Conductor Properties and Coil Technology for a Bi2212 Dipole Insert for 20 Tesla Hybrid Accelerator Magnets

Abstract: Developing HTS dipole inserts producing fields larger than 5 T within 15 T Nb3Sn outserts is necessary to generate 20 T or higher fields for future high energy colliders. Dipole inserts based on the cos-theta coil geometry with various stress management concepts and Bi2212 superconducting strand and cable are being developed at Fermilab both within and beyond the U.S.-MDP effort. The ultimate goal is to develop coil technology and an approach to manage azimuthal and radial strains of high temperature superconductor inserts when integrated within Nb3Sn outserts as a hybrid magnet system. This white paper reviews Bi2212 conductor properties and coil technologies, and proposes new ideas to face the challenges that Bi2212 still presents as an accelerator magnet conductor.