A Numerical Analysis of Pulsed-Field Magnetization Characteristics of REBCO Bulk Magnets When Using Various Soft-Iron Yokes

We aim to improve the magnetizing efficiency while maintaining the trapped magnetic field of REBCO bulk magnets activated by pulsed-field magnetization (PFM). Recently, we performed numerical analysis using a 3D simulation model based on our bulk PFM system and estimated the magnetizing characteristics when using disk-, ring-, and cross-shaped yokes. In this paper, a detailed analysis model that accounts for the inhomogeneity of the REBCO bulk is created, and the magnetizing properties are evaluated at different temperatures and applied fields. Comparison of the experimental and numerical results for the dependence of the total magnetic flux on the applied magnetic field shows a similar trend of change. From the results of the time variation of the one-dimensional magnetic field distribution in the ascent and descent processes of the applied field, we can reproduce the experimentally confirmed fact that the magnetic flux enters from the GSR and is trapped in the GSR by considering the difference in the
J_c
of the GSB and the GSR in the analysis. Furthermore, it was confirmed not only in the previous experiment but also in the present analysis that the GSB arrangement of the cross-type yoke enables efficient magnetization.