It is well known that the highest current densities in MgB_(2)superconducting wires can be achieved using the internal magnesium diffusion(IMD)method.We present a square 19-filament MgB_(2)wire made by the IMD process...It is well known that the highest current densities in MgB_(2)superconducting wires can be achieved using the internal magnesium diffusion(IMD)method.We present a square 19-filament MgB_(2)wire made by the IMD process with dominant rolling deformation,which yields a high MgB_(2)filling factor of 14.2%and,consequently,a high engineering current density.Non-insulated wind-and-react coils were made from 1.1 mm to 0.68 mm wire,and their critical currents were compared with corresponding short wire samples.The threshold engineering current density of the present 19-filament MgB_(2)/Nb/CuNi wire,Jet=104 A cm^(-2),was measured at an external field of 6.5 T and a temperature of 4.2 K,representing the best performance reported in the literature for undoped filamentary wires made by the IMD process.The presented results demonstrate progress in the quality of filamentary MgB_(2)wires produced by the IMD process,which could be of interest for future DC coil applications.展开更多
基金supported by the Slovak Scientific Agency under the projects APVV-24-0654 and VEGA-2/0064/26.
文摘It is well known that the highest current densities in MgB_(2)superconducting wires can be achieved using the internal magnesium diffusion(IMD)method.We present a square 19-filament MgB_(2)wire made by the IMD process with dominant rolling deformation,which yields a high MgB_(2)filling factor of 14.2%and,consequently,a high engineering current density.Non-insulated wind-and-react coils were made from 1.1 mm to 0.68 mm wire,and their critical currents were compared with corresponding short wire samples.The threshold engineering current density of the present 19-filament MgB_(2)/Nb/CuNi wire,Jet=104 A cm^(-2),was measured at an external field of 6.5 T and a temperature of 4.2 K,representing the best performance reported in the literature for undoped filamentary wires made by the IMD process.The presented results demonstrate progress in the quality of filamentary MgB_(2)wires produced by the IMD process,which could be of interest for future DC coil applications.
