Durham Publishes Large-Scale Verification of ITER Superconducting Strands, Establishing Reliable Testing Method

Durham, an official ITER reference lab since 2011, processed over 5,500 samples and about 13,000 measurements on Nb3Sn and Nb–Ti strands. Nb3Sn required heat treatment above 650°C before testing, preventing repeat measurements on the same piece. Statistical analysis shows adjacent strands tested across laboratories can substitute for remeasuring a single strand, improving QA and reducing uncertainty. Results confirm strand quality for ITER’s high-current magnets, with data and protocols published in Superconductor Science and Technology as an open resource. The work comes as fusion efforts gain pace, with ITER assembly progressing and companies announcing early fusion power deals alongside UK funding for its STEP prototype.