Silicon pore optics: design and feasibility of a 4-m focal length x-ray telescope

Silicon Pore Optics (SPO) has been developed to create lightweight x-ray telescopes with a substantial collecting area. SPO is a key component of ESA's next-generation flagship observatory, NewAthena, which features a 2.6-meter diameter aperture composed of up to 600 co-aligned mirror modules (12m focal length). In this paper, we explore the versatility of SPO by applying it to a shorter telescope design with a 4-meter focal length. By customizing the plate length, the number of plates in each module, and the arrangement of the modules, we develop an innovative design providing effective area in the 0.2 keV to 2 keV band, reaching ~3000 cm² at 1 keV. The Wolter-Schwarzshild configuration, together with the tight plate nesting afforded by SPO, provides a field of view larger than 30 arc minutes. This performance matches the requirements of mission concepts like ExCEED, where a fast optics is needed. Compared to NewAthena, no major change is required for the manufacturing of the mirror modules, meaning that the high technology readiness level of SPO applies, and all the mass-production equipment equipment currently being implemented can be used.