U.S. patent application number 09/941104 was filed with the patent office on 2002-02-21 for connection structure for superconducting conductors.
Invention is credited to Ohkura, Kengo, Sato, Kenichi, Ueyama, Munetsugu.
Application Number | 20020020546 09/941104 |
Document ID | / |
Family ID | 14723284 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020020546 |
Kind Code |
A1 |
Ueyama, Munetsugu ; et
al. |
February 21, 2002 |
Connection structure for superconducting conductors
Abstract
A connection structure for superconducting conductors which can
simply connect superconducting conductors with each other with
small connection resistance and no sophisticated technology is
provided. In a connection structure for multifilamentary
superconducting conductors, superconducting wires forming the
superconducting conductors respectively are joined with each other
through solder.
Inventors: |
Ueyama, Munetsugu; (Osaka,
JP) ; Ohkura, Kengo; (Osaka, JP) ; Sato,
Kenichi; (Osaka, JP) |
Correspondence
Address: |
David A. Blumenthal
FOLEY & LARDNER
Suite 500
3000 K Street, N.W.
Washington
DC
20007-5109
US
|
Family ID: |
14723284 |
Appl. No.: |
09/941104 |
Filed: |
August 28, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09941104 |
Aug 28, 2001 |
|
|
|
08846170 |
Apr 28, 1997 |
|
|
|
Current U.S.
Class: |
174/125.1 |
Current CPC
Class: |
Y10T 29/49014 20150115;
Y10S 505/926 20130101; H01R 4/68 20130101; H01L 39/02 20130101 |
Class at
Publication: |
174/125.1 |
International
Class: |
H01B 012/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 13, 1996 |
JP |
8-117913(P) |
Claims
What is claimed is:
1. A connection structure for connecting first and second
superconducting conductors, wherein: portions of first and second
superconducting conductors to be connected are divided respectively
into at least first and second tape-shaped superconducting wires,
each of said at least first and second superconducting wires of
said first and second superconducting conductors includes a
filament assembly containing superconducting filaments, said first
superconducting wire of said first superconducting conductor is
aligned widthwise with said first superconducting wire of said
second superconducting conductor and joined therewith to form a
first joined body such that broad surfaces of the first wire of the
first superconducting conductor and of the first wire of the second
superconducting conductor are opposed to each other, said second
superconducting wire of said first superconducting conductor is
aligned widthwise with said second superconducting wire of said
second superconducting conductor and joined therewith to form a
second joined body such that broad surfaces of the second wire of
the first superconducting conductor and of the second wire of the
second superconducting conductor are opposed to each other, the
broad surfaces of each of the at least first and second
superconducting wires of the first and second joined bodies are
aligned widthwise, and the first and second joined bodies are
joined by a solder layer.
2. The connection structure claimed in claim 1, wherein said
superconducting wires are metal coated.
3. The connection structure claimed in claim 2, wherein said metal
comprises at least one metal selected from the group consisting of
silver, gold, silver alloy and gold alloy.
4. The connection structure claimed in claim 1, wherein said
superconducting wires comprise an oxide superconductor.
5. The connection structure claimed in claim 4, wherein said oxide
superconductor comprises a bismuth oxide superconductor.
6. A connection structure for connecting first and second
superconducting conductors, wherein: portions of first and second
superconducting conductors to be connected are divided respectively
into at least first and second tape-shaped superconducting wires,
each of said at least first and second superconducting wires of
said first and second superconducting conductors includes a
filament assembly containing superconducting filaments, said first
superconducting wire of said first superconducting conductor is
aligned widthwise with said first superconducting wire of said
second superconducting conductor and joined therewith to form a
first joined body such that broad surfaces of the first wire of the
first superconducting conductor and of the first wire of the second
superconducting conductor are opposed to each other, said second
superconducting wire of said first superconducting conductor is
aligned widthwise with said second superconducting wire of said
second superconducting conductor and joined therewith to form a
second joined body such that broad surfaces of the second wire of
the first superconducting conductor and of the second wire of the
second superconducting conductor are opposed to each other, the
broad surfaces of each of the at least first and second
superconducting wires of the first and second joined bodies are
aligned widthwise, and the first joined body is insulated from the
second joined body.
7. The connection structure claimed in claim 6, wherein said
superconducting wires are metal coated.
8. The connection structure claimed in claim 7, wherein said metal
comprises at least one metal selected from the group consisting of
silver, gold, silver alloy and gold alloy.
9. The connection structure claimed in claim 6, wherein said
superconducting wires comprise an oxide superconductor.
10. The connection structure claimed in claim 9, wherein said oxide
superconductor comprises a bismuth oxide superconductor.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a connection structure for
superconducting conductors each prepared by assembling a plurality
of superconducting wires, and more particularly, it relates to a
connection structure for superconducting conductors employed in the
field of power transportation, high-energy transportation, medical
care or the like effectively utilizing superconductors.
[0003] 2. Description of the Background Art
[0004] In order to apply superconducting conductors to a coil or
the like, for example, it is necessary to connect the conductors
with each other. If superconducting conductors each prepared by
assembling a plurality of superconducting wires with each other are
directly connected with each other by solder or the like, however,
connection resistance is disadvantageously increased.
[0005] On the other hand, various studies have been generally made
as to a connection structure for superconducting wires having small
connection resistance.
[0006] In relation to structures of connected portions of metal
superconducting wires, for example, such studies include a method
of directly connecting superconducting filaments with each other
for reducing connection resistance, as described in
"Superconductivity-Cryoge- nic Engineering Handbook" (by Ohmsha,
issued on Nov. 30, 1993) pp. 913 to 914. According to this method,
the connection resistance is extremely reduced and hence the
superconducting conductors can be applied to a nuclear magnetic
resonance imaging apparatus employed for medical care or the like,
for example.
[0007] As a connection structure for oxide superconducting wires,
on the other hand, superconductors of metal-coated superconducting
wires are connected with each other as disclosed in Japanese Patent
Laying-Open No. 4-269471 (1992), or superconducting filaments of
superconducting multifilamentary wires are connected with each
other as disclosed in Japanese Patent Laying-Open No. 5-234626
(1993). According to this method, connection resistance is
suppressed to allow persistent current joining.
[0008] Further, "Applied Superconductivity" (by the Nikkan Kogyo
Shimbun Ltd., the first edition issued on Jul. 15, 1986, pp. 111 to
112) discloses a method of directly connecting filaments with each
other while removing matrices for reducing connection resistance if
superconducting wires must be connected with each other in an
intermediate stage of wiring in an MRI coil driven in a persistent
current mode which must avoid magnetic field attenuation.
[0009] However, every such prior art disadvantageously requires
sophisticated technology for the connection, although small
resistance can be attained as described above.
[0010] In the method disclosed in Japanese Patent Laying-Open No.
5-234626 (1993), for example, coatings of the multifilamentary
wires must be removed for exposing portions of the superconducting
filaments to be connected with each other, while it is predicted
that this operation is complicated and difficult due to extremely
small diameters of the filaments. Particularly in multifilamentary
superconducting wires each having a number of filaments embedded
therein, it is extremely difficult to connect such filaments with
each other. Further, it is particularly difficult to expose
filaments of oxide superconductors, due to inferior flexibility of
ceramics.
SUMMARY OF THE INVENTION
[0011] In order to solve the aforementioned problems, an object of
the present invention is to provide a connection structure for
superconducting conductors which can simply connect superconducting
conductors with each other with small connection resistance and no
requirement for sophisticated technology.
[0012] The connection structure for superconducting conductors
according to the present invention is characterized in that each of
first and second superconducting conductors to be connected with
each other includes first and second superconducting wires, each of
the first and second superconducting wires includes a filament
assembly containing superconducting filaments, the first
superconducting wire of the first superconducting conductor is
joined with that of the second superconducting conductor, and the
second superconducting wire of the first superconducting conductor
is joined with that of the second superconducting conductor.
[0013] Namely, the present invention mainly relates to a connection
structure for connecting two superconducting conductors, each
prepared by assembling a plurality of multifilamentary
superconducting wires, with each other on end portions thereof.
[0014] While first and second superconducting conductors having
identical sectional structures are connected with each other in
general, the present invention is adapted to join the first
superconducting wire forming the first superconducting conductor
with the first superconducting wire, which is in a position
corresponding to the first superconducting wire of the first
superconducting conductor in a section of the conductor, in the
superconducting wires forming the second superconducting conductor.
Similarly, the respective superconducting wires forming the first
superconducting conductor are joined with the superconducting
wires, which are in corresponding positions, forming the second
superconducting conductor.
[0015] For example, the superconducting conductors are divided into
the respective superconducting wires on the end portions thereof,
so that the superconducting wires to be joined are thereafter
superposed with each other in constant lengths and joined with each
other.
[0016] According to the present invention having the aforementioned
structure, a connection structure having smaller connection
resistance is obtained as compared with the case of directly
connecting superconducting conductors with each other. Further, the
present invention requires no sophisticated technology for the
connection as compared with the case of connecting filaments with
each other, dissimilarly to the prior art.
[0017] Consequently, superconducting conductors can be simply
connected with each other with small connection resistance and no
requirement for sophisticated technology.
[0018] Preferably, a first joined body defined by connecting the
first superconducting wires forming the first and second
superconducting conductors with each other is further joined with a
second joined body defined by connecting the second superconducting
wires forming the first and second superconducting conductors with
each other.
[0019] When the joined bodies are further joined with each other,
the connection between the superconducting conductors is further
fixed.
[0020] Preferably, the first joined body defined by connecting the
first superconducting wires forming the first and second
superconducting conductors with each other may be electrically
insulated from the second joined body defined by connecting the
second superconducting wires forming the first and second
superconducting conductors with each other.
[0021] When the joined bodies are electrically insulated from each
other, the connection resistance is further reduced.
[0022] In order to electrically insulate the joined bodies from
each other, a method of inserting an insulating material such as a
Teflon tape between the joined bodies is employed, for example. In
this case, it is preferable to employ an insulating material having
a length at least identical to those of joined portions defined by
two superconducting wires which are superposed with each other, and
an insulating material having a length larger than those of the
joined portions may be employed.
[0023] In order to electrically insulate the joined bodies from
each other, a method of winding a Teflon tape or the like on the
joined portion of each joined body is also employed, in place of
the method of inserting the insulating material between the joined
bodies. Also in this case, it is preferable to wind an insulating
material having a length at least identical to those of the joined
portions, and an insulating material having a length larger than
those of the joined portions may be wound.
[0024] According to the present invention, the joining between the
superconducting wires and the further joining between the joined
bodies are attained by electrical connection with solder, for
example. The solder may be prepared from Pb--Sn, for example.
[0025] According to the present invention, the superconducting
wires can be formed by metal-coated superconducting wires, for
example. A material employed for such metal coating is preferably
unreactive to superconductors and easy to work, and in more
concrete terms, silver or gold, or an alloy such as a gold-silver
alloy, a gold-manganese alloy or a silver-antimony alloy is
employed.
[0026] While the present invention is applicable to both of
connection between metal superconducting conductors and that
between oxide superconducting conductors, the effect of the present
invention is further excellently attained in case of connecting
oxide superconducting conductors with each other in particular, as
compared with the prior art having remarkable disadvantages in
operation.
[0027] According to the present invention, a yttrium, bismuth or
thallium oxide superconductor is employed as an oxide
superconductor, the bismuth oxide superconductor is most preferable
in view of a high critical temperature, a high current density, low
toxicity and no requirement for a rare earth element.
[0028] The present invention is not restricted to dc conductors,
but is also applicable to connection of ac superconducting
conductors.
[0029] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 illustrates a cross section of a tape-like
multifilamentary superconducting wire;
[0031] FIGS. 2 to 6 are longitudinal sectional views showing
exemplary connection structures for superconducting conductors
according to the present invention;
[0032] FIG. 7 is a cross sectional view showing a further exemplary
connection structure for superconducting conductors according to
the present invention;
[0033] FIG. 8 is a cross sectional view showing an exemplary
structure of a superconducting conductor;
[0034] FIGS. 9 to 14 are cross sectional views showing exemplary
connection structures according to the present invention for
superconducting conductors each having the structure shown in FIG.
8;
[0035] FIG. 15 is a cross sectional view showing another exemplary
structure of a superconducting conductor;
[0036] FIGS. 16 to 21 are cross sectional views showing exemplary
connection structures according to the present invention for
superconducting conductors each having the structure shown in FIG.
15;
[0037] FIG. 22 is a cross sectional view showing still another
exemplary structure of a superconducting conductor;
[0038] FIGS. 23 to 25 are cross sectional views showing exemplary
connection structures according to the present invention for
superconducting conductors each having the structure shown in FIG.
22; and
[0039] FIG. 26 is a longitudinal sectional view showing an
exemplary connection structure for superconducting conductors
according to comparative example.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] Oxides or carbonates were mixed with each other so that Bi,
Pb, Sr, Ca and Cu were in the composition ratios of
1.80:0.41:2.01:2.18:3.02, for preparing powder mainly consisting of
a 2212 phase and a non-superconducting phase by heat treatment.
This powder was degassed in the atmosphere at 800.degree. C. for
two hours. The degassed powder was charged in a silver pipe of 12
mm in outer diameter and 10 mm in inner diameter, and drawn to a
diameter of 1.93 mm. 61 such drawn powder materials were charged in
a silver pipe of 21.23 mm in outer diameter and 17.37 mm in inner
diameter, which in turn was drawn to an outer diameter of 1.4 mm.
The obtained wire was rolled to a thickness of 0.26 mm.
[0041] FIG. 1 illustrates a cross section of a tape-like
multifilamentary superconducting wire 1 prepared in the
aforementioned manner.
[0042] Referring to FIG. 1, this tape-like multifilamentary
superconducting wire 1 is formed by a stabilizing material 3
consisting of silver and 61 filaments 2, consisting of an oxide
superconductor, embedded therein.
[0043] This tape-like multifilamentary superconducting wire 1 had a
width of 3.6 mm and a thickness of 0.24 mm, and exhibited a
critical current of 60 A and a critical current density of 30,000
A/cm.sup.2.
[0044] Then, pairs of superconducting conductors A and B each
formed by stacking three such tape-like multifilamentary
superconducting wires 1 were prepared and connected with each other
in the following various methods:
EXAMPLE 1
[0045] First, each of the superconducting conductors A and B was
divided into the respective superconducting wires up to a portion
of about 40 mm from an end thereof. Then, the superconducting wires
forming the superconducting conductor A and those forming the
superconducting conductor B were superposed with each other one by
one by about 30 mm, and electrically connected with each other
through solder consisting of Pb--Sn.
[0046] FIG. 2 is a longitudinal sectional view showing a connection
structure for the superconducting conductor A formed by assembling
three multifilamentary superconducting wires 11a, 21a and 31a and
the superconducting conductor B formed by assembling
multifilamentary superconducting wires 11b, 21b and 31b.
[0047] Referring to FIG. 2, the superconducting wires 11a and 11b
of the superconducting conductors A and B respectively were joined
with each other through a solder layer 4 while superposing the ends
thereof with each other by about 30 mm. The solder layer 4 had a
thickness of about 10 to 100 .mu.m, and a length of about 30 mm,
which was identical to those of the joined portions.
[0048] Similarly, the superconducting wires 21a and 21b and 31a and
31b of the superconducting conductors A and B respectively were
joined with each other through solder layers 4 in a state
superposed with each other by about 30 mm.
[0049] Then, a joined body defined by connecting the
superconducting wires 11a and 11b with each other was further
joined at their broad surfaces with that defined by connecting the
superconducting wires 21a and 21b with each other through solder.
Similarly, the joined body defined by connecting the
superconducting wires 21a and 21b with each other was joined with
that defined by connecting the superconducting wires 31a and 31b
with each other through solder.
[0050] FIG. 3 is a longitudinal sectional view showing a connection
structure for the superconducting conductors A and B obtained in
the aforementioned manner.
[0051] Referring to FIG. 3, the joined body defined by connecting
the superconducting wires 11a and 11b with each other was further
joined with that defined by connecting the superconducting wires
21a and 21b with each other through a solder layer 4. Similarly,
the joined body defined by connecting the superconducting wires 21a
and 21b with each other was further joined with that defined by
connecting the superconducting wires 31a and 31b with each other
through a solder layer 4. Each of the solder layers 4 further
joining these joined bodies with each other also had a thickness of
about 10 to 100 .mu.m, and a length of about 30 mm.
EXAMPLE 2
[0052] After the superconducting wires forming the superconducting
conductors A and B respectively were joined with each other as
shown in FIG. 2, the joined body defined by connecting the
superconducting wires 11a and 11b with each other was electrically
insulated from that defined by connecting the superconducting wires
21a and 21b with each other by inserting a Teflon tape
therebetween. Similarly, the joined body defined by connecting the
superconducting wires 21a and 21b with each other was also
electrically insulated from that defined by connecting the
superconducting wires 31a and 31b with each other by inserting a
Teflon tape therebetween.
[0053] FIG. 4 is a longitudinal sectional view showing a connection
structure for the superconducting conductors A and B obtained in
the aforementioned manner.
[0054] Referring to FIG. 4, the joined body defined by connecting
the superconducting wires 11a and 11b with each other was
electrically insulated from that defined by connecting the
superconducting wires 21a and 21b with each other through a Teflon
tape 5. Similarly, the joined body defined by connecting the
superconducting wires 21a and 21b with each other was also
electrically insulated from that defined by connecting the
superconducting wires 31a and 31b with each other through a Teflon
tape 5. Each of these Teflon tape 5 had a thickness of about 50
.mu.m, and a length of about 30 mm similarly to the joined
portions.
[0055] While the Teflon tapes 5 must have lengths which are at
least identical to those of the joined portions in order to
electrically insulate the joined bodies from each other, such
Teflon tapes 5 may have lengths larger than those of the joined
portions, as shown in FIG. 5.
[0056] As a method of electrically insulating joined bodies from
each other through Teflon tapes, a method of winding Teflon tapes
on peripheries of connected portions of the joined bodies is also
conceivable, in addition to the aforementioned method of inserting
the Teflon tapes between the joined bodies.
[0057] FIGS. 6 and 7 are longitudinal and cross sectional views
showing a connection structure for superconducting conductors in
case of winding Teflon tapes respectively.
[0058] Referring to FIGS. 6 and 7, Teflon tapes 5 are wound on
overall peripheries of joined bodies. According to this structure,
further reduction of connection resistance can be expected.
[0059] Also in this case, the Teflon tapes 5 must be wound over
lengths at least identical to those of the joined portions, or may
be wound over ranges longer than the joined portions.
COMPARATIVE EXAMPLE 1
[0060] For the purpose of comparison, superconducting conductors A
and B were electrically connected with each other through solder
consisting of Pb--Sn in a state superposed with each other by about
30 mm.
[0061] FIG. 26 is a longitudinal sectional view showing a
connection structure for the superconducting conductors A and B
obtained in the aforementioned manner.
[0062] Referring to FIG. 26, the superconducting conductor A formed
by assembling superconducting wires 11a, 21a and 31a was integrally
joined with the superconducting conductor B formed by assembling
superconducting wires 11b, 21b and 31b through a solder layer
4.
[0063] (Connection Resistance Measuring Test)
[0064] As to each of the connection structures according to
Examples 1 and 2 and comparative example 1 shown in FIGS. 3, 4 and
26 respectively, three samples were subjected to measurement of
connection resistance, and the obtained values were compared with
each other.
[0065] The connection n resistance was calculated by cooling each
sample with liquid nitrogen, mounting terminals on portions of 10
mm from both ends of connected portions for feeding a dc current,
and measuring a current value and a voltage value at an
inter-terminal distance of about 50 mm.
[0066] Table 1 shows the results of the measurement.
1 TABLE 1 Sample No. Connection Resistance (.mu..OMEGA.) Example 1
1 0.04 2 0.03 3 0.05 Example 2 1 0.01 2 0.007 3 0.008 Comparative 1
0.1 Example 1 2 0.2 3 0.15
[0067] Referring to Table 1, it is understood that the connection
resistance was reduced in Example 1 connecting the superconducting
wires with each other as compared with comparative example 1
integrally connecting the conductors with each other.
[0068] It is also understood that the connection resistance was
further reduced in Example 2 electrically insulating the joined
bodies from each other.
[0069] The aforementioned disclosure in relation to Examples shows
mere concrete examples of the present invention, and restricts no
technical scope of the present invention at all. In other words,
application of the present invention is not restricted to
connection between three-layer conductors of tape-like
multifilamentary superconducting wires. Exemplary application of
the present invention to superconducting conductors having another
structure is now described with reference to the remaining
drawings.
[0070] FIG. 8 is a cross sectional view typically showing an
exemplary structure of a superconducting conductor.
[0071] FIGS. 9 to 14 are cross sectional views typically showing
connection structures for pairs of superconducting conductors A and
B, each having the structure shown in FIG. 8, with each other
respectively.
[0072] In an additional method of connecting two superconducting
conductors A and B each having the structure shown in FIG. 8 with
each other, superconducting wires 11a and 11b of the
superconducting conductors A and B are respectively connected with
each other thorough a solder layer 4 so that tape surfaces are
superposed with each other, while superconducting wires 21a and 21b
and 31a and 31b of the superconducting conductors A and B are
similarly connected through solder layers 4 as shown in FIG. 9, for
example.
[0073] As shown in FIG. 10, a joined body defined by connecting the
superconducting wires 11a and 11b with each other may be further
joined with that defined by connecting the superconducting wires
21a and 21b with each other through a solder layer 4 while also
joining the joined body defined by connecting the superconducting
wires 21a and 21b with each other with that defined by connecting
the superconducting wires 31a and 31b with each other similarly
through a solder layer 4.
[0074] Alternatively, the joined body defined by connecting the
superconducting wires 11a and 11b with each other may be
electrically insulated from that defined by connecting the
superconducting wires 21a and 21b with each other through an
insulating tape 5 while also electrically insulating the joined
body defined by connecting the superconducting wires 21a and 21b
with each other from that defined by connecting the superconducting
wires 31 and 31b with each other similarly through an insulating
tape 5, as shown in FIG. 11.
[0075] The examples shown in FIGS. 9, 10 and 11 coincide with those
shown in FIGS. 2, 3 and 4 or 5 respectively.
[0076] An additional method of connecting two superconducting
conductors A and B each having the structure shown in FIG. 8 with
each other involves a method of joining superconducting wires 11a
and 11b of the superconductors A and B respectively with each other
through a solder layer 4 so that side surfaces of the tape-like
wires 11a and 11b are superposed with each other. This method can
also include joining superconducting wires 21a and 21b and 31a and
31b of the superconducting conductors A and B respectively, with
each other similarly through solder layers 4 as shown in FIG. 12,
for example.
[0077] Further, the joined body defined by connecting the
superconducting wires 11a and 11b with each other may be further
joined with that defined by connecting the superconducting wires
21a and 21b with each other through a solder layer 4 while also
joining the joined body defined by connecting the superconducting
wires 21a and 21b with each other with that defined by connecting
the superconducting wires 31a and 31b with each other similarly
through a solder layer 4, as shown in FIG. 13.
[0078] Alternatively, the joined body defined by connecting the
superconducting wires 11a and 11b with each other may be
electrically insulated from that defined by connecting the
superconducting wires 21a and 21b with each other through an
insulating tape 5 while also electrically insulating the joined
body defined by connecting the superconducting wires 21a and 21b
with each other from that defined by connecting the superconducting
wires 31a and 31b with each other similarly through an insulating
tape 5, as shown in FIG. 14.
[0079] FIG. 15 is a cross sectional view showing another exemplary
structure of a superconducting conductor.
[0080] FIGS. 16 to 21 are cross sectional views showing connection
structures for pairs of superconducting conductors A and B each
having the structure shown in FIG. 15 respectively.
[0081] In case of connecting two superconducting conductors A and B
each having the structure shown in FIG. 15 with each other, a
method of joining superconducting wires 11a and 11b of the
superconducting conductors A and B respectively with each other
through a solder layer 4 so that tape surfaces are superposed with
each other while also joining superconducting wires 21a and 21b and
31a and 31b forming the superconducting conductors A and B
respectively with each other similarly through solder layers 4 as
shown in FIG. 16 is conceivable, for example.
[0082] As shown in FIG. 17, a joined body defined by connecting the
superconducting wires 11a and 11b with each other may be further
joined with that defined by connecting the superconducting wires
21a and 21b with each other through a solder layer 4 while also
joining the joined body defined by connecting the superconducting
wires 21a and 21b with each other with that defined by connecting
the superconducting wires 31a and 31b with each other similarly
through a solder layer 4.
[0083] Alternatively, the joined body defined by connecting the
superconducting wires 11a and 11b with each other may be
electrically insulated from that defined by connecting the
superconducting wires 21a and 21b with each other through an
insulating tape 5 while also electrically insulating the joined
body defined by connecting the superconducting wires 21a and 21b
with each other from that defined by connecting the superconducting
wires 31a and 31b with each other similarly through an insulating
tape 5, as shown in FIG. 18.
[0084] In case of connecting two superconducting conductors A and B
each having the structure shown in FIG. 15 with each other, on the
other hand, a method of joining superconducting wires 11a and 11b
of the superconductors A and B respectively with each other through
a solder layer 4 so that side surfaces of the tape-like wires 11a
and 11b are superposed with each other while also joining
superconducting wires 21a and 21b and 31a and 31b of the
superconducting conductors A and B respectively with each other
similarly through solder layers 4 as shown in FIG. 12 is also
conceivable, for example.
[0085] Further, a joined body defined by connecting the
superconducting wires 11a and 11b with each other may be further
joined with that defined by connecting the superconducting wires
21a and 21b with each other through a solder layer 4 while also
joining the joined body defined by connecting the superconducting
wires 21a and 21b with each other with that defined by connecting
the superconducting wires 31a and 31b with each other similarly
through a solder layer 4, as shown in FIG. 20.
[0086] Alternatively, the joined body defined by connecting the
superconducting wires 11a and 11b with each other may be
electrically insulated from that defined by connecting the
superconducting wires 21a and 21b with each other through an
insulating tape 5 while also electrically insulating the joined
body defined by connecting the superconducting wires 21a and 21b
with each other from that defined by connecting the superconducting
wires 31a and 31b with each other similarly through an insulating
tape 5, as shown in FIG. 21.
[0087] FIG. 22 is a cross sectional view showing still another
exemplary structure of a superconducting conductor.
[0088] FIGS. 23 to 25 are cross sectional views typically showing
connection structures for pairs of superconducting conductors A and
B each having the structure shown in FIG. 22 respectively.
[0089] In case of connecting two superconducting conductors A and B
each having the structure shown in FIG. 22 with each other, a
method of joining superconducting wires 11a and 11b of the
superconducting conductors A and B respectively with each other
thorough a solder layer 4 while also joining superconducting wires
21a and 21b, 31a and 31b, 41a and 41b and 51a and 51b of the
superconducting conductors A and B respectively with each other
similarly through solder layers 4 as shown in FIG. 23 is
conceivable, for example.
[0090] As shown in FIG. 24, a joined body defined by connecting the
superconducting wires 11a and 11b with each other may be further
joined with that defined by connecting the superconducting wires
31a and 31b with each other through a solder layer 4 while also
joining joined bodies defined by connecting the superconducting
wires 21a and 21b, 41a and 41b and 51a and 51b with each other with
that defined by connecting the superconducting wires 31a and 31b
with each other similarly through solder layers 4.
[0091] Alternatively, an insulating tape 5 may be wound on the
joined body defined by connecting the superconducting wires 11a and
11b with each other for insulating this joined body from the
remaining ones while also winding insulating tapes 5 on the joined
bodies defined by connecting the superconducting wires 31a and 31b,
41a and 41b and 51a and 51b with each other respectively for
insulating these joined bodies from each other, as shown in FIG.
25.
[0092] Although the present invention has been described and
illustrated in detail, it is clearly understood that the same is by
way of illustration and example only and is not to be taken by way
of limitation, the spirit and scope of the present invention being
limited only by the terms of the appended claims.
* * * * *