Hysteretic surface effects in multifilamentary NbTi wires exposed to transverse applied fields

Discrepancies in the magnetic hysteresis have been found between bare and clad samples of fine filamentary, multifilamentary, NbTi wires. This difference manifests itself as a greater hysteresis loss in bare than in clad filaments that is significant even in the transverse field orientation. These effects are investigated over a wide range of samples, and for various filament diameters. The dependence of these losses on the orientation of the field with respect to the filaments is studied as well. These effects are attributed to interface pinning.