Among HTS options, only Bi2212 enables high Je in many wire forms by the use of melt texturing. Although applications are emerging for HTS tapes, they remain unsuitable in key areas. As a result, low cost, round and rectangular commercial HTS wires and cables are being developed primarily with the Bi2212 oxide. Focus areas on HTS development in this paper include 1) As drawn 2212 wires with optimal configurations for high Je’s in low-cost, long lengths, 2) Reinforced 2212 wires and cables for high field coil windings without excessive coil strengthening, 3) Low loss 2212 wires and cables with loss-reducing features for AC / fast ramp magnet systems and 4) Low cost flexible high current HTS cable based on Sumitomo Type-NX tape.

A 2212/Ag wire production line is being qualified.  Wire configurations and 1 atm melt texturing processes have recently been identified that yield Jc levels close to the levels attained by the over-pressure process pioneered by Florida State University. These processes are being scaled up along with optimization for higher Je and lower costs.

Strong wire designs are established in which high modulus strips are helically wrapped onto 2212/Ag round wires, with narrow gaps between the strips for oxygen exchange with the atmosphere during melt texturing. These wires exhibit in excess of 400 MPa axial stress tolerance and support more than 3X the radial compression load that is supported by nonreinforced 2212/Ag wire. Cables have been produced without Jc degradation and with rolling increasing packing to above 65%, similar to LTS cables.

HTS usage in ac and fast ramp magnets has not been considered as an option due the challenges of attaining low AC loss with tapes. Recent advances, however, with our low loss Bi2212 program now enable fabrication of first-of-their-kind HTS wires with loss-reducing features. These include much smaller wire diameters, non-merged filaments of < 15 micrometers in size with high Jc’s, short pitch length axial twist, and enhanced resistances between filaments. When formed at 1 atm reaction conditions, the Jc of these wires is found to match standard wire Jc. AC loss measurements, and modeling are under way to establish the loss benefits of each features within wires and cables. Strategies for reducing loss will be presented, along with data about structures and Ic(B,T) operating envelopes for these wires and cables in ac and fast ramp coils.

Keywords: Bi2212, High temperature superconductor, Round Wire, Cable