A superconducting power cable system includes a superconducting power cable in a first temperature environment separated from a second temperature environment by a thermal barrier. The first temperature environment is an interior of a cryostat and is at a lower temperature than the second temperature environment located outside of the cryostat. At least one superconducting feeder cable has a first end electrically coupled to the superconducting power cable in the first temperature environment, and a second end electrically coupled to a normal conducting current lead in the second temperature environment. Each superconducting feeder cable is a flexible superconducting cable or wire formed of multiple superconducting tapes that are wound in a helical fashion and in multiple layers around a round former.

A superconducting power cable system includes a superconducting power cable in a first temperature environment separated from a second temperature environment by a thermal barrier. The first temperature environment is an interior of a cryostat and is at a lower temperature than the second temperature environment located outside of the cryostat. At least one superconducting feeder cable has a first end electrically coupled to the superconducting power cable in the first temperature environment, and a second end electrically coupled to a normal conducting current lead in the second temperature environment. Each superconducting feeder cable is a flexible superconducting cable or wire formed of multiple superconducting tapes that are wound in a helical fashion and in multiple layers around a round former.

Provided is a method for manufacturing a base material powder having a carbon nanocoating layer, the method including adding a polycyclic aromatic hydrocarbon to a base material powder, heating the mixture to a temperature that is higher than or equal to the boiling point of the polycyclic aromatic hydrocarbon and is lower than or equal to the relevant boiling point temperature+300 C., and that is higher than or equal to the thermal decomposition temperature of the polycyclic aromatic hydrocarbon, and thereby coating the surface of the base material powder with a layer of carbon having a thickness of 0.1 nm to 10 nm. According to the method, when a source of carbon that covers a base material powder is appropriately selected, the base material powder having the carbon nanocoating layer can be provided, which does not have a possibility of causing inconveniences in the applications of a final manufactured product of the base material powder and exhibits satisfactory productivity of the base material powder, and from which a modified final manufactured product is obtained.

Provided is a method for manufacturing a base material powder having a carbon nanocoating layer, the method including adding a polycyclic aromatic hydrocarbon to a base material powder, heating the mixture to a temperature that is higher than or equal to the boiling point of the polycyclic aromatic hydrocarbon and is lower than or equal to the relevant boiling point temperature+300 C., and that is higher than or equal to the thermal decomposition temperature of the polycyclic aromatic hydrocarbon, and thereby coating the surface of the base material powder with a layer of carbon having a thickness of 0.1 nm to 10 nm. According to the method, when a source of carbon that covers a base material powder is appropriately selected, the base material powder having the carbon nanocoating layer can be provided, which does not have a possibility of causing inconveniences in the applications of a final manufactured product of the base material powder and exhibits satisfactory productivity of the base material powder, and from which a modified final manufactured product is obtained.

It is an object of the present invention to provide an MgB.sub.2 wire helping to achieve compatibility between the ease with which superconducting connection is effected and thermal stability. A superconducting wire according to the present invention includes: an elemental wire formed of MgB.sub.2; and a first metal not reacting with Mg. In a section orthogonal to the longitudinal direction of the superconducting wire, the region extending from the center of the superconducting wire to the installation position of the elemental wire is formed by the elemental wire and the first metal.

Provided is a low-temperature superconducting wire having a low stabilizing matrix ratio. The present invention provides a superconducting wire including: a low-temperature superconducting filament; a stabilizing Matrix encompassing the filament; and a sheath of a Metal-Insulator Transition (MIT) material, which encompasses the stabilizing matrix on the exterior of the stabilizing matrix. According to the present invention, a low stabilizing matrix ratio is achieved while coping with heat caused by a quench phenomenon, thereby reducing manufacturing cost and achieving a high current density.

Provided is a low-temperature superconducting wire having a low stabilizing matrix ratio. The present invention provides a superconducting wire including: a low-temperature superconducting filament; a stabilizing Matrix encompassing the filament; and a sheath of a Metal-Insulator Transition (MIT) material, which encompasses the stabilizing matrix on the exterior of the stabilizing matrix. According to the present invention, a low stabilizing matrix ratio is achieved while coping with heat caused by a quench phenomenon, thereby reducing manufacturing cost and achieving a high current density.

Disclosed herein are cryogenic wires and methods of making and use thereof. For example, disclosed herein are cryogenic wires comprising a conductor having a mass density of 5000 kg/m.sup.3 or less; and a cladding material disposed around the conductor, the cladding material comprising a ductile and malleable metal, wherein the conductor comprises lithium, beryllium, calcium, sodium, magnesium, titanium, or a combination thereof. In some examples, the conductor comprises lithium or an alloy thereof, beryllium or an alloy thereof, calcium or an alloy thereof, sodium or an alloy thereof, magnesium or an alloy thereof, titanium or an alloy thereof, or a combination thereof.

Disclosed herein are cryogenic wires and methods of making and use thereof. For example, disclosed herein are cryogenic wires comprising a conductor having a mass density of 5000 kg/m.sup.3 or less; and a cladding material disposed around the conductor, the cladding material comprising a ductile and malleable metal, wherein the conductor comprises lithium, beryllium, calcium, sodium, magnesium, titanium, or a combination thereof. In some examples, the conductor comprises lithium or an alloy thereof, beryllium or an alloy thereof, calcium or an alloy thereof, sodium or an alloy thereof, magnesium or an alloy thereof, titanium or an alloy thereof, or a combination thereof.

A method for producing a long length high temperature superconductor wire, includes providing a substrate, having a surface with a length of at least 50 meters and a width. The surface supports a biaxially textured high temperature superconducting layer and the biaxially textured high temperature superconducting layer has a length and a width corresponding to the length and width of the surface of the substrate. The method includes irradiating the biaxially textured high temperature superconductor layer with an ion beam impinging uniformly along the length and across the width of the biaxially textured high temperature superconductor layer to produce a uniform distribution of pinning microstructures in the biaxially textured high temperature superconductor layer.