Hot pressing of Ge crystals toward a reflection-plane-selective neutron monochromator

We determined a hot-pressing condition of temperature and pressure to fabricate a Ge-crystal monochromator. After hot pressing under the optimal condition, a reflected beam by the Ge crystals shows an appropriate peak width (~0.3° in FWHM) and an enhanced peak reflectivity (~40%). The feasibility of reflection-plane-selective monochromator, which consists of Ge crystals, is confirmed by magnetic powder neutron diffraction in the high-Q survey mode as well as in the fine Q-resolution mode.