  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.
