in-situ/PIT法で作製したMgB2線材及びコイルの臨界電流特性

This paper reports on the fabrication and testing of four MgB2 coils made using a wind-and- react method. We made round 100 m-long class MgB2 mono-core wires sheathed with a Cu/Fe composite. The SiC concentration was fixed at 0, 2.5, 5.0 and 10.0 atomic-%. The round SiC-doped MgB2-superconducting wire was made using an in-situ PIT process. The 0 to 5% SiC-doped wire have Jc of the coil was almost equal to that of a short sample obtained at 4.2 K in external fields. This indicates that the 100 m-long class wire has a very homogeneous Jc distribution. The Ic degradation of the round mono-core wire occurred at the bending strain of as high as 0.53%. This shows that the react-and-wind method is reliable for large-size coils.