Advanced strand design for precision DC-field and ramp-field magnets

The use of the solid-solution alloy Cu-Mn as an interfilamentary matrix to eliminate proximity effect coupling in multifilamentary strands is discussed. Eddy current measurements indicate that the presence of Mn does little to increase the transverse resistivity of a fine-filament composite, which is controlled primarily by interfilamentary size effect. The introduction of Ni into the strand, either as a replacement filament or an electroplated coating, can compensate for superconductor magnetization and assist in eliminating axial-field distortions in magnets wound from that strand