No abstract

ac losses at 60 Hz have been measured for silver-sheathed (Bi,Pb)2Sr2Ca2Cu3O10 multifilamentary tapes at 27 and 77 K to investigate the role of interfilamentary coupling. The results are qualitatively well described by the use of the concept of the critical coupling length lc. Further, it is shown that to obtain effective reduction of the coupling loss, a very small twist pitch length (≪1 cm) as well as a substantial reduction in the filament thickness are required for an applied ac field of, for example, 100 rms A/cm at 77 K.

No abstract

In determining the short sample critical current of conductors of large cross section or high current density (he self field produced by the transport current must be taken account in order to obtain a "true value" for the critical current. A simple model calculation for determining this effect is described. Measurements on wires, cables, and monoliths show the validity and self consistency of the procedures.

No abstract