Influence of the Internal Architecture of MgB2 Conductors in the Load Line of Magnet Coils

MgB
₂
conductors have a multifilamentary superconducting structure encased in sheaths of different materials. Conductors with ferromagnetic sheaths, such as Ni or Fe, redistribute the magnetic field, which can affect the critical current of the superconducting filaments. The internal magnetic field distribution inside the conductor is not considered in general when modeling magnets, where the winding is considered as a bulk. The previous assumption can lead to discrepancies between the experimental results and numerical Ic predictions. Hence, a correct analysis of the effects of the ferromagnetic matrix in conductors will lead to savings in cost and weight of the coil design. In this work, the magnetic field distribution inside tapes with different architectures based on existing MgB
₂
tapes has been obtained. The magnetic field in the filaments is modeled focusing on the influence of the ferromagnetic matrix in the field distribution. The study is extended to round pancake coils based on the prototype coils aimed for its application in wind turbines in the SUPRAPOWER project.