Fabrication of small superconducting coils using (Ba,A)Fe₂As₂ (A: Na, K) round wires with large critical current densities

Critical current densities in superconducting materials

We discuss recent research in the area of critical current densities (JC) in superconductors. This shall cover recent work on newly discovered superconductors, as well as on the magnetic-field dependence of JC .

A Superconducting Joint Technique for Round Wires

This paper describes a technique to superconductively splice multifilament wires. To date the technique has achieved joints capable of carrying a superconducting current of 200 A at 10 K in self field. Joints details, as well as testing methods and results are presented here.

Transport and magnetic critical current in superconducting MgB2 wires

Direct comparison of the magnetic and transport critical current density (Jc) for the same pieces of copper-sheathed MgB2 wires shows a large discrepancy in magnitude and field dependence of the two. The value of magnetic Jc can differ from the value of transport Jc by a factor of 10 or more. This discrepancy does not occur merely because of the difference in the voltage at which the magnetic a...

Fabrication of Chemically Doped, High Upper Critical Field Magnesium Diboride Superconducting Wires

Controlled chemical doping of magnesium diboride (MgB2) has been shown to substantially improve its superconducting properties to the levels required for high field magnets, but the doping is difficult to accomplish through the usual route of solid state reaction and diffusion. Further, superconducting cables of MgB2 are difficult to fabricate because of the friable nature of the material. In t...

Critical-current reduction in thin superconducting wires due to current crowding