摘要:
A method of producing a material of an oxide superconductor comprises the following steps: (a) in a solution, ionizing a material containing an atom for constituting the oxide superconductor, (b) by removing a solvent by spraying the solution in a first atmosphere, producing a material powder containing the atom for constituting the oxide superconductor, and (c) cooling the material powder in a second atmosphere into which a cooling gas is introduced. In this method, the concentration of carbon dioxide in the second atmosphere is lower than that in the first atmosphere, which contains the removed solvent component. The concentration of nitrogen oxide in the second atmosphere is lower than that in the first atmosphere, which contains the removed solvent component. The concentration of water vapor in the second atmosphere is lower than that in the first atmosphere, which contains the removed solvent component. These specifications enable the method to increase the density and purity of the oxide superconductor.
摘要:
This invention relates to an oxide superconducting wire comprising oxide superconducting filaments, a high-density ceramic layer uniformly surrounding each of the filaments, and a silver sheath that directly covers the ceramic layer. The ceramic layer becomes non-superconducting when the filaments are cooled to an operating temperature of oxide superconductors. The oxide superconductors can be isolated by the ceramic that acts as a highly resistive material or an insulator. A high normal resistance is achieved, and thereby AC loss is reduced remarkably.
摘要:
An object of the present invention is to provide a method of manufacturing a bismuth-based oxide superconductor capable of obtaining a high critical current density and a superconducting wire containing a bismuth-based oxide superconductor manufactured by this method.The present invention is directed to a method of manufacturing a bismuth-based oxide superconductor containing a 2223 phase having a 2223 composition in a composition Bi—Sr—Ca—Cu or (Bi,Pb)—Sr—Ca—Cu, comprising a first step of charging a raw material containing a 2212 phase having a 2212 composition in a composition Bi—Sr—Ca—Cu or (Bi,Pb)—Sr—Ca—Cu with a critical temperature of not more than 70 K into a metal sheath, a second step of performing plastic working on the metal sheath charged with the raw material and a third step of performing heat treatment on the metal sheath charged with the raw material.
摘要:
A method of manufacturing a superconducting wire is provided. The method is provided with the steps of filling a raw material powder in a metal pipe, the raw material powder being composed of an oxide superconductor or a precursor to become an oxide superconductor through heat treatment; heating the metal pipe filled with the above-described raw material powder to 400° C. or more and 800° C. or less; depressurizing the inside of the above-described heated metal pipe to 100 Pa or less; sealing an opening at an end portion of the metal pipe under the above-described depressurized condition; and subjecting the sealed metal pipe containing the above-described raw material powder to wire drawing, wherein the packing density of the above-described raw material powder is controlled at 10 percent or more and 40 percent or less and, thereby, the degasification of the inside of the metal pipe is adequately performed, so that the critical current density can be increased.
摘要:
A method of manufacturing an oxide superconducting wire which can manufacture the longest possible wire by connecting relatively short wires with each other and is capable of suppressing reduction of a critical current resulting from influence by strain when the wires connected with each other are bent, an oxide superconducting wire, a superconducting coil and a superconducting apparatus are provided. According to the method of manufacturing an oxide superconducting wire by superposing end portions of two oxide superconducting wires with each other thereby bonding the end portions and connecting the oxide superconducting wires with each other, a junction formed by superposing the end portions with each other is so worked as to reduce the quantity of strain on an end of the junction when the two oxide superconducting wires and connected with each other are bent. Each of the oxide superconducting wire, the superconducting coil and the superconducting apparatus has the aforementioned junction, and the quantity of strain on the end of the junction is reduced in the aforementioned manner.
摘要:
The diameter of a first metal tube charged with raw material powder is reduced for obtaining an elementary wire. A plurality of such elementary wires are charged into a second metal tube, which in turn is reduced in diameter for obtaining a round first wire having a plurality of first filaments. The first wire is uniaxially compressed thereby obtaining a tape-like second wire having a plurality of second filaments. The second wire is heat treated thereby obtaining an oxide superconducting wire including a plurality of superconductor filaments. The maximum grain size of the raw material powder is smaller than the minor diameter of the first or second filaments.
摘要:
An Nb.sub.3 Al multi-filamentary superconducting wire capable of realizing both stabilization of a superconducting state and increase in capacity is provided. The Nb.sub.3 Al multi-filamentary superconducting wire includes a core formed of copper or copper alloy and located at the center of the wire; a multi-filamentary superconductor layer located around the core and having filaments containing Nb and Al as constituent elements embedded in a matrix formed of copper or copper alloy; and a high resistance layer located around the multi-filamentary superconductor layer, and is characterized in that a sectional area of the core is at least 15% of the total sectional area of the core and the matrix and that the core and the matrix are formed of copper or copper alloy of at least 99.9% purity.
摘要:
A precursor wire of an oxide superconducting wire includes a first sheath made of silver or silver alloy, a center portion in the first sheath, and a plurality of peripheral segments placed close to one another at the inside of the first sheath so as to surround the center portion. Each of the peripheral segments is formed as a monofilamentary segment that has an arch-shaped cross section and that includes a ribbon-shaped filament made of a precursor of an oxide superconductor and covered with a second sheath made of silver or silver alloy. The multiple peripheral segments are placed in a multilayer state in the form of concentric circles such that wide-width surfaces of the peripheral segments surround the center portion.
摘要:
The invention offers a superconducting tape that maintains both high allowable tension and low splice resistance and a method of producing the superconducting tape. The superconducting tape is provided with a main-body portion and a reinforcement portion. The main-body portion has the shape of a tape and has a superconductor. The reinforcement portion is composed of precipitation-hardened-type copper alloy or alloy of tin and copper and is formed on at least one surface side of the main-body portion.
摘要:
A method of manufacturing an oxide superconducting wire which can manufacture the longest possible wire by connecting relatively short wires with each other and is capable of suppressing reduction of a critical current resulting from influence by strain when the wires connected with each other are bent, an oxide superconducting wire, a superconducting coil and a superconducting apparatus are provided. According to the method of manufacturing an oxide superconducting wire by superposing end portions of two oxide superconducting wires with each other thereby bonding the end portions and connecting the oxide superconducting wires with each other, a junction formed by superposing the end portions with each other is so worked as to reduce the quantity of strain on an end of the junction when the two oxide superconducting wires and connected with each other are bent. Each of the oxide superconducting wire, the superconducting coil and the superconducting apparatus has the aforementioned junction, and the quantity of strain on the end of the junction is reduced in the aforementioned manner.