Proposal of a new superconducting wire for high field usage

A new superconducting (S.C.) wire for fusion reactors is proposed, which employs both high and low Tc S.C. materials. As the low Tc S.C., NbTi, which is commonly used in S.C. magnets, is chosen as S.C. cable for transport currents, while the high Tc material works as the shielding conductor protecting the low Tc S.C. inside it from the magnetic field generated by other transport currents. Simple evaluation indicates that it is possible to shield approximately 20 T magnetic field. Numerical analysis also indicates that the effect of cracking in the high Tc S.C. on the shielding performance can be reduced by introducing multilayer high Tc S.C. materials.