Critical current measurements on Ag/Bi-Pb-Sr-Ca-Cu-O composite coils as a function of temperature and external magnetic field

Transport critical currents have been measured on two coils of high-temperature superconducting (HTSC) tape as a function of temperature and external magnetic field. The sample coil windings have inside and outside diameters of roughly 25 mm and 40 mm, respectively, and a length of 50 mm. They contain about 300 turns of filamentary Bi-Pb-Sr-Ca-Cu-O 2223 HTSC material sheathed in Ag to form a 0.18-mm by 2.54-mm tape, with a total length of about 30 m. Critical current results are reported for temperatures between 4.2 K and 90 K, in magnetic fields ranging up to 5.5 T.<
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