Novel magnetic field imaging technique using pulsed polarized neutrons

Shinohara, Takenao   ; Kai, Tetsuya   ; Hiroi, Kosuke  ; Oikawa, Kenichi   ; Su, Y. H.  ; Hayashida, Hirotoshi*; Matsumoto, Yoshihiro*; Parker, J. D.*; Kiyanagi, Yoshiaki*

Visualization of magnetic field in materials or a surrounding space is one of the important techniques to understand magnetic properties of objects. Since the neutron has a magnetic moment, it is possible to sense the magnetic field directly. As a result, the neutron spin state changes depending on the magnetic field strength and direction in the passage along which neutron travels changes. Especially because the neutron spin rotation around the magnetic field vector can be measured by means of the polarization analysis, visualizing magnetic field distribution becomes possible by the position dependent neutron polarization measurements. Recently the authors have developed a neutron imaging facility, named RADEN, at the Materials and Life Science Experimental Facility (MLF) in the J-PARC, and have installed a polarimetry apparatus for the three-dimensional neutron polarization analysis to conduct pulsed polarized neutron imaging experiments.