Magnetic field imaging of a model motor under driving state using polarized pulsed neutron imaging

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

Quantification of a magnetic field in an electric motor under driving state and comparing it with the designed value are important in developing high efficiency motors. However, measuring techniques of field distribution in the motor has not been established so far. Magnetic field imaging technique using polarized pulsed neutrons is thought to be a promising method to quantify field distribution in the rotating motor. In this study, we observed field distribution in a rotating model electric motor using polarized pulsed neutron imaging at BL22 RADEN in MLF. The model motor was driven by an AC current whose frequency was 21.5 Hz and temporal changes in polarization distribution of the rotating motor was measured by means of the AC field imaging technique. We successfully observed change in polarization distribution between driving and static state, which is caused by the energy loss of the motor driving.