DESC0024759

The utilization of REBa2Cu3O1-? coated conductors to construct very strong superconducting magnets for fusion energy reactors is under intensively exploited and has received billions of investments. Despite many attractive characteristics, the grand challenge of performance drop-outs and non-uniformity of REBa2Cu3O1-? coated conductors and cables, which could cause device running instability and even the loss of million-of-dollars magnets, significantly impedes the progress of the projects. An innovative quality control tool will be developed to exclude the performance drop-outs and non- uniformity from superconducting magnet construction by identifying and localizing the drop-outs and non- uniformity before the conductor enters magnet construction, or as a quality assurance tool for conductor manufacturers before they deliver the conductor to costumers. Additionally, it will provide in-situ feedback for conductor manufacturers by integrating the system into conductor production line. The proposed system will utilize pick-up coils to sense magnetic field change generated by conductor drop-outs and non- uniformity as a non-destructive detection tool to interrogate conductor to identify and localize performance non-uniformities along conductor length. The proposed quality control tool possesses the advantages of low cost, high efficiency, and more importantly unique capability of working at low temperatures and strong magnetic fields, over other currently existing approaches. Developing a commercial quality control tool for superconducting tapes and cables is the overall technical goal for this STTR project. In the phase I effort, the feasibility of pick-up coils for performance variation characterization of long length superconducting wires and cables will be demonstrated. The viability of the proposed technique will be demonstrated on ~5 m long REBa2Cu3O1-? tapes at 4.2 K and 15 T using a 15 T superconducting magnet to provide similar working condition of the conductor for fusion magnets at ~20 K and 20 T, in terms of the strength of Lorentz force and dominant pinning mechanisms that define conductor performance. A more versatile system that will provide testing temperatures from 77 K down to 4.2 K and fields up to 20 T will be developed for kilometer long conductors and cables in the following Phase II. After completing this project, an advanced quality assurance/control tool will be available for fusion energy applications, and it will also strongly benefit to biomedical diagnosis, public transportation, high energy physics, and very high field magnet communities.