Effect of mirror curvature on the angular resolution of silicon pore optics

ESA’s upcoming X-ray telescope Athena uses Silicon Pore Optics, and relies on over 90.000 precisely shaped mirror plates, which must work in tandem to produce a clear image. Mirror sections must therefore both work by themselves and be correctly integrated into a larger assembly. Assessing the impact of imperfections in this mirror geometry is an important part of mission development. This paper presents an analysis of the effect of geometric imperfections on the performance of high-energy reflective optics. It uses Athena as a case study to show the impact of deformations and misalignment of the mirrors on the effective area and angular resolution of the telescope. This is achieved by using the Silicon Pore Optics Raytracing Tool, to simulate observations of astronomical sources, and to assess how these are affected by geometrical imperfections in the mirror assembly.