JPH025311A - superconducting wire - Google Patents

Abstract

PURPOSE:To make it possible to increase the critical current density and to reduce the alternating current loss by placing a barrier layer which consists of at least one sort of metal selected from a group of Nb, Ta, and V between a superconductive filament and a Cu-Ni layer. CONSTITUTION:Between a superconductive filament 1 and a Cu-Ni layer 2, a barrier layer which consists of at least one sort of metal selected from a group of Nb, Ta, and V is placed. The diameter of the filament is made 0.1 to 20mum normally. The thickness of the Cu-Ni layer is made 0.01 to 10mum normally. And the thickness of the barrier layer is made 0.01 to 5mum, normally.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to superconducting wires, particularly pulsed magnets, alternating current magnets, and permanent magnets. This invention relates to a superconducting wire suitable for IJE Switzerland.

[Conventional technology] Conventionally, in order to achieve magnetic stability and complete stability in normal DC superconducting magnets, Nb-Ti or Nb3Sn is made thinner, and the surrounding area is surrounded by highly conductive materials such as Cu or AQ. Stabilized superconducting wire coated with

Recently, as the field of application of superconductivity has expanded, superconducting wires with less loss due to magnetic field fluctuations are being developed as conductors for persistent current switches, as well as in the field of fluctuating magnetic fields and alternating current.

In such fields, in order to reduce losses such as eddy current loss and coupling loss, the diameter of the superconducting filament is reduced to 7 tons, and the surroundings of the superconducting filament are made of a metal with low conductivity such as a Cu-Ni alloy. A covered composite superconducting wire is often used. Fig. 2 shows a cross-sectional view of a conventional composite superconducting wire. In the superconducting wire 21, a high-resistance wire made of Cu-Ni is placed around the filament 1 made of Nb-Ti. Layer 2 is
Being useful.

Composite superconducting wires are generally processed to have a filament diameter of 10-odd microns, sometimes submicron or less. There were problems such as easy formation of carbon dioxide and the inability to obtain a high current density.

[Problem to be Solved by the Invention 1] An object of the present invention is to provide a superconducting wire that is less likely to cause filament breakage and has a high critical current density and low AC loss.

[Means for Solving the Problems] The gist of the present invention is to provide a superconducting wire in which a Cu-Ni layer is arranged around a Nb-TikB conductive filament, in which Nb, Nb, 'r
The present invention is a superconducting wire material characterized by interposing a barrier layer consisting of a metal, a metal, and a metal.

FIG. 1 is a sectional view of the superconducting wire of the present invention.

Superconducting wire (O11, filament 1 and CuNi
A barrier layer 3 is provided between the layers 2 .

The diameter of the filament is usually 0.1 to 20 μm.

The speed of the Cu-Ni layer is typically 0.01-1071 m.

The thickness of the barrier layer is typically 0.01-5 μm.

In the production of the superconducting wire of the present invention, for example, Nl), 1'
After a note made of at least one type of gold j14 selected from the group consisting of a and This can be done by drawing wire.

[Effect of the invention] A metal layer such as Nb, Ta or v interposed between the superconducting filament (mainly Ti in Nb-Ti) layers prevents the reaction between Cu and Ti. A Cu/Ti reaction layer is not generated during heat treatment for the purpose of increasing the superconducting critical current density. Therefore, it is possible to provide a superconducting wire that is less prone to filament breakage and has both high current density and low AC loss.

The super 1×1 conductive wire of the present invention is optimal for pulsed magnets and AC magnets, and can also be applied to conductors for persistent current switches.

E Example] Examples and comparative examples of the present invention are shown below.

Example 1 A Nb-Ti rod with a thickness of about 0.1 mm is placed around a diameter of about 3 mm.
N1) Add a note to the inner diameter of 3 mm, 5 mm,
It was inserted into a Cu-10% Ni alloy tube with an outer diameter of 4.5 mm to form a composite wire. This composite wire was drawn to a diameter of 0.2 mm, and after cutting, about 350 wires were assembled in a Cu vibe with an inner diameter of 4.51 mm to produce a second fitting material. This second fitting material was drawn to a diameter of 0,411In+, and an inner diameter of 4III
They were assembled in the Cu vibe of I and made into 21,000 pieces of secondary fitting material. The secondary fitting material was heated to 350°C with a diameter of 11
After heat treatment for 0 hours, the wire was drawn to a diameter of 0.11 to produce a super Ti conductive wire. The critical current density at 1'v is 400 Q
The property of slipping was A/m*'.

Comparative Example I A superconducting wire was produced in the same manner as in Example 1, except that the Nb barrier was not used. Critical current density is 2000Δ/I
It was as low as ++2', and many filament breaks were observed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a superconducting wire according to the present invention, and FIG. 2 is a sectional view of a conventional superconducting wire. 1... Filament, 2 cu-Ni layer, 3 A barrier layer, 11.21... Superconducting wire. Patent originator Sumitomo Electric Industries, Ltd. Agent Patent attorney Haka Aoyama 1 person Figure 2 Mochikaiho 2-5311 (3)

Claims (1)

[Claims] 1.Cu-Ni around Nb-Ti superconducting filament
A superconducting wire comprising layers, characterized in that a barrier layer made of at least one metal selected from the group consisting of Nb, Ta and V is interposed between the superconducting filament and the Cu-Ni layer. .