A fine-filamentary CuZn sheathed MgB_(2)wires produced by Hyper Tech Inc were used for 12 strand Rutherford cable of thickness 0.70-0.76 mm.Critical currents of short cable samples were measured at 4.2 K and external ...A fine-filamentary CuZn sheathed MgB_(2)wires produced by Hyper Tech Inc were used for 12 strand Rutherford cable of thickness 0.70-0.76 mm.Critical currents of short cable samples were measured at 4.2 K and external fields 4.0-8.0 T and also at temperatures 15-25 K and magnetic fields 1.0-5.5 T.The threshold of engineering current density J_(e)=10^(4)Acm^(-2)for the cable size of 0.72 mm×2.55 mm was obtained at field of 4.5 T and temperature 4.2 K and at 2.3 T for 20 K,respectively.Magnetization measurements of the cable with transposed strands and twisted 20μm filaments have shown reduced AC losses,but,the coupling currents loss contribution was still visible.AC losses measured for the same size Rutherford cable made of single-core wires demonstrate the effect of well decoupled filaments.Consequently,the cabling of thin single-core MgB_(2)wires shows a promising way for low loss conductors suitable for AC applications.展开更多
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funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No.09I04-03-V02-00039.
文摘A fine-filamentary CuZn sheathed MgB_(2)wires produced by Hyper Tech Inc were used for 12 strand Rutherford cable of thickness 0.70-0.76 mm.Critical currents of short cable samples were measured at 4.2 K and external fields 4.0-8.0 T and also at temperatures 15-25 K and magnetic fields 1.0-5.5 T.The threshold of engineering current density J_(e)=10^(4)Acm^(-2)for the cable size of 0.72 mm×2.55 mm was obtained at field of 4.5 T and temperature 4.2 K and at 2.3 T for 20 K,respectively.Magnetization measurements of the cable with transposed strands and twisted 20μm filaments have shown reduced AC losses,but,the coupling currents loss contribution was still visible.AC losses measured for the same size Rutherford cable made of single-core wires demonstrate the effect of well decoupled filaments.Consequently,the cabling of thin single-core MgB_(2)wires shows a promising way for low loss conductors suitable for AC applications.
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.
