Temperature dependence of critical current at 4.2 K-55 K of conduction-cooled Bi2212/Ag wires for SMES

In this paper, fundamental characteristics of conduction-cooled Bi2212/Ag wires and coils for HTS SMES were investigated, in terms of critical current at different temperatures at 4.2 K-55 K. Experimental results revealed that the critical current did not always increase with the temperature decrease, but was saturated or even decreased, depending on the test sample condition. Thermal analysis considering temperature dependence of specific heat and thermal conductivity of the materials could explain the critical current-temperature characteristics, and suggest the possibility to optimize the operating temperature of SMES.