Abstract
The magnetic field dependence of the time constant has been studied of coupling currents among filaments in a multifilamentary superconducting NbTi wire. The time constant was measured with resolution of 0.1T in the background fields from zero T to 10T by a newly developed direct method. The measured time constant values showed a peak at around 1T with a maximum time constant of 43ms. This peak effect could be theoretically explained by the effective transverse resistivity and effective permeability of the composite wire with the magnetic field dependence. The variance of the permeability of the NbTi filaments in a magnetic field is adequately accounted for by the critical state model.
