Speaker
Description
High-temperature superconductors (HTS), particularly rare-earth barium copper oxide (REBCO), are critical for ultra-high-field magnets in next-generation accelerators and compact fusion reactors due to their superior performance under high magnetic fields. However, existing characterization techniques cannot continuously evaluate long HTS conductors under simultaneous low-temperature and high-field conditions, which are essential for real-world operation. This limitation, coupled with the sensitivity of HTS magnets to low-critical current density (Jc) defects that can trigger quenches, underscores the need for advanced inspection methods. This study introduces a novel continuous characterization system developed at Princeton Plasma Physics Laboratory, designed for rapid and contactless evaluations of HTS conductors under applied magnetic fields. The initial prototype integrates a 0.5 T superconducting magnet with a liquid nitrogen saturation cooling system and achieves measurement speeds exceeding 100 mm/s at temperatures between 65-77 K. Preliminary results demonstrate the system's capability to detect Jc variations caused by inhomogeneous artificial pinning centers and defects in REBCO conductors at 65 K. While currently optimized for REBCO and bismuth strontium calcium copper oxide conductors at 65 K, a separate system operating at 20 K is under development to extend testing capabilities to higher background magnetic fields and other superconductors with lower critical temperatures. Building on this proof of concept, we are advancing toward higher-field cryogen-free systems: a 7.5 T system nearing completion, a 12 T system under design, and a planned 20 T reel-to-reel inspection system—all operating at 20 K. These developments aim to enable conductor characterization under conditions closely replicating high-field magnet applications, providing robust quality assurance protocols for superconducting magnets in fusion energy and other high-field technologies.
