Optimal Design Methodology of Multiwidth HTS Magnet for Minimum Wire Consumption

This paper investigates an optimal design methodology for multiwidth (MW) high-temperature superconductor (HTS) magnets, where pancake coils wound with the narrowest tapes were placed at and near the magnet center and those with progressively wider tapes toward the top and bottom of the magnet. For a given design, target of field strength and winding bore, input parameters include tape width, number of grading tapes, and number of pancakes coils, while the main objective is to minimize the magnet volume, i.e., essentially the stored energy and thus the cost. A magnet with a single-width tape is also designed as a control sample for comparison. A case study on a design of 3-T 240-mm HTS magnet was carried out. In that case, MW magnets save 40% wire consumption of single-width magnets. The results are expected to be beneficial to determine the practical level of HTS tape grading and estimate a volume of an MW magnet.