Simulation on Electrical Field Generation by Hall Effect in No-Insulation REBCO Pancake Coils

The no-insulation (NI) winding technique is one of the most promising high-temperature superconducting (HTS) coil protection methods to realize the practical use of HTS magnets. Many NI REBa
₂
Cu
₃
O
₇
-x (REBCO, RE = Rare Earth) magnets have been developed to generate ultrahigh magnetic fields for NMR or MRI magnets. When NI REBCO magnets are operated in a high magnetic field, uncommon phenomena can be observed, because the NI REBCO magnets have multicomplicated current paths. An unexpected voltage rise was experimentally observed during charging NI coils or after quench. The cause of such a voltage rise cannot be explained by means of a partial element equivalent circuit method, which was proposed to clarify such complicated current behavior. We think one of causes is an electric field generation by Hall effect. In this paper, therefore, we will investigate the electrical field behavior of NI REBCO coils by Hall effect. An unforeseen voltage would appear between terminals.