Seya-Namioka类型真空紫外光谱系统的研制和性能测试  

Development and Performance Test of a Seya-Namioka Vacuum Ultraviolet Spectroscopy System

作　　者：沈永才 钮雨凡 孔德峰 叶扬 张寿彪 李大创 谭名昇 黄艳清 赵志豪 訾鹏飞 张小辉 文斐 SHEN Yong-cai;NIU Yu-fan;KONG De-feng;YE Yang;ZHANG Shou-biao;LI Da-chuang;TAN Ming-sheng;HUANG Yan-qing;ZHAO Zhi-hao;ZI Peng-fei;ZHANG Xiao-hui;WEN Fei(School of Physics and Materials Engineering,Hefei Normal University,Hefei 230601,China;Institute of Energy,Hefei Comprehensive National Science Center,Hefei 230031,China;Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,China;School of Physics and Electronic Engineering,Hengyang Normal University,Hengyang 421008,China;School of Computer Science and Information Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥师范学院物理与材料工程学院,安徽合肥230601 [2]合肥综合性国家科学中心能源研究院(安徽省能源实验室),安徽合肥230031 [3]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 [4]衡阳师范学院物理与电子工程学院,湖南衡阳421008 [5]合肥工业大学计算机与信息学院,安徽合肥230009

出　　处：《光谱学与光谱分析》2024年第8期2158-2165,共8页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(12205072);安徽高校协同创新项目(GXXT-2021-029,GXXT-2021-014);合肥综合性国家科学中心能源研究院项目(19KZS205,21KZS202);合肥师范学院2022年度引进高层次人才科研启动基金项目(2022rcjj07);合肥师范学院横向课题(HXXM2022019,HXXM2022051)资助。

摘　　要：为了满足磁约束核聚变领域的杂质测量要求,研制了一套Seya Namioka真空紫外光谱仪。该光谱仪的主要部件是可调宽度的入射狭缝、凹面光栅和探测器。光谱仪的光通量通过可调节宽度的入射狭缝来调节,入射狭缝宽度可以在10~1000μm范围内调节。分光元件选用线密度为1200 lines·mm^(-1)的凹面全息光栅。光栅表面涂有铝(Al)和氟化镁(MgF2),以提高衍射效率。光栅的可使用波段为50~460 nm,针对其中的50~250 nm波段进行光路优化设计。选用深度制冷背照式电荷耦合器件(CCD)作为光谱仪的探测器。通过转动光栅转台旋转光栅来改变衍射角,实现50~250 nm范围内的光谱观测。基于凹面光栅的参数,确定了具体光路,并分析了波长随光栅旋转角度的变化关系及不同波长处的线色散率。基于凹面光栅成像理论,对系统的光谱分辨率进行了计算分析。通过分析不同出射臂下的光谱分辨率,确定最优出射臂为205 mm。在出射臂为205 mm、入射狭缝为20μm的情况下,分析了入射狭缝宽度、像素大小、像差和衍射极限对光谱分辨率影响。结果表明:衍射极限对光谱分辨率的影响最小,基本上可以忽略不计,出射狭缝的宽度对光谱分辨率有较大贡献,大约为0.09~0.10 nm,且在50~250 nm波长范围内缓慢增加。分析了不同入射狭缝宽度(10~80μm)下光谱分辨率,光谱分辨率随狭缝宽度呈递增趋势,变化范围为0.10~0.32 nm,当狭缝宽度达到80μm时,光谱分辨率已经变的较差,不利于高分辨线辐射光谱测量。在实际测量中,应该综合考虑光通量和光谱分辨率需求。采用低压汞灯和微波等离子体光源进行波长校准和性能测试。基于零阶光谱和汞灯的特征光谱HgⅠ(185 nm)对光谱仪进行了波长标定。通过HgⅠ(185 nm)谱线的高斯拟合分析,得到仪器在185 nm处的光谱分辨率为0.1243 nm,与理论计算值接近。通过实验与理论计算对比不同Impurity behavior study is very important in magnetic confined fusion research as impurity may cause the dilution of fuel ions,affect the power balance,and degrade plasma performance.Spectroscopic diagnostic is important for impurity measurement and transport study in fusion devices.Spectroscopy in the vacuum ultraviolet(VUV)range offers a useful tool for investigating impurity radiation from low-temperatureareasof edge tokamak plasma.To meet the impurity measurement requirement in fusion research,a Seya-Namioka spectrometer was designed,and the main parts of the spectrometer are adjustable width incident slits,concave gratings,and a detector.The luminous flux of the spectrometer is adjusted through an adjustable width of the incident slit,which is of the linear guide type.The position of the incident slit baffle is adjusted through the linear guide to achieve slit width adjustment.The grating surface is coated with aluminum(Al)and magnesium fluoride(MgF_(2))to enhance the refractive efficiency.The usable wavelength range of the grating is 50~460 nm,and the optical path optimization design is carried out for the 50~50 nm wavelength range.The spectrometer's detector was chosen as a deeply cooled back-illuminated charge-coupled device(CCD).By turning the grating turntable to rotate the grating and change the diffraction angle,spectral observations in the 50~250 nm range can be achieved.Based on the parameters of the concave grating,the specific optical path was determined,and the relationship between wavelength and grating rotation angle,as well as the line dispersion rate at different wavelengths,was analyzed.According to the theory of concave grating imaging,the spectral resolution of the system was calculated and analyzed.The optimal exit arm was determined to be 205 mm by analyzing the spectral resolution under different exit arms.The effects of incident slit width,pixel size,aberration,and diffraction limit on spectral resolution were analyzed with an exit arm of 205 mm and an incident slit of 20μm.The main c

关 键 词：真空紫外光谱仪 凹面全息光栅 光谱分辨率 波长标定 

分 类 号：O433.1[机械工程—光学工程]