Application of hot-pressed Ge-crystal monochromators for reactor-based neutron beam experiments

A renewed Ge-crystal monochromator was installed in a neutron spectrometer at JRR-3. The beam size at the sample position is vertically about 1.5 times as large as before, while the neutron luminosity is unchanged. Wellcollimated, monochromatic beams with quite different incident energy (Ei) are available through a slight rotation in the monochromator-crystal angle by making use of discrete Bragg reflections of Ge. The ability of inelastic-neutronscattering measurements is examined through observation of magnetic Brillouin scattering with extremely high resolution and with a supplementary use of two Eis.