Second Generation Superconducting Cable with Exfoliated YBCO Filaments
High Temperature Superconducting YBCO wire technology has a significant potential to become the wire of choice for Helium-free magnet systems. Helium-free magnet systems are attracting more interest as the world supply of Helium is depleted. Currently the wire is manufactured as a thin, 1 micron, superconducting layer deposited on a 1 cm wide 100 microns thick metal substrate. Due to this geometry a magnet wound from the wire suffers from high losses.
Brookhaven Technology Group (BTG) will partner with AMSC Corp. to develop and demonstrate the feasibility of a new type of a cable bundled from exfoliated YBCO filaments. The approach is based on our recent successful experiments on stress-induced exfoliation of YBCO filaments. The filaments were demonstrated to retain up to 90% of the original critical current. We will develop technology for bundling filaments into a narrow, 2-3 mm diameter, cable with up to 20% fill factor. The cable is symmetric: both sides of the superconductor layer are in contact with the metal stabilizer. This geometry will deliver significantly improved quench stability of the cable and enhance the traditionally low c-axis yield strength and cleavage strength of YBCO wires up to at least 50 MPa both.