Johansson-type Point-focusing Monochromator Crystal Realized by Hot Plastic Deformation of Ge Single-crystal Wafer

摘要

The realization of a point-focusing monochromator to increase the intensity of the X-ray beam from a conventional X-ray generator without having to broaden it at the focus has long been one of the most important aims in X-ray instrumentation. We realize such a monochromator with moderate angular resolution and high photon flux by using the hot plastic deformation of a Ge single-crystal wafer.In 1933, Johansson proposed an advanced design of a curved crystal with its surface exactly on the focusing circle. Generally, the deformation of perfect crystals into an arbitrary shape for compact optics without deteriorating the crystal quality is not possible. Therefore, previous work has mostly concentrated either on small and precise deformation without introducing lattice defects or on large deformation with relatively broad diffraction peaks.