ac loss in a twisted filamentary superconducting wire. I

Publisher Website
Google Scholar
Abstract
Calculations are made for the ac losses in a twisted filamentary superconductor by assuming a continuum model with anisotropic conductivity. The Maxwell equations are solved for a long wire of radius R 0 and twist length L. In terms of the classical skin depth δ, appropriate for the conductivity perpendicular to the filaments, the losses are calculated for an applied magnetic field transverse to the wire axis in the case of (i) a uniform field ( 2 R 0 /δ≪1, L/2πδ≪1) , (ii) shielding from surface currents ( 2 R 0 /δ≪1, L/2πδ≫1) , and (iii) skineffect ( 2 R 0 /δ≫1) . Losses are also calculated for the case of a transport current in no applied field. The model can be used in more general cases and has the virtue of giving precise results with a minimum of auxiliary postulates.