Fabrication, Transport Current Testing, and Finite Element Analysis of MgB2 Racetrack Coils

This paper reports the fabrication, transport current testing, and finite element analysis of magnesium diboride (MgB2) racetrack coils made by a wind and react method at 4.2 K in self-field. This type of coil can be potentially appropriate for applications aimed at building block coils that can serve as wind turbine generator coils and correction coils for fusion magnets. We have fabricated racetrack coils using an in situ monofilament MgB2/Niobium/Monel wire; each coil had a wire length of 45 m and 80 turns. The best measured critical current of the coil was 134.9 A at 4.2 K and self-field of 0.55 T. In addition, the magnetic field and the Lorentz force contribution in the coil were estimated using finite element analysis.