介绍了东方超环(experimental advanced supereonducting tokamak, EAST)托卡马克上的两套快速极紫外(EUV)光谱仪系统波长的原位标定方法、 结果及其应用。 这两套谱仪均为掠入射平场谱仪, 时间分辨均为5 ms·frame-1。 两套谱仪分别工作在20～500和10～130 的波段范围, 由步进电机控制探测器在焦平面上移动实现整个观测波段上的波长扫描。 利用这两套谱仪系统观测极紫外波段光谱, 计算EAST中低-高Z杂质离子特征线辐射强度随时间的演化, 监测和研究等离子体中杂质的行为。 高Z杂质尤其是钨、 钼等金属元素, 发出的EUV波段光谱的构成非常复杂, 准确识谱对谱仪精确的波长测量能力以及谱分辨能力要求很高, 因此精确的波长标定是识别钨、 钼等高Z杂质谱线以及研究它们行为的最关键的技术之一。 利用EAST等离子体中类氢到类铍的低、 中Z杂质的特征谱线以及它们的二阶甚至三阶谱线, 结合谱仪系统的色散能力, 对这两套快速极紫外光谱仪的波长进行了精确的原位标定。 用于波长标定的杂质谱线有O Ⅷ 18.97 , O Ⅶ 21.60 , C Ⅵ 33.73 , Li Ⅲ 113.9 , Li Ⅲ 135.0 , Li Ⅱ 199.28 , Ar ⅩⅤ 221.15 , He Ⅱ 256.317 , He Ⅱ 303.78 , Ar ⅩⅥ 353.853 及C Ⅳ 384.174 等。 利用波长标定的结果对观测到的EUV光谱进行谱线识别, 两套谱仪观测到的绝大多数谱线波长与美国技术标准局(National Institute of Standards and Technology, NIST)数据库的标准波长相差分别小于0.08和0.03 。 开发了谱仪波长原位标定程序模块, 将这个模块内嵌到谱仪数据实时上传的交互式软件中, 实现了全谱数据以及特征谱线强度随时间演化数据的实时处理和上传。 同时利用开发的全谱分析交互式软件以及EAST上的数据查看软件, 最终实现了快速EUV谱仪自采数据的准实时分析、 读取和查看。

In this work, the in-situ wavelength calibration method for the newly installed fast-time-response Extreme Ultraviolet (EUV) Spectrometers on EAST is introduced and the result and its application are described. Both of the spectrometers are grazing incidence flat-field spectrometers with temporal resolution of 5 ms·frame-1. The two spectrometer works at 20～500 and 10～130  respectively, and wavelength scanning is done by moving the detector along the focal plane. The impurity behavior is monitored for EAST operation with observed EUV spectrum and the calculated time evolution of impurity line intensity. High spectral resolution and capability of accurate wavelength measurement is required for line identification of EUV spectra from high-Z impurities especially tungsten, due to the complexity of the spectrum composition. Exact wavelength calibration is therefore one of the key techniques for the tungsten spectroscopy diagnosis and tungsten behavior study. Emission lines from hydrogen-, helium-, lithium- and beryllium-like low- and medium-Z impurities, e. g., O Ⅷ 18.97 , O Ⅶ 21.60 , CⅥ 33.73 , CⅥ 40.27 , LiⅢ 113.9 , LiⅢ 135.0 , LiⅡ 199.28 , ArⅩⅤ 221.15 , HeⅡ 256.317 , HeⅡ 303.78 , ArⅩⅥ 353.853 , CⅣ 384.174 , and their 2nd even 3rd order emission lines are used to perform the in-situ wavelength calibration for the two EUV spectrometers in the whole wavelength range. Line identification is then carried out with the result of wavelength calibration. It is found that for most of the emission lines the difference between observed wavelength and their standard value is very small, e. g., ≤0.08  and ≤0.03  for the spectrometer working at 20～500 and 10～130 , respectively. A module for the in-situ wavelength calibration is developed and is inserted into the interactive software developed for real-time data upload, which realizes a real-time upload of the calibrated EUV spectra and calculated time-evolution of line intensity to the EAST data server. Meanwhile, the interactive software for spectrum analysis and visualization is also developed, combining with the use of the routine EAST data visualization tools, the quasi real-time analysis, reading and visualization of EUV spectrometer data are realized during the EAST operation.