JPH06309955A - Oxide superconductor - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to obtain a silver sheath oxide superconducting conductor suitable for a current lead conductor. [Structure] Five silver sheath oxide superconducting tape wire rods 1, 2, 3, 4 and 5 are made of Pb in a reinforcing material 6 made of stainless steel.
After storing in a state of being impregnated with -Sn solder 8, this is heat-treated to diffuse the Pb-Sn solder 8 into the silver sheath 6 of each wire and alloy it to reduce the thermal conductivity of the silver sheath 6. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver sheath oxide superconducting conductor suitable as a current lead conductor for exciting a superconducting coil.

[0002]

2. Description of the Related Art As an oxide superconducting conductor, a conductor is known in which silver is used as a composite material to cover the oxide superconducting material to improve the critical current density and to achieve thermal stability of the conductor. Attempts have been made to use it as a current lead for coil excitation.

[0003]

However, in an oxide superconducting wire having a sheath material of silver, the thermal conductivity of silver, which is a sheath material, is very high at a low temperature portion, so that the heat generated from a high temperature portion of the silver sheath wire material is high. A large amount of a cryogen such as liquid helium is consumed due to the invasion, which is not very preferable as a current lead conductor.

In view of the above points, an object of the present invention is to obtain a silver sheath oxide superconducting conductor suitable for a current lead conductor.

[0005]

In order to achieve the above object, in the present invention, a metallic adhesive is diffused into silver, which is a sheath material of an oxide superconducting conductor, to improve the thermal conductivity of the sheathed silver itself. It is decreasing.

As the oxide superconductor of each conductor,
Yttrium-based, bismuth-based, thallium-based and many other materials can be used.

The silver sheath material may be an alloy obtained by adding a trace amount of Au, Cu, Mn, Ni, Ti or the like to silver, and as the metallic adhesive, Pb-Sn solder or In solder may be used. Etc. can be used.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, FIG. 1 shows an example of an aggregate conductor of silver sheath oxide superconducting conductors.

This conductor is composed of a reinforcing material 7 made of stainless steel and five silver sheath oxide superconducting tape wire rods 1, 2,
3, 4 and 5 are housed and stored while being impregnated with the Pb-Sn solder 8, and the sheath 6 of each wire is alloyed by the Pb-Sn solder 8 being diffused.

As a method for alloying the silver sheath 6, a method is used in which the wires 1 to 5 are stored together with the Pb-Sn solder 8 in the reinforcing material 7, and then the conductor is heat treated.

With the conductor having such a structure, silver, which is the sheath 6 of each wire, is alloyed with a part of the Pb-Sn solder 8, and the thermal conductivity of silver itself is reduced.

[0012]

According to the present invention, the following effects can be obtained.

(1) Since the thermal conductivity of silver is reduced by alloying a metallic adhesive with silver and the low heat penetration of the superconducting conductor is improved, when this is used as a conductor for current lead,
It is possible to reduce the amount of cryogen consumed.

(2) By alloying a metallic adhesive with silver, a high resistance of the sheath material is realized, and the conductor is advantageous for use in the AC mode.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of an oxide superconducting conductor according to the present invention.

[Explanation of symbols]

 1 to 5 silver sheath oxide superconducting wire 6 silver sheath 7 stainless steel reinforcing material 8 Pb-Sn solder as a metallic adhesive

Claims (2)

[Claims] 1. An oxide superconducting conductor having a sheath material of silver or a silver alloy, characterized in that a metallic adhesive is diffused in the sheath material. 2. The conductor according to claim 1, wherein a plurality of conductors are assembled and impregnated with a metallic adhesive.