Follow this link to skip to the main content


The concept involves an assembly of two mirrors, mounted in tandem, with highly polished reflecting surfaces set at very shallow angles. The forward mirror is parabolic. The rear is hyperbolic.

X-rays entering the assembly barely graze the surfaces of the two mirrors, reflected rather than being absorbed or simply passing through the mirrors. The x-rays are concentrated and focused at a point.

AXAF design configuration is a double array assembly of six nested and concentrically mounted cylinder-like mirrors. The x-rays are focused roughly ten meters back from the mirror assembly.

With an outer diameter of 1.2 meters and an effective area of 1600 square centimeters, the AXAF mirror is the largest of its type.

Video shows the two curved mirrors of AXAF conctrating the X-rays and focusing them at a point.


A service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/GSFC

NASA Logo, National Aeronautics and Space Administration