915 MHz/1 kW连续波固态源测控系统设计

为了保障915 MHz/1 kW连续波固态源能稳定可靠地运行,设计了一个基于嵌入式的测控系统。在分析系统原理和设计思路的基础上,给出了系统的硬件电路和软件流程,并进行了实验测试和结果分析。该系统通过使用DMA配合多路ADC采样,实现了对温度、入射功率、反射功率的实时检测;通过使用数据拟合和变积分PID控制算法,实现了对输出相位及功率的控制;通过控制定时器和PIN开关,实现了对固态源异常工作状态下的报警和保护。实验表明,该测控系统能实现对固态源的监测、控制和保护,控制精度能达到预期要求。     

Development and Preliminary Commissioning Results of a Long Pulse 140 GHz ECRH System on EAST Tokamak(Invited)

A long pulse electron cyclotron resonance heating(ECRH)system has been developed to meet the requirements of steady-state operation for the EAST superconducting tokamak,and the first EC wave was successfully injected into plasma during the 2015 spring campaign.The system is mainly composed of four 140 GHz gyrotron systems,4 ITER-Like transmission lines,4 independent channel launchers and corresponding power supplies,a water cooling,control &inter-lock system etc.Each gyrotron is expected to deliver a maximum power of 1 MW and be operated at 100-1000 s pulse lengths.The No.1 and No.2 gyrotron systems have been installed.In the initial commissioning,a series of parameters of 1 MW 1 s,900 k W 10 s,800 k W 95 s and650 k W 753 s have been demonstrated successfully on the No.1 gyrotron system based on calorimetric dummy load measurements.Significant plasma heating and MHD instability suppression effects were observed in EAST experiments.In addition,high confinement(H-mode)discharges triggered by ECRH were obtained.     

基于Qt4的LHCD相位控制软件的设计

低杂波相位控制软件是实现低杂波相位自动控制的重要组成部分,它可以完成对低杂波相位检测电路的输出数据进行读取和处理,并通过相位反馈来驱动移相器以达到调节低杂波天线上主波导之间的相位差和控制波谱分布的目的。基于Qt的LHCD相位控制软件使用C++应用程序框架Qt作为开发工具,利用信号与槽机制,多线程机制,Qt定时器以及Qt绘图工具等软件技术进行编写。相位控制软件在模拟实验中已经实现了其主要功能,期望在实际应用中得到进一步验证。     

Experimental Investigation of Lower Hybrid Wave Coupling in HT-7

Experiments on lower hybrid wave(LHW)coupling were investigated in the HT-7 tokamak.Good coupling of LHW plasma has been demonstrated at different conditions in the HT-7 tokamak.Relevant results have proved that LHW-plasma coupling is affected by the phase difference between adjacent waveguides.Furthermore,the edge density around the grill and relevant coupling can be adjusted by changing the plasma line average density or the gap value between the LH grill and the last closed flux surfaces(LCFS).It is found that the coupling of LHWs becomes poor when the edge density around the LH grill is large enough in the HT-7tokamak,and that coupling remains good with a proper edge density.With increasing LHW power,it is also found that the reflection coefficients(RCs)increase due to non-linear effects under conditions of low edge recycling,but can decrease under high edge recycling.The edge density depends mainly on the competition between the ponderomotive force(PMF)and the edge recycling intensity in the HT-7 tokamak.