High efficiency, high quality x-ray optic based on ellipsoidally bent highly oriented pyrolytic graphite crystal for ultrafast x-ray diffraction experiments.

By the use of a thin highly oriented pyrolytic graphite crystal (HOPG) bent to a high-performance ellipsoidal shape it was possible to focus monochromatic x-rays of 4.5 keV photon energy with an efficiency of 0.0033, which is 30 times larger than for previously used bent crystals.