Electric characteristics of contact junctions between NbTi multifilamentary wires

Anomalous current-voltage characteristics have been found for a mechanical contact junction between NbTi superconducting multifilamentary wires. The pressure contact junctions between superconductors were created by either parallel-conductor contact or crossed-conductor contact. The junctions are superconductive over a limited current range. The current-voltage characteristics show switching phenomena, that are both large and very fast, at transitions between zero voltage and resistive states. The switching time is about 2 /spl mu/s. A zero-voltage current of about 60 A was obtained for a 75-mm-long junction at zero applied magnetic field. The current-voltage curve of the junction shows hysteresis that varies with the contact junction's structure. It has been confirmed that mechanical pressure contact junctions can be used as persistent switches without heaters. Additionally, contact junctions may provide uniform current distribution for multistrand cables.