Production of NbTiCICC's for SST-1 project at IPR

A Total of 24 pieces of NbTi CICC with outer dimension of 14.8 mm X 14.8 na n and a piece length of 600 m each have been successfully fabricated for bu ilding TF and PP coils. The CICC is made through roll forming and welding p rocess, The insert cable with a scheme of 3X3X3X5 is made front 0.86mm diam eter multifilamentary NbTi/Cu strand with 10 mu m diameter NbTi filaments e mbedded in Cu matrix at a Cu ratio of 4.9. No treatment is applied to the s trand surface. A 0.025 mm thick SS304 tape is wrapped on the finished fourt h stage cable, A 1.5 mm thick SS304L strip is then roll formed around the w rapped fourth stage cable and TIG; welding is applied continuously at the t op longitudinal seam. The welded conduit is finished to the final square di mension, bl passing it through sizing Polls and turks head rolls set at the end of the jacketing line. Tile critical current for a CICC, estimated thr ough multiplying an average I-c (without self-field correction) for the 10 extracted strands by the number of strands of 135 in a CICC, is approximate ly 38 kA at 5 T, 4.2 K. This means that there is no significant degradation of I-c 's for the strands due to the cabling and jacketing process. It is confirmed that the finished CICC pieces of 600 m each show a He leakage lev el well below 0.2 X 10(-8) Toll l/s.