Results of Investigations of 500 kg ${\rm Nb}_{3}{\rm Sn}$ Bronze Strand Produced in Russian Federation for ITER Project

The results of investigations of first 500 kg Nb₃Sn bronze strand are presented. This batch of strands was meant for the production of 100 m of Toroidal Field Conductor in the frame of fulfillment the Phase II of Procurement Arrangement between Russian Domestic Agency and International Organization ITER. In order to provide the industrial-scale production of strands design documentation and all necessary quality assurance documents were developed. The developed industrial technology of Nb₃Sn strand production was applied in Joint Stock Company "Chepetsky Mechanical Plant" (JSC "ChMP"). Strands were produced in JSC "ChMP" from final billets with diameter of 203 mm. The microstructure investigations of produced strands were performed before and after diffusion annealing by optical microscopy, X-ray microprobe analysis. Mechanical properties of annealed Nb₃Sn strands were investigated. Current-carrying capability of Nb₃Sn strands at 12 T, 4.22 K were studied. It was shown, that all produced strands met all the requirements, in particular I_c was from 202 to 220 A; hysteresis losses were from 165 to 194 mJ/cm³ (± 3 T ).