JP2003115225A - Oxide superconductive coil and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxide superconductive coil capable of providing a continuous superconductor having a uniform characteristic over a total length by making an oxidative atmosphere spread throughout a superconductive wire in heat treatment in the oxidative atmosphere. SOLUTION: In this oxide superconductive coil, the oxide superconductive wire with an oxide superconductor disposed in a stabilized metal having electric conductivity is wound around a winding frame having a metallic wire-winding bobbin and flange plates mounted to both ends of the bobbin. The coil is characterized in that the metallic wire-winding bobbin has plural through-holes regularly disposed, and the through-holes are tilted with respect to the axial direction of the bobbin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel oxide superconducting coil and a method for producing the same.

[0002]

2. Description of the Related Art An example of a process for manufacturing a reactor and wind type oxide superconducting coil is shown below. The steps are the oxide superconducting wire manufacturing step, the winding step, the heat treatment step, and the insulation treatment step.

First, in a process for producing an oxide superconducting wire, a powder of an oxide superconductor is densely packed in a silver sheath material,
After wire drawing, rolling, etc., the surface is covered with an insulating material of a heat resistant insulating material to complete an oxide superconducting wire.

In the next winding step, a bobbin made of a heat resistant material is wound with a predetermined number of turns of an oxide superconducting wire to form a coil. In the heat treatment step, the bobbin wound with the oxide superconducting wire is put in a heat treatment furnace, and heat-treated at a predetermined temperature and time in a mixed gas of a predetermined concentration to bond the oxide superconductor powder, Heat treatment is carried out so that the superconductor powder becomes a superconductor continuously over the entire length of the oxide superconducting wire. In the final insulation treatment step, the coil is impregnated with an insulating material and the insulating material is solidified by a predetermined method. Further, the superconducting wire terminal portion is subjected to a fixing process or the like so that it can be used as an electrode.

As a coil as described above, the 63rd 20th
An example can be found on page 103 of the Autumn 2000 low temperature engineering / superconductivity conference lecture summary.

JP-A-9-283326, JP-A-20
JP-A-01-15324 discloses that a bobbin around which an intermetallic compound superconducting wire is wound is provided with a plurality of through holes. The former through-hole is for suction when impregnating with epoxy resin, and the latter through-hole causes insulation failure due to carbonization of the organic material remaining in the ceramic fiber used to insulate the superconducting wire during the heat treatment. Therefore, the organic material is gasified so that it can be easily released.

[0007]

The conventional oxide superconducting coil has some problems, but one of them is that the entire coil is not heat-treated under the same conditions during the partial melting heat treatment of the oxide superconducting coil. That's what it means. As a result of disassembling the oxide superconducting coil manufactured up to now and measuring the critical current by sampling the superconducting wire from each part of the superconducting winding, it was found that the critical current decreases toward the inside of the superconducting winding. Since a high critical current can be secured outside the coil and the temperature inside the coil is uniform, this is because the bobbin acts as a shielding layer inside the superconducting winding during heat treatment, It is considered that it became difficult for the components of the mixed gas to permeate into the superconducting gas sufficiently, and as a result, the critical current of the superconducting wire decreased.

Further, the above-mentioned publication does not disclose the oxide superconducting coil and the relation to the specific heat treatment.

An object of the present invention is to provide an oxide superconducting coil and a method for producing the same, in which the superconducting wire is subjected to a heat treatment in an oxidizing atmosphere so that the oxidizing atmosphere is spread over the entire superconducting wire to obtain uniform superconducting properties over the entire length. To provide.

[0010]

According to the present invention, an oxide superconducting wire in which an oxide superconductor is arranged inside a stabilizing metal having electrical conductivity is provided on a metal winding bobbin and both ends of the bobbin. In the oxide superconducting coil wound around a winding frame having a flange plate, the metal winding bobbin has a plurality of through holes arranged regularly, and the through holes are arranged in the axial direction of the bobbin. It is characterized by being inclined with respect to.

With the structure of the present invention, it is necessary to carry out the optimization heat treatment for a long time by using a dilute gas (in order to reduce the amount of gas to be introduced so that the temperature difference in the entire furnace is 1 degree or less). There is. In order to efficiently permeate the diluted gas into the coil winding, the natural convection phenomenon can be efficiently used.

According to the present invention, in the above oxide superconducting coil, the metal winding bobbin and the flange plate have a plurality of through holes arranged regularly, and the through holes of the metal winding bobbin are the above-mentioned through holes. It is characterized in that it is inclined with respect to the axial direction of the bobbin.

Further, according to the present invention, an oxide superconducting wire in which a bismuth oxide superconductor is arranged inside silver is wound on a winding frame having a metal winding bobbin and flange plates provided at both ends of the bobbin. In the rotated oxide superconducting coil, the metal winding bobbin has a plurality of through holes that are inclined with respect to its axial direction and are regularly arranged, and the flange plate is a plurality of regularly arranged through holes. It is characterized by having through holes. In addition to silver, gold, silver, aluminum, copper, iron, platinum,
Palladium, nickel, stainless steel, chromium, magnesium, tantalum, niobium, titanium, tin, beryllium,
A metal coating material of a metal selected from tungsten or cobalt or an alloy composed of a plurality of them can be used.

The through hole of the flange plate is inclined toward the axial center of the bobbin.

According to the present invention, a stabilized metal sheath having electrical conductivity is filled with oxide superconductor powder, drawn and rolled, and then the metal winding bobbin and both ends of the bobbin are attached. In a method for manufacturing an oxide superconducting coil, which is wound around a winding frame having a flange plate provided and then heat-treated in a flow of an oxidizing gas, the metal winding bobbin has a plurality of regularly arranged through holes. It has a hole, and the through hole is formed so as to be inclined with respect to the axial direction of the bobbin and to follow the flow. The oxidizing gas is preferably air, oxygen, or nitrogen gas containing 2 to 5% oxygen.

Further, the present invention is the above method for manufacturing an oxide superconducting coil, wherein the metal winding bobbin and the flange plate have a plurality of through holes arranged regularly, and the metal winding bobbin is Through holes are inclined and regularly arranged with respect to the axial direction of the bobbin, and the through holes are formed along the flow.

The through hole of the flange plate is inclined toward the axis center of the bobbin, and the flow is formed in a direction toward the axis.

As described above, according to the present invention, a large number of through holes are provided in the bobbin so that the bobbin does not shield the gas, so that the gas is uniformly permeated.

That is, by providing the bobbin with a large number of through-holes which are regularly inclined with respect to the axial direction of the bobbin, it is possible to sufficiently extend the inside of the superconducting windings which are dozens of finely overlapped ones during the heat treatment. It becomes possible for gas components to permeate, and a superconducting coil having a high critical current can be obtained over the entire coil. Since the superconducting windings overlap each other between the lines, a space is formed at an angle of 60 degrees, so that a uniform gas flow can be formed by flowing the gas in that direction. Therefore, the angle is preferably 50 to 70 degrees with respect to the bobbin axis. It is preferable that the through holes with respect to the flange plate also have the same angle. By stacking round superconducting wires, they are overlapped at an angle of 60 degrees. There is a gap there. Gas will flow into this gap.

It is considered that the reason why the critical current is greatly increased by the present invention is that the gas passage is improved during the heat treatment by providing the bobbin with through holes directed in a specific direction.

The following are used as the oxide superconducting wire.
it can. T1-Ba-Ca-Cu-O system Tl_1.5-2.2-Ba_1.5-2.2-Cu_0.5-1.3
-O_5-7, Tl_{1.5-1 .2}-Ba_1.5-2.2-Ca
_0.5-1.3-Cu_1.5-2.3-O_7-9, Tl_1.5
-2.2-Ba_1.5-2.3-Ca_1.5-2.3-Cu
_2.5-3.3-O_9-11, Tl _0.5-1.2-Ba
_1.5-2.2-Cu_0.5-1.3-O_4-6, Tl
_0.5-1.2-Ba_1.5-2.2-Ca_0.5-1.2-C
u_1.5-2.3-O_6-8, Tl_{0.5-1. Two}-Ba
_1.5-2.2-Ca_2.5-3.2-Cu_3.5-4.3-O
_8-10.

Tl-Sr-Ca-Cu-O system Tl_1.5-2.2-Sr_1.5-2.2-Cu_0.5-1.3
-O_5-7, Tl_{1.5-1 .2}-Sr_1.5-2.2-Ca
_0.5-1.3-Cu_1.5-2.3-O_7-9, Tl_1.5
-2.2-Sr_1.5-2.3-Ca_1.5-2.3-Cu
_2.5-3.3-O_9-11, Tl _0.5-1.2-Sr
_1.5-2.2-Cu_0.5-1.3-O_4-6, Tl
_0.5-1.2-Sr_1.5-2.2-Ca_0.5-1.2-C
u_1.5-2.3-O_6-8, Tl_{0.5-1. Two}-Sr
_1.5-2.2-Ca_2.5-3.2-Cu_3.5-4.3-O
_8-10.

Tl-Ba-Sr-Ca-Cu-O system Tl_1.5-2.2-(Ba_x-Sr_1-x)_1.5-2.2-C
u_0.5-1.3-O_{5- 7} , Tl_1.5-1.2-(Ba_x-S
r_1-x)_1.5-2.2-Ca_0.5-1.3-Cu
_1.5-2.3-O_7-9, Tl_1.5-2.2-(Ba_x-Sr
_1-x)_1.5-2.3-Ca _1.5-2.3-Cu_2.5-3.3
-O_9-11, Tl_0.5-1.2-(Ba_x-Sr_1-x)
_1.5-2.2-Cu_0.5-1.3-O_4-6, Tl
_0.5-1.2-(Ba_x-Sr_1-x) _1.5-2.2-Ca
_0.5-1.2-Cu_1.5-2.3-O_6-8, Tl
_0.5-1.2-(Ba_x-Sr_1-x)_1.5-2.2-Ca
_2.5-3.2-Cu_3.5-4.3-O_8-10(x = 0.1-
0.9).

Tl-Pb-Sr-Ca-Cu-O system (Tl_y-Pb_1-y)_1.5-2.2-Sr_1.5-2.2-C
u_0.5-1.3-O_{5- 7}, (Tl_y-Pb_1-y)
_1.5-1.2-Sr_1.5-2.2-Ca_0.5-1.3-C
u _1.5-2.3-O_7-9, (Tl_y-Pb_1-y)
_1.5-2.2-Sr_1.5-2.3-Ca _1.5-2.3-C
u_2.5-3.3-O_9-11, (Tl_y-Pb_1-y)
_0.5-1.2-Sr_1.5-2.2-Cu_0.5-1.3-O
_4-6, (Tl_y-Pb_1-y)_0.5-1.2-Sr
_1.5-2.2-Ca_0.5-1.2-Cu_1.5-2.3-O
_6-8, (Tl_y-Pb_{1- y})_0.5-1.2-Sr
_1.5-2.2-Ca_2.5-3.2-Cu_3.5-4.3-O
_{8- 10}(y = 0.1-0.9).

Tl-Pb-Ba-Sr-Ca-Cu-O
System _{(Tl y -Pb 1-y)} 1.5-2.2 - (Ba x -Sr 1-x)
_{1.5-2.2 -Cu 0.5- 1.3 -O 5-7, (} Tl y -Pb
_{1-y) 1.5-1.2 -. (} Ba x -Sr 1-x) 1.5-2 2 -C
_{a 0.5-1.3 -Cu 1.5-2.3 -O 7-9, (} Tl y -P
_{b 1-y) 1.5-2 2 -} . (Ba x -Sr 1-x) 1.5-2.3 -
_{Ca 1.5-2.3 -Cu 2.5-3.3 -O 9 -11,} (Tl y
_{-Pb 1-y) 0.5-1.2 - (} Ba x -Sr 1-x)
_{1.5-2.2 -Cu 0 .5-1.3 -O 4-6, (} Tl y -Pb
_{1-y) 0.5-1.2 - (Ba} x -Sr 1-x) 1.5- 2.2 -C
_{a 0.5-1.2 -Cu 1.5-2.3 -O 6-8, (} Tl y -P
_{b 1-y) 0.5- 1.2 -} (Ba x -Sr 1-x) 1.5-2.2 -
Ca _2.5-3.2- Cu _3.5-4.3- O _8-10 (x = 0.
1-0.9; y = 0.1-0.9).

Bi-Sr-Ca-Cu-O system Bi _1.5-2.2 -Sr _1.5-2.2- Cu _{0.5-1.3
-O 5-7, Bi 1.5-1 .2 -Sr 1.5-2.2} -Ca
_0.5-1.3- Cu _1.5-2.3- O _7-9 , Bi _1.5
-2.2- Sr _1.5-2.3- Ca _1.5-2.3- Cu
_2.5-3.3- O _9-11 .

Bi-Pb-Sr-Ca-Cu-O system (Bi_y-Pb_1-y)_1.5-2.2-Sr_1.5-2.2-C
u_0.5-1.3-O_{5- 7}, (Bi_y-Pb_1-y)
_1.5-1.2-Sr_1.5-2.2-Ca_0.5-1.3-C
u _1.5-2.3-O_7-9, (Bi_y-Pb_1-y)
_1.5-2.2-Sr_1.5-2.3-Ca _1.5-2.3-C
u_2.5-3.3-O_9-11(y = 0.1-0.9).

Ln-Ba-Cu-O system Ln _1.5-2.3- Cu _0.5-1.3- O _4-6 , Ln
_0.5-1.3 -Ba _{1.5-2 .3} Cu _2.5-3.3 -O
_6-8 (Ln: Y, Sc, La, Ac, Ce, Pr, N
d, Pm, Sm, Eu, Gd, Tb, Dy, Ho, E
r, Tm, Yb, Lu).

Ln-Sr-Cu-O system Ln _0.5-1.3 -Sr _1.5-2.3 Cu _2.5-3.3-
O _6-8 (Ln: Y, Sc, La, Ac, Ce, Pr, N
d, Pm, Sm, Eu, Gd, Tb, Dy, Ho, E
r, Tm, Yb, Lu).

Bi-Sr-Y-Cu-O system (Bi _1-x Cu _x ) -Sr _2- (Y _1-y Cu _y ) -Cu ₂ -O
_6-8 (x = 0.1 to 0.9; y = 0.1 to 0.9).

Ba-Ca-Cu-O system Cu _0.5-1.2- Ba _1.5-2.2- Cu _{0.5-1.3
-O 4-6, Cu 0.5-1 .2 -Ba 1.5-2.2} -Ca
_0.5-1.2- Cu _1.5-2.3- O _6-8 , Cu _0.5
-1.2- Ba _1.5-2.2- Ca _2.5-3.2- Cu
_{3.5-4.3 -O 8-10, (Ag x,} Cu 1-x)
_0.5-1.2- Ba _1.5-2.2- Cu _0.5-1.3- O
_4-6 , (Ag _x , Cu _1-x ) _0.5-1.2 -Ba
_1.5-2.2 -Ca _0.5-1.2 -Cu _{1.5- 2.3} -O
_6-8 , (Ag _x , Cu _1-x ) _0.5-1.2 -Ba
_1.5-2.2 -Ca _{2.5- 3.2} -Cu _3.5-4.3 -O
_8-10 (x = 0 to 1).

Sr-Ca-Cu-O system Cu _0.5-1.2- Sr _1.5-2.2- Cu _{0.5-1.3
-O 4-6, Cu 0.5-1 .2 -Sr 1.5-2.2} -Ca
_0.5-1.2- Cu _1.5-2.3- O _6-8 , Cu _0.5
-1.2- Sr _1.5-2.2- Ca _2.5-3.2- Cu
_{3.5-4.3 -O 8-10, (Ag x,} Cu 1-x)
_0.5-1.2- Sr _1.5-2.2- Cu _0.5-1.3- O
_4-6 , (Ag _x , Cu _1-x ) _0.5-1.2 -Sr
_1.5-2.2 -Ca _0.5-1.2 -Cu _{1.5- 2.3} -O
_6-8 , (Ag _x , Cu _1-x ) _0.5-1.2 -Sr
_1.5-2.2 -Ca _{2.5- 3.2} -Cu _3.5-4.3 -O
_8-10 (x = 0 to 1).

Hg-Ba-Ca-Cu-O system Hg_1.5-2.2-Ba_1.5-2.2-Cu_0.5-1.3
-O_5-7, Hg_{1.5-1 .2}-Ba_1.5-2.2-Ca
_0.5-1.3-Cu_1.5-2.3-O_7-9, Hg_1.5
-2.2-Ba_1.5-2.3-Ca_1.5-2.3-Cu
_2.5-3.3-O_9-11, Hg _0.5-1.2-Ba
_1.5-2.2-Cu_0.5-1.3-O_4-6, Hg
_0.5-1.2-Ba_1.5-2.2-Ca_0.5-1.2-C
u_1.5-2.3-O_6-8, Hg_{0.5-1. Two}-Ba
_1.5-2.2-Ca_2.5-3.2-Cu_3.5-4.3-O
_8-10.

Hg-Sr-Ca-Cu-O system Hg_1.5-2.2-Sr_1.5-2.2-Cu_0.5-1.3
-O_5-7, Hg_{1.5-1 .2}-Sr_1.5-2.2-Ca
_0.5-1.3-Cu_1.5-2.3-O_7-9, Hg_1.5
-2.2-Sr_1.5-2.3-Ca_1.5-2.3-Cu
_2.5-3.3-O_9-11, Hg _0.5-1.2-Sr
_1.5-2.2-Cu_0.5-1.3-O_4-6, Hg
_0.5-1.2-Sr_1.5-2.2-Ca_0.5-1.2-C
u_1.5-2.3-O_6-8, Hg_{0.5-1. Two}-Sr
_1.5-2.2-Ca_2.5-3.2-Cu_3.5-4.3-O
_8-10.

The Hg-Ba-Sr-Ca- Cu-O -based _{Hg 1.5-2.2 - (Ba x -Sr 1} -x) 1.5-2.2 -C
_{u 0.5-1.3 -O 5- 7, Hg 1.5-1.2} - (Ba x -S
r _1-x ) _1.5-2.2- Ca _0.5-1.3- Cu _{1
.5-2.3 -O 7-9, Hg 1.5-2.2 - (} Ba x -Sr
_{1-x) 1.5-2.3 -Ca 1. 5-2.3} -Cu 2.5-3.3
-O _9-11 , Hg _0.5-1.2- (Ba _x -Sr _{1 -x} ) _1
.5-2.2- Cu _0.5-1.3- O _4-6 , Hg <sub>0.5-1.2
- (Ba x -Sr 1-x</sub> ) 1. 5-2.2 -Ca 0.5-1.2 -
_{Cu 1.5-2.3 -O 6-8, Hg 0.5-1.2 -} (Ba x -
Sr _1-x ) _1.5-2.2- Ca _2.5-3.2- Cu
_{3.5-4.3 -O 8-10 (x = 0.1~0.9)} .

Hg-Pb-Sr-Ca-Cu-O system (Hg_y-Pb_1-y)_1.5-2.2-Sr_1.5-2.2-C
u_0.5-1.3-O_{5- 7}, (Hg_y-Pb_1-y)
_1.5-1.2-Sr_1.5-2.2-Ca_0.5-1.3-C
u _1.5-2.3-O_7-9, (Hg_y-Pb_1-y)
_1.5-2.2-Sr_1.5-2.3-Ca _1.5-2.3-C
u_2.5-3.3-O_9-11, (Hg_y-Pb_1-y)
_0.5-1.2-Sr_1.5-2.2-Cu_0.5-1.3-O
_4-6, (Hg_y-Pb_1-y)_0.5-1.2-Sr
_1.5-2.2-Ca_0.5-1.2-Cu_1.5-2.3-O
_6-8, (Hg_y-Pb_{1- y})_0.5-1.2-Sr
_1.5-2.2-Ca_2.5-3.2-Cu_3.5-4.3-O
_{8- 10}(y = 0.1-0.9).

Hg-Pb-Ba-Sr-Ca-Cu-O
system (Hg_y-Pb_1-y)_1.5-2.2-(Ba_x-Sr_1-x)
_1.5-2.2-Cu_{0.5- 1.3}-O_5-7, (Hg_y-Pb
_1-y)_1.5-1.2-(Ba_x-Sr_1-x)_{1.5-2. Two}-C
a_0.5-1.3 -Cu_1.5-2.3-O_7-9, (Hg_y−
Pb_1-y)_{1.5-2 .2}-(Ba_x-Sr_1-x)_1.5-2.3
-Ca_1.5-2.3-Cu_2.5-3.3-O _9-11, (H
g_y-Pb_1-y)_0.5-1.2-(Ba_x-Sr_1-x)
_1.5-2.2-Cu _0.5-1.3-O_4-6, (Hg_y-Pb
_1-y)_0.5-1.2-(Ba_x-Sr_1-x)_{1. 5-2.2}-C
a_0.5-1.2-Cu_1.5-2.3-O_6-8, (Hg_y-P
b_1-y)_{0. 5-1.2}-(Ba_x-Sr_1-x)_1.5-2.2−
Ca_2.5-3.2-Cu_3.5-4.3-O_8-10(x = 0.
1-0.9; y = 0.1-0.9).

The Hg-Tl-Ba-Ca- O system _{(Hg y -Tl 1-y)} 1.5-2.2 - (Ba x -Sr 1-x)
_{1.5-2.2 -Cu 0.5- 1.3 -O 5-7, (} Hg y -Tl
_{1-y) 1.5-1.2 -. (} Ba x -Sr 1-x) 1.5-2 2 -C
_{a 0.5-1.3 -Cu 1.5-2.3 -O 7-9, (} Hg y -T
_{l 1-y) 1.5-2 2 -} . (Ba x -Sr 1-x) 1.5-2.3 -
_{Ca 1.5-2.3 -Cu 2.5-3.3 -O 9 -11,} (Hg y
-Tl _1-y ) _0.5-1.2- (Ba _x -Sr _1-x )
_{1.5-2.2 -Cu 0 .5-1.3 -O 4-6, (} Hg y -Tl
_{1-y) 0.5-1.2 - (Ba} x -Sr 1-x) 1.5- 2.2 -C
_{a 0.5-1.2 -Cu 1.5-2.3 -O 6-8, (} Hg y -T
_{l 1-y) 0.5- 1.2 -} (Ba x -Sr 1-x) 1.5-2.2 -
Ca _2.5-3.2- Cu _3.5-4.3- O _8-10 (x = 0
˜1y = 0.1 to 0.9).

[0039]

1 is a diagram showing a cross section of a bobbin structure used in an oxide superconducting coil according to the present invention.
The bobbin comprises a cylindrical bobbin shaft 1 and disc-shaped flange plates 3 and 4 attached to both ends thereof. This bobbin was provided with through holes 2 having a diameter of about 2 mm at a density of 1 per cm 2 so that the gas could pass through the bobbin during the partial melting heat treatment. The through hole 2 of the bobbin shaft 1 was formed at 60 degrees with respect to the bobbin shaft 1. The through holes 2 of the flange plates 3 and 4 were manufactured into two types, one with the angle of 60 degrees, one with the center of the flange plates 3, 4 and the other with the through holes 2 facing outward. The through holes 2 were formed by processing at intervals of 25 mm in the axial direction and at intervals of 30 degrees in the circumferential direction.

Also in this example, an oxide superconducting coil was manufactured by the reactor-and-wind method. The steps are the oxide superconducting wire manufacturing step, the winding step, the heat treatment step, and the insulation treatment step.

First, in the oxide superconducting wire manufacturing process, the oxide superconducting powder is densely packed in a silver sheath material,
After wire drawing, rolling, etc., the surface is covered with an insulating material of a heat resistant insulating material to complete an oxide superconducting wire.

In the next winding step, a bobbin made of a heat resistant material is wound with a predetermined number of turns of an oxide superconducting wire to form a coil. In the heat treatment step, a bobbin wound with an oxide superconducting wire is put in a heat treatment furnace, and heat-treated at a predetermined temperature and time in a mixed gas of 0.5% oxygen with a predetermined concentration and nitrogen, whereby the oxide superconductivity is reduced. The body powders are combined and heat-treated so that the oxide superconductor powder becomes a superconductor continuously over the entire length of the oxide superconducting wire. In the final insulation treatment step, the coil is impregnated with an insulating material and the insulating material is solidified by a predetermined method. Further, the superconducting wire terminal portion is subjected to a fixing process or the like so that it can be used as an electrode. The bobbin is a stainless bobbin wound with a cloth woven by combining alumina fibers and silica fibers. When the wire and stainless steel come into direct contact with each other, the reaction may occur, so that the reaction can be eliminated.

FIG. 2 is a sectional view of a superconducting coil in which an oxide superconducting wire is wound around the bobbin shown in FIG. 1 like a solenoid. The superconducting wire 5 used is a silver sheath material filled with bismuth-based superconductor powder, and the outer surface is covered with a heat-resistant insulating material. A coil outer circumference fixing material 8 is wound around the outermost circumference. The terminal part of the superconducting wire 5 is 6,
7 and these have a structure that can be connected to an external power source. The silver sheath material is pure silver, a silver alloy containing Mg, or the like, and the coil outer peripheral fixing material 8 is a silver plate, a copper plate, a metal-based superconducting wire, or the like.

These are heat-treated in a mixed gas of a predetermined concentration at a predetermined temperature of 800 ° C. for 100 hours. At this time, by supplying the mixed gas from the right side of FIG. 2, the mixed gas enters the winding through the outer surface of the superconducting coil or through the through hole provided in the bobbin into the winding through the gap of the winding, and the oxide superconducting It can penetrate to the inside of the wire. In this embodiment, since the bobbin is provided with the through hole 2, the components of the mixed gas are supplied not only from the outer surface of the coil but also from the bobbin side. As a result, the entire coil exhibits a uniform and high critical current. After the heat treatment is completed, the portion around which the oxide superconducting wire is wound is impregnated with an electrically insulating substance, and the impregnating material made of beeswax is solidified by a predetermined method. Therefore, the through hole 2 provided in the bobbin is filled with the impregnating material.

FIG. 3 is a diagram comparing the current-voltage / characteristics of the oxide superconducting coil manufactured according to the present invention and the conventional oxide superconducting coil. The entire oxide superconducting coil manufactured as described above exhibits superconductivity by cooling it with a coolant or the like so that the temperature becomes equal to or lower than the critical temperature. The bobbin of the oxide superconducting coil according to the present invention has one through hole 2 with a diameter of 2 mm per cm 2. On the other hand, the bobbin of the conventional oxide superconducting coil has no gas passing through it. The only difference between the two is the presence or absence of through holes, and there is no difference in the superconducting wire used, the number of turns, the dimensions of the coil, the manufacturing procedure, and the like. The results of conducting an electric current test on these oxide superconducting coils are described below.

Immediately after the current started to flow at a rate of 1 A / s in both oxide superconducting coils, a voltage of 0.08 V was generated between both ends of the coil. This is due to the inductance of the coil, and there is no difference between the two having the same number of turns and dimensions. That is, the inductance was the same.

Further, when the value of the applied current was increased, the voltage gradually increased in proportion to the current in the conventional oxide superconducting coil. This shows that the entire coil is not in the state of the superconducting coil, and it means that there is a normal conducting part in part and an electric resistance component exists. On the other hand, in the oxide superconducting coil according to the present invention, since the voltage generated as compared with the above current is not generated, it is considered that the whole is superconducting.

When the current was further increased, a voltage suddenly started to be generated from about 150 A in the conventional oxide superconducting coil. This is because the above-mentioned normal conducting portion was expanded and the resistance was increased. On the other hand, in the oxide superconducting coil according to the present invention, a voltage suddenly started to be generated from about 400A.

The generated voltage of the oxide superconducting coil is 1 μV / cm.
There is a method of defining the current when the current becomes as the critical current. Comparing the performances of the two tested coils by this specified method, the oxide superconducting coil of the conventional method is 165A, whereas the oxide superconducting coil of the present invention is 4A.
It was 25 A, and it was confirmed that the present invention can obtain a high critical current. The oxide superconducting coil of the present invention has 1
It is extremely effective in GHz NMR.

[0050]

According to the present invention, an oxide superconducting coil and a superconducting coil which can obtain a uniform superconducting property over the entire length of the superconducting wire in a heat treatment in an oxidizing atmosphere so that the oxidizing atmosphere is spread over the entire superconducting wire, and the same. A manufacturing method can be provided.

[Brief description of drawings]

FIG. 1 is a view showing a cross section of a bobbin of an oxide superconducting coil according to the present invention.

FIG. 2 is a diagram showing a cross section of an oxide superconducting coil according to the present invention.

FIG. 3 is a diagram comparing current-voltage characteristics of a conventional oxide superconducting coil with current-voltage characteristics of the oxide superconducting coil according to the present invention.

[Explanation of Codes] 1 ... Wire bobbin, 2 ... Through hole, 3, 4 ... Flange plate, 5 ...
Superconducting wire, 6, 7 ... Superconducting wire end, 8 ... Peripheral fixing material.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Michiya Okada             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Kazuhide Tanaka             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Keiji Fukushima             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. F-term (reference) 5G321 AA01 AA02 AA03 AA04 AA05                       AA06 AA07 BA03 DB29 DB46

Claims (8)

[Claims] 1. A winding frame having a metal winding bobbin and flange plates provided at both ends of the bobbin, wherein an oxide superconducting wire in which an oxide superconductor is arranged inside a stabilizing metal having electrical conductivity is provided. In the wound oxide superconducting coil, the metal winding bobbin has a plurality of through holes arranged regularly, and the through holes are inclined with respect to the axial direction of the bobbin. An oxide superconducting coil. 2. A winding frame having a metal winding bobbin and flange plates provided at both ends of the bobbin, wherein an oxide superconducting wire in which an oxide superconductor is arranged inside a stabilizing metal having electrical conductivity. In the wound oxide superconducting coil, the metal winding bobbin and the flange plate have a plurality of through holes arranged regularly, and the through holes of the metal winding bobbin are arranged in the axial direction of the bobbin. An oxide superconducting coil characterized by being inclined with respect to it. 3. Oxidation of an oxide superconducting wire in which a bismuth-based oxide superconductor is arranged inside silver, wound around a winding frame having a metal winding bobbin and flange plates provided at both ends of the bobbin. In the object superconducting coil, the metal winding bobbin has a plurality of through holes arranged regularly, and the through holes are inclined with respect to the axial direction of the bobbin. coil. 4. Oxidation of a bismuth-based oxide superconducting wire in which an oxide superconductor is arranged inside silver, wound around a winding frame having a metal winding bobbin and flange plates provided at both ends of the bobbin. In the object superconducting coil, the metal winding bobbin and the flange plate have a plurality of through holes arranged regularly, and the through holes of the metal winding bobbin are inclined with respect to the axial direction of the bobbin. An oxide superconducting coil characterized by being present. 5. The oxide superconducting coil according to claim 2, wherein the through hole of the flange plate is inclined toward the axial center of the bobbin. 6. A stabilized metal sheath having electrical conductivity is filled with an oxide superconductor powder, subjected to wire drawing and rolling, and then provided on a metal winding bobbin and both ends of the bobbin. In a method of manufacturing an oxide superconducting coil, which is wound around a winding frame having a flange plate and then heat-treated in a flow of an oxidizing gas, the metal winding bobbin is regularly inclined with respect to its axial direction. A method for manufacturing an oxide superconducting coil, comprising a plurality of through holes arranged, the through holes being formed in a direction that is inclined with respect to the axial direction of the bobbin and along the flow. 7. A stabilized metal sheath having electrical conductivity is filled with an oxide superconductor powder, subjected to wire drawing and rolling, and then provided on a metal winding bobbin and both ends of the bobbin. In a method for manufacturing an oxide superconducting coil, which is wound around a winding frame having a flange plate and then subjected to heat treatment in a flow of an oxidizing gas, the metal winding bobbin and the flange plate are regularly arranged. Through-holes, the through-holes of the metal winding bobbin are regularly arranged to be inclined with respect to the axial direction of the bobbin, the through-holes are inclined with respect to the axial direction of the bobbin, and the flow is A method of manufacturing an oxide superconducting coil, characterized in that the oxide superconducting coil is formed in a direction along the. 8. The through hole of the flange plate according to claim 7, wherein the through hole of the flange plate is inclined toward the axis center of the bobbin, and the flow on the inlet side of the gas is directed toward the axis center. A method of manufacturing an oxide superconducting coil, characterized in that