Recent ICRF coupling experiments on EAST

Recent ion cyclotron resonance frequency(ICRF) coupling experiments for optimizing ICRF heating in high power discharge were performed on EAST. The coupling experiments were focus on antenna phasing and gas puffing, which were performed separately on two ports of the ion cyclotron resonance heating(ICRH) system of EAST. The antenna phasing was performed on the I-port antenna, which consists of four toroidally spaced radiating straps operating in multiple phasing cases; the coupling performance was better under low wave number ∣k_‖∣(ranging from 4.5 to 6.5). By fuelling the plasma from gas injectors, placed as uniformly spaced array from top to bottom at each side limiter of the B-port antenna, which works in dipole phasing, the coupling resistance of the B-port antenna increased obviously.Furthermore, the coupling resistance of the I-port antenna was insensitive to a smaller rate of gas puffing but when the gas injection rate was more than a certain value(1021 s~(-1)), a sharp increase in the coupling resistance of the I-port antenna occurred, which was mainly caused by the toroidal asymmetric boundary density arising from gas puffing. A more specific analysis is given in the paper.     

Investigation of the Energy Confinement in Ohmic and LHCD Plasmas in HT-7

Investigation of the energy confinement in ohmic and lower hybrid current drive （LHCD） plasmas in HT-7 has been performed. In ohmic discharges at low densities the global energy confinement time rE increases almost linearly with the density, saturates at a critical density （2.5×10^13/cm^3 for HT-7） and is nearly constant at higher densities. The energy confinement time is in good agreement with the Neo-Alcator scaling law at different densities and currents. In the LHCD plasmas the global energy confinement time similar to that of the L-mode discharges has been observed to be in good agreement with the low confinement mode （L mode） scaling law of ITER89-P in higher electron density and plasma current.     

配电箱温湿度自控门禁监测终端

随着科技的发展,很多智能化的终端运用到低压配电箱中,本文主要介绍了目前配电箱的现状,并研究了温湿度自控门禁监测终端的工作原理,及其应用在配电箱中带来的作用与效益。以求加快温湿度门禁自控终端在配变箱的应用,提高工作效率,延长配电箱中电力设备的寿命。     

多媒体课件在英语教学中的运用

息技术是21世纪教育的重要手段,它打破了传统的教学手段,集声,像,形,色于一体,在英语课堂教学观指导下实现了教材原有文本的拓展和完善,实现了超文本与文本的统一,体现了结构的开放性和信息的多元性化,为打造精彩的英语课堂提供了功能强大的平台.     

A Dip Structure in the Intrinsic Toroidal Rotation Near the Edge of the Ohmic Plasmas in EAST

Ion＇s toroidal velocity, vt, in both the outermost 4 cm of the confined region and the scrap-off layer of Ohmic L-mode plasmas in EAST was measured using Mach p...     

Vertical Instability in EAST： Comparison of Model Predictions with Experimental Results

Growth rates of the axisymmetric mode in elongated plasmas in the experimental advanced superconducting tokamak （EAST） are measured with zero feedback gains and then compared with numerically calculated growth rates for the reconstructed shapes. The comparison is made after loss of vertical position control. The open-loop growth rates were scanned with the number of vessel eigenmodes, which up to 20 is enough to make the growth rates settled. The agreement between the growth rates measured experimentally and the growth rates determined numerically is good. The results show that a linear RZIP model is essentially good enough for the vertical position feedback control.     

Algorithm Validation of the Current Profile Reconstruction of EAST Based on Polarimeter/Interferometer

The method of plasma current profile reconstruction using the polarimeter/interferometer(POINT) data from a simulated equilibrium is explored and validated.It is shown that the safety factor(q) profile can be generally reconstructed from the external magnetic and POINT data.The reconstructed q profile is found to reasonably agree with the initial equilibriums.Comparisons of reconstructed q and density profiles using the magnetic data and the POINT data with 3%,5%and 10%random errors are investigated.The result shows that the POINT data could be used to a reasonably accurate determination of the q profile.     

Spontaneous current relaxation in NBI heated plasmas on EAST

We report on current profile evolution in EAST NBI driven plasmas where two neutral beams are injected,one during the current ramp phase and the second during flattop.At the end of the current ramp phase,it is found that a flat q profile with q0?~?1 is achieved with low magnetic shear in the core.It is observed that plasma current and density both relax much faster than resistive time,even in the absence of sawtooth activity when H–L transition occurs.Density fluctuations associated with magnetic perturbations(3/2) as a precursor to the H–L transition are observed.It is likely that these modes play a role in fast current transport.     

Ideal MHD Stability Prediction and Required Power for EAST Advanced Scenario

The Experimental Advanced Superconducting Tokamak(EAST) is the first fully superconducting tokamak with a D-shaped cross-sectional plasma presently in operation.The ideal magnetohydrodynamic(MHD) stability and required power for the EAST advanced tokamak(AT) scenario with negative central shear and double transport barrier(DTB) are investigated.With the equilibrium code TOQ and stability code GATO,the ideal MHD stability is analyzed.It is shown that a moderate ratio of edge transport barriers’(ETB) height to internal transport barriers’(ITBs) height is beneficial to ideal MHD stability.The normalized beta βN limit is about 2.20(without wall) and 3.70(with ideal wall).With the scaling law of energy confinement time,the required heating power for EAST AT scenario is calculated.The total heating power Pt increases as the toroidal magnetic field BT or the normalized beta βN is increased.     

Diagnostics of Internal Inductance in HT-7

1. IntroductionMagnetic measurements have been used exten-sively since the early days of tokamaks. Many prop-erties of a tokamak plasma can be determined byusing simple loops or coils of wire. Basic measurements aJre for the plasma current, loop voltage,plasma position and shape, stored plasma energy,and current distribution. InfOrmation about instabilities [l] is also obtained. For efficient operationsof these tokarnaks, it is essentiaJ to have a fast, y6tan accurate method for the deterndn…