HTS coated conductors that can operate in magnetic fields above 20 T are becoming very attractive now for applications such as compact fusion, accelerators for high energy physics, high-field magnets and superconducting magnetic energy storage. High-performance coated conductors with record-high engineering current density (J_e) of 5200A/mm² at 4.2K, 15T (corresponding critical current density (J_c) of 10MA/cm²) have been possible using an Advanced MOCVD process where 4-5 µm thick films with controlled film composition are routinely fabricated. Pinning force characteristics have been studied for a wide range of compositions of 4 – 5 µm thick REBCO films; the Ba content has been found to be a critical factor. In contrast to the pinning force behavior at B||c orientation, which saturates to a constant value of 1.7 – 1.8 TN/m³ above ~5-6 T, the pinning force at the B||ab orientation in the thick films increases near-linearly, reaching a remarkable value of over 11.5 TN/m³ at 31.2 T. We have also developed a Symmetric Tape Round (STAR) wire technique to fabricate 1.3 to 1.9mm diameter round REBCO wires with high J_e and excellent tolerance to bend strain. STAR REBCO wires can be bent to a radius of just 15mm while sustaining a J_e of 600A/mm² at 4.2K, 20T which meets key stringent requirements of accelerator magnets. Both high performance REBCO tapes and round wires are being scaled to long lengths to fabricate prototype coils and magnets. Details of the recent progress in HTS coated conductor tapes and round wires for high magnetic field applications will be discussed in this presentation.

This work was supported by the U.S. Department of Energy through awards DE-EE0007869 from the Advanced Manufacturing Office, DE-SC0016220 from the Office of High Energy Physics, and SBIR awards DE-SC0015983 and DE-SC0018850 from the Office of High Energy Physics.

Keywords: REBCO, MOCVD, magnetic field, pinning force