Temperature-Dependent Current Transfer Behavior of Cu- and Fe-Sheathed MgB$_2$ Superconducting Wires With Vanadium Barrier

Temperature-dependent current transfer properties of copper (Cu)and iron (Fe)-sheathed magnesium diboride (MgB
₂
) superconducting wires are studied by the estimation of current transfer length (CTL) and the electric field for various crosssectional area combinations of the superconducting core, barrier, and outer metallic sheath. The result indicates that the CTL values increase with increasing operational temperatures. The least CTL values are obtained for Fe-sheathed wires (MgB
₂
)/V/Fe) for all the studied cross-sectional area combinations in the wide temperature range (10-25 K) as compared to Cu-sheathed wires (MgB
₂
/V/Cu). The change in CTL values with varying operational temperature is small for both types of studied superconducting wires. The estimation of heat flux density generated on the metallic sheath suggests that the electrical dissipation is lower for Fe-sheathed superconducting wires. Hence, the lower CTL values suggest that the Fe-sheathed MgB
₂
wire with vanadium barrier is operational with the lowest electrical dissipation.