Abstract:Two 100-m MgB2 wires with different conductor structures (Cu core and CuNb core) were designed and successfully fabricated by the central Mg diffusion process (IMD), and the mechanical and transport superconductivity of the wires were tested. The uniformity of MgB2 superconducting layer distribution along the longitudinal direction of the two wires was analysed by different methods, and it was found that the distribution of superconducting layer tended to be more uniform as the diameter of the wire decreased, and the MgB2 FF fluctuation range of the wire with Φ 0.8 mm was the smallest, and the extreme difference of the base super ratio was 0.02. The results of the uniformity of MgB2 layer distribution showed that the Mg and B densities in the wire were well distributed. The results of the superconductivity tests show that the critical current Ic of the Cu replacement core wire is 19 A (4.2 K, 4 T) higher than the critical current Ic of the CuNb replacement core wire, while the Jc performance is basically the same. The Mg/B/Nb/Monel matrix composite enable to manufacture high performance MgB2 wires with 100-m class.