Magnetization characteristics of HTS-stacked ring magnets with and without HTS stack inserts

High-temperature superconducting (HTS) trapped field magnets can generate and maintain stable, high magnetic fields without requiring external power supplies. Recently, HTS-stacked ring magnets have garnered significant attention due to their flexible geometry, robust mechanical strength, and proven trapped field performance. In this study, we examine the magnetization characteristics of HTS-stacked ring magnets and observed a trapped field higher than the applied field during field cooling magnetization. We also observed that by inserting HTS stacks into the hollow cavity of the HTS-stacked rings, the center field ceased to exhibit an increased center field. Our analysis revealed that the unique induced current distribution and the penetration sequence are the underlying causes. Inspired by the investigation results, we explored deeper into the magnetization properties and identified that a final trapped field higher than the applied field can be achieved through proper design and magnetization of the HTS-stacked ring magnets. However, even though the trapped central field experiences an increase, this does not translate into an increment in the total trapped flux. Instead, a redistribution of the flux is observed. These findings hold significant implications for the design and application of superconducting magnets.