Development and testing of novel hybrid CICC joint

The electrical joints are very important parts for any kind of superconducting magnet like solenoid magnet, hybrid magnet and superconducting bus-bar etc. Joints preparation is very crucial for superconducting magnets because of the local heating from resistive losses can drive the superconductor into unstable condition of the magnet and as a result the superconducting magnet get premature quench. In this paper a joint has been developed in shake-hand type. The joint has been made by using the two different type of cable in conduit conductor (CICC) i.e. Nb₃Sn and NbTi CICC. The 15×15 mm² Nb₃Sn and 14.8×14.8 mm² NbTi CICCs of length ~ 200 mm have been used for preparing superconducting joint. The joint length is approximately 110 mm and enclosed with copper jacket. Lead-Tin (Pb 60% & Tin 40%) solder material having melting point 188º C, is used for the preparation of the joint. The four probe method was used for the joint resistance measurement. The measured joint resistance is ~2 nΩ. The main aim of this type of joint fabrication is the testing of Nb₃Sn based CICC solenoid magnets. In this paper we have discussed the joint fabrication procedure, & its electrical characterization with different wattage of heating pulse near liquid helium (LHe) temperature.