JPH10294213A - Manufacture for oxide based superconducting magnet system and oxide based superconducting magnet system and superconducting magnetic field generation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an oxide based superconducting magnet system fit to utilize an oxide based superconductor. SOLUTION: According to the manufacture for an oxide based superconducting magnet system, a superconducting magnet 1, a persistent current switch 4 and a current lead 6 superconductively connecting the magnet 1 and switch 4, each formed of an oxide based superconducting material, are included to constitute an oxide based superconducting persistent current magnet. Each part of the oxide series superconducting persistent current magnet is molded beforehand in a predetermined shape and a predetermined arrangement. Moreover, connecting terminals of the parts are held in touch at a connecting part 7 and subjected to partial melting solidification heat treatment, so that each part including the connecting part 7 is turned to a superconductor. Thereafter, a cooling system of a predetermined constitution necessary for driving of the persistent current magnet is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an oxide-based superconducting magnet system using an oxide-based superconductor discovered in recent years and an oxide-based superconducting magnet system.

[0002]

2. Description of the Related Art Conventional oxide-based superconductors include:
For example, "Materia" Vol. 34 No. 12 (1995) p. 1378-
As disclosed on page 1383, it is known to exhibit a higher critical temperature and critical magnetic field than metal-based superconductors. In particular, at extremely low temperatures of 20 K or less, it is known to exhibit a remarkable superiority in terms of a critical magnetic field as compared with metal-based materials. The development of magnetic field magnets is under consideration. That is, as an example of a prototype of a permanent current magnet using an oxide superconductor, see “Japanese Journal of Applied Physics” (JJAP) Vol. 35
(1996), pp. 627-629.

On the other hand, in a system using a conventional metal-based superconductor in a practical stage, liquid helium is introduced from a storage container into a cryostat via a transfer tube, and a superconducting coil and a permanent current switch are immersed in natural convection. An immersion cooling method using a chiller is known. In recent years, a system in which an oxide-based superconductor is formed into a linear shape and the coil is wound in a coil shape and cooled by a regenerative refrigerator is disclosed in, for example, Japanese Patent Application No. 3-104040.

[0004]

However, in the above prior art, since the oxide-based superconductor is a ceramic, a new problem that has not occurred in a metal-based superconductor, such as poor machinability, It has been found that the superconducting connection is not easy, which is an obstacle in practical use. In particular, the latter has a problem in manufacturing because there is an obstacle to the storage of magnetic energy in the persistent current mode, which is one important element of superconductivity.

On the other hand, the size of the magnet of the prototype example disclosed in the above document is a large fist, a permanent current is 30 A or less at most, and a generated magnetic field is less than 1000 Gauss. Also,
In this document, a thermal permanent current switch is used, but it takes a long time of several hundred seconds to operate the switch, and thermal design such as the cooling method of the system has not been sufficiently studied. It cannot be said that a large coil is considered. Further, the technology disclosed in Japanese Patent Application No. Hei 3-1004042 is not a cooling technology for a permanent current magnet,
Moreover, the cooling method of the system using the metal-based superconductor is not directly applied, and the cooling method of the permanent current magnet including the thermal permanent current switch using the oxide-based superconductor is not described. It has not been reported, and there is a problem in terms of cooling.

[0006] The above cooling and fabrication issues will be described in detail below. If oxide superconducting magnets can be used as permanent current magnets, for example, superconducting power storage (SMES), nuclear magnetic resonance analyzer (N
MR), a magnetic resonance diagnostic apparatus (MRI) for medical use, and a superconducting magnet for physicochemical analysis / test. For example, regarding the effectiveness of a strong magnetic field due to a permanent current in the study of physical properties by NMR, one is, of course, necessary for studying the magnetic field dependence of physical properties, but more important is the increase in signal strength due to the strong magnetic field.

This is because (1) the signal strength is proportional to H / T
(H: magnetic field, T: temperature), the larger H, the better. In particular, it is absolutely necessary for signal detection of a nucleus with a small magnetic moment or a nucleus with a small natural abundance. Recently, research on high-quality single crystals and research under high pressure have become necessary. In this case, a strong magnetic field is also required for signal detection of a small amount of sample.
(2) Since the width of the electric quadrupole interaction due to the second-order perturbation is inversely proportional to H, the larger the H, the narrower the width and the higher the signal strength.
(3) As the H increases, the resonance frequency increases, the Q of the circuit increases, and the sensitivity increases. (4) Similarly, the dead time of the pulse is reduced, and measurement of a short T2 becomes possible. (5) In a low magnetic field, overlapping signals can be separated and measured.

[0008] In the field of life science, research on DNA, which is a gene of an organism, has been actively conducted.
At the beginning of the 21st century, the full picture of human genes is about to be revealed. Proteins are biological macromolecules in which a number of amino acids are linked according to a "design drawing" written on DNA, and are very important substances that play a role in various life phenomena such as immunity. These proteins perform essential functions in life through the three-dimensional structure of how amino acids are folded and how they are positioned relative to each other.

[0009] Therefore, it can be said that knowing the three-dimensional structure of a protein is an indispensable task for elucidation of life phenomena. The body of an organism has more than 100,000 types of proteins, each having a different three-dimensional structure.
However, these various three-dimensional structures are considered to be combinations of about 1000 types of basic structures. If the basic structure of such a protein can be clarified, the protein can be easily modified and designed according to the purpose. For example, the mechanisms of diseases such as cancer, infectious diseases, and genetic diseases are more clearly elucidated, and there is an effect that diagnostic and therapeutic techniques can be dramatically improved. Further, it is expected that the development of pharmaceuticals will be promoted, for example, by greatly improving the process of screening for substances that suppress the toxicity of pathogenic proteins.

Furthermore, it is expected to contribute to solving food problems and environmental problems by creating plants having desirable properties, in addition to being applicable to the development of bioreactors, biodegradable plastics, biosensors and the like. . NMR using permanent current magnet by superconductivity
The device is a nuclear magnetic resonance generator (Nuclea
It is a device that uses rmagnetic Resonance) to obtain information on the structure of various compounds. X-ray crystal diffraction and electron microscopy can be used to elucidate the structure of proteins.However, these methods require crystallization of proteins, whereas NMR can be measured in an aqueous solution. Since there is no need for an operation for crystallization, there is an advantage that it can be applied to a sample that is difficult to crystallize.

By the way, such a substance / material, a living body /
The upper limit of the detection frequency of a superconducting NMR apparatus used for high-precision atomic / molecular structure analysis in the field of medicine is 750 MHz (17.6 T) due to the limit of the generated magnetic field.
Therefore, by generating an ultra-high magnetic field that breaks this limit, dramatic development such as structural analysis of high molecular weight proteins can be expected. Therefore, there is an urgent need to develop a strong magnetic field magnet utilizing the properties of an oxide superconductor. However, in order to apply an oxide-based superconducting magnet as a practical superconducting magnet, a metal-based superconductor has a practically sufficient critical current of about several hundred to 1,000 amperes, which is already realized, and In addition, not only the permanent current value and the generated magnetic field need to be improved by one digit or more than the current state as a magnet system, but also the switch operation speed needs to be increased to at least the order of several tens of seconds. That is, it is necessary to devise the construction of the cooling system.

In cooling a system to which a conventionally known metal-based superconductor is applied, liquid helium is introduced from a storage container into a cryostat via a transfer tube, and a superconducting coil and a permanent current switch are immersed. An immersion cooling system using natural convection is used. The permanent current switch in such a case, for example, in the case of the most common thermal permanent current switch, is operated by the following operation. (1) The magnet and the switch element are cooled with liquid helium to be superconductive. (2) The switch element is heated by a heater while maintaining the magnet in a superconducting state to be in normal conduction, and is used as a resistor. (3)
The superconducting magnet is excited by an external power supply. (4) The switching element is cooled to make it superconductive. (5) Turn off the external power. With the above operation, it functions as a permanent current magnet.

However, in the case of a metal-based superconductor, it is sufficient to heat the superconducting portion to a temperature of about 10 to 20 K at the most when the general thermal switch is turned off, as described above. In the case of oxide superconductors,
As a problem in physical properties, the critical temperature is about 80 to 100K higher, and it is necessary to increase the temperature to a significantly higher temperature than before in order to turn off the switch. Danger of heating and loss of superconductivity. Therefore, it can be said that such a system having a large difference between the critical temperature and the operating temperature requires a cooling system design based on a new concept that has not existed before.

On the other hand, a problem peculiar to the oxide-based superconductor is the formation of a superconducting connection. In the case of an oxide-based superconductor, since it is a sintered ceramic, there is a great problem in connection and bending as in a conventional metal-based superconductor. For example, in the case of bending, the bending strain must be 0.2% or less. In order to perform superconducting connection, for example, connection is performed by a heat treatment such as a partial melting and solidification heat treatment method. In this case, since the final heat treatment step can be performed only once, there has been a problem that even if the parts obtained by combining the preliminarily heat-treated wires are collected, they cannot be superconductively connected.

[0015] Accordingly, an object of the present invention is to overcome the above-mentioned manufacturing problems peculiar to an oxide-based superconductor, and to realize a cooling system that satisfies the function of a permanent current magnet. The object of the present invention is to provide an oxide-based superconducting magnet system and a superconducting magnetic field generating device manufactured using the method.

[0016]

A feature of the method of manufacturing an oxide-based superconducting magnet system according to the present invention that achieves the above object is that each of the above-described oxide-based superconducting materials constitutes an oxide-based superconducting permanent current magnet. A superconducting magnet section, a permanent current switch section, and a current lead section for superconducting connection between the superconducting magnet section and the permanent current switch section in a predetermined shape and arrangement in advance, and a connection between the respective sections. After the ends are abutted at the connection portion, and simultaneously the respective portions including the connection portion are subjected to partial melting and solidification heat treatment to form a superconductor, a cooling system having a predetermined configuration required for operation of the oxide-based superconducting permanent current magnet is provided. Is to form.

Further, an oxide-based superconducting magnet system according to the present invention, which achieves the object, is manufactured by using the method for manufacturing an oxide-based superconducting magnet system according to any one of claims 1 to 7. is there. Or
Each part of the superconducting magnet, the permanent current switch, and the current lead for superconducting connection between the superconducting magnet and the permanent current switch is composed of an oxide superconducting wire, and each of the oxide superconducting wires is made superconducting. Prior to the partial melting heat treatment, pre-molded in a desired arrangement and shape, the ends of the oxide-based superconducting wire are butted together at a connecting portion connecting the respective parts in the molded state, and thereafter, It is also possible to have a permanent current magnet in which each part including the connection part is simultaneously subjected to partial melting and solidification heat treatment to be a superconductor.

Further, the superconducting magnetic field generating apparatus according to the present invention uses the oxide superconducting magnet system according to the eighth or ninth aspect. According to the present invention, a desired cooling system is formed after each part constituting the oxide-based superconducting permanent current magnet is partially melted and heat-treated, so that an oxide-based superconducting magnet system having excellent cooling performance without distortion in superconducting connection. can get.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment An oxide superconducting magnet system (hereinafter, abbreviated as a superconducting magnet system) according to an embodiment of the present invention will be described with reference to FIG. That is,
A method for manufacturing a superconducting magnet system according to an embodiment of the present invention and a method for forming a cooling system configuration will be described.
In Figure 1, a superconducting magnet 1 made of superconducting _coils, are wound silver-coated 55-core tape-like wire material using the _{Bi 2 Sr 2 Ca 1 Cu 2} Ox -based oxide superconductor. And the thermal type permanent current switch 4 is Bi ₂ Sr ₂ C
The a ₁ Cu ₂ Ox-based oxide superconductor of silver -10 wt% gold alloy coating 55 core tape-shaped wire material used was windings unguided. The two current leads 6 for electrically and superconductingly connecting the permanent current switch 4 and the superconducting magnet 1 are Bi
It was composed of a 55-core tape-shaped wire coated with a silver alloy containing approximately 10% by weight of gold using a ₂ Sr ₂ Ca ₁ Cu ₂ Ox-based oxide superconductor.

All of the above parts (a total of four parts) were separately manufactured before the partial melting and solidification heat treatment. Then, according to the design layout of the system described later, both ends 1a of the superconducting magnet 1, both ends 4a of the persistent current switch 4 and each end of the current lead 6 are connected to the tape at the respective connection portions 7 by the tape. After butting the ends of the wire,
A partial melting and solidification heat treatment was performed in an oxygen stream at 880 ° C. for 30 minutes, and the entire circuit including each part (a total of eight parts) including the connection part 7 was made into a superconductor. Here, each connection part 7 as a superconducting connection part was partially melt-processed after holding the end faces of the tape-shaped multi-core wire in abutting relation with each other so that the superconducting connection was reliably performed. Thereafter, a manganin heater wire was wound around the outer periphery of the permanent current switch 4 to form the heater 5, thereby forming a permanent current switch section as a thermal switch. The superconducting magnet of this embodiment corresponds to the superconducting magnet 1 and the end 1a, the permanent current switch corresponds to the permanent current switch 4, the end 4a and the heater 5, and the current lead corresponds to This corresponds to the current lead 6. If necessary, each component including the connection portion 7 can be impregnated with an epoxy resin for reinforcement after the heat treatment.

Thereafter, the superconducting magnet system shown in FIG. 1 is inserted into the stainless steel cryostat 2 while paying sufficient attention so that the distortion of the superconducting magnet system is within the allowable distortion range. It was configured to be immersed and cooled by liquid helium as the refrigerant 3. Further, the permanent current circuit was formed by connecting the copper current lead 8 connected to the external power supply and the connection portion 7. It is desirable that the copper current lead 8 be detachable. On the other hand, the permanent current switch 4 and the heater 5
Was insulated by a cryostat 9 as a switch part cryostat and immersed and cooled by liquid helium as a refrigerant 10. Note that liquid nitrogen, liquid hydrogen, liquid neon, or the like can be used instead of liquid helium. Here, the refrigerant necessary for supplying to the superconducting magnet part is the tank 11,
Refrigerants required to cool the permanent current switch are supplied from the tanks 12. In the following description, the refrigerant 3
And 10 will be described as liquid helium 3 and 10.

By the way, as shown in FIG. 1, the cryostat 9 and the superconducting magnet 1 which adiabatically include the permanent current switch 4 are adiabatically included in the cryostat 2 together. With such a configuration, the influence of the heat generated by the heater 5 can be avoided by the cryostat 9 and also by controlling the supply amount of the refrigerant 10. However, in the case where the above-described cooling system including the permanent current switch section is formed later by the cryostat 9, in the case of an oxide-based superconductor having less processing flexibility than a metal-based superconductor,
There is a problem in ensuring reliable superconducting connection and a small bending strain, and the present embodiment employs the following measures.

That is, the permanent current switch 4 and the current lead 6
Is electrically and superconductively connected to each other, and has a larger outer dimension than the end 4a of the permanent current switch 4 and the current lead 6 and a higher strength. Therefore, the connecting portion 7 is provided so as to be supported (fixed) in advance on the partition wall portion of the cryostat 9 as a part of the cooling system. With such a configuration, even if a cooling system including a cryostat 9 and the like is assembled to complete the superconducting magnet system later, since the stress and deformation at the time of assembly are received at the connection portion 7, the generated distortion becomes minute. What you get.

It is also possible to adopt a configuration in which the connecting portion 7 is made of a superconductor, and then the connecting portion 7 reinforced with an epoxy resin, a filler or the like is provided in advance on the partition wall of the cryostat 9. Further, a separate connection portion is provided separately from the connection portion 7 described above, which covers and reinforces the end portion 4a of the permanent current switch 4 and the current lead 6 itself, and the another connection portion is disposed on the partition wall portion of the cryostat 9 in advance. It is also possible to adopt a configuration in which Therefore, the connection portion defined in the present invention includes the connection portion 7 for superconducting connection, another reinforced (or covered) connection portion, and the like. And it can be said that it is more preferable to reinforce the coating with a heat insulating material.

Comparative Example FIG. 6 shows a comparative example. In this comparative example, an oxide-based superconducting magnet system was manufactured using an oxide-based superconductor and by a conventional method for forming a cooling system for a superconducting permanent current magnet.

Superconducting magnet 1 comprising a superconducting coil
Has wound a silver-coated 55-core tape-shaped wire using a Bi ₂ Sr ₂ Ca ₁ Cu ₂ Ox-based oxide superconductor. The superconducting magnet 1 is inserted into a stainless steel cryostat 2 and immersed and cooled by liquid helium 3. Persistent current switch 4 of the heat equation, and winding the _{Bi 2 Sr 2 Ca 1 Cu 2} O x based oxide superconductor of silver -10 wt% gold alloy coating 55 core tape-shaped wires used in unguided, further that The manganin heater wire 5 is wound around the outer periphery. The current lead 6 for superconducting connection between the permanent current switch 4 and the superconducting magnet 1 is made of Bi ₂ Sr ₂ Ca ₁ Cu ₂ Ox-based oxide superconductor and contains approximately 10% by weight of gold. The superconducting magnet 1 and the permanent current switch 4 are superconductingly connected via a current lead 6 and a connecting portion 7. Further, a permanent current circuit is formed by being connected to an external power supply by the copper current lead 8. The permanent current switch 4 is inserted into the same cryostat 2 together with the superconducting magnet 1, and the permanent current switch 4 is not particularly insulated and is immersed and cooled in the same liquid helium 3.

Next, the configuration, operation, effects, and the like of this embodiment will be described while comparing this embodiment with a comparative example. First, a method for manufacturing the oxide superconducting magnet system shown in FIG. 1 will be described. In configuring the permanent current magnet in the oxide-based superconducting magnet system, it is necessary to take into consideration the cooling performance (that is, the cooling system configuration) determined from the manufacturability and physical properties of the oxide-based superconductor. In other words, in order to make these compatible, in the superconducting magnet system, the "shape and arrangement" required for the cooling system to be assembled later, and the "shape and arrangement" that ensures reliable superconducting connection and minute bending distortion The superconducting magnet part, the permanent current switch part and the current lead part are constituted by a wire before being subjected to the partial melting heat treatment in accordance with the design in consideration of the above, and these are simultaneously subjected to the partial melting heat treatment at the same time for superconducting connection. Together with a superconducting closed circuit (that is, a permanent current magnet)
It is assumed that.

In other words, before the partial melting heat treatment, the shape and the arrangement should be made close to the actual system shape in advance, that is, when the superconducting magnet system is to be finally formed, there is no possibility of adding to the oxide superconductor or the like. It is important that the necessary stress and deformation can be kept within an allowable range, that is, the “geometric shape and arrangement of the cooling system” should be designed and put in consideration of manufacturability. As a result, even if a desired cooling system is added after the partial melting heat treatment, the above-mentioned demand for superconducting connection and minute bending strain has been overcome, and the problem of manufacturability related to superconducting connection has been overcome. The operation can be performed stably. In other words, it can be said that a permanent current mode operation of a practical oxide superconducting permanent current magnet becomes possible for the first time in the oxide superconducting magnet system manufactured as described above.

Returning to FIG. 1, the operation in the permanent current mode of the first embodiment will be described. First, the superconducting magnet 1 is immersed and cooled in liquid helium 3. Next, the permanent current switch 4 is also immersed and cooled with liquid helium 10. This brings the superconducting closed circuit into a superconducting state. Thereafter, the heater 5 was heated, and the temperature of the permanent current switch 4 was increased to 90K within a few minutes, and the temperature was changed to normal conduction. The heat input at this time was about 20 W. Further, by heating, all of the liquid helium 10 became helium gas and evaporated. In this state, an external power supply not shown in the figure is used, and a maximum of 50
A current of 0 A was injected to excite the magnetic field to 15 Tesla in about 10 minutes.

In this state, liquid helium 10 is injected from a tank 12 of about 2 liters and the permanent current switch 4
Was cooled down to 4.2K in about 50 seconds and switched on. Thereafter, the external power supply was returned to zero in 3 minutes, and the operation was performed in the permanent current mode. Here, the resistance value of the persistent current switch in the normal conduction state is determined by the resistance value of the alloy sheath. The optimum value is determined by the inductance value depending on various coil applications and designs. The values are difficult to state here. However, the resistance value is desirably about 1 to several + ohms. After entering the permanent current mode, it is desirable to remove and remove the copper current lead 8 to prevent heat intrusion through the copper current lead 8.

As described above, in the configuration of the first embodiment,
Although the superconducting magnet could be operated in the permanent current mode, in the case of the comparative example shown in FIG. 6, even if the heater 5 was heated to turn off the permanent current switch 4, the liquid helium 3 was not The temperature of the permanent current switch could not be sufficiently raised because it had just evaporated, and the temperature could be raised only after the liquid helium 3 up to the bottom of the switch was completely evaporated. The time required for this temperature rise was about 50 minutes, and the consumed liquid helium 3 reached 50 liters.

Then, after confirming that the temperature of the switch has risen to 90K, an attempt was made to turn on the external power supply.
The temperature at the upper end of the coil has reached 40K, and the critical current value of the coil is less than about 1/10 of 500A.
It was possible to energize only up to about A. this is,
It is considered that the superconducting magnet was above the liquid surface and exchanged heat with gas helium, causing the temperature to rise. Then, liquid helium is poured from the tank 11 for about 20 minutes,
After the liquid level was returned to the initial state, the external power was turned off and the permanent current mode was set. However, in the comparative example, only a magnetic field of 1/10 or less of that in the first embodiment was generated. could not.

As described above, according to the oxide superconducting magnet system of the first embodiment, after the respective portions as the superconducting closed circuit necessary for the permanent current mode operation are simultaneously partially melt-solidified and heat treated, the superconducting permanent magnet A superconducting magnet is installed in a cryostat that encloses the current switch part insulated, and a cooling system that can immerse and cool each part individually with a refrigerant is formed, thereby increasing the operating speed of the permanent current switch 4 more than ten times as compared with the conventional system. It is possible,
Further, the consumption of liquid helium can be reduced by one digit at the time of heating or cooling, and the economic effect is great. Further, since the temperature is stabilized, there is an effect that the generated magnetic field of the superconducting magnet 1 is improved as a result. Incidentally, by devising a method such as disposing a conventional metallic permanent current magnet further outside the superconducting magnet system of the present embodiment, it is possible to generate a permanent current mode greatly exceeding 20T. Therefore, when applied to an NMR apparatus or the like, when the resonance frequency is, for example, a hydrogen atom, 1 GHz or higher can be detected, so that a remarkable ripple effect is desired in the fields of medicine and life science.

As described above, when an oxide-based superconductor is used, if the superconducting connection technology according to the present invention and the cooling technology of the superconducting magnet and the permanent current switch are applied,
The above objective is accomplished. That is, the feature of the oxide-based superconducting magnet system according to the present invention is “a superconducting magnet section, a permanent current switch section, and a current lead section for superconducting connection between the superconducting magnet section and the permanent current switch section”.
Each part of is composed of a tape-shaped oxide superconducting wire that performs a partial fusion solidification heat treatment after winding, and before the partial fusion heat treatment of this tape wire, each part is separately configured in advance,
In addition, these parts are molded in a desired arrangement and shape of the cooling system in consideration of the manufacturability of the superconducting magnet system, and in this state, the end faces of the tape wires are joined to each other at a connection portion between the parts. Then, the whole is to be partially melt-solidified and heat-treated simultaneously to form a superconductor.

With this configuration, all parts including the connection part are made superconducting, and a superconducting closed circuit required for permanent current mode operation can be formed. That is, in the above-described step of manufacturing the superconducting connection system, partial melting after abutting the ends of the wire is effective in obtaining high crystal orientation at the connection portion, and as a result, a high critical current density is obtained. It is effective for obtaining characteristics. Then, after the step of forming the connection system, a cooling system configuration essential to the superconducting magnet system is added. That is, in the above-described process of manufacturing the superconducting cooling system, if at least the permanent current switch portion of the superconducting magnet portion or the permanent current switch portion is insulated, it is possible to independently maintain a desired temperature and adjust the temperature. At the very least, an oxide-based superconducting permanent current magnet is operated efficiently.

Through the above manufacturing steps, a method of manufacturing an oxide-based superconducting magnet system capable of solving the problem of manufacturability peculiar to oxide-based superconductors and simultaneously solving the problem of cooling properties due to physical properties. Is provided.
The superconducting tape can be slightly deformed even after the heat treatment. For example, a bending strain of 0.2% or less is permissible.
When actually incorporating it into a product, it can be set to be within the allowable distortion. Generally, the oxide-based superconductor changes its dimensions due to heat treatment because it is a ceramic, but it can be said that such a change is within an allowable range. However, simply assembling the cooling system afterwards in the same manner as in the prior art generates a bending strain of 0.2% or more, so that the manufacturing method according to the present invention is effective.

In addition, the problem of high critical temperature, which is a restriction on physical properties, requires a device for thermally insulating both the magnet and the switch in order to stably operate both the magnet and the switch.
For example, as in the superconducting magnet system according to the present embodiment, the permanent current switch unit and the superconducting magnet unit are each installed in a thermally independent cryostat, and each unit can be individually immersed and cooled by a refrigerant. Thus, when liquid helium is used as the refrigerant, not only can the circuit contribute to the stability of the circuit, but also the effect of reducing the consumption of liquid helium can be obtained. Here, as the refrigerant, liquid neon, liquid oxygen, liquid hydrogen, liquid nitrogen, or the like can be properly used depending on the application.

On the other hand, in the above-mentioned oxide superconducting magnet system, the oxide superconductor (including the wire) constituting the superconducting magnet contains silver or a silver alloy, for example, and 0.3 wt. It is desirable to use a silver alloy containing a small amount of magnesium, titanium, and nickel as small as 0.1 to 1%, preferably 0.1 to 0.5%. With these materials, it is possible to increase the tensile strength to three times or more compared to pure silver, to withstand electromagnetic force, and to prevent the coating material from reacting with the oxide-based superconductor and deteriorating. There is an effect that the system can be configured.

Further, in a superconducting magnet system using an oxide-based superconductor, the oxide-based superconductor includes:
Silver-coated long Bi ₂ Sr ₂ Ca ₁ Cu with flat cross section
It is desirable to be a ₂ O ₈ superconductor, and more desirably, a multi-core wire. It is desirable to use a silver alloy containing 1 to 15% by weight of gold for the covering material of the wire constituting the permanent current switch and the current lead. By using a silver alloy containing 1 to 15% of gold, it becomes possible to impart high resistance and low thermal conductivity to the coating material. As a result, the resistance of the permanent current switch at the time of turning off can be sufficiently maintained, and heat conduction between the switch section maintained at a high temperature and the superconducting magnet maintained at a low temperature can be prevented, and the stable superconducting magnet can be prevented. There is an effect that operation becomes possible.

In summary, the features of the method for manufacturing the oxide-based oxide superconducting magnet system according to the present invention are as follows.
A superconducting magnet portion made of a tape-shaped oxide superconducting wire that performs a partial melting and solidification heat treatment after winding, a permanent current switch portion, and a current lead portion for superconducting connection between the superconducting magnet portion and the permanent current switch portion. Prior to partially melting and solidifying the superconducting magnet portion, the persistent current switch portion, and the current lead portion of the oxide-based superconducting permanent current magnet containing, these are generally pre-molded into a desired arrangement and shape by the system. In addition, the end faces of the tape wires are abutted at the connection between the respective parts, and then the whole is simultaneously partially melt-solidified and heat-treated to form a superconductor, and thereafter, a desired cooling system configuration for the superconducting magnet system Is to form

(Second Embodiment) An oxide superconducting magnet system according to a second embodiment of the present invention will be described with reference to FIG. That is, although the basic configuration of the superconducting magnet system of this embodiment is almost the same as that of the first embodiment,
The method of cooling the superconducting magnet 1 is different. Superconducting magnet 1 as the superconducting coil is in winding the silver-coated 55-core tape-like wire material using the _{Bi 2 Sr 2 Ca 1 Cu 2} Ox -based oxide superconductor. The superconducting magnet 1 is inserted into a cryostat 2 made of stainless steel, placed in a vacuum, and cooled by a regenerative refrigerator 13.

Here, the regenerative refrigerator has a Gifford McMahon type (commonly called GM type) having two cooling stages.
Although a refrigerator is used, it is also possible to use a refrigerator having three cooling stages in order to increase the refrigerating capacity at low temperatures depending on the application. Further, a pulse tube refrigerator or the like can be used. The pulse tube refrigerator has an advantage that it has no refrigeration ability but has no vibration as compared with the GM system. That is, in the superconducting magnet system, there is an advantage that a low temperature can be easily achieved by using a GM type or pulse tube type refrigerator as the regenerative refrigerator.

On the other hand, the thermal type permanent current switch 4 is composed of Bi ₂
Silver with Sr ₂ Ca ₁ Cu ₂ Ox-based oxide superconductor -10 wt%
A 55-core gold alloy coated tape-shaped wire is wound without induction, and a manganin heater wire 5 is wound from the outer periphery thereof. The current lead 6 for electrically connecting the permanent current switch 4 and the superconducting magnet 1 is made of Bi ₂ Sr ₂ Ca
It is composed of a 55-core tape-shaped wire coated with a silver alloy containing approximately 10% by weight of gold using a ₁ Cu ₂ Ox-based oxide superconductor. The superconducting magnet 1 is heat-transfer cooled by the second cooling stage 14. The superconducting magnet 1 is superconductingly connected to the permanent current switch 4 via a connection 7.

The permanent current circuit is connected to an external power supply by a copper current lead 8, but the low-temperature end 1
5 is heat-transfer-cooled through a first cooling stage 16 and is formed between the superconducting magnet 1 and a current lead 17 using an oxide-based superconductor having small heat conduction.
The first cooling stage 16 is also used for cooling the heat shield 18 of the cryostat 2. The heat shield 18 is made of thin copper and formed in a cup shape, forms a double case together with the cryostat 2, directly encloses the superconducting coil 1, and screws one end of the opening to the cooling stage 16 in close contact. is there. It is desirable that the copper current lead 8 be detachable.

On the other hand, the permanent current switch 4 has the same configuration as that of the first embodiment, is insulated by the cryostat 9, and is immersed and cooled by liquid helium. Instead of liquid helium 10 as a refrigerant, liquid nitrogen, liquid hydrogen, liquid neon, or the like can be used. Here, liquid helium necessary for supplying to the superconducting magnet unit is supplied from the tank 11, and refrigerant necessary for cooling the permanent current switch unit is supplied from the tank 12.

Hereinafter, the effect of this embodiment in the case of FIG. 2 will be described in comparison with a comparative example. In the example of FIG. 2, the superconducting magnet 1 is held at 15K by a regenerative refrigerator. On the other hand, the permanent current switch is immersed and cooled by liquid helium and kept at 4.2K. Thereby, all circuits are superconducting. In this state, using an external power supply not shown in the figure, a current of 300 A at maximum was injected into the magnet 1 from the copper current lead 8, and about 10 A
It was excited to a magnetic field of 9 Tesla in a minute. In this state, 2 liters of liquid helium was injected from the tank 12, the permanent current switch 4 was cooled down to 4.2K in about 50 seconds, and the switch was turned on. Thereafter, the external power supply was returned to zero in about 3 minutes, and a permanent current mode operation was performed.

As described above, according to the second embodiment, after the respective portions as the superconducting closed circuit necessary for the persistent current mode operation are simultaneously subjected to the partial melting and solidification heat treatment, the permanent current switch portion and the superconducting magnet portion are thermally separated. By installing a cooling system that is installed in an independent cryostat, maintains a permanent current switch section at a desired temperature by a regenerative refrigerator, and forms a cooling system that immerses and cools the superconducting magnet section with a refrigerant, a thermal permanent current switch is provided. Can be easily operated, and the consumption of the refrigerant can be reduced.

(Third Embodiment) A superconducting magnet system according to a third embodiment of the present invention will be described with reference to FIG. That is, the configuration of the superconducting magnet system of this embodiment is almost the same as that of the first embodiment, but the method of cooling the permanent current switch 4 is different. In the figure, a superconducting magnet 1 as a superconducting coil is made of Bi ₂ S as in the first embodiment.
A silver-coated 55-core tape-shaped wire using an r ₂ Ca ₁ Cu ₂ Ox-based oxide superconductor is wound. The superconducting magnet 1 is inserted into a stainless steel cryostat 2 and is immersed and cooled by liquid helium 3.

On the other hand, the thermal permanent current switch 4 is composed of Bi ₂ Sr
The ₂ Ca ₁ Cu ₂ Ox-based oxide superconductor of silver -10 wt% gold alloy coating 55 core tape-shaped wire was used to windings unguided, further from the outer periphery, and constituted by winding a manganin heater wire 5 I have. The current leads 6 connecting the superconducting magnet 1 persistent current switch 4 electrically uses a _{Bi 2 Sr 2 Ca 1 Cu 2} Ox -based oxide superconductor, comprising a generally 10% by weight gold and silver The superconducting magnet 1 and the permanent current switch 4 are superconductingly connected to each other through a current lead 6 and a connecting portion 7. The permanent current circuit is connected to an external power supply by a copper current lead 8. It is desirable that the copper current lead 8 be detachable.

The permanent current switch 4 is insulated by the cryostat 9, heat-transfer-cooled by the regenerative refrigerator 19 via the second cooling stage 20, and installed in a vacuum. The first cooling stage 21 of the refrigerator is used for cooling the heat shield 22 of the cryostat 9. The heat shield 22 is made of thin copper and is formed in a cup shape, forms a double case together with the cryostat 9, directly encloses the permanent current switch 4, and screws one end of the opening into close contact with the cooling stage 21. It is. Further, liquid helium necessary for supplying to the superconducting magnet unit is supplied from the tank 11, but liquid nitrogen, liquid hydrogen, liquid neon, or the like can be used as a refrigerant instead of liquid helium.

Hereinafter, the effects of this embodiment will be described in comparison with a comparative example. In the example of FIG. 3, the superconducting magnet 1 is immersed and cooled in liquid helium, and the permanent current switch 4 is heat-transfer cooled to about 10K by a regenerative refrigerator. In this state, the switch is set to about 90 K by the heater 5 for about 10 K.
After the temperature was raised in 0 seconds, an external power supply was input to excite the superconducting magnet to 10T. In this state, energization of the heater 5 is continued until the switch 4 is cooled by the refrigerator 19 until the temperature reaches about 20K.
When the time reached 0 minutes, the external power supply was turned off and the operation was started in the permanent current mode. In order to increase the cooling speed of the switch portion and improve the usability of the system, a configuration as shown in FIG. 5 to be described later can be adopted. As shown in FIG. 5, there is an advantage that cooling of the switch portion takes only several tens of seconds, and a high-speed switch operation is possible.

As described above, in the superconducting magnet system of the third embodiment, after the respective parts forming the superconducting closed circuit necessary for the persistent current mode operation are simultaneously partially melt-solidified and heat-treated, the superconducting permanent current switch section is formed. And a superconducting magnet unit is installed in a cryostat that is thermally independent of each other, cooling the permanent current switch unit at a desired temperature by a regenerative refrigerator, and immersing and cooling the superconducting magnet unit with a refrigerant. By forming the system, the operation of the thermal permanent current switch can be facilitated, and the consumption of the refrigerant can be reduced.

(Fourth Embodiment) An oxide superconducting magnet system according to a fourth embodiment of the present invention will be described with reference to FIG. That is, the basic configuration of the superconducting magnet system of the present embodiment is similar to that of the second embodiment, except that both the superconducting magnet 1 and the permanent current switch 4 are cooled by the regenerative refrigerator. Superconducting magnet 1 as the superconducting coil is in winding the silver-coated 55-core tape-like wire material using the _{Bi 2 Sr 2 Ca 1 Cu 2} Ox -based oxide superconductor. Meanwhile, the persistent current switch 4, silver -10 wt% gold alloy coating with the _{Bi 2 Sr 2 Ca 1 Cu 2} Ox -based oxide superconductor 55
The core tape-shaped wire is wound without induction, and a manganin heater wire 5 is wound from the outer periphery thereof.
The current leads 6 connecting the superconducting magnet 1 persistent current switch 4 electrically uses a _{Bi 2 Sr 2 Ca 1 Cu 2} O x based oxide superconductor, containing approximately 10 percent by weight gold Of a 55-core tape-shaped wire coated with a silver alloy.

The superconducting magnet 1 and the permanent current switch 4 are inserted into a stainless steel cryostat 2 and placed in a vacuum to be insulated from each other, and cooled individually by regenerative refrigerators 13 and 19 respectively. I have. Here, the regenerative refrigerator uses a Gifford McMahon type (commonly called GM type) refrigerator having two stages of cooling stages. However, depending on the application, three stages of cooling are required in order to increase the refrigerating capacity at low temperatures. It is also possible to use a refrigerator having a stage or the like. Further, a pulse tube refrigerator or the like can be used. The pulse tube refrigerator has an advantage that it has no refrigeration ability but has no vibration as compared with the GM system.

The superconducting magnet 1 includes a regenerative refrigerator 13
The heat is transferred and cooled by the second cooling stage 14. The superconducting magnet 1 is superconductingly connected to the permanent current switch 4 at a connection portion 7. The permanent current circuit is connected to an external power supply by a copper current lead 8, and the low-temperature end 15 of the copper lead is heat-transfer-cooled via the first cooling stage 16, and is connected to the superconducting magnet 1. It is composed of a current lead 17 using an oxide-based superconductor having low thermal conductivity.

The first cooling stage 16 is also used for cooling the heat shield 18. The heat shield 18 is formed in a thin copper cup shape, directly encloses the superconducting coil 1 and the permanent current switch 4 and the like, and one end of the opening is screwed tightly to the cooling stage 16. It is desirable that the copper current lead 8 be detachable. Further, the permanent current switch 4 is heat-transfer-cooled by the regenerative refrigerator 19 via the second cooling stage 20, and the vacuum heat shield 1
8. The cryostat 2 and the heat shield 18 form a double case, which is suitable for heat insulation formation or vacuum formation.

Further, the first cooling stage 2 of the refrigerator 19
1 is also used for cooling the heat shield 18. And there is no cryostat that adiabatically encloses the permanent current switch, but the permanent current switch has the effect of preventing heat conduction by keeping a sufficient distance from the superconducting magnet 1, and the performance due to the leakage magnetic field from the magnet. This has the effect of preventing the drop. On the other hand, in this embodiment, the connecting portion 7 (the end 1a of the superconducting magnet 1 or the current lead 6) is used.
A connecting portion 7) including a connecting portion for covering and reinforcing itself is pre-supported and fixed to the second cooling stage 14 as a part of the cooling system so that distortion generated at the time of assembly is small. .

Hereinafter, the effects of this embodiment will be described in comparison with a comparative example. In FIG. 4, the superconducting magnet 1 and the permanent current switch 4 are placed in the same space, but are insulated by vacuum and each is cooled to 15K by a refrigerator.
In this state, the heater 5 was heated to reach 90K in about one minute. In this state, the superconducting magnet 1 is excited to 7T by the external power supply, then the switch is cooled by turning off the heater. After confirming that the temperature reaches 20K in about 20 minutes, the external power supply is turned off and the permanent current mode is turned off. I started driving.

As described above, in the superconducting magnet system according to the fourth embodiment, each part as a superconducting closed circuit required for the permanent current mode operation is simultaneously partially melt-solidified and heat-treated, and then the superconducting permanent current switch and By installing a superconducting magnet section in a thermally independent cryostat, and forming a cooling system that individually holds the permanent current switch section and the superconducting magnet section at a desired temperature by a regenerative refrigerator, The operation of the system can be facilitated, and the consumption of the refrigerant can be eliminated. Further, in the superconducting magnet system, the permanent current switch section and the superconducting magnet section are each a thermally independent cryostat, and the superconducting magnet section is maintained at a desired temperature, for example, 20K by a regenerative refrigerator. The operating speed of the permanent current switch can be increased, the operation of the magnet system can be facilitated, and the amount of refrigerant consumed by the system can be reduced.

(Fifth Embodiment) A superconducting magnet system according to a fifth embodiment of the present invention will be described with reference to FIG. That is, the basic configuration of the superconducting magnet system of this embodiment is almost the same as that of the third embodiment, except that the cooling method of the permanent current switch 4 is provided with an accelerated cooling means. The superconducting magnet 1 as a superconducting coil is a first superconducting magnet.
EXAMPLE similarly to using a _{Bi 2 Sr 2 Ca 1 Cu 2} Ox -based oxide superconductor and have winding 19 core tape-like wire silver coating. The superconducting magnet is inserted into a stainless steel cryostat 2 and immersed and cooled by liquid helium 3. On the other hand, the thermal permanent current switch 4 is Bi ₂
Silver with Sr ₂ Ca ₁ Cu ₂ Ox-based oxide superconductor -10 wt%
A 19-core gold alloy coated tape-shaped wire is wound without induction, and a manganin heater wire 5 is wound from the outer periphery thereof without induction. The current lead 6 for electrically connecting the permanent current switch and the superconducting magnet is made of Bi ₂ Sr ₂ Ca ₁ C
A superconducting magnet 1 and a permanent current switch 4 are formed of a 55-core tape-shaped wire coated with a silver alloy containing approximately 10% by weight of gold using a u ₂ O _x -based oxide superconductor.
And the connection part 7 is superconductively connected. Further, the permanent current circuit is connected to an external power supply by a copper / copper current lead 8. In this case, it is desirable that the copper current lead 8 be detachable.

The permanent current switch 4 is insulated by the cryostat 9, heat-transfer-cooled by the regenerative refrigerator 19 via the second cooling stage 20, and installed in a vacuum. The first cooling stage 20 of the regenerative refrigerator 19 is used for cooling the heat shield 22. The heat shield 22 is made of thin aluminum and is formed in a cup shape. The heat shield 22 directly encloses the permanent current switch 4, and has one end of the opening portion in close contact with the cooling stage 21.
The liquid helium necessary for supplying to the superconducting magnet unit is supplied from the tank 11, but liquid nitrogen, liquid hydrogen, liquid neon, or the like can be used as the refrigerant instead of liquid helium.

In this embodiment, in addition to the above configuration, a refrigerant pipe 23 for forced cooling is arranged to improve the cooling speed of the permanent current switch. As the refrigerant, low-temperature helium gas, liquid helium, liquid nitrogen, or the like, or low-temperature nitrogen gas, liquid neon, or low-temperature neon gas can be used. When the permanent current switch is small, the cooling pipe 23 is preferably provided around the switch. When the permanent current switch is large, the cooling pipe 23 is preferably provided inside the switch. The member is preferably made of a material having good heat conductivity such as copper.

Hereinafter, the effects of this embodiment will be described in comparison with a comparative example. As described above, in the permanent current switch section cooled by the regenerative refrigerator of the fifth embodiment, at least at the time of cooling the permanent current switch section, auxiliary cooling by a refrigerant is possible, By increasing the cooling rate of the switch, the switch operation can be facilitated. Further, in the superconducting magnet system, the switch operation speed can be further finely adjusted by the permanent current switch section including at least a switch for thermally raising and lowering the temperature. At this time, an external magnetic field may be applied to the switch section to make the switching operation easier.

Incidentally, the oxide superconductor of the above embodiment is a long Bi2Sr2C coated with silver having a flat cross section.
It is preferably an a1Cu2O8-based superconductor, and more preferably a multi-core wire. Bi-Sr-C
The following are examples of the a-Cu-O system.

[0065] Bi-Sr-Ca-Cu- O -based _{Bi 1.5-2.2 -Sr 1.5-2.2 -Cu 0.5-1.3 -O 5-7} Bi 1.5-2.2 -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 As other superconducting materials, the following superconducting materials can be used.

[0066] Tl-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 -Cu 1.5-2.3}
-O _6-8 Tl _0.5-1.2 -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 -Cu 1.5-2.3}
-O _6-8 Tl _0.5-1.2 -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 -Cu 0.5-1.3}
-O _5-7 Tl _1.5-1.2- (Ba _x -Sr _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 -Cu _{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
_{-Cu 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
_{-Cu 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 -Ca
_{0.5-1.3 -Cu 1.5-2.3 -O 7-9 (Tl 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 (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 -Ca
_{0.5-1.2 -Cu 1.5-2.3 -O 6-8 (Tl y} -Pb 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-Pb-Sr-Ca-Cu-O system (Bi _y -Pb _{1 -y} ) _{1.5-2.2 -Sr} 1.5-2.2 _{-Cu 0.5-1.3}
-O _5-7 (B _y -Pb _1-y ) _1.5-1.2 -Sr _1.5-2.2 -Ca _{0.5-1.3
-Cu 1.5-2.3} -O _7-9 (B _y -Pb _1-y ) _1.5-2.2 -Sr _1.5-2.3 -Ca _{1.5-2.3
-Cu 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, Nd, P
m, Sm, Eu, Gd, Tb, Dy, Ho, Er, 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, Nd, P
m, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu Bi-Sr-Y-Cu-O -based _{(Bi 1-x -Cu x)} -Sr 2 - (Y 1-y - Cu _y ) Cu ₂ -O
_6-8 x = 0.1-0.9, y = 0.1-0.9 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 = 0~1 Sr} -Ca-Cu-O -based _{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 -Cu 1.5-2.3}
-O _6-8 Hg _0.5-1.2 -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 -Cu 1.5-2.3}
-O _6-8 Hg _0.5-1.2 -Sr _1.5-2.2 -Ca _{2.5-3.2 -Cu 3.5-4.3
-O 8-10 Hg-Ba-Sr-} Ca-Cu-O -based _{Hg 1.5-2.2 - (Ba x -Sr 1} -x) 1.5-2.2 -Cu 0.5-1.3
-O _5-7 Hg _1.5-1.2- (Ba _x -Sr _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 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 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 -Cu _{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
_{-Cu 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
_{-Cu 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 to 0.9 Hg-Pb-Ba-Sr-Ca-Cu-O (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 ) _1.5-2.2 −Ca
_{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 (Hg _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 −Ca
_{0.5-1.2 -Cu 1.5-2.3} -O _6-8 (Hg _y -Pb _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 to 0.9, y = 0.1 to 0.9 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 −Ca
_{0.5-1.3 -Cu 1.5-2.3} -O _7-9 (Hg _y -Tl _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 −Ca
_{0.5-1.2 -Cu 1.5-2.3} -O _6-8 (Hg _y -Tl _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, y = 0.1-0.9 In a system containing mercury, a part of the mercury site is reduced to 0 in atomic ratio. Substitution of .1 to 0.5 with rhenium (Re) facilitates the synthesis of the crystal phase, and further has the advantage of improving the critical magnetic field.

[0067]

According to the present invention, by forming a desired cooling system after the partial melting heat treatment according to the present invention, it is possible to overcome the manufacturability problems such as connection and distortion and to stably perform the persistent current mode operation. There is an effect that a magnet system can be provided. In addition, the magnetic field generator using the oxide superconducting magnet system according to the present invention is applied as a magnetic field generator such as an analyzer, a nuclear magnetic resonance analyzer, a strong magnetic field generator, a magnetic separator, a superconducting energy storage device, and the like. Therefore, it is possible to construct a practically useful system, and there is also an effect of widely contributing to society.

[Brief description of the drawings]

FIG. 1 is a diagram showing a superconducting magnet system according to one embodiment of the present invention.

FIG. 2 is a view showing a superconducting magnet system according to a second embodiment of the present invention.

FIG. 3 is a view showing a third embodiment of a superconducting magnet system according to the present invention.

FIG. 4 is a diagram illustrating a superconducting magnet system according to a fourth embodiment of the present invention.

FIG. 5 is a view showing a superconducting magnet system according to a fifth embodiment of the present invention.

FIG. 6 is a diagram illustrating a conventional superconducting magnet system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Superconducting magnet, 1a, 4a ... End part, 2, 9 ... Cryostat, 3, 10 ... Refrigerant, 4 ... Permanent current switch, 5 ... Heater (manganin heater wire), 6, 17 ... Current lead, 7 ... Connection part , 8 ... Copper current lead, 11, 12 ...
Tanks 13, 19: regenerative refrigerator, 14, 20: second cooling stage, 15: low-temperature end, 16, 21: first cooling stage, 18, 22: heat shield, 23: refrigerant pipe.

Claims (10)

[Claims] 1. A superconducting magnet portion, a permanent current switch portion, and a superconducting connection between the superconducting magnet portion and the permanent current switch portion, each comprising an oxide superconducting material to form an oxide superconducting permanent current magnet. And the current lead portion to be molded in a predetermined shape and arrangement in advance, and abutting the connection ends between the respective portions at the connection portion, and simultaneously performing partial melting and solidification heat treatment on the respective portions including the connection portion. A method for manufacturing an oxide-based superconducting magnet system, comprising forming a cooling system having a predetermined configuration necessary for operating the oxide-based superconducting permanent current magnet after forming the superconductor. 2. The cooling system according to claim 1, wherein the cooling system having the predetermined configuration includes the permanent current switch section and the superconducting magnet section installed in each of the thermally independent cryostats, and supplies the permanent current switch section and the superconducting magnet section to the respective cryostats. Wherein the two parts can be individually immersed and cooled by a cooling medium. 3. The cooling system according to claim 1, wherein the cooling system having the predetermined configuration is installed in a cryostat that adiabatically includes the switch section cryostat including the permanent current switch section adiabatically and the superconducting magnet section. The permanent current switch section is immersed and cooled by a refrigerant supplied into the switch section cryostat, and the superconducting magnet section is immersed and cooled by a refrigerant or cooled and held at a desired temperature by a regenerative refrigerator. A method for manufacturing an oxide-based superconducting magnet system. 4. The cooling system according to claim 1, wherein the cooling system having the predetermined configuration is installed in a cryostat that adiabatically includes the permanent current switch section and the superconducting magnet section. An oxide superconducting magnet characterized in that the superconducting magnet portion is cooled and held at a desired temperature by a machine, and the superconducting magnet portion is immersed and cooled by a refrigerant or cooled and held at a desired temperature by a regenerative refrigerator. System manufacturing method. 5. The cooling system according to claim 1, wherein the cooling system having a predetermined configuration for cooling the permanent current switch unit includes an auxiliary cooling unit for accelerating a cooling speed of the permanent current switch unit. A method for manufacturing an oxide-based superconducting magnet system, comprising: 6. The method according to claim 1, wherein the connecting portion is provided so as to be supported by a part of the cooling system. 7. A method for manufacturing an oxide-based superconducting magnet system according to claim 3, wherein said regenerative refrigerator is a GM type or pulse tube refrigerator. . 8. An oxide-based superconducting magnet system manufactured by using the method for manufacturing an oxide-based superconducting magnet system according to any one of claims 1 to 7. 9. A superconducting magnet section, a permanent current switch section, and a current lead section for superconducting connection between the superconducting magnet section and the permanent current switch section are each made of an oxide superconducting wire, and Before the partial melting heat treatment for superconducting the superconducting wire, it is pre-molded in a desired arrangement and shape, and ends of the oxide-based superconducting wire are connected with each other at the connecting portion connecting the respective portions in the molded state. Match,
An oxide-based superconducting magnet system, further comprising: a permanent current magnet which is a part of a superconductor obtained by partially melting and solidifying the respective parts including the connection part at the same time. 10. A superconducting magnetic field generator using the oxide superconducting magnet system according to claim 8.