Quantitative magnetic field imaging by polarized pulsed neutrons at J-PARC

One of the most interesting applications of neutron imaging is that it enables the observation of magnetic field. Because the interaction between the neutron spin and the magnetic field depends on the neutron energy, it is important to study the neutron energy dependence of magnetic field imaging to quantitatively treat the characteristics of the magnetic field. In this study, we have performed a polarized pulsed neutron imaging experiment using a time-of-flight method at J-PARC and have analyzed the energy dependence of the obtained polarization image. We have also quantitatively analyzed the strength and the direction of the magnetic field relative to the quantized axis inside a solenoid coil.