Test results of SeCRETS, a stability experiment about segregated copper in CICC

Two Nb₃Sn cable-in-conduit conductors have been manufactured with identical non-Cu cross sections and the stabilizer either included in the Nb₃Sn composite or partly segregated as copper wires. The two conductors are series connected and wound as a bifilar, single layer solenoid, assembled in the high field bore (11 T) of the SULTAN test facility. Beside the DC and AC losses characterization, the key tests include stability under pulsed transversal field (dB/dt up to 180 T/s), at DC operating current up to 12 kA. The results show that strong, transverse field transients can be withstood by both conductors with small temperature margin. Cost reduction measures for fusion conductors are discussed