the Transmission Lines for 140 GHz ECRH System on HL-2A

A new 140 GHz/2 MW/3 s electron cyclotron resonance heating （ECRH） system composed of two units is now being constructed on HL-2A. As a part of the system, two trans- mission lines marked No.7 ＆ 8 play the role of carrying microwave power from two gyrotrons to the tokamak port. Based on the oversized circular corrugated waveguide technology, an evacu~ ated transmission system with high power capability and high transmission efficiency is designed. Details are presented for the design of the corrugated waveguide, the layout of the proposed lines and the vacuum pumping system. Then mode conversion losses due to coupling, misalignment, bends and gaps are discussed to serve as a reference for analyzing the transmission efficiency and alignment. Finally, a dual-modes propagation case consisting of the HEll and LPn even modes is discussed.     

A Non-neutral Plasma Device: Electron Beam Penning Trap

1.IntroductionPenningtrapshavebeenwidelyusedtotrapchargedparticles,suchaselectronsorions,forstudyonthefundamentalpropertiesofparticles,andthetransportandequilibriumpropertiesofnon--neutralplasmas[1-4].InaPenningtrap,auniformaxialmagneticfieldprovidesradialconfinement,whiletheelectricfieldbetweentheelectrodesprovidesaxialone.Thetrapcanconfineasmallnumberofchargedparticlesforverylongtime.However,becauseoftheself-electricfieldeffect,themaximumdensityofnonneutralplasma(electron)radicallyconfinedb…     

反射内存网络在托卡马克装置快控制器中的应用

本文介绍了反射内存网络在托卡马克装置快控制器中的具体应用。选用PMC-5565反射内存卡和ACC-5565网络集线器在快控制器中构建了一反射内存实时网络,并在LabVIEW RT实时操作系统下测试了基于反射内存网络的快控制器控制电源设备的实时性、快速性和延迟确定性。通过使用反射内存技术,实现了在多个快控制器之间实时同步数据的功能,可利用多台快控制器完成一个控制任务。实验结果表明,反射内存网络能满足快控制器对设备进行反馈控制的实时性要求。     

Plasma Response to Supersonic Molecular Beam Injection in J-TEXT简

Recently, hydrogen fueling experiments with supersonic molecular beam injection （SMBI） system have been performed in the J-TEXT tokamak. To evaluate the effects of the in- jection amount of SMBI on plasma behaviors, moderate and intensive SMBs have been separately injected and compared with each other in Ohmic discharges. With moderate SMBs, electron den- sity increases about twice as before, the size of magnetic island slightly decreases, and the edge toroidal rotation speed in a counter-current direction, measured by a high resolution spectrometer （Carbon V ion, 227.09 nm, r/a-= 0.7-0.8）, is accelerated from 8 km/s to 12 km/s. The state of higher electron density with moderate SMBI can be maintained for a long period, which indicates that plasma confinement is improved. However, with intensive SMBs, the accompanied magne- tohydrodynamic （MHD） activities are triggered, and the electron density increases moderately. The edge toroidal velocity is decreased, in certain cases even reversed in the co-current direction. The statistical result of experimental data for moderate and intensive SMBs suggests a preferred fueling amount （less than 3.2 ~ 1019） to improve the SMBI fueling efficiency in experiments.     

Design and platform testing of the compact torus central fueling device for the EAST tokamak

Compact torus(CT) injection is a highly promising technique for the central fueling of future reactor-grade fusion devices since it features extremely high injection velocity and relatively high plasma mass. Recently, a CT injector for the EAST tokamak, EAST-CTI, was developed and platform-tested. In the first round of experiments conducted with low parameter settings, the maximum velocity and mass of the CT plasma were 150 km·s^-1 and 90 μg, respectively.However, the parameters obtain...     

Design of the Control System of Toroidal Field （TF） Power Supply for J-TEXT Tokamak

J-TEXT, formerly TEXT-U at the University of Texas at Austin in USA, is a medium-sized tokamak at the Huazhong University of Science and Technology. The toroidal field （TF） power supply of this tokamak should provide a current of 160 kA and a flat duration of 500 ms for the toroidal field coils to generate a maximum toroidal field of 3 T at the geometric center of the vaccum vessel. This paper presents a design of a new control system which takes the real-time feedback control option for the TF power supply operation. The system was tested successfully during the commissioning. In the first experimental campaign of J-TEXT, the system effectively controlled the power supply to provide a fiat current up to 92.5 kA and therein the TF produced reached 1.74 T, which enabled the machine to generate the first plasma successfully.     

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。     

Neural Network Prediction of Disruptions Caused by Locked Modes on J-TEXT Tokamak

Prediction of disruptions caused by locked modes using the Back-Propagation （BP） neural network is completed on J-TEXT tokamak. The network, which is based on the BP neural network, uses Mirnov coils and locked mode coils signals as input data, and outputs a signal including information of prediction of locked mode. The rate of successful prediction of locked modes is more than 90%. For intrinsic locked mode disruptions, the network can give a prewarning signal about 1 ms ahead of the locking-time. For the disruption caused by resonant magnetic perturbation （RMPs） locked modes, the network can give a prewarning signal about 10 ms ahead of the locking-time.