ALTERNATING-CURRENT LOSSES IN SILVER-SHEATHED (BI,PB)(2)SR2CA2CU3O10 TAPES .2. ROLE OF INTERFILAMENTARY COUPLING

ac losses at 60 Hz have been measured for silver-sheathed (Bi,Pb)(2)Sr 2Ca2Cu3O10 multifilamentary tapes at 27 and 77 K to investigate the ro le of interfilamentary coupling. The results are qualitatively well de scribed by the use of the concept of the critical coupling length l(c) . Further, it is shown that to obtain effective reduction of the coupl ing loss, a very small twist pitch length (much less than 1 cm) as wel l as a substantial reduction in the filament thickness are required fo r an applied ac field of, for example, 100 rms A/cm at 77 K. (C) 1995 American Institute of Physics.