极紫外平场光栅光谱仪的研制和性能测试

研制了一台高分辨率极紫外光谱仪，用于磁约束等离子体诊断。采用一块具有平场特性的全息球面变线距光栅作为分光元件，光栅公称线密度为1 200 lines·mm-1，掠入射角为3°。一台可深度制冷、背照式面阵CCD作为光谱探测器，用机械快门控制曝光时间。通过CCD在光谱聚焦面的移动，可以记录的光谱范围为5～50 nm。用Penning放电光源测试了光谱仪的性能; 利用光源的标准谱线，进行了波长标定，波长精度为0.003 nm，并计算出系统各参数的实际值;当入缝宽度设置为30 μm时，在20 nm附近，光谱分辨率达0.015 nm，达到设计指标。

EUV Flat Field Grating Spectrometer and Performance Measurement

A high-resolution extreme ultraviolet (EUV) spectrometer has been developed to diagnose the magnetically confined plasmas. A holographic spherical varied line spacing concave grating which provides a flat focal plane is used as the diffraction element working with the grazing incidence angle of 3°. The nominal groove density is 1 200 lines·mm-1. A deeply cooled back-illuminated CCD camera is used as the spectra detector and a mechanical shutter is used to control the time of exposure. It covers the wavelength range of 5~50 nm with the CCD cameral moving along the spectra focal plane to cover different wavelength range interested. Spectrometer design is presented and it was tested by a Penning discharge light source. By the wavelength calibration, the actual parameters of the optical system were calculated and the wavelength accuracy is 0.003 nm. Results show that the spectral resolution is about 0.015 nm at 20 nm with the width of entrance slit opened at 30 μm, which agrees with the design goal.