CORC cables wound from overlapping tapes

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 that can be produced at high volumes and relatively low cost. Current HTS cables are expensive and lead times are long. Advanced Conductor Technologies and Lawrence Berkeley National Laboratory propose to develop high-current CORC® conductors wound with overlapping tapes. These conductors require much lower winding precision, allowing for much higher winding speeds. They would also have better current sharing between the HTS REBCO tapes, potentially allow for use of tapes with significant tape dropouts. During Phase I, the feasibility of winding CORC® conductors with overlapping tapes will be determined by confirming their bending performance and currentcarrying capability are similar to conventional CORC® conductors wound with gaps between tapes. The bending, current-carrying capability and resilience against axial tensile and transverse compressive loads of several prototype conductors will be measured in liquid nitrogen. Several short CORC® conductors will be wound from REBCO tapes with multiple, significant dropouts, in which parameters such as tape overlap will be used as variables. Their performance will be compared to baseline samples wound using pristine tapes that don’t contain dropouts to determine the severity and frequency of tape dropouts that potentially could be accepted in the CORC® conductors without significantly affecting their performance. If successful, the outcome of the program will result in a novel CORC® winding layout that significantly reduces their cost and lead time, while maintaining the high performance required for accelerator magnets. CORC® conductors wound from overlapping tapes will enable next generation of high-energy physics magnets, lightweight gantry systems for proton cancer treatment facilities and compact fusion magnets for energy generation. They will also benefit superconducting magnetic energy storage systems for use in the power grid and within the Department of Defense.