The Scaling Parameterization of ITER Superconducting Nb-Ti Strands Throughout Worldwide Production

The ITER superconducting magnet system will require approximately 650 tons of toroidal field and central solenoid Nb 3 Sn strands with different designs, and more than 250 tons of Nb-Ti strands. This called for a significant scale up of the worldwide production of Nb 3 Sn and Nb-Ti strands. Over the worldwide and mass productions, it is essential to accurately analyze and characterize the properties of ITER superconducting strands in terms of critical current (I c ) and ac loss, and thus determine the operational limits of the conductors, ultimately optimizing the operating scenarios of the Tokamak. In this paper, the proper scaling parametrization I c (B, T) and n-value as a function of I c (n(I c )) are investigated for Nb-Ti strands throughout massive production. Despite the differences in ITER Nb-Ti strand's architecture and their composition, optimized Nb-Ti strand scaling parameterizations throughout production for each supplier have been reached with the minimal deviation (