JP2016009721A - Superconducting current lead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable superconducting current lead in which a superconducting wire and a metal electrode are prevented from being brought into contact to each other to be damaged.SOLUTION: A superconducting current lead 10 includes a tape-like superconducting wire and a metal electrode 13 to which one end part 11a of the superconducting wire is joined. The superconducting wire is joined to a joining surface 132 via a solder 140, the joining surface being an inside side surface of a fixing groove 130 of the metal electrode. The superconducting wire extends from an opening edge 135 of the fixing groove 130, and the opening edge 135 has a chamfered shape.

Description

  The present invention relates to a superconducting current lead using an oxide superconducting wire, and more particularly to a superconducting current lead including a superconducting wire and a metal electrode joined to the superconducting wire.

  In recent years, in the field of superconducting applied equipment using superconductivity such as superconducting cables and superconducting magnets, research and development have been conducted for practical use. In general, a superconducting application device is installed in a low temperature part (low temperature container) and connected to an external device (for example, a power source) installed in the normal temperature part via a current lead.

  Since the operation of superconducting equipment is performed in a cryogenic environment, the heat insulation of the low temperature part is extremely important. If the heat insulation property of the low temperature part is poor and the heat penetration into the low temperature part is large, the cooling efficiency of the superconducting application equipment will decrease and the cooling cost for maintaining the superconducting state will increase. This is because it becomes impossible to drive. As one of the paths of heat penetration into the low temperature portion, a path for transferring heat through the current lead can be considered.

  As a technique for preventing heat intrusion through the current lead, a superconducting current lead using an oxide superconductor has been proposed. An oxide superconductor has zero electrical resistance and low thermal conductivity below the liquid nitrogen temperature (one tenth of copper). Therefore, in the superconducting current lead, Joule heat is not generated during energization, and the amount of heat transferred to the low temperature portion is extremely small. Therefore, according to the superconducting current lead, heat penetration into the low temperature portion is reduced.

  In general, a superconducting current lead is a tape-shaped superconducting wire, a first metal electrode disposed at one end (high temperature side) of the superconducting wire, and a second disposed at the other end (low temperature side) of the superconducting wire. A metal electrode is provided. The superconducting wire is bonded to the first metal electrode and the second metal electrode by soldering, or fixed by sandwiching both ends of the superconducting wire between the metal electrodes, and protrudes from each metal electrode. To be arranged.

  For example, in Patent Document 1, metal electrodes are bonded to both ends of a linearly arranged superconducting wire, and the superconducting wires are supported by the load support by attaching these metal electrodes to both ends of the load support. Yes.

JP 2013-69664 A

  By the way, in the structure of the superconducting current lead described above, the superconducting wire is attached to the metal electrode so as to protrude from one end surface orthogonal to the surface to which the superconducting wire is joined. As a result, when the superconducting current lead is transported to the site, the superconducting wire itself contacts and is damaged by the corner portion, which is the joining portion between the joining surface and one end surface, and the superconducting characteristics (eg, critical current value Ic) are reduced. It may be difficult to pass a large current.

  Further, when a superconducting magnet device is connected as a superconducting application device, a magnetic field is generated by a current flowing through the superconducting coil. Therefore, the Lorentz force due to this magnetic field acts on the superconducting current lead. In particular, when a superconducting current lead is used in a high magnetic field environment, such as when the superconducting current lead is arranged so that the direction of the magnetic field matches the width direction of the superconducting wire, the wide surface of the superconducting wire (hereinafter referred to as “tape surface”) )), The Lorentz force increases. Since both ends of the superconducting wire are fixed to the metal electrode, and the intermediate portion is not fixed, the superconducting wire is bent by this Lorentz force, and the bending strain in the thickness direction of the superconducting wire (hereinafter referred to as “flatwise bending strain”). ) Occurs. Due to the occurrence of this flat-wise bending strain, the superconducting wire itself is damaged at the end of the metal electrode by being bent at the end of the metal electrode, causing a large current to flow as described above. Can be difficult.

  The object of the present invention is to prevent deterioration of superconducting characteristics due to flatwise bending strain even when the superconducting wire is displaced and flatwise bending strain occurs in the superconducting wire, for example, when placed in a magnetic field. It is to provide a highly reliable superconducting current lead.

  A superconducting current lead according to the present invention has a tape-shaped superconducting wire and a metal electrode having a joining surface to which one end of the superconducting wire joins, and the superconducting wire extends from a corner of the joining surface. It arrange | positions so that it may take out and the said corner | angular part takes the structure which has comprised the chamfering shape.

  According to the present invention, for example, when placed in a magnetic field, the superconducting wire is displaced, flatwise bending distortion occurs in the superconducting wire, and even if it contacts the metal electrode, damage due to contact in the superconducting wire, That is, it is possible to prevent deterioration of superconducting characteristics (for example, critical current value Ic) due to flatwise bending strain, and to ensure high reliability.

The figure which shows the superconducting magnet apparatus using the superconducting electric current lead which concerns on one embodiment of this invention External view of superconducting current lead according to the same embodiment Diagram showing general configuration of superconducting wire Front view of the superconducting current lead viewed from the base end side in the Y direction Plan view of the superconducting current lead as seen from the Z-direction tip side IV-IV arrow sectional view in FIG. VI-VI arrow sectional view in FIG. Partial enlarged view for explaining the joint between the superconducting wire and the electrode It is a figure which shows the bending formed in a superconducting wire. The elements on larger scale which show typically the principal part structure of the modification 1 of the superconducting electric current lead which concerns on one embodiment of this invention. The elements on larger scale which show typically the principal part structure of the modification 2 of the superconducting electric current lead which concerns on one embodiment of this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a superconducting magnet device 1 using a superconducting current lead 10 according to an embodiment of the present invention. FIG. 2 is an external view of the superconducting current lead 10. FIG. 3 is a diagram showing a general configuration of the superconducting wire 11. FIG. 4 is a front view of the superconducting current lead as viewed from the base end side in the Y direction. FIG. 5 is a plan view of the superconducting current lead as viewed from the front end side in the Z direction. 6 is a cross-sectional view taken along arrow IV-IV in FIG. 7 is a cross-sectional view taken along the line VI-VI in FIG.

  As shown in FIG. 1, the superconducting magnet device 1 includes a superconducting current lead 10, a normal conducting current lead 15, a superconducting coil 20, a power source 30, a cryogenic container 40, and the like.

  The cryogenic container 40 has a double structure composed of an inner container 41 and an outer vacuum chamber 42. The container 41 is connected to a refrigerator (not shown). The vacuum chamber 42 is connected to a vacuum pump (not shown), and the inside is kept in a vacuum state.

  The superconducting coil 20 is a coil wound with a superconducting wire. The superconducting coil 20 is disposed in a container 41 serving as a low temperature part. The superconducting coil 20 has a coil electrode 21 for connecting to the superconducting current lead 10.

  The power source 30 is disposed outside the low-temperature container 40 serving as a normal temperature part. The power supply 30 supplies current to the superconducting coil 20 via the normal conducting current lead 15 and the superconducting current lead 10. The normal conductive current lead 15 is, for example, a copper wire.

  The superconducting current lead 10 includes a superconducting wire 11, a first electrode 12, a second electrode 13, and a reinforcing member 14. The superconducting current lead 10 is disposed in the container 41. One end of the superconducting wire 11 on the high temperature side is joined to the first electrode 12, and the other end on the low temperature side is joined to the second electrode 13. The superconducting wire 11, the first electrode 12, and the second electrode 13 constitute a lead body.

  In the present embodiment, a superconducting current lead 10 using one superconducting wire 11 will be described. However, the present invention can also be applied to a superconducting current lead having a plurality of superconducting wires 11.

  The superconducting wire 11 is a tape-like wire having a superconducting layer 113 as shown in FIG. The superconducting wire 11 has a laminated structure in which, for example, an intermediate layer 112, a superconducting layer 113, and a stabilizing layer 114 are formed in this order on a tape-shaped metal substrate 111.

  The metal substrate 111 may be, for example, a Ni—Cr system (specifically, a Ni—Cr—Fe—Mo system Hastelloy (registered trademark) B, C, X, etc.), a W—Mo system, a Fe—Cr system (for example, , Austenitic stainless steel) or Fe—Ni (for example, non-magnetic composition type) and other low magnetic crystal grain non-oriented heat resistant high strength metal substrates.

The intermediate layer 112 has, for example, a first intermediate layer (diffusion prevention layer) for preventing the diffusion of elements from the metal substrate 111 to reach the superconducting layer 113, and orients crystals of the superconducting layer 113 in a certain direction. A plurality of intermediate layers, such as a second intermediate layer (alignment layer). The first intermediate layer is composed of, for example, a gallium-doped zinc oxide layer (GZO) or an yttrium-stabilized zirconia layer (YSZ). For example, an ion beam assisted deposition (IBAD) can be applied to form the first intermediate layer. The second intermediate layer is composed of, for example, a cerium oxide layer (CeO ₂ ). For example, an RF sputtering method can be applied to form the second intermediate layer. Further, as an intermediate layer 112 having a structure of two or more layers, an MgO layer formed by an IBAD method and an LaMnO ₃ layer formed by a sputtering method are sequentially stacked between a GZO layer as a first intermediate layer and a CeO ₂ layer. It is good also as what you did.

Superconducting layer 113, for example REBa _y Cu ₃ O _z based superconductor (RE is, Y, Nd, Sm, Eu , Gd, Tb, Dy, Ho, Er, 1 or 2 or more selected from Tm and Yb It is a rare earth element and is composed of an oxide superconductor such as y ≦ 2 and z = 6.2 to 7). A typical example of the RE-based superconductor is an yttrium-based superconductor represented by YBa ₂ Cu ₃ O ₇ . The superconducting layer 113 is formed by metal-organic deposition (MOD), pulsed laser deposition (PLD), sputtering, or metal organic chemical vapor deposition (MOCVD). Vapor Deposition) can be applied.

In the superconducting layer 113, it is preferable that 50 [nm] or less oxide particles containing at least one of Zr, Sn, Ce, Ti, Hf, and Nb are dispersed as magnetic flux pinning points. In this case, as a method for forming the superconducting layer 113, a TFA-MOD method using trifluoroacetate (TFA) is suitable. For example, Zr-containing oxide particles (BaZrO ₃ ) are added to the superconducting layer 113 made of a RE-based superconductor by mixing a Zr-containing naphthenate having a high affinity with Ba into a Ba solution containing TFA. It can be distributed as flux pinning points. A known technique can be applied to the method of dispersing the magnetic flux pinning points in the superconducting layer 113 (for example, JP 2012-059468 A).

  By dispersing the magnetic flux pinning points in the superconducting layer 113, even if the superconducting wire 11 is used in a curved state, it is hardly affected by the magnetic field and exhibits stable superconducting characteristics.

  The stabilization layer 114 is a layer for protecting the superconducting layer 113 mainly from moisture and the like, and for diverting the current when the superconducting state is partially broken and resistance is generated (normal conducting transition). The stabilization layer 114 is preferably made of a material having a low electrical resistivity and a high thermal conductivity, for example, Ag or Cu. For example, a sputtering method can be applied to form the stabilization layer 114.

  Note that the thermal contraction rate of the superconducting wire 11 mainly depends on the metal substrate 111. The thermal contraction rate of Hastelloy when cooled from room temperature to 77 K is 0.204 [%]. Further, the thermal conductivity of the superconducting wire 11 mainly depends on the metal substrate 111 and the stabilization layer 114. The thermal conductivity of Hastelloy at 77K is 5.164 [W / (m · K)], and the thermal conductivity of Ag is 237.3 [W / (m · K)].

  The 1st electrode 12 (high temperature side electrode) and the 2nd electrode 13 (low temperature side electrode) are comprised with metal materials, such as copper or a copper alloy. For example, the 1st electrode 12 (high temperature side electrode) and the 2nd electrode 13 (low temperature side electrode) are comprised with the metal electrode made from oxygen-free copper by which the tin plating process was performed to the surface.

  The first electrode 12 is disposed in the vicinity of the bottom surface of the container 41 and is connected to the normal conductive current lead 15 via a conductor lead-out part (not shown). The temperature in the vicinity of the first electrode 12 is, for example, 77 [K]. The second electrode 13 is disposed in the vicinity of the superconducting coil 20 and connected to the coil electrode 21 of the superconducting coil 20. The temperature in the vicinity of the second electrode 13 is, for example, 4.2 [K].

  The first electrode 12 and the second electrode 13 have fixing grooves 120 and 130 for fixing the superconducting wire 11 on one end face (end face portions 121 and 131) in the length direction (X direction), respectively. Both ends in the width direction (Y direction) of the fixing grooves 120 and 130 may be opened or closed. The height (Z direction) of the fixing grooves 120 and 130 is set slightly larger than the thickness of the superconducting wire 11. The depth (X direction) of the fixing grooves 120 and 130 may be such that it can be firmly joined to the superconducting wire 11, the connection resistance is sufficiently small, and can be supported.

  The first electrode 12 is inserted into the fixed groove 120 until one end of the superconducting wire 11 hits the bottom of the fixed groove 120. The other end of the superconducting wire 11 is inserted into the fixing groove 130 of the second electrode 13 until it hits the bottom of the fixing groove 130. The gap between the superconducting wire 11 and the fixing grooves 120 and 130 is filled with molten solder. That is, the superconducting wire 11 and the first electrode 12 and the second electrode 13 are joined by soldering and mechanically and electrically connected.

  FIG. 8 is an enlarged cross-sectional view showing the main configuration of the fixing groove 130.

  The second electrode 13 having the fixed groove 130 and the first electrode 12 are configured similarly. Therefore, in the following, the configuration of the second electrode 13 will be mainly described. Since the configuration of the first electrode 12 is the same as that of the second electrode 13, the components of the first electrode 12 are illustrated in the drawings. Are indicated corresponding to the reference numerals indicating the same names in the second electrode 13, and the detailed description of the configuration of the first electrode 12 is omitted.

  In the fixing groove 130, the solder 140 in a state where one end 11 a of the superconducting wire 11 is inserted between the joint surfaces 132 (132-1 and 132-2) facing each other along the extending direction of the superconducting wire 11. It is connected so that it can conduct. Specifically, the joining surfaces 132-1 and 132-2 constitute inner wall surfaces facing each other in the fixing groove 130, and each of these joining surfaces 132 is connected to the end portion 11a of the superconducting wire 11 via the solder 140. Are joined. The joining surfaces 132-1 and 132-2 intersect and are continuous with the one end surface 131 of the electrode 13 (here, orthogonal), and the corners of the joining surfaces 132-1 and 132-2, that is, the opening of the fixing groove 130. An edge 135 is formed.

  As described above, the superconducting wire 11 is formed on the inner side forming the fixing grooves 130 and 120 adjacent to the one end surfaces 131 and 121 so as to protrude from the one end surfaces 131 and 121 of the electrodes 13 and 12 with respect to the electrodes 13 and 12. Electrically joined to the electrodes 13 and 12 by joint surfaces 132 and 122 which are wall surfaces.

  The opening edge 135 (125) extending in the width direction in the fixed groove 130 (120) is chamfered to form a chamfered shape. Here, the opening edge portion 135 (125) which is a corner portion of the fixing groove 130 (120) is chamfered on the R surface, and the outer surface thereof is the R surface. The chamfered shape of the opening edge 135 (125) may be any shape as long as it is chamfered, such as a rounded shape (R surface shape). As will be described later, the chamfered shape has an angle of more than 90 degrees and less than 180 degrees, more preferably a chamfered shape with an angle of 100 degrees to 160 degrees.

  The bending radius (R) constituting the R surface of the curved opening edge 135 (125) is such that when the superconducting current lead 10 is placed under an external magnetic field, the wire is pulled by Lorentz force, and the electrode edge ( Here, the flat-wise bending strain of the superconducting wire 11 bent in contact with the opening edge 135 (125) is set so as not to exceed 0.3%. This is because the superconducting wire 11 deteriorates the current-carrying characteristics when it abuts on the electrode 13 (12) (specifically, the opening edges 135 and 125) due to flatwise bending strain. Here, the bending radius of the opening edge 125 (135) is set to 20 [mm] or more.

  Thus, even if the superconducting wire is displaced by the external magnetic field so as to come into contact with the opening edge 135 (125), the opening edge 135 (125) is not damaged, and the superconducting characteristics are lowered during energization. Can be prevented.

  The superconducting wire 11 is accommodated in the reinforcing member 14 with a predetermined distance between the electrodes (a distance between the first electrode 12 and the second electrode 13).

  The reinforcing member 14 is a hollow rectangular parallelepiped member, and includes a housing part 142 whose top surface is open and a lid part 141 that closes the opening. After the lead main body is accommodated in the accommodating portion 142, the lid portion 141 is bonded so as to close the opening of the accommodating portion 142. Note that an opening may be partially formed in the accommodating portion 142 and the lid portion 141.

  When the reinforcing member 14 is made of GFRP, stainless steel, or the like, the thermal contraction rate of the superconducting wire 11 is smaller than the thermal contraction rate of the reinforcing member 14. In this case, the superconducting wire 11 having a higher thermal conductivity is faster in cooling, and the amount of shrinkage at the initial stage of cooling is larger in the superconducting wire 11 than in the reinforcing member 14. Thereby, if the opening edge part 135 (125) of the superconducting wire 11 is an acute angle shape orthogonal, the superconducting wire 11 may come into contact with each of the first electrode 12 and the second electrode 13 to be damaged. .

  According to the superconducting current lead 10, even if the superconducting wire 11 is displaced due to a flat-wise bending strain generated in the superconducting wire 11 due to a difference in heat shrinkage generated between the superconducting wire 11 and the reinforcing member 14 during cooling. The contact between the superconducting wire 11 and the first electrode 12 and the second electrode 13 does not damage the superconducting wire 11 itself. Therefore, it is possible to secure suitable superconducting characteristics and realize high reliability as a superconducting current lead.

  Further, in the present embodiment, when the lead body is accommodated in the reinforcing member 14, the superconducting wire 11 may be bent between the first electrode 12 and the second electrode 13. The bending formed in the superconducting wire 11 is shown in FIG.

  The exposed length of the superconducting wire 11 shown in FIG. 9 is a length obtained by removing the depths (length in the X direction) of the fixing grooves 120 and 130 from the entire length of the superconducting wire 11. If the distance between the electrodes when the lead body is accommodated in the reinforcing member 14 is shorter than the exposed length of the superconducting wire 11, the superconducting wire 11 bends by the amount of bending as shown in FIG. 9.

  As described above, even when the superconducting wire 11 is bent between the metal electrodes 12 and 13, the opening edge portion (corner portion of the joint surfaces 132 and 122) 135 (125) of the fixing groove 120 (130) has a chamfered shape. (Here, it is R-shaped and rounded), so that even if the superconducting wire 11 bends and contacts the opening edge 135 (125), it will not be damaged. Therefore, suitable superconducting characteristics can be obtained, and high reliability as a superconducting current lead can be secured.

  In the superconducting current lead 10, the opening edge of at least one fixed groove of the first electrode 12 and the second electrode 13 may have a chamfered shape with an angle of more than 90 degrees and less than 180 degrees. . This can be formed by chamfering the opening edge. An example of this is shown in FIG.

  FIG. 10 is a partially enlarged view schematically showing the main configuration of Modification 1 of the superconducting current lead according to the embodiment of the present invention.

  The superconducting current lead 10A shown in FIG. 10 differs from the superconducting current lead 10 configuration only in the shape of the opening edges 125 and 135 in the superconducting current lead 10, and the other components are the same. Therefore, the same name is attached | subjected to the same component and the code | symbol corresponding to it, and the description is abbreviate | omitted.

  A superconducting current lead 10A shown in FIG. 10 includes a tape-shaped superconducting wire 11 and metal electrodes 12A and 13A including joining surfaces 132A and 122A to which both ends of the superconducting wire 11 are joined, respectively. In the superconducting current lead 10A, the superconducting wire 11 is arranged so as to extend from the opening edge portion 135A (125A) which is a corner portion of the joining surface 132A (132A-1, 132A-2). In addition, the opening edge portion 135A (125A) has a chamfered shape with an angle of more than 90 degrees and less than 180 degrees. For example, the opening edge portion is formed by cutting a corner with a right-angled triangle having a predetermined length, such as a right-angled isosceles triangle. According to this configuration, the same effect as that of the superconducting current lead 10 having the opening edge portion 135 (125) can be obtained.

  In addition, as a joining structure of the superconducting wire 11 and the electrodes 12 and 13, for example, like the superconducting current lead 10B shown in FIG. 11, one end portion 11a of the superconducting wire 11 is soldered to the joining surface 128 that is the outer surface of the electrode 12B. The attached structure may be used. FIG. 11 is a partially enlarged view schematically showing the main configuration of Modification 2 of the superconducting current lead according to the embodiment of the present invention. FIG. 11 schematically shows a connection portion between one electrode 12B and the superconducting wire 11 among the electrodes connected to both ends of the superconducting wire 11 in the superconducting current lead 10B.

  As shown in FIG. 11, in the electrode 12B, the corner portion 129 of the joining surface 128 as the outer surface where the one end portion 11a of the superconducting wire 11 is joined by the solder 140B is formed in a chamfered shape (here, R-surface shape). Yes. Thereby, the superconducting wire 11 extending from the outer surface of the electrode 12B is disposed so as to pass over the corner portion 129 having a curved shape. The superconducting current lead 10B is configured so that the outer surface of the corner (edge) of the other electrode to which the other end of the superconducting wire 11 is joined also has a chamfered shape. Thereby, even if the superconducting wire 11 is thermally contracted during cooling and the superconducting wire 11 itself is displaced and contacts the corner portion 129 of the electrode, it is not damaged. That is, damage due to contact in the superconducting wire, that is, deterioration of superconducting characteristics such as the critical current value Ic due to flatwise bending strain can be prevented, and high reliability can be secured.

[Example 1]
In Example 1, one superconducting wire having a superconducting layer made of YBCO formed by the TFA-MOD method is prepared, the end of the groove is chamfered at both ends, and the surface is tin-plated. A metal electrode made of oxygen-free copper was joined. Furthermore, the superconducting wire was accommodated in a reinforcing member made of GFRP to produce a superconducting current lead 10A shown in FIG. That is, in the superconducting current lead of Example 1, the shape of the opening edge portion of the fixing groove portion of the first and second electrodes made of metal is a shape of 135 degrees. The length of the superconducting wire is 150 [mm], the distance between the electrodes is 100 mm, and the superconducting wire itself is not bent.
[Example 2]
In Example 2, in the superconducting current lead having the same configuration as that of Example 1, as shown in FIG. 1 to FIG. 8, the opening edge of the metal electrode is formed into an R surface shape (radius 20 [mm]). A current lead was manufactured. In the superconducting current lead of Example 2, there is no bending of the superconducting wire.
[Example 3]
In Example 3, a superconducting wire similar to that in Example 1 was manufactured by bending the superconducting wire between the electrodes.
[Example 4]
In Example 4, the superconducting wire between the electrodes was bent to produce the same superconducting current lead as in Example 2.

[Comparative Example 1]
In Comparative Example 1, a superconducting current lead having the same configuration as in Example 1 is manufactured, and the shape of the opening edge of the fixing groove portion of the metal electrode is set to a right angle and the superconducting wire between the electrodes is not bent. did.
[Comparative Example 2]
In Comparative Example 2, a superconducting current lead having the same configuration as that of Example 1 is manufactured, and the shape of the opening edge of the fixed groove portion of the metal electrode is set to a right angle, and the superconducting wire between the electrodes is bent. did.

  The critical current characteristics of the superconducting current leads according to Examples 1 to 4, Comparative Example 1 and Comparative Example 2 were evaluated in a cryogenic environment. Specifically, a heat conduction plate is attached to the metal electrode of the superconducting current lead, and the superconducting current lead is cooled to 77 [K] (high temperature side) -4.2 [K] (low temperature side) by conduction cooling. It was measured. The external magnetic field was set to 0.5 [T], which is a high magnetic field. The evaluation results are shown in Table 1.

  As shown in Table 1, it was found that there was a difference in the conduction characteristics of the superconducting current lead depending on the presence or absence of chamfering at the opening edge (groove end) of the fixed groove of the metal electrode. That is, if the corner portion of the portion where the superconducting wire is joined is a chamfered shape, the energization characteristic, that is, the superconducting characteristic does not deteriorate. On the other hand, in Comparative Examples 1 and 2, the energization characteristics are degraded. In Examples 1 to 4, even if the superconducting wire is bent by the Lorentz force, the metal electrode is not damaged by contact with it. In Comparative Examples 1 and 2, the opening edge of the fixed groove portion of the electrode ( Since the corner portion is a right angle, it is considered that the superconducting wire is in contact with this and the superconducting properties are deteriorated.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and can be changed without departing from the gist thereof.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Superconducting Magnet Device 10, 10A, 10B Superconducting Current Lead 11 Superconducting Wire 11a One End 111 of Superconducting Wire Metal Substrate 112 Intermediate Layer 113 Superconducting Layer 114 Stabilizing Layer 12, 12A First Electrode (Metal Electrode)
12B electrode 13, 13A second electrode (metal electrode)
14 Reinforcing member 15 Normal conducting current lead 20 Superconducting coil 30 Power supply 40 Cryogenic container 120, 120A, 130, 130A Fixed groove (fixed groove)
121, 121A, 131, 131A One end surface 122, 122A, 128, 132, 132A Joint surface 125, 125A, 135, 135A Open edge (corner)
129 Corner 140, 140B Solder

Claims (6)

A tape-shaped superconducting wire,
A metal electrode having a joining surface to which one end of the superconducting wire is joined;
Have
The superconducting wire is arranged so as to extend from a corner of the joint surface,
The corner portion has a chamfered shape,
Superconducting current lead. The metal electrode has a fixed groove into which the superconducting wire is inserted,
The joint surface is at least one of the inner wall surfaces facing each other in the fixed groove portion,
The corner is an opening edge of the fixed groove.
The superconducting current lead according to claim 1. The corner portion has a chamfered shape with an angle of more than 90 degrees and less than 180 degrees,
The superconducting current lead according to claim 1 or 2. The corner portion has an R-surface shape.
The superconducting current lead according to claim 1 or 2. The metal electrode is bonded to both ends of the superconducting wire,
A reinforcing member that accommodates the lead body including the superconducting wire and the metal electrode in a state of being positioned so as to have a predetermined inter-electrode distance;
The superconducting wire has bending between the metal electrodes,
The superconducting current lead according to any one of claims 1 to 4. The superconducting wire is formed by sequentially laminating an intermediate layer, a superconducting layer, and a stabilizing layer on a metal substrate,
The superconducting layer is formed by a TFA-MOD method,
In the superconducting layer, oxide particles of 50 nm or less containing at least one of Zr, Sn, Ti, and Ce are dispersed as magnetic flux pinning points.
The superconducting current lead according to any one of claims 1 to 5.

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