Ambient temperature dependence on superconducting properties of MgB2 wires synthesized with low temperature diffusion process

Abstract

In the previous study, we investigated the Cu addition using the Mg2Cu compound and the reconsidering of heat treatment through lower temperatures and longer time treatments, the so called "Low temperature diffusion process". The critical current density (Jc) under the low magnetic field was enhanced by the "Low temperature diffusion process" compared to the conventional PIT process. In this study, transport critical current (Ic)-temperature (T)-magnetic field (B) measurements of the Cu added low temperature processed MgB2 wires were carried out in order to investigate the possibility of high temperature operation. In the Ic-T-B measurement, the samples were cooled by helium (He) gas and its temperature was controlled by the out put of the external heater. The transport Ic values of the mono-cored and 19 multifilamentary wires under the 20 K and 0 T were obtained to be above 100 A. Furthermore, the transport Ic degradation by the ambient temperature and bending strain was also investigated for a large scaled low temperature diffusion processed MgB2 cable.