Investigation on the AC loss characteristics of MgB2 wires by using a conduction cooling device

Abstract In this study, we have experimentally investigated the AC loss characteristics of MgB 2 wires with matrix of Fe and Cu by using a conduction cooling device. We fabricated the conduction cooling device to cool MgB 2 wires down to 4 K. We also developed our unique test method, which is called AC pulse technique, to evaluate their AC loss characteristics within few hundred milliseconds. The test results show that the AC loss of the Fe/MgB 2 wire is mainly generated in the ferromagnetic Fe matrix. Its AC loss is ten times larger than that of the Cu/MgB 2 wire. In this paper, the evaluation technique of AC loss by using the conduction cooling device is described and the test results are discussed.