A CORC <sup>®</sup> cable insert solenoid: the first high-temperature superconducting insert magnet tested at currents exceeding 4 kA in 14 T background magnetic field
D C van der Laan, Jeremy Weiss, U.P. Trociewitz, Dmytro Abraimov, Ashleigh Francis, J. Gillman, Daniel Davis, Y. Kim, Van S. Griffin, George E. Miller, H.W. Weijers, L. D. Cooley, D. C. Larbalestier, Xiaorong Wang
Abstract
Abstract The results presented in this Letter describe the successful test of the first high-temperature superconducting multi-tesla insert solenoid tested at currents exceeding 4 kA while operating in a background magnetic field of a low-temperature superconducting outsert magnet. A 45-turn insert solenoid, wound from 19 meters of CORC ® cable, was designed to operate at high current, high current density, and high hoop stress in high magnetic background field; a combination that is essential in the development of low-inductance, high-field magnets. The CORC ® cable insert solenoid was successfully tested in liquid helium in background magnetic fields of up to 14 T, resulting in a combined central magnetic field of 15.86 T and a peak magnetic field on the conductor of 16.77 T at a critical current of 4404 A, a winding current density of 169 A mm −2 , an engineering current density of 282 A mm −2 , and a JBr source stress of 275 MPa. Stable operation of the CORC ® cable insert magnet in its superconducting-to-normal transition was demonstrated, during charging at rates of 20–50 A s −1 , without inducing a quench. The results are a clear demonstration of the major benefits of this multi-tape CORC ® magnet conductor in which current sharing between tapes is possible, thereby removing some of the stringent conductor requirements of single-tape magnets. The CORC ® cable insert solenoid demonstrated operation at about 86% of the expected CORC ® cable performance and showed no significant degradation after 16 high-current test cycles in background fields ranging from 10 to 14 T. CORC ® cables have matured into practical and reliable high-field magnet conductors, achieving important high current, high current density, stress tolerance, and quench protection milestones for high field magnet technology. They have established a straightforward path towards low-inductance magnets that operate at magnetic fields exceeding 20 T.