Magnetic imaging of an AC field applied electric steel using polarized pulsed neutrons at J-PARC/MLF

J-PARC/MLFにおける偏極パルス中性子磁気イメージングによる交流磁場印加電磁鋼板の観察

廣井 孝介  ; 篠原 武尚   ; 林田 洋寿*; Parker, J. D.*; 及川 健一   ; 原田 正英   ; Su, Y. H.  ; 甲斐 哲也   

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

Electric steels are widely used as a key material in magnetic industrial products, whose magnetic properties define the performance and energy efficiency. Since the magnetic properties of an electric steel strongly depends on the internal domain structure, understanding of the domain structure and its response to an AC magnetic field is necessary for improving energy efficiency of electric devices. In this study, we aim to visualize both the internal domain motion of an electric steel under the AC field and the leakage field emanating from it. A ring-shaped grain oriented Fe-Si steel was used as a sample, which was magnetized by an AC field produced by a coil wound around it. Polarization images were obtained by the time-of-flight method and then wavelength dependent polarization was analyzed around the boundary of an easy-to-magnetize region and a hard-to-magnetize region of the steel sample. In this presentation we will show the polarization imaging results of the AC field applied electric steel and discuss the dynamic behavior of the leakage field from the steel sample and the magnetic structure within it.