Abstract: Powder of not more than 1 &mgr;m in mean particle diameter is prepared to contain a mixture of superconducting phases mainly composed of 2212 phases of Bi—Sr—Ca—Cu or (Bi, Pb)—Sr—Ca—Cu and non-superconducting phases which is obtained by calcining and pulverizing raw material powder at least once, this powder is heat treated at a high temperature and thereafter coated with a metal to prepare a round wire by deformation processing, thereafter a tape type or flat type wire is prepared by deformation processing, then the wire is heat treated under conditions for allowing phase transformation of the 2212 phases of main superconducting phases to 2223 phases with facilitation of grain growth, thereafter the as-formed 2223 phases are highly densified by deformation processing or pressurization, and the wire is again heat treated so that the 2223 phases are strongly bonded with each other and the non-superconducting phases are finely dispersed.

Abstract: In order to obtain a superconducting wire containing an oxide superconductor, whose critical current density is not much reduced upon application of bending, a plurality of strands 3, comprising oxide superconductors 1 covered with first metal sheaths 2, are filled into a second metal sheath 4, and deformation processing is performed to sectionally apply a compressive load to the second metal sheath, so that the thickness of the oxide superconductor 1 contained in each strand 3 is not more than 5% of the overall thickness of the superconducting wire 6.

Abstract: Powder of not more than 1 &mgr;m in mean particle diameter is prepared to contain a mixture of superconducting phases mainly composed of 2212 phases of Bi—Sr—Ca—Cu or (Bi, Pb)—Sr—Ca—Cu and non-superconducting phases which is obtained by calcining and pulverizing raw material powder at least once, this powder is heat treated at a high temperature and thereafter coated with a metal to prepare a round wire by deformation processing, thereafter a tape type or flat type wire is prepared by deformation processing, then the wire is heat treated under conditions for allowing phase transformation of the 2212 phases of main superconducting phases to 2223 phases with facilitation of grain growth, thereafter the as-formed 2223 phases are highly densified by deformation processing or pressurization, and the wire is again heat treated so that the 2223 phases are strongly bonded with each other and the non-superconducting phases are finely dispersed.

Abstract: A method of producing a Bi—Pb—Sr—Ca—Cu oxide superconductor by thermally treating raw material comprises steps of performing first plastic deformation on the raw material, performing first heat treatment on the material being subjected to the first plastic deformation, performing second plastic deformation on the material being subjected to the first heat treatment, and performing second heat treatment on the material being subjected to the second plastic deformation.

Abstract: Provided is an oxide superconducting conductor consisting of a plurality of metal-covered multifilamentary superconducting wires which are assembled with each other. Bending is applied to the superconducting conductor for improving its critical current density. It is possible to obtain a compact superconducting conductor having higher capacity, since its critical current density is increased by such application of bending.

Abstract: In order to obtain a superconducting wire containing an oxide superconductor, whose critical current density is not much reduced upon application of bending, a plurality of strands 3, comprising oxide superconductors 1 covered with first metal sheaths 2, are filled into a second metal sheath 4, and deformation processing is performed to sectionally apply a compressive load to the second metal sheath, so that the thickness of the oxide superconductor 1 contained in each strand 3 is not more than 5% of the overall thickness of the superconducting wire 6.

Abstract: According to one aspect, provided is a junction between tape-type superconductors, which are formed of metal-coated oxide superconductors. The superconductors of the superconducting wires, which are oppositely joined to each other, are overlapped with each other. According to another aspect, provided is a method of joining tape-type superconducting wires formed of metal-coated oxide superconductors, which comprises a step of preparing tape-type superconducting wires having portions to be joined, a step of separating metal coatings from first sides of the superconductors in the portions to be joined for exposing the superconductors, a step of overlapping the exposed superconductors with each other, and a step of joining the overlapped superconductors to each other. In the junction obtained according to these aspects, it is possible to stably carry a uniform superconducting current.

Abstract: According to one aspect, provided is a junction between tape-type superconductors, which are formed of metal-coated oxide superconductors. The superconductors of the superconducting wires, which are oppositely joined to each other, are overlapped with each other. According to another aspect, provided is a method of joining tape-type superconducting wires formed of metal-coated oxide superconductors, which comprises a step of preparing tape-type superconducting wires having portions to be joined, a step of separating metal coatings from first sides of the superconductors in the portions to be joined for exposing the superconductors, a step of overlapping the exposed superconductors with each other, and a step of joining the overlapped superconductors to each other. In the junction obtained according to these aspects, it is possible to stably carry a uniform superconducting current.

Abstract: In order to provide a flexible oxide superconducting cable conductor which is reduced in ac loss, tape-shaped multifilamentary superconducting wires covered with a stabilizing metal are spirally wound on a flexible former. Each of the multifilamentary superconducting wires has a plurality of filaments. The filament contains an oxide superconductor. The superconducting wires are preferably wound on the former at a bending strain of not more than 0.3 %. In winding on the former, a prescribed number of tape-shaped multifilamentary superconducting wires are wound on a core member in a side-by-side manner, to form a first layer. Then, an insulating layer is provided on the first layer. This insulating layer can be formed by an insulating tape. A prescribed number of tape-shaped superconducting multifilamentary wires are wound on the insulating layer in a side-by-side manner, to form a second layer. The insulating layer is adapted to reduce ac loss of the conductors.

Abstract: According to an aspect, a tape-type high temperature superconducting wire is provided by applying compression work to a wire manufactured by drawing so that an oxide high temperature superconductor is divided into a plurality of superconductors by a stabilizing material of substantially equal thickness. According to another aspect, a high temperature superconducting wire is provided by packing a material which becomes a superconductor portion into a metal sheath which becomes the stabilizing material and applying drawing work thereto, followed by bundling an assembly of these wire in a metal sheath and applying drawing work thereto. The thickness of the superconductor portion is approximately 10% or less than the thickness of the wire. The critical current density is hardly decreased in the high temperature superconducting wire even if subjected to bending work.

Abstract: A holder (1) provided with a spirally extending groove (2) is prepared and an oxide superconducting wire (3) is arranged in the groove (2) to be heat treated, so that each portion thereof is not bonded to another portion during the heat treatment.

Abstract: A method of producing a Bi-Pb-Sr-Ca-Cu oxide superconductor by thermally treating raw material comprises steps of performing first plastic deformation on the raw material, performing first heat treatment on the material being subjected to the first plastic deformation, performing second plastic deformation on the material being subjected to the first heat treatment, and performing second heat treatment on the material being subjected to the second plastic deformation.

Abstract: A high temperature superconducting coil includes an oxide superconducting wire 2 wound in a coil, a container 3 for accommodating the superconducting wire 2, and a filling resin portion 4 for fixing the superconducting wire 2 in the container 3 by being injected into the container 3 and then cured.

Abstract: In order to prevent inflation of a metallic coating during heat treatment so that no ununiformity is caused in the critical current density in a method of preparing an oxide superconducting wire which is obtained by heat treating and sintering metal-coated raw material powder for an oxide superconductor, raw material powder (5) for an oxide superconductor is filled up in a metal billet (1), which in turn is degassed and sealed in the degassed state, elongated with application of hydrostatic extrusion, and then heat treated.

Abstract: In order to prevent inflation of a metallic coating during heat treatment so that no ununiformity is caused in the critical current density in a method of preparing an oxide superconducting wire which is obtained by heat treating and sintering metal-coated raw material powder for an oxide superconductor, raw material powder (5) for an oxide superconductor is filled up in a metal billet (1), which in turn is degassed and sealed in the degassed state, elongated with application of hydrostatic extrusion, and then heat treated.

Abstract: Disclosed herein is a method which enables permanent current junction of a tape-type oxide superconducting wire and suppresses reduction of its critical current. An end portion of a tape-type wire (10) to be joined is removed to expose oxide superconductor filaments. Another tape-type wire (10') to be joined with the wire (10) is processed in a similar manner. The tape-type wires (10, 10') are so superposed that the surfaces exposing the filaments face with each other, and the superposed portions are pressed in a direction perpendicular to principal surfaces of the tapes and heat treated at a temperature of 800.degree. to 900.degree. C., to be completely joined with each other.

Abstract: A superconducting conductor, having an excellent repeated temperature property with no reduction of critical current density against a temperature cycle, comprises an oxide superconductor and an fiber reinforced plastic ("FRP"), serving as a support member, which is composed with the oxide superconductor for integrally moving with the oxide superconductor in thermal expansion and thermal shrinkage. The oxide superconductor is bonded to the FRP with an adhesive agent, or wound on and fixed to the same with a Teflon tape or the like.

Abstract: An improved process for producing superconducting dipole electromagnets is proposed. A plurality of coil cables are fed simultaneously toward and wound around a core so as to form a plurality of layers superimposed upon one another in the direction of thickness of the core. This makes it possible to decrease the size of power supply, lead wires, power cables, etc., to cut down the consumption of refrigerant, and to reduce accumulated energy level.