Next generation high-temperature superconducting CORC® conductors for high-field accelerator magnets

The next-generation low-inductance accelerator magnets generating magnetic fields exceeding 20 T and magnets for muon colliders that operate at 20 K require highly flexible, high current, high-temperature superconducting (HTS) cables. Such cables are currently not available. Advanced Conductor Technologies and Lawrence Berkeley National Laboratory propose to develop the next generation of high-current CORC® conductors with double the bending flexibility of current-generation CORC® conductors. During the Phase I program, the cabling and lubrication processes will be improved to reduce the friction between REBCO tapes in CORC® conductors to promote sliding of the tapes during CORC® conductor bending. The flexibility of CORC® wires, based on 2 mm wide REBCO tapes with 30 ?m thick substrates, will be improved to allow bending to radii of less than 20 mm without significant performance degradation, enabling efficient and compact inserts for 20 T LTS/HTS hybrid magnets. ACT will develop CORC® cables wound from 3- and 4-mm wide tapes that allow bending to radii of less than 30 mm, enabling efficient, stand-alone accelerator magnets that generate dipole fields of 10 – 15 T at 20 K, needed for a 3 TeV muon collider. Prototype magnets will be developed in Phase II to assist with the conductor development. If successful, the program would result in CORC® conductors that would enable compact HTS inserts for 20 T LTS/HTS hybrid magnets, and efficient, stand- alone HTS magnets that would generate a dipole field of at least 10 T at 20 K, thereby removing the need for liquid helium. Highly flexible CORC® cables and wires will enable next generation of high-energy physics magnets, lightweight gantry systems for proton cancer treatment facilities, compact fusion magnets for energy generation, and numerous other scientific magnets. These conductors will also benefit superconducting magnetic energy storage systems for use in the power grid and within the Department of Defense.