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.