Optical design and coating optimization of the Wolter-I X-ray telescope

The optical design of the nested paraboloid and hyperboloid Wolter I X-ray telescope of the eXTP satellite in the 1-8 keV band was systematically studied. The recursive relationship of nested structures is derived, and an analysis is conducted on the influence of initial parameters on performance. Considering the requirements of X-ray astronomical observation in China, we propose the initial structure of the model and design seven groups of Au/C/Ni non-periodic dual-layer coatings between the innermost and outermost layers of the mirror. The effective area, half-power diameter, and stray light were calculated in the simulation. The results show that the effective area can reach 1000 cm(2) at 2 keV, the effective area can reach 890 cm(2) at 6 keV without hub obscuration, the half-power diameter is 10 arcsec, and the proportion of stray light is 4.2%. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI)training, and similar technologies, are reserved.