Design consideration and optimization procedure for a no-insulation multi-width REBCO magnet

This paper reports the optimization procedure for a no-insulation (NI) multi-width (MW) REBCO magnet, which enables the fabrication of a highly compact and competitively priced superconducting magnet. In order to identify the design considerations for the NI-MW magnet, the electromagnetic performances of 3 different magnets were investigated using the finite element method (FEM). Based on the comparison results, it was verified that the critical current distribution-factor (CCD-factor), which is the ratio of the highest pancake critical current (Ic) to the lowest pancake Ic within the magnet, should be close to 1.00 for the MW configuration to be most effective. In the optimized MW magnet, the center Bz (7.54 T) remarkably exhibited an ∼ 51% increase compared to the 4-mm single width magnet (5.00 T). Furthermore, the CCD-factor of the optimized MW magnet was 1.04, which is quite close to 1.00, sufficiently demonstrating the validity of the optimization process and result.