Calculations using the helical filamentary structure for current distributions of twisted superconducting multifilamentary composites

The current and magnetic field distributions within twisted superconducting multifilamentary composites have been studied with the assumption that the current distribution within each filament is uniform. The current distributions among each filament are obtained by solving the equation with the inductance matrix for the case of insulated filaments and by requiring zero magnetic flux enclosed between any pair of filaments for the case of noninsulated filaments. As a result, it is shown that the negative current in the inner filaments is a universal feature of the current distributions for superconducting multifilamentary composites during the current sweep. In addition, the magnetic field distributions of a twisted superconducting multifilamentary composite have been obtained. For comparison, the current distributions for the twisted concentric cylindrical structure have been also calculated.