基于光弹调制的运动斯塔克效应诊断  

A Photoelastic Modulator Based MSE Spectroscopic Diagnostic on EAST

作　　者：李义超 符佳 吕波 黄耀 钱金平 罗正平 傅盛宇 李建康 魏永清[3] 刘冬梅[4] 肖炳甲[1] LI Yi-chao;FU Jia;LÜ Bo;HUANG Yao;QIAN Jin-ping;LU Zheng-ping;FU Sheng-yu;LI Jian-kang;WEI Yong-qing;LIU Dong-mei;XIAO Bing-jia(Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China;School of Instrument Science and Optoelectronic Engineering,Hefei University of Technology,Hefei 230009,China;School of Electrical and Automation Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]中国科学院合肥物质科学研究院等离子体物理研究所,安徽合肥230031 [2]中国科学技术大学,安徽合肥230026 [3]合肥工业大学仪器科学与光电工程学院,安徽合肥230009 [4]合肥工业大学电气与自动化工程学院,安徽合肥230009

出　　处：《光谱学与光谱分析》2023年第1期111-115,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(12075280);国家自然科学基金国际(地区)合作与交流项目(11911540463);中国科学院合肥大科学中心“高端用户培育基金”项目(2019HSC-UE011);国家磁约束核聚变能发展研究专项(2019YFE03040000)资助。

摘　　要：电流密度分布是等离子体物理研究的关键分布参数,在托卡马克先进运行模式发展,电流驱动,约束与输运等方面发挥着重要的作用。中性束与等离子体相互作用产生的分裂光谱,包括σ分量与π分量,水平观测时,σ分量的偏振方向垂直于等效电场的方向,π分量的偏振方向平行于等效电场的方向,通过测量分裂光谱的偏振方向可以反演出等离子体电流密度分布。基于光弹调制器的偏振检测系统具有检测精度高、时间响应迅速的独特优点,非常适用于等离子体电流快速变化下的电流密度分布测量。光弹调制器的双折射晶体在周期性外部驱动源的作用下发生弹性形变,其折射率会产生周期性的变化,当偏振光通过时,出射光的偏振特性将相应产生周期性变化,再经过偏振片,形成调制的光强变化。运动斯塔克效应(MSE)诊断的偏振检测系统由两个光弹调制器(PEM)和一个偏振片组成,通过检测不同调制频率的调制强度的比值,从而快速、精确地获得分裂光谱的偏振方向的实时变化,进而得到等离子体电流密度分布。详细介绍了东方超环托卡马克(EAST)装置上的MSE诊断,初步完成了离线测试与标定,参与中性束电流本文驱动物理实验,初步获得了等离子体电流密度分布的信息。Current density distribution is a crucial parameter in plasma physics,which plays an important role in plasma simulation,advanced operation mode development,current drive,confinement,and transport.The stark spectrum caused by injecting a neutral beam into plasma containsσcomponent,andπcomponent.When viewed transversely to the electric field,the polarization direction of theσcomponent is perpendicular to the direction of the equivalent electric field,and the polarization direction ofπcomponent is parallel to the equivalent electric field,the distribution of current plasma density can be deduced by measuring polarization direction of the splitting spectrum.The polarization detection system based on a dual photoelastic modulator system has the unique advantages of high detection accuracy and quick time response,which is very suitable for measuring current density distribution under the rapid variation of plasma current.An external driving source causes the elastic deformation of birefringent crystals,and the refractive index changes periodically,then the modulated light intensity changes are formed through the polarizer.The polarization detection system of MSE diagnostic consists of two Photoelastic Modulators(PEM)and a polarizer.By detecting the ratio of modulation intensities at different modulation frequencies,the polarization direction of the splitting spectrum can be obtained quickly and accurately,and then the plasma current density distribution can be obtained.This paper introduces the polarization detection system of MSE diagnosis on Experimental Advanced Superconducting Tokamak(EAST),The off-line test and calibration of the system were completed,and the preliminary result of plasma current density distribution was obtained in experiments.

关 键 词：光谱诊断 偏振检测 光弹调制器 

分 类 号：O433.1[机械工程—光学工程]