The qualification of the Nb₃Sn superconducting cables for the DTT PF6 coil has been successfully completed. The final design has been selected and series production has been launched.

The qualification tests of the conductor for the DTT Poloidal Field PF6 coil were successfully finalized. The final analysis of the results, completed in December 2025, led to the selection of the definitive cable design.

The conductor, based on Nb₃Sn superconducting technology, is manufactured by the Italian company ICAS, building on ENEA’s long-standing expertise in superconductivity. The Nb₃Sn strands are manufactured by Oxford Superconducting Technology (OST), also involved in the supply of the superconducting strands for ITER coils. Two alternative configurations, differing in the arrangement and length of the twists of the Nb₃Sn strands, were developed and tested.

The experimental campaign was carried out at the SULTAN facility (Swiss Plasma Center, Villigen), at cryogenic temperature 4.5 K, with currents up to 31.1 kA and magnetic fields up to 9 T. Both solutions met and exceeded the PF6 specifications, demonstrating excellent operational stability.

The configuration showing the highest performance has been selected for the start of series production at ICAS. This achievement confirms the technological maturity of the PF6 conductor and represents a significant step forward in the realization of the DTT superconducting magnet system.