Abstract
A three-dimensional neutron depolarization beamline was commissioned in Tsing-Hua Open Pool Reactor (THOR). In this beamline, with the neutron depolarization technique, provides information of the mean domain size, the mean square direction cosine of the magnetic induction in the domains, and the mean magnetization of a magnetic sample. In this work, the surface magnetic domain and inner magnetic domain of Ni-ferrite samples with different densities are studied. The MFM results show the surface magnetic domain size is about 2 □m, which is consistent with 2 □m of inner magnetic domain size measured by depolarized neutron technique. In addition, the problems of improving the polarization ratio of neutron beamline were discussed. The final polarization factor of this beamline is 92%.