Hitachi, Ltd.

Hitachi Cable, Inc.

Japan Atomic Energy Research Institute

Hitachi Engineerings and Services Co I, Ltd.

Naofumi Tada

Fumio Iida

Ryukichi Takahashi

Katsuzo Aihara

Takaaki Suzuki

Hiroshi Kimura

Yasuo Suzuki

Nobuhiro Hara

Yoshiji Hotta

Toshio Ogawa

Yoshikazu Takahashi

Masataka Nishi

Naoki Maki

Toshinari Ando

Hisanao Ogata

Susumu Shimamoto

Teruhiro Takizawa

Masahiro Ogihara

Joo Ishihara

Kunishige Kuroda

Kazuo Kuroishi

Shuji Sakai

Katsuo Kouriki

Object of the present invention is to obtain a Nb.sub.3 Al group superconductor having a high critical current density under a whole range of magnetic field from low to high such as 20 T level, manufacturing methods thereof, a Nb.sub.3 Al group superconducting precursory composition, and a magnet for high magnetic field. In a process for manufacturing Nb.sub.3 Al phase by a diffusion reaction of Nb.sub.2 Al phase and Nb phase, a part of the Nb.sub.2 Al phase is remained and dispersed in the Nb.sub.3 Al phase homogeneously as for magnetic flux pinning centers for a high magnetic field. As for a method for dispersing the Nb.sub.2 Al phase homogeneously, a Nb.sub.3 Al group superconducting precursory composition obtained by dispersing Nb particles and Nb.sub.2 Al ultrafine particles by a mechanical alloying method is used, and further, by a conventional method for generating Nb.sub.3 Al phase by a diffusion reaction of Nb and an aluminum alloy, the object of the present invention can be achieved. In accordance with the present invention, a high magnetic field such as 20 T level which has never been achieved with only superconductor at 4.2K can be generated economically with a more compact apparatus than ever, and a coil for generating a high magnetic field can be manufactured with only the Nb.sub.3 Al group superconductor. Therefore, the present invention is significantly effective for a nuclear fusion apparatus of a magnetic confinement type.

Nb.sub.3 Al Group superconductor containing ultrafine Nb.sub.2 Al

In a method for manufacturing Nb.sub.3 Al phase by a diffusion reaction of Nb.sub.2 Al phase and Nb phase, a part of the Nb.sub.2 Al phase is remained and dispersed in the Nb.sub.3 Al phase homogeneously as for magnetic flux pinning centers for a high magnetic field. As for a method for dispersing the Nb.sub.2 Al phase homogeneously, a Nb.sub.3 Al group superconducting precursory composition obtained by dispersing Nb particles and Nb.sub.2 Al ultrafine particles by a mechanical alloying method is used, and further, by a conventional method for generating Nb.sub.3 Al phase by a diffusion reaction of Nb and an aluminum alloy, A Nb.sub.3 Al group superconductor can be achieved.

Method for manufacturing Nb.sub.3 Al group superconductor

A tightly wound superconducting coil device includes a cooling medium vessel, a coil winding disposed in the cooling medium vessel, the coil winding including an unspliced superconducting wire and having a configuration such that a cooling medium disposed in the cooling medium vessel does not contact the unspliced superconducting wire, and an insulating member disposed between the coil winding and the cooling medium vessel, wherein a portion of the unspliced superconducting wire forming outer portions of the coil winding on two opposite sides of the coil winding has a composition which causes a stability margin of the outer portions of the coil winding to be greater than a stability margin of a remaining portion of the coil winding.

Unspliced superconducting coil device with high stability

A track vehicle such as a Maglev train has a body with superconducting coils mounted thereon which superconducting coils interact with vertically extending coils on guideways of a track to generate a propulsive force. The vehicle runs on wheels at low speeds but at higher speeds the superconducting coils may interact with ground coils to generate a lifting force. In order to reduce or eliminate stresses between the superconducting coils and the vehicle body, the vehicle has one or more wings of airfoil shape which generate lift. That lift may be sufficient to support the whole of the weight of the vehicle, enabling the ground coils to be eliminated. Furthermore, the shape of the superconducting coils may be changed so that they supply more energy to propulsive effects. Preferably the angle of incidence of the wing(s) is variable, to permit the lift generated thereby to be varied. This variation in the angle of incidence may be controlled by a sensor detecting the height of the body above the track, to maintain that height constant.

Track system and vehicle having both magnetic and aerodynamic

Disclosed is a superconductor which has an aluminum area at the center of the cross section of the superconductor and a copper-covered multifilamentary NbTi composite conductor at the periphery parts of the cross section formed around the aluminum area, wherein the cross-sectional area ratio of (Cu+Al)/NbTi is in the range of 0.5 to 3.0 and the cross-sectional area ratio of Al/Cu is in the range of 0.05 to 0.5.. The superconductor is provided by a method comprising a first step of providing a superconductor-copper composite hollow body in which copper films are applied around the superconductors, a second step of area reducing the composite hollow body, a third step of heat treating the body, a fourth step of inserting an aluminum body into the hollow of the hollow body, a fifth step of subjecting the body to working such as drawing, a sixth step of subjecting the body to working such as twisting, forming or the like, with an additional area reduction being carried out, if necessary, subsequent to the third step. A superconducting coil is made using the superconductor, and the coil is used for a magnetically levitated vehicle or a nuclear magnetic resonance apparatus.

Aluminum-stabilized superconductor and superconducting coil, and method

In a superconducting magnet apparatus including one winding of coiled superconductor wire, another winding of coiled superconductor wire, a cooling device for supplying coolant to cooling vessels which contain the respective windings therein and a non-magnetic partition wall interposed between the cooling vessels containing the respective windings to airtightly separate them, with these windings being located at relative positions enabling mutual inductance therebetween, even if quenching occurs in the superconducting magnet apparatus. It is designed to not lose the magnetic repulsive force such that equipment traveling at high speed can be safely transferred at least to the nearest station. In addition, electromagnetic levitation traveling equipment on which the above-described apparatus is installed and a control method therefore is also described.

Superconducting magnet apparatus, cooling system therefor, and

A superconducting magnetic levitated train and train system which includes a plurality of cars connected to each other, a group of superconducting magnets attached to the cars and a coil provided on the ground so that the superconducting magnetic levitated train is levitated by the magnetically induced repulsion between the superconducting magnets and the coil on the ground. The invention is characterized in that the superconducting magnet on a specified car has a predetermined stability margin which is larger than the stability margin of a superconducting magnet on the other cars. A method of controlling the superconducting magnetic levitated train which includes detecting a driven state of a superconducting magnet on a specified car and varying and controlling the travelling conditions for the train so that the stability margin of the superconducting magnet on the specific car is changed in accordance with the command from a train control. A superconducting coil for the superconducting magnetic levitated train includes a coil of a composite superconducting wire composed of multifilmentary NbTi wire having a low copper ratio. The outer surface thereof is coated with thin high-purity aluminum or the wire accommodates high-purity aluminum at the central portion of the cross section thereof.

Superconducting magnetic levitated train, train system method of

In a superconducting switching device including a switching member comprising a superconducting wire, and a magnetic field generation section for controlling superconducting-normal conducting transition caused in the switching member, the switching member comprises an oxide superconductor having a high critical temperature and having a large electric resistivity value under the normal conductive state.

Superconducting switching device

The present invention provides an intermetallic compound-based, composite superconductor suitable for use in superconducting coils for a high magnetic field, where the superconductive part is formed by thermal diffusion reaction, and which has such a structure that a metal layer of high melting point and high resistance is provided at the outermost periphery of a strand comprising a plurality of filaments containing a superconductive compound formed by diffusion reaction with the surrounding matrix, a stabilizer surrounding the matrix, and a diffusion barrier provided between the stabilizer and the matrix for preventing diffusion of superconductive compound-forming element in the matrix from diffusion into the stabilizer during the diffusion reaction, and the coupling current induced between the intermetallic compound-based superconductive wire members can be reduced by the provision of the metal layer of high melting point and high resistance. Furthermore, the superconductive parts can be formed by heat treatment, and the AC loss can be reduced thereby.

Intermetallic compound-based, composite superconductor

In a forced flow cooling-type superconducting coil apparatus including a superconducting coil having superconducting wires inserted into a hollow conduit, current leads for supplying a current to said superconducting coil, and cooling means for cooling said superconducting wires by forcibly flowing the coolant through said hollow conduit, a part of the coolant flowing through said cooling means is branched to cool said current leads.

Forced flow cooling-type superconducting coil apparatus

An aluminum-stabilized superconducting wire comprises an aluminum member, a copper member, and a first diffusion barrier layer formed between the aluminum member and the copper member. The copper member contains a plurality of bundles each having a multiplicity of fine filaments of Nb.sub.3 Sn embedded in a copper alloy and a second diffusion barrier layer surrounding the copper alloy. Preferably, the ratio m in the cross-sectional areas between the first diffusion barrier layer and the aluminum member is selected to meet the condition of 0.03.ltoreq.m&lt;3. The aluminum member is disposed at the central portion of the superconducting wire.

Aluminum-stabilized superconducting wire

A method of producing a composite material of and Nb or V used for a superconductive wire comprises vacuum - melting two kinds of raw materials, 70 wt % Cu and 30 wt % Nb or V to form a melt; scattering the melt by a rotating disc to form a plurality of fine droplets each of which includes Cu and Nb or V at substantially the same compounding rate as the raw materials; and cooling rapidly the fine droplets by spraying an inert gas onto the scattering droplets thereby providing particulate bodies each of which dendrites of Nb or V are precipitated in Cu. The fine particles are compression - molded to form a molded product. The molded product is sintered to form an ingot in which the dendrites of Nb or V are dispersed homogeneously in the Cu base. The ingot is used for producing a superconductive wire, namely, it is subjected to cold rolling to reduce its sectional area, coating with Su or Ga, and diffusion heat-treating the wire to form Nb.sub.3 Sn or V.sub.3 Ga in the Cu base, whereby a superconductive wire is provided in which Nb.sub.3 Sn or V.sub.3 Ga are homogeneously dispersed in the Cu base.

Method of producing material for superconductor

Herein disclosed is a superconducting magnet device which is produced by winding both intermetallic compound superconducting wires and cold-worked oxygen-free copper wires in parallel and in multiple layers upon the core of a coil.

Superconducting magnet device

A superconductor has a coolant passage in the internal portion to cool itself by flowing a coolant in the coolant passage. The coolant passage is formed in the stabilizing material portion in such a manner that the inner wall of the coolant passage is wave-shaped, proportion of the cross-sectional area of the coolant passage occupied in the cross-section of the superconductor is 4-22 percent, and a ratio of the circumferential length to the cross-sectional area of the coolant passage is greater 25 (cm.sup.-1).

Internal cooling type superconductor

A superconductive magnet device comprising a coil assembly having a plurality of coil sections stacked along a center axis of the coil assembly, each of the coil sections being formed by winding a composite superconductive wire, which exhibits different superconductivities in one direction to another direction perpendicular to the one direction in a cross section of the wire, in layers in a direction perpendicular to the center axis, wherein the critical current density in a direction parallel to the center axis in the innermost layer of at least a central one of the coil sections is larger than the critical current density in a circumferential direction of the coil assembly. The present superconductive magnet device can withstand quenching of the superconductive state at a higher magnetic field than conventional ones.

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Hitachi, Japan

Naofumi Tada