【摘要】 对于磁约束聚变实验装置,磁探针诊断是一种基础又非常重要的研究等离子体磁涨落的诊断.中国首台准环对称仿星器(Chinese First Quasi-axisymmetric Stellarator, CFQS)实验运行的第1阶段(也称为CFQST准环对称仿星器)的物理实验研究需要磁探针诊断提供相应的等离子体磁涨落测量.本文报道了在CFQST准环对称仿星器上新研制的高频磁探针阵列诊断,其由8个相同的三维高频磁探针组成,每个高频磁探针可以同时测量极向、径向及环向3个方向的磁涨落信号;优化的空间布置使得高频磁探针阵列可以用于研究磁涨落的极向和环向传播特征,其最高环向模数分辨相比于低频磁探针阵列的n=±6提高至n=±16.本文将简要介绍高频磁探针阵列诊断的机械系统、信号传输线、采集与控制系统等主要子系统及在研制各系统过程中克服的挑战,以及对高频磁探针的有效面积标定和原位频率响应标定的研究结果, CFQS-T高频磁探针每个测量方向的共振频率均大于400 k Hz,满足测量50—300 k Hz高频磁涨落的设计需求.初步的应用研究显示高频磁探针阵列诊断可用于低频和高频磁涨落的时频谱、极向和环向传播分析,值得注意的是,本文首次报道了对CFQS-T上高频磁涨落的测量分析结果.高频磁探针阵列诊断的成功研制有助于CFQS-T深入开展等离子体电磁涨落的相关研究.更多还原

【Abstract】 For magnetic confined fusion devices,magnetic probe diagnostic is a basic but very important diagnostic tool for studying plasma magnetic fluctuations.The first experimental phase of the Chinese First Quasiaxisymmetric Stellarator(CFQS),which is also called CFQS-T,needs magnetic probe diagnostics to provide plasma magnetic fluctuation measurements,especially the high-frequency(50≤f≤300 kHz) magnetic fluctuation measurements.In this paper,a newly developed high-frequency magnetic probe array(HFMPA)diagnostic on the CFQS-T is reported.This array consists of 8 identical three-dimensional high-frequency magnetic probes,each of which can simultaneously measure magnetic fluctuations in the poloidal,radial and toroidal directions.The HFMPA magnetic probes are carefully mounted on the inner vacuum vessel wall of the CFQS-T,and their positions are precisely measured by the laser tracker system.The HFMPA can be used to study the poloidal and toroidal propagation characteristics of magnetic fluctuations due to the optimized spatial arrangement,and its maximum toroidal mode number resolution is improved to n=±16 compared with n=±6 of the low-frequency magnetic probe array(LFMPA,used for the f≤ 50 kHz magnetic fluctuation measurements).The main subsystems of the HFMPA diagnostic,such as the mechanical system,signal transmission lines,acquisition and control systems,and the challenges overcome in the development of each subsystem,will be briefly introduced in this paper.The effective areas of the HFMPA magnetic probes are calibrated by the relative calibration method,which shows that their areas are all around 0.02 m~2.The in-situ frequency response of the HFMPA magnetic probes is calibrated with an LCR digital bridge with a maximum working frequency of 10 MHz.The resonance frequency of the HFMPA magnetic probe in each measurement direction is greater than 400 kHz,which meets the design requirements for measuring 50-300 kHz highfrequency magnetic fluctuations in CFQS-T.Preliminary applications of the HFMPA diagnostic in studying the low-frequency(1.5-16.0 kHz) magnetic fluctuations and high-frequency(65-105 kHz) magnetic fluctuations in CFQS-T are briefly introduced,which shows that the HFMPA diagnostic works well for providing the spectrogram,poloidal,and toroidal propagation information of low-frequency and high-frequency magnetic fluctuations.It is worth noting that the measurement and analysis results of high-frequency(65-105 kHz)magnetic fluctuations in CFQS-T are reported for the first time in this paper.The successful development of the HFMPA diagnostic will help to carry out in-depth research on plasma magnetic fluctuations in CFQS-T stellarator.更多还原