Evaluation of the Thermal Performance of the SC Feeders for the Magnetic System of the Divertor Tokamak Test Facility

The Divertor Tokamak Test (DTT) facility, under construction in Frascati, Italy, will rely on a fully-superconductive magnetic system. Superconductive feeders, designed as Nb-Ti cable-in-conduit conductors, will run into the cryostat from the cold boxes to the magnet winding terminations. They will be cooled by Supercritical Helium at 0.6 MPa and 4.5 K, entering the cables at the location of the peak field. The feeders will be subject to AC losses during plasma operation, as well as radiative parasitic load from the thermal shield and Joule heating in the terminations. The minimum temperature margin, computed for the different feeders in the worst operating condition, is presented and discussed in this paper, showing the conservativeness of the design for such components.