Magnetic field effects on dynamical diffraction of neutrons by perfect crystals

Experiments have been performed on the effect of magnetic fields on dynamical diffraction phenomena of neutrons, using a perfect Si crystal in symmetric Laue geometry. A crystal collimator was used to define the incoming beam. The small change of neutron wavelength when entering a modest magnetic field results in large changes of neutron-propagation direction within the crystal. Energy changes as small as ${10}^{-8\mathrm{}}$ eV were detectable in the system by observing these directional changes. By combining prism refraction with the magnetic field action, the polarized states could be separated within the crystal and the polarization of these separated beams was studied.