The influence of an intermediate cold isostatic pressing (C. I. P.) on the superconducting properties of Bi-Pb-Sr-Ca-Cu-O superconducting bulk has been investigated, and heat input per a pair of the bulk between 4.2K and 77K has been evaluated. The critical current density (
Jc) was improved by the effect of C. I. P. and sintering after initial sintering. The maximum transport
Jc at 77K under zero magnetic field was indicated as 580A/cm
2, and that at 4.2K under zero magnetic field was indicated as about 3, 500A/cm
2. The reasons for these improvements are the formation of the high
Tc single phase with a fraction of low
Tc phase and the higher density increasing of microstructure. The heat input per a pair of the bulk between 4.2K and 77K has been indicated to be about 60mW and also considered to be of nearly one-third lower than the level of 100A DC condition for the optimum designed current leads with helium vapor cooling.
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