X‐Ray Interferometry and Space Instrumentation

In x‐ray astronomy the technique of interferometry has the potential to provide ultra‐high angular resolution imaging of at least 100 μas and possibly 1 μas, which would be good enough to image the event horizon of a black hole. At the University of Leicester we are proposing a practical x‐ray interferometer to give 100 μas angular resolution, which can be built using current x‐ray optics capabilities and existing detector technology. The complete instrument would be about 20 m long and about 2 m in diameter. The key to the design is the use of a slatted mirror to combine the two beams. Simulations and recent measurements of an optical demonstrator have been encouraging.