Continuous Manufacturing of Twisted Stacked Superconductor Cables with Integral Electrical Insulation

REBCO superconductors are being considered for use in high field magnets for Magnetic Fusion Energy (MFE) due to their potential for reducing facility size and cost. However, the anisotropy of REBCO tapes resulting from the planar nature of the crystals in the material leads to significant losses in expected current as well as leading to non-uniform magnetic fields. Transposition of the tapes in a cable structure (e.g., Twisted Stacked Tape Conductors (TSTC) remains the best means of minimizing these effects. Production of long continuous lengths of these cables will be required in order realize the potential of high field magnets based on these materials. How is this problem being addressed? In this program, Composite Technology Development (CTD), working with the Plasma Science and Fusion Center (PSFC) at the Massachusetts Institute of Technology (MIT), will develop methods for the production of Twisted Stacked Tape Conductor (TSTC) cables using an insulation scheme developed in prior work for simple stacked cables. The work in this program will enable the production of long continuous TSTC cables and will demonstrate their effectiveness in cable-in-plate configurations that are common in fusion magnet constructions. What is to be done in Phase I? To achieve the goals of the program, CTD will develop plans to modify the design of an existing, pilot-scale reel-to-reel system designed for insulating round wire to accommodate the continuous assembly, twisting, and insulating of TSTC cable. Phase I production work will be done on laboratory-scale equipment with the modifications to the pilot system taking place in Phase II. Cable designs will be developed by MIT, and they will also develop testing methods and verify the function of the insulated TSTC cables produced during the course of the Phase I program. Commercial Applications and Other Benefits as described by the applicant. This technology is expected to enable the production of next generation fusion devices as well impacting other applications including increases in beam luminosity and energy, both of which are planned for the Large Hadron Collider (LHC), the construction of HTS magnets for Magnetic Resonance Imaging (MRI) and Nuclear Magnetic Resonance (NMR) systems, Superconducting Magnetic Energy Storage (SMES) systems, superconducting generators for large (10 MW) offshore wind turbines, power cables for industry and utility applications (e.g., data centers and high population density areas), and electric motors for ships and rail systems. Key Words: HTS, superconductor, insulation, high-field magnets, cables, fusion