KB Silicon Pore Optics for high-angular-resolution hard X-ray telescope

We present a concept of hard X-ray telescope that could realistically reach angular resolution of arc- second level. The optics is based on Kirkpatrick-Baez (KB) configuration realized with Silicon Pore Optics (SPO) technology. SPO has been developed for 15 years at cosine (The Netherlands) for the European Space Agency's next generation large X-ray telescope, NewAthena. It provides all the elements to realise a high-angular-resolution KB optics. In this configuration the plates only need a slight meridional curvature and are flat in the sagittal direction, which reduces drastically the stress they undergo, and consequently the formation of slope errors. SPO is well suited for KB configuration as the ribs running along the plates block efficiently stray light. Without sagittal curvature, the KB mirror modules can be designed for the very small grazing incidence required for reflectivity at high energies. This type of telescope could be well suited for solar physics or astrophysics as a complement to NewAthena.