Fabrication of MgB2 superconducting wires as low activation superconducting materials for an advanced fusion reactor application

Magnesium diboride (MgB2) superconducting wires are interesting as alternative conductor of Nb-based superconducting wire applying for the advanced nuclear fusion reactor from viewpoint of decay time of induced radioactivity. However, Jc property of MgB2 wire is insufficient for alternative material of Nb-based superconductor, and it is necessary to improve further Jc property. In order to improve Jc property, we tried to fabricate the several trace amounts of Cu addition MgB2/Fe-sheathed wires through PIT process using Mg2Cu as Cu addition source. Tc values of Cu addition samples were higher than those of non-Cu addition samples and they were improved with increasing amount of Cu addition. On the other hand, core Jc value were decreased with increasing amount of Cu addition and the maximum core Jc values were estimated to be over 100 A/mm2 at 4.2 K under 8 T for 1 and 3 at% Cu addition sample.