Mitigation of Screening Current-Induced Magnetic Field Effect in HTS Dipole Magnet Based on Coated Conductors: Overshooting and Shim Coil Study

High-temperature superconductors (HTS) show strong advantage in high-energy accelerators applications due to their excellent current-carrying and mechanical properties at high fields. However, most HTS tapes like coated conductors are often strongly magnetized due to the high aspect ratio of filaments, which in turn causes the deterioration of magnetic field quality in high-field superconducting accelerators magnets. A subscale block-type dipole magnet has been designed and fabricated with ReBCO tapes to make it clear about the mechanics of Screening Current-Induced Magnetic Field (SCIF) and find effective methods to mitigate the effect. TA formulation is applied to calculate the degradation of the magnetic field quality caused by the SCIF and predict the critical current of the coil at liquid nitrogen. Then the overshooting and the shim coil are investigated to reduce the field distortion caused by the SCIF effect.