Abstract: A superconducting wire connector includes superconducting wires and a sintered body containing MgB2. The superconducting wires are connected by the sintered body. At least one of the superconducting wires includes a superconducting core having a first outer surface. The sintered body is in contact with the first outer surface. A method of connecting superconducting wires by a sintered body containing MgB2 includes exposing a superconducting core of at least one of the superconducting wires by removing a portion, positioned in the middle in a longitudinal direction of the at least one of the superconducting wires, of a metal sheath disposed around the superconducting core, disposing the at least one of the superconducting wires through a container, filling the container with a raw material of MgB2, and forming the sintered body being in contact with an outer surface of the superconducting core by sintering the raw material filled in the container.

Abstract: A superconducting magnet apparatus includes a superconducting coil, a persistent current switch, a cryostat, an external resistance element that attenuates energy accumulated in the superconducting coil when the superconducting coil is demagnetized, an external power supply capable of energizing a reverse current of a persistent current to the superconducting coil, and a circuit breaker capable of freely cutting off energization between the external power supply and the superconducting coil. A method for demagnetizing a superconducting magnet includes causing the reverse current of the persistent current to flow from the external power supply, and switching the persistent current switch to an off-state and switching the circuit breaker to an off-state, and demagnetizing the superconducting magnet by causing a current flowing through the superconducting coil to flow to an external resistance element when the amount of current flowing through the persistent current switch decreases.

Abstract: In the connection portion for a superconducting wire, a plurality of superconducting wires are integrated by a sintered body containing MgB2, end portions of the superconducting wires each having an outer peripheral surface of a superconducting filament exposed are inserted into a container in parallel. The container has an opening having a diameter larger than a wire diameter of the superconducting wires on at least one side in a longitudinal direction of the superconducting wires, and the sintered body is in contact with the outer peripheral surfaces of the superconducting filaments. The method for connecting a superconducting wire includes: exposing the outer peripheral surfaces of the superconducting filaments; inserting the superconducting wires into the container; filling the container with a raw material; and heat-treating the raw material to generate the sintered body. The raw material is pressurized in parallel to the longitudinal direction of the superconducting wires and then heat-treated.

Abstract: It is an object of the present invention to provide an MgB2 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 MgB2; 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.

Abstract: A superconducting wire connector includes superconducting wires and a sintered body containing MgB2. The superconducting wires are connected by the sintered body. At least one of the superconducting wires includes a superconducting core having a first outer surface. The sintered body is in contact with the first outer surface. A method of connecting superconducting wires by a sintered body containing MgB2 includes exposing a superconducting core of at least one of the superconducting wires by removing a portion, positioned in the middle in a longitudinal direction of the at least one of the superconducting wires, of a metal sheath disposed around the superconducting core, disposing the at least one of the superconducting wires through a container, filling the container with a raw material of MgB2, and forming the sintered body being in contact with an outer surface of the superconducting core by sintering the raw material filled in the container.

Abstract: The present invention provides a joint portion of MgB2 superconducting wires having exceptional energization characteristics and high reliability. The joint portion of the superconducting wires according to the present invention has a space for filling Mg into a portion inside a container or pressurizing member, the portion not being adjacent to an MgB2 sintered body.

Abstract: The problem is to attain a joint for multi-core superconducting wires having a high critical current property. The joint for superconducting wires of the present invention has a first sintered body containing MgB2 configured to fix a plurality of superconducting wires, and a second sintered body containing MgB2 configured to joint the superconducting wires.

Abstract: It is an object of the present invention to provide an MgB2 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 MgB2; 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.

Abstract: The present invention provides a joint portion of MgB2 superconducting wires having exceptional energization characteristics and high reliability. The joint portion of the superconducting wires according to the present invention has a space for filling Mg into a portion inside a container or pressurizing member, the portion not being adjacent to an MgB2 sintered body.

Abstract: A technical problem is to turn a persistent current switch on and off at high speed with less heat input. The invention relates to a conductive cooling-type persistent current switch, including: a superconductive wire 1 through which a current is passed; a cooling stage 9 which cools the superconductive wire; and a heater 8 which heats the superconductive wire, wherein the superconductive wire is placed between faces which are each formed by the cooling stage and the heater, a core of the superconductive wire is magnesium diboride 6, and a base material 5 placed around an outer periphery of the core is a material having a resistivity of 10 ??cm or more at 40 K.

Abstract: The problem is to attain a joint for multi-core superconducting wires having a high critical current property. The joint for superconducting wires of the present invention has a first sintered body containing MgB2 configured to fix a plurality of superconducting wires, and a second sintered body containing MgB2 configured to joint the superconducting wires.

Abstract: A technical problem is to turn a persistent current switch on and off at high speed with less heat input. The invention relates to a conductive cooling-type persistent current switch, including: a superconductive wire 1 through which a current is passed; a cooling stage 9 which cools the superconductive wire; and a heater 8 which heats the superconductive wire, wherein the superconductive wire is placed between faces which are each formed by the cooling stage and the heater, a core of the superconductive wire is magnesium diboride 6, and a base material 5 placed around an outer periphery of the core is a material having a resistivity of 10 ??cm or more at 40 K.

Abstract: Provided is a superconducting apparatus, including a joint of superconducting wires having high electric conduction characteristics and a superconducting magnet or the like. The superconducting joint comprises a plurality of superconducting wires and a sinter which integrates the plurality of superconducting wires. Herein, at least any one of the superconducting wires is a MgB2 superconducting wire, the sinter contains MgB2, and the sinter is compressed form the direction different from the direction toward which the superconducting wires protrude. Further, in order to form such a joint, a compression vessel provided with an opening used for introducing raw material powders to construct the sinter and another opening used for inserting the superconducting wires is utilized, and the openings are directed to different directions each other. Accordingly, MgB2 is filled in the sinter at high density, allowing the joint structure to have a good bonding property among particles.

Abstract: In a superconducting coil, a parallel conductor includes a plurality of superconducting wires bundled and wound in a coil. The superconducting wires have at least two connections therebetween. A current source connected to the superconducting wires to form a loop via the superconducting wires and the connection to supply a current in the loop when a quench is detected. A superconducting magnet includes the superconducting coil, a persistent current switch connected to the superconducting coil, and a quench detector configured to detect quench occurring in the superconducting coil.

Abstract: Provided is a superconducting apparatus, including a joint of superconducting wires having high electric conduction characteristics and a superconducting magnet or the like. The superconducting joint comprises a plurality of superconducting wires and a sinter which integrates the plurality of superconducting wires. Herein, at least any one of the superconducting wires is a MgB2 superconducting wire, the sinter contains MgB2, and the sinter is compressed form the direction different from the direction toward which the superconducting wires protrude. Further, in order to form such a joint, a compression vessel provided with an opening used for introducing raw material powders to construct the sinter and another opening used for inserting the superconducting wires is utilized, and the openings are directed to different directions each other. Accordingly, MgB2 is filled in the sinter at high density, allowing the joint structure to have a good bonding property among particles.

Abstract: Magnetic field attenuation in a persistent current mode operation is prevented, heat generation at a connecting part between the persistent current switch and the superconducting coil, and increase in a cooling temperature of the superconducting coil in a current supplying mode is suppressed to a minimum.

Abstract: In a superconducting coil, a parallel conductor includes a plurality of superconducting wires bundled and wound in a coil. The superconducting wires have at least two connections therebetween. A current source connected to the superconducting wires to form a loop via the superconducting wires and the connection to supply a current in the loop when a quench is detected. A superconducting magnet includes the superconducting coil, a persistent current switch connected to the superconducting coil, and a quench detector configured to detect quench occurring in the superconducting coil.

Abstract: It is an objective of the present invention to provide a method for manufacturing long lengths of MgB2 superconducting wire having excellent superconducting properties and an MgB2 superconducting wire manufactured thereby. There is provided a method for manufacturing a magnesium diboride superconducting wire, comprising the successive steps of: filling a metallic tube with a raw material powder; and subjecting the tube to wiredrawing processing, in which a fatty acid metal salt or a mixture of the fatty acid metal salt and a fatty acid is added to the raw material powder.

Abstract: A parallel conductor comprising a bundle of a plurality of high temperature superconducting wire materials, ends of the wire materials being electrically connected to each other, wherein each of the high temperature wire materials has at least one short-circuited portion where the wire materials are connected by means of a non-superconducting conductive material, and portions other than the short-circuited portion being covered with an insulating material.