The Measurement and Analysis of the Hysteresis Loss in a Multifilament MgB2 Superconducting Wire

Abstract

The article presents the results obtained from measuring the magnetization of and hysteresis loss in a multifilament MgB2 superconducting wire (produced by ASG Superconductors) for magnetic field applied in two directions: in parallel and perpendicular to the conductor axis. The measurement temperatures were varied in the range of 5–45 K. The MgB2 superconducting fraction magnetization curves were obtained by subtracting the magnetization of the wire ferromagnetic matrix measured at temperature T = 45 K, which is above the superconductor critical temperature Tc , from the magnetization value of the entire specimen. From these magnetization curves, the dependences of the hysteresis energy loss on the external magnetic field strength Qh(Н) were obtained. It is shown that, with the field oriented perpendicular to the MgB2 wire axis and at the external field characteristic values, the hysteresis loss is twice as large. A method for calculating the hysteresis loss in a superconducting wire and methods for reducing it are proposed. The obtained results can be used to optimize NMR and MRI facilities, superconducting motors and generators made using MgB2 superconducting wire produced by ASG Superconductors.