Development of a polarization analysis method for visualization of the magnetic field distribution in a small electric transformer using pulsed polarized neutron imaging

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

We have been developing magnetic imaging method for industrial products using polarized pulsed neutrons. In this presentation, we report observation results of magnetic field distribution in a small electric transformer as a demonstration of our magnetic imaging method. The polarized pulsed neutron imaging experiment was performed at BL22 RADEN at MLF of J-PARC. 9 polarization distribution images were obtained with changing incident polarization and analyzing direction in 3D. By analyzing wavelength dependent polarization position by position, distribution of field strength and direction around the core of the transformer were successfully visualized. Obtained field distribution images were well corresponded with that expected by the simulation and clearly demonstrated a leaked field from the gap of step lap.