DEVELOPMENT OF (NB,TI)(3)SN AND NB-TI CONDUCTORS FOR 15 T SUPERCONDUCTING MAGNET OF 40 T CLASS HYBRID MAGNET

Tube processed (Nb,Ti)(3)Sn and NbTi conductors have been developed fo r a 15 T class superconducting magnet with a 400 mm clear bore of a 40 T class hybrid magnet. Prior to testing the actual conductor, the tra nsverse compressive stress effects on the critical current (I-c) of th e (Nb,Ti)(3)Sn conductors were studied using a 1/7 scale reduced condu ctor. The I-c of the samples with clearance of gap length of over 0.3 mm between Cu-housings and (Nb,Ti)(3)Sn monolith reached over 90% of u nloaded I-c(I-c0) at 14 T and 60 MPa of the transverse compressive str ess. Based on the above-mentioned results, a new structure for full-sc ale Cu-housing (Nb,Ti)(3)Sn conductors has been designed and fabricate d. Fabricated (Nb,Ti)(3)Sn conductors flowed more than 3870 A at 15 T and had 300 MPa of 0.2% proof stress. All these values exceeded the va lues in the specification with a good margin.