Reduction of Irregular Magnetic Field Generated by Screening Current in REBCO Coil

Abstract

In REBCO coils, the screening current flows in the tape in response to the normal component of the linkage flux to the tape's wide face. Generally, the radial component of the magnetic field is large at both ends of the coil winding. Therefore, changes in the winding arrangement may be expected to reduce screening current induction. Furthermore, multifilamentary or narrow REBCO tapes with widths of a few millimeters can be also expected to reduce the magnitude of the screening current. Based on the above considerations, in this paper, we numerically investigated the reduction effect on a magnetic field generated by a screening current in a REBCO coil, due to thinning tape width and varying coil winding arrangements. It was found that the screening field is inversely proportional to the number of tape filaments, whereas a smaller coil winding aspect ratio leads to a decrease in the screening field.