Optical design of sub-angular second spatially resolved solar extreme ultraviolet broadband imaging spectrometer

The slit imaging spectrometer is one of the important tools for solar extreme ultraviolet (EUV) spectralimaging detection. However, at present, there is no such instrument load in China. The research of solar physicsand space weather in the field of EUV spectral diagnosis mainly depends on foreign instrument data, whichseriously restricts the development of related disciplines. The spectral imaging instruments that have beenlaunched internationally have only a spatial resolution of , and it is difficult to observe the corecharacteristics of the plasma related to the coronal heating mechanism predicted by the theoretical model. Inorder to better understand the coupling process between different layers of the sun's atmosphere, solar physicsresearch requires the observed data with wider spectral coverage. In light of this, we propose and design a sub-angular second spatially resolved solar extreme ultraviolet broadband imaging spectrometer operating in a bandrange of 62-80 nm and 92-110 nm. Compared with the existing instruments, the system can achieve highspatial resolution and spectral resolution, and wide spectral range coverage. Performance evaluation resultsindicate that the imaging spectrometer's spatial resolutions in both bands are better than 0.4'', and theirspectral resolutions are both better than 0.007 nm, with spectral imaging quality approaching the diffractionlimit. The system designed in this work holds significant reference value for developing the first Chinese space-based solar EUV spectroscopic instrument in the future