Dependence of quench current level of superconducting wire and cable on the winding tension

Mechanical instabilities in an AC Nb-Ti superconducting wire and cable are experimentally investigated. The quench current levels of the sample conductors were measured for different winding tensions and current increase rates. We have developed a new type of experimental bobbin to apply the tension uniformly and to adjust it to the specified value from the outside of the cryostat. It is found that the influence of the mechanical instabilities on the quench current level decreases with an increase in the winding tension and/or the current increase rate.