JP2017046987A - Superconducting magnet device and magnetic resonance imaging apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconducting magnet device that can maintain a homogeneous magnetic field distribution and a stable temperature in a superconducting state by making it easy to install a conductive cooling member at a superconducting coil requiring a calcination reaction and to replace a bobbin with a good heat conductor and also by preventing failed winding of a wire after calcination, and provide a magnetic resonance imaging apparatus using the same.SOLUTION: A superconducting magnet device has: a toric superconducting coil; and a refrigerator that cools the superconducting coil. The superconducting coil includes: superconducting wire 17 that is wound multiple times; and an adhesive 18 that mutually fixes the superconducting wire 17 between each winding. The superconducting wire 17 is made of a member that: is obtained after a superconductive material is sintered; and has a superconductive transition temperature of 25K or higher. The adhesive 18 has a hardening temperature lower than a calcination temperature of the superconducting wire 17 and has a softening temperature higher than the calcination temperature of the superconducting wire 17.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a superconducting magnet apparatus and a magnetic resonance imaging apparatus using the same.

  As a background art in this technical field, there is a publication of Japanese Patent Application Laid-Open No. 8-316022. In this public relations, a superconducting wire is coated with an inorganic insulating layer or an insulating layer to be mineralized to produce an insulating conducting wire, and this insulating conducting wire is wound around a bobbin to form a winding portion, followed by heat treatment and firing. In such a superconducting coil, a technique has been shown in which a fixing material such as aluminum, which is softened or melted at a firing temperature, or an aluminum alloy is wound around a winding portion when an insulated conductor is wound, thereby generating a coil.

  Further, as background art in this technical field, there is a publication of Japanese Patent Laid-Open No. 62-19682 (Patent Document 2). This publicity shows a technique in which a thin winding frame is placed between a bobbin having a split structure and a winding, fired, and impregnated with resin to be cured.

JP-A-8-316022 JP-A 62-19682

  However, in the case of Patent Document 1, since the fixing material is also fixed to the bobbin at the time of the firing reaction, it is considered that after the firing reaction, shearing occurs due to the difference in thermal shrinkage between the bobbin and the wire, causing the normal conduction transition. It is done. In addition, when installing a cooling member for the coil, only the part where the winding is exposed from the bobbin can be installed, so it can be installed between the bobbin and the winding, or the bobbin itself can be made of a metal with good thermal conductivity. It may be difficult to replace, and thus it may be difficult to stably maintain the superconducting coil at the operating temperature.

  In addition, as shown in Patent Document 2, the double structure with the divided bobbin and the thin winding frame is not fixed between the wire materials at the time of firing. . Moreover, when installing a cooling member after a mold, it is necessary to install in the outer side of a thin winding frame, and it is considered that it becomes the cause of the thermal resistance of a conduction cooling path.

Thus, in the conventional technology, in a superconducting coil that requires a firing reaction at a high temperature after winding the superconducting wire, the winding can be integrated at the time of firing or after firing, but the installation of a cooling member for conductive cooling is possible. In some cases, it was limited to the above, or the wire rod collapsed.
Accordingly, an object of the present invention is to provide a superconducting magnet device capable of suppressing the collapse of the wire after firing and maintaining the operation temperature stably, and a magnetic resonance imaging apparatus using the superconducting magnet device.

  In order to solve the above problems, various embodiments of the present invention are studied. As an example, the superconducting magnet apparatus of the present invention includes an annular superconducting coil and a refrigerator that cools the superconducting coil. The superconducting coil includes a superconducting wire wound around a plurality of turns and an adhesive for fixing the superconducting wires to each other between different turns, and the superconducting wire is formed by sintering a superconducting material. The adhesive is a member having a superconducting transition temperature of 25K or higher, and the adhesive has a curing temperature lower than a firing temperature of the superconducting wire and a softening temperature higher than a firing temperature of the superconducting wire. Features.

  According to the present invention, a uniform magnetic field can be obtained by facilitating the installation of a conductive cooling member in a superconducting coil that requires a firing reaction or replacing it with a bobbin by a good thermal conductor, and preventing the wire rod from collapsing after firing. It is possible to provide a superconducting magnet apparatus capable of maintaining the distribution and the temperature of a stable superconducting state, and a magnetic resonance imaging apparatus using the superconducting magnet apparatus.

1 is a cross-sectional view showing the structure of a superconducting coil according to a first embodiment of the present invention. 1 is a vertical external perspective view of an MRI apparatus according to an embodiment of the present invention. It is a vertical external perspective view which shows the other system of the MRI apparatus which is embodiment of this invention. FIG. 3 is a partial cross-sectional view showing an arrangement configuration of a superconducting coil and a heat transfer cooling member used in the MRI apparatus according to the first embodiment of the present invention. It is sectional drawing which shows the structure after baking reaction of the superconducting coil which is 1st Embodiment of this invention. It is sectional drawing which shows the state before baking of the superconducting coil which is 2nd Embodiment of this invention. It is sectional drawing which shows the state after baking of the superconducting coil which is 3rd Embodiment of this invention. It is sectional drawing which shows the state after baking of the superconducting coil which is 4th Embodiment of this invention.

  The technical significance of the present invention will be described.

  A superconducting magnet device is a device that generates a desired magnetic field by passing a current through a coil made of a superconducting material cooled to a cryogenic temperature. Superconducting material is a substance whose electric resistance becomes zero when the temperature falls below a certain temperature, and it can pass a larger current than a normal conductive metal at normal temperature, so it is a device that requires a strong magnetic field, especially magnetic It is used in a resonance imaging apparatus (hereinafter referred to as an MRI apparatus).

  An MRI device is a device that obtains a cross-sectional image showing the physical and chemical properties of a subject by utilizing the nuclear magnetic resonance phenomenon that occurs when a subject placed in a uniform static magnetic field is irradiated with a high-frequency pulse. In particular, it is used for medical purposes.

  An MRI apparatus generates a magnetic field that generates a uniform static magnetic field mainly in an imaging space into which a subject is inserted, and a magnetic field that is spatially gradient in intensity to give positional information to the imaging space. A gradient magnetic field coil, an RF coil that irradiates a subject with a high frequency pulse, a receiving coil that receives a magnetic resonance signal from the subject, and a computer system that processes the received signal and displays an image.

  As a main means for improving the performance of the MRI apparatus, there is an improvement in the strength of the static magnetic field generated by the magnet apparatus. Since the stronger the static magnetic field, the clearer the image, the MRI system is being developed to improve the magnetic field strength. In particular, in an MRI apparatus having a static magnetic field strength of 0.5 Tesla or more, a magnet apparatus using a superconducting coil has become mainstream.

  The superconducting coil is made of a superconducting material whose electric resistance becomes zero when cooled to a very low temperature. The temperature varies depending on the material, but it must be cooled from 4 to 77 Kelvin in absolute temperature. For this reason, a superconducting coil made of niobium / titanium, which is a material of a superconducting coil currently used in a general MRI apparatus, is immersed in liquid helium in order to maintain a state cooled to 4 Kelvin. .

  In addition, since helium maintains a liquid state, the superconducting coil and liquid helium are a metal container called a helium container, a radiation shield that surrounds it and shields heat transfer by radiation, and heat conduction from the outside with a vacuum inside. It is housed in a vacuum vessel that reduces heat intrusion due to. Furthermore, the cryogenic state is maintained by suppressing evaporation of liquid helium by a refrigerator.

  Liquid helium is expensive because it is difficult to collect, and the demand for downsizing of the apparatus has led to the development of MRI apparatuses that reduce or do not use liquid helium. One method that does not use liquid helium is to employ a conduction cooling type superconducting coil that is cooled from a refrigerator through a solid heat conductive material. In particular, it is preferable that a superconducting material with a temperature at which a superconducting state is 20 Kelvin or higher, at which the thermal conductivity of copper, which is a good heat conductor, is maximized, can be used for the wire. One such superconducting material is magnesium diboride (MgB2).

  In order to use this as a superconducting wire, a heat treatment at a high temperature of 600 ° C. or higher, that is, a firing reaction is required. Since the wire after the firing reaction becomes brittle, when it is wound around a coil, the current-carrying performance may be reduced. In order to avoid this, there is a method of forming a coil by winding the wire before the firing reaction around the bobbin and firing it at a high temperature together with the bobbin.

  In the firing reaction, the wire becomes superconducting. However, since the wound wires are independent of each other, frictional heat is generated by electromagnetic force or thermal stress during energization, which may cause a normal conduction transition. The normal conduction transition causes the coil current to be lost, and as a result, it becomes difficult to pass a large current. Moreover, since the thermal resistance between the strands is large, it is difficult to cool the coil uniformly by the conduction method.

  According to the superconducting coil of this configuration described below, it is possible to provide a superconducting magnet device that is less likely to be collapsed after the firing reaction in a superconducting coil that requires a firing reaction at a high temperature in the manufacturing process. In addition, the winding and bobbin are prevented from sticking while the winding is integrated during the firing reaction, and the winding member is prevented from collapsing in the cooling member installation process, bobbin replacement process, or resin molding process after the firing reaction. It becomes possible to do. In this way, by suppressing the possibility of collapse, installation of the conductive cooling member is facilitated, and deterioration of the magnetic field accuracy due to collapse can be prevented. As a result, it is possible to realize a superconducting magnet device that can suppress power consumption of a refrigerator that is a heat removal means and can maintain a stable magnetic field generation state, and an MRI apparatus using the superconducting magnet device.

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

  As shown in FIG. 2, a general MRI apparatus has a cylindrical magnetic pole 1 made of a superconducting coil, and generates a static magnetic field in an imaging space 2 in a direction indicated by an arrow 3. The subject 4 is carried to the imaging space 3 by the movable bed 5 and acquires an image. The MRI apparatus has a concentric cylindrical gradient coil 6 and a high-frequency irradiation coil 7 inside the magnetic pole formed by a superconducting coil, which generate position information and magnetic resonance for image acquisition and acquire normal signals, respectively. Coil. These are covered with a cover (not shown) integral with the magnetic pole.

  In addition, in the MRI apparatus, there are a power supply device that supplies current to the gradient magnetic field coil and the normal conduction coil and a computer system for displaying operations and images as other main components, but these are omitted in the figure. Has been.

  FIG. 3 shows a structure of an MRI apparatus called an open type, which is another general method of the MRI apparatus. Disk-shaped upper and lower magnetic poles 1 are arranged above and below the imaging space 2, and a static magnetic field is generated in the direction of the arrow 3 in the imaging space.

  The subject 4 is carried to the imaging space 3 by the movable bed 5 to acquire an image, as in FIG. In the MRI apparatus of this embodiment, the upper and lower magnetic poles are supported by a structure such as a column, and may be connected by a magnetic return yoke 8 having a substantially C shape as shown in FIG. Can be seen in devices with a magnetic field strength of 1 Tesla or less. In the open-type MRI apparatus, the gradient magnetic field coil 6 and the high-frequency irradiation coil have a disk shape arranged on the top and bottom of the imaging space 3 like the magnetic pole, and are covered with a cover (not shown) integrally with the magnetic pole.

  As shown in FIG. 4, the magnetic pole 1 is composed of an annular superconducting coil 9, and a desired static magnetic field is generated in the imaging space 3 by combining one or a plurality of superconducting coils so as to be concentric with each other. . The superconducting coil 9 is composed of a superconducting wire composed of a superconducting material (for example, magnesium diboride) and a metal material such as copper, iron, or nickel, and a winding around which the superconducting wire is wound with a resin or wax such as epoxy. It is an integrated composite. The superconducting coil is usually wound around a winding frame 10 called a bobbin made of metal such as stainless steel, aluminum, or copper, and maintains its position and shape.

  The superconducting coil is cooled to a temperature at which the electrical resistance of the superconducting wire becomes zero (depending on the material, but usually 4 to 77 Kelvin or less). To maintain this temperature, liquid helium (4 Kelvin) or liquid nitrogen (77 Kelvin) There are cases where the superconducting coil is cooled by being immersed in a liquid refrigerant such as a cooling medium, and cooling from a heat removal device such as the refrigerator 30 via a heat transfer cooling member made of a structure. Although both may be used together, the former requires a container for enclosing the superconducting coil together with the bobbin in the liquid refrigerant, so that the magnetic pole tends to be larger than the latter.

  On the other hand, in the latter case, the liquid refrigerant container is not necessary, but the heat transfer cooling member 11 for cooling the coil is necessary. The heat transfer cooling member is generally made of a metal having good thermal conductivity such as copper or aluminum. In order to cool the superconducting coil 9 to a desired temperature by the heat transfer cooling member and maintain the superconducting state, the thermal resistance between the heat transfer cooling member and the superconducting coil needs to be sufficiently small. In particular, there is a gap at the interface between the superconducting coil and the heat transfer cooling member, which tends to increase the thermal resistance.

  When magnesium diboride or niobium tin (Nb3Sn) is used for the superconducting wire, in order for the wire to exhibit superconducting properties at extremely low temperatures, a firing reaction (sintering reaction, simply firing) in an environment of 400 ° C to 600 ° C. It is necessary to give rise to (also referred to as conclude). In some cases, the wire after the firing reaction is wound around a bobbin to generate a coil, but the superconducting material after the firing reaction becomes brittle, and the current-carrying performance tends to be lowered in a winding process involving bending or pulling.

  For this reason, a method is adopted in which the wire material before the firing reaction is wound around a winding frame (bobbin) made of a member that can withstand the firing temperature, such as stainless steel, and is fired at a high temperature. Since the coil structure must be able to withstand the firing temperature, it has been difficult to use a copper material or an aluminum material having good thermal conductivity as the bobbin member. In addition, in order to install a heat transfer cooling member made of copper or aluminum after the firing reaction, the bobbin at the time of firing is replaced or part of the member is replaced, but at that time, the wire wound around the bobbin May collapse.

  For this reason, in this embodiment, as shown in FIG. 1, the bobbin 10 (cylindrical portion 10), the flange portion made of a heat-resistant member such as a stainless material, etc. at the time of winding the superconducting wire 17 before firing (winding process) On the surface of 13, a member 19 (organic sheet member 19) made of organic material such as thin paper or resin is installed. In advance, heat resistant adhesive 18 that can withstand the firing temperature (softening temperature is higher than firing temperature) is applied to superconducting wire 17 before firing (coating process), and then superconducting wire 17 is wound around bobbin 10 . Alternatively, the heat-resistant adhesive 18 is applied after the superconducting wire is wound. For the sake of simplicity, the heat-resistant adhesive 16 and the heat-resistant adhesive 18 are given different signs before and after curing, but these are the same adhesive.

  The bobbin 10 and the flange portion 13 have a structure that can be disassembled and separated from the winding portion 20 after firing. In FIG. 1, at least one of the flange portions 13 provided at both ends of the bobbin winding shaft portion has a structure that can be removed by fastening bolts 12 as shown in FIG. In addition, the coil | winding part 20 means the structure where the superconducting wire 17 was wound by multiple turns as shown in FIG.

  As the heat-resistant adhesive 16 (18), for example, an alumina-based one can be used. Alumina-based heat-resistant adhesive has a curing temperature of about 200 ° C and a heat-resistant temperature of 1000 ° C or higher. Then, before the firing reaction, the heat-resistant adhesive 16 is cured at a curing temperature (about 200 ° C.), so that the superconducting wire 17 is bonded and the winding portion 20 is integrated (first curing step). Thus, since the curing temperature of the heat-resistant adhesive 18 in this embodiment is lower than the firing temperature of the superconducting wire 17, it is cured before the firing reaction of the superconducting wire 17 and fixes the superconducting wires 17 belonging to each turn to each other. Further, since the heat-resistant adhesive 18 after curing has a softening temperature higher than the firing temperature, even if the superconducting wire 17 is heated to the firing temperature, the superconducting wires 17 of each turn are firmly bonded to each other and curling is suppressed. Is done.

  At this time, the winding part 20 organic material sheet member 19 is integrated by the heat resistant adhesive 16, but the bobbin 10 is not in contact with and not bonded to the bobbin 10 because the organic material sheet member 19 exists. Further, the temperature is raised to near the firing temperature, and the paper or resin is burned away by a reduction reaction in an oxygen atmosphere (heat cleaning step). Thereafter, a firing reaction is caused at a predetermined firing temperature and time, and then cooled to room temperature (firing step). As shown in FIG. 5, the winding part 20 after the firing reaction is integrated, and since the bobbin 10 and the flange part 13 are not fixed, the fastening of the bolt fastening part 12 is released, and the bobbin Even if 10 and the flange portion 13 are disassembled (dividing step), the winding portion 20 is unlikely to collapse.

  For this reason, a part of the bobbin 10 (flange portion 13) or all of the bobbin 10 is replaced with a good heat conductive member such as copper or aluminum (bobbin replacement step or flange portion replacement step), or as shown in FIG. It becomes easy to install the heat transfer cooling member 11 that serves as a cooling path from the refrigerator 30 between the part 20 and the flange part 13 (installation process). Further, the heat transfer cooling member 11 and the winding portion 20 are impregnated with resin and cured (second curing step), that is, molded integrally, so that the heat transfer cooling member 11 and the winding portion 20 and between the superconducting wires 17 are formed. , The power consumption of the refrigerator 30 can be reduced, and the temperature of the superconducting coil 9 can be made uniform easily.

  After the heat-resistant adhesive 18 is cured at the curing temperature, the winding portion 20 is not easily collapsed even if it is removed from the bobbin 10 necessary for winding the wire as shown in FIG. Is removed from the bobbin 10 and fired with only the winding part 20, and then attached to a bobbin (not shown) made of copper or aluminum material having good thermal conductivity, or attached to the bobbin 10 provided with the heat transfer cooling member 11. I can do it. Also in this case, if the winding part 20 and the bobbin or the heat transfer cooling member 11 are integrally molded or bonded, the cooling capacity by heat conduction from the refrigerator 30 is further increased.

  As described above, in Example 1, in the magnet device using the superconducting coil 9 that is brought into the superconducting state by being cooled to a temperature lower than the normal temperature, the superconducting coil 9 has a property of the superconducting state at an extremely low temperature by performing a firing reaction at a high temperature. The superconducting wire 17 is wound around the bobbin 10 and is applied to the superconducting wire 17 with a heat-resistant adhesive 18 that cures at a temperature lower than the firing reaction temperature and withstands the firing temperature after curing. The superconducting coil 9 has been described in which the heat-resistant adhesive 16 is cured and integrated with the superconducting wire 17 in an environment and has superconducting characteristics at a very low temperature by a firing reaction.

  The superconducting coil 9 has a sheet-like organic material made of paper or resin disposed between the superconducting wire 17 and the bobbin 10, and the superconducting wire 17 coated with the heat-resistant adhesive 18 is wound around the bobbin 10. After turning, a baking reaction was performed so as to have superconducting properties at extremely low temperatures.

  Further, the superconducting coil 9 cures the heat-resistant adhesive 18 at a temperature lower than the temperature of the firing reaction before the firing reaction, and integrates the winding portion 20 composed of the superconducting wire 17 portion. A member made of a sheet-like organic material made of paper or resin is burned out in an oxygen atmosphere so that the winding portion 20 and the bobbin 10 are not bonded by the heat-resistant adhesive 16. Further, the winding part 20 may be wound around the separable bobbin 10 and the winding part 20 and the bobbin 10 may be separated from each other. Part 13) may be made of a high thermal conductivity member such as copper or aluminum. Alternatively, the separable bobbin 10 may be divided once, a high thermal conductivity member such as copper or aluminum material may be disposed so as to be in contact with the winding portion 20, and then the divided bobbin 10 may be reassembled.

  Further, after the firing reaction, the superconducting coil 9 may be further impregnated with a resin with the winding portion 20 integrated by the heat-resistant adhesive 16 and cured. At this time, when the flange portion 13 of the separable bobbin 10 is replaced with a high thermal conductivity material or the high thermal conductivity member 2 is disposed between the flange portion 13 and impregnated with resin, it is cured or adhered. It may be integrated.

  FIG. 6 shows an example of a superconducting superconducting coil before the firing reaction in the second embodiment of the present invention. In the present embodiment, in the winding portion 20, a heat-resistant adhesive 18 is applied to the surface of the superconducting wire 17 before the firing reaction, and a paper or resin plate 19 (between the surface of the winding portion and the bobbin 10 and the flange portion 13 ( The organic material sheet-like member is installed in the same manner as in Example 1, but a heat-resistant insulating member 21 is installed between the paper or resin plate 19 and the superconducting superconducting wire 17.

  According to this embodiment, after the heat-resistant adhesive 18 is cured, the superconducting wire 17, the insulating member 21, and the organic sheet-like member 19 are formed as a unitary winding part 20, and after the firing reaction, the surface of the winding part 20 is An insulating structure can be generated between the superconducting wire 17 and the bobbin or heat transfer cooling member 11 covered with the insulating member 21 and made of a material having good thermal conductivity. Thereby, even when a transient voltage is generated in the superconducting wire 17 due to excitation and demagnetization and normal conduction transition of the superconducting superconducting coil 9, it is possible to suppress the occurrence of dielectric breakdown and to stably shift to the normal conduction state. It becomes possible.

  As the heat-resistant insulating member 21, for example, a sheet or plate made of alumina, glass fiber, ceramic, or the like can be used. Also in the present embodiment, the winding part 20 after the firing reaction is integrally molded with or bonded to a bobbin or heat transfer cooling member 11 made of a good heat conductor so that the heat transfer path from the refrigerator 30 can be obtained. Thermal resistance can be reduced. Further, after the heat-resistant adhesive 18 is cured, it is possible to remove the winding part 20 from the bobbin 10 and cause a baking reaction alone, as in the first embodiment.

  FIG. 7 shows an example of the superconducting coil 9 after the firing reaction in the third embodiment of the present invention. The conductive cooling member 11 may be constituted by a bobbin that replaces the winding part 20 after the firing reaction, a part of the flange part, or all of the metal made of a good heat conductor such as aluminum or copper. As shown, the bobbin 22 and the flange portion 23 are high resistance or high strength members such as SUS, iron or ceramic material, and the conductive cooling member 11 is installed between the winding portion 20, the bobbin 22 and the flange portion 23. May be.

  In addition, although the different symbols of the bobbin 22 and the flange portion 23 are given to the bobbin 10 and the flange portion 13 in the first embodiment and the second embodiment, this has a difference in material, so that this is clarified. They are given different reference numerals, and they are not different in the sense that they are members that support the shape of the bobbin and the flange part and the winding part 20.

  According to the present embodiment, the deformation of the superconducting coil 9 can be suppressed more than the above-described example by maintaining the rigidity of the bobbin 22 and the flange portion 23, and further the cooling effect by the conductive cooling member 11 is obtained. I can do it. Even in the present embodiment, by integrating the winding part 20, the bobbin 23, and the heat transfer cooling member 11 by resin molding or adhesion, the thermal resistance from the refrigerator 30 can be reduced, and the cryogenic temperature can be reduced. It becomes possible to keep the state stable.

  In FIG. 8, the example of the superconducting coil after the baking reaction in 4th Embodiment of this invention is shown. The conductive cooling member 11 is in contact with the winding part 20 between the bobbin 22, the flange part 23, and the winding part 20 that replace the winding part 20 after the firing reaction. According to the present embodiment, the bobbin 22 and the flange portion 23 are made of a high-strength member such as SUS, iron, or a ceramic material, and the winding portion 20 has a heat resistance against the refrigerator 30 by the heat transfer cooling member 11. The coil portion 20 can be kept small, and is also formed by resin molding or bonding so that the heat transfer cooling member 11 and the winding portion 20 after the firing reaction are integrated (fixed to each other). It is possible to further reduce the thermal resistance of the superconducting state at a very low temperature even with conduction cooling by the refrigerator 30.

  In addition, since the space between the bobbin 22 and the conductive cooling member 11 is not fixed, the superconducting coil 9 due to the difference between the thermal contraction rate of the bobbin 22 and the flange portion 23 and the thermal contraction rate of the winding portion 20 during cooling. It is possible to relieve the deformation and stress concentration, and to suppress the heat generation due to the release of the stress, friction between the winding part 20 and the bobbin 22, and the magnetic field non-uniformity due to the deformation of the superconducting coil 9, thereby achieving a stable superconducting state. Magnetic field generation can be made possible. Further, in order to further reduce the contact thermal resistance between the winding portion 20 and the cooling heat transfer member 11, a push spring 24 may be installed on the fastener 12 as shown in FIG.

  In addition, about the superconducting coil 9 demonstrated in each Example mentioned above, when the manufacturing method is arranged in a process, it will become as follows, for example. First, the application process of applying the heat-resistant adhesive 18 to the superconducting wire 17, the winding process of winding the superconducting wire 17 and an organic sheet member 19 such as paper or resin around the bobbin 10, and the curing temperature of the heat-resistant adhesive 18 A first curing step for curing the heat-resistant adhesive 18 at a temperature lower than the firing temperature of the superconducting wire 17, and firing the superconducting wire 17 at a temperature that is equal to or higher than the firing temperature of the superconductive wire 17 and lower than the softening temperature of the heat-resistant adhesive 16. The baking process to be combined is a basic process. The coating process and the winding process may be interchanged. In addition, you may put the heat cleaning process which burns down a sheet-like organic member in oxygen atmosphere below baking reaction temperature between a 1st hardening process and a baking process.

In addition, after the firing process, a splitting process of the separable bobbin 10 is provided, followed by a bobbin replacement process (or a thermally conductive bobbin 10 for replacing the heat-resistant bobbin 10 that can withstand the firing reaction with an excitation bobbin having good thermal conductivity. A flange replacement step for replacing the flange portion with a good flange portion or an installation step for installing the high thermal conductivity member 11 between the flange portion 13 may be performed. A dividing step may be provided before the firing step, the winding part 20 may be removed from the bobbin 10, a firing process for separately firing the winding part 20 may be provided, and then a bobbin replacement process may be provided. Further, after these steps, a second curing step may be provided in which the winding portion 20 is impregnated with resin and cured. According to the manufacturing method as described above, the annular superconducting coil 9 and the superconducting coil 9 The superconducting coil 9 includes a superconducting wire 17 wound around a plurality of turns and an adhesive 16 that fixes the superconducting wire 17 to each other between different turns. The wire 17 is a member in which a superconducting material is sintered and has a superconducting transition temperature of 25 K or more. The adhesive 18 has a curing temperature lower than the firing temperature of the superconducting wire and a softening temperature. A superconducting magnet device higher than the firing temperature of the superconducting wire 17 can be manufactured.

  Since this superconducting magnet device is less likely to collapse before and after the superconducting wire 17 is fired, for example, a heat-resistant bobbin suitable for firing is replaced with a high heat-transfer bobbin for excitation, or the bobbin flange 13 is removed. Therefore, it is possible to easily replace the flange portion with high heat conductivity. In particular, when a high-temperature superconducting wire having a transition temperature of 25K or higher is used, an effective cooling structure can be provided while suppressing collapse of the winding, even if the coil molding method is not used for winding after firing. It is useful in.

  Further, as described above, the superconducting magnet device having the superconducting coil 9 described in the above-described embodiment includes a cylindrical portion (bobbins 10 and 22) disposed on the inner diameter side of the superconducting coil 9, and a cylindrical portion. The superconducting coil 9 has a structure that is supported from the flange portion and the tubular portion. The flange portion is detachably attached to the tubular portion via, for example, a bolt fastening portion 12.

  This makes it possible to divide the cylindrical portion and the flange portion. Therefore, after the firing process, the flange portion is replaced with a member made of a high thermal conductivity member typified by copper or aluminum, or the cylindrical portion. After the cooling heat transfer member 11 is installed between the flange portion and the flange portion, the flange portion can be fixed again. In addition, as shown in FIG. 1, if the flange portion is structured to be fastened to the tubular portion by a fastener from the axial direction (z-axis direction) of the tubular portion, the flange portion can be easily removed.

  In addition, the fastener has a push spring that applies pressure to the flange portion in the axial direction, so that the winding portion and the heat transfer cooling member 11, or a flange portion formed of a material having high thermal conductivity. The surface pressure can be secured, the contact thermal resistance can be suppressed, and the superconducting coil 9 can be operated more stably. Note that the flange portion may have a portion formed of a material having a higher thermal conductivity than the cylindrical portion.

  Note that the heat transfer cooling member 11 installed between the flange portion and the winding portion 20 or the flange portion made of a high thermal conductivity member has a heat transfer path member 31 connected to the refrigerator 30.

  In addition, in the above-mentioned each Example, a shape and material can be changed suitably in the range which does not exceed the summary of this invention. In addition, the superconducting coil used in the magnetic resonance imaging apparatus has been assumed and described. However, the present invention is not limited to this and can be widely applied to, for example, a particle trapping apparatus and an accelerator using the superconducting coil. In addition, it is possible to provide a superconducting magnet device that is less likely to cause winding collapse even when applied to an immersion cooling superconducting coil, not limited to a conduction cooling superconducting coil.

DESCRIPTION OF SYMBOLS 1 Magnetic pole 2 Imaging space 3 Static magnetic field and the arrow which shows the direction 4 Subject 5 Movable bed 6 Gradient magnetic field coil 7 High frequency irradiation coil 8 Return yoke 9 Superconducting coil 10 Bobbin (cylindrical part)
11 Heat transfer cooling member 12 Fixing bolt (fastening part)
13 Flange part 14 Flange part removal direction 15 Bobbin removal direction 16 Heat-resistant adhesive 17 after curing 17 Superconducting superconducting wire 18 Heat-resistant adhesive 19 before curing 19 Paper or resin plate (organic sheet member)
20 Winding part 21 Heat-resistant insulating member 22 Bobbin replaced after firing reaction (high-strength bobbin)
23 Bobbins exchanged after firing reaction (high-strength flange)
24 Press spring 30 Refrigerator 30
31 Heat transfer path member 31

Claims (8)

An annular superconducting coil;
A refrigerator for cooling the superconducting coil,
The superconducting coil is
A superconducting wire wound by multiple turns,
An adhesive for fixing the superconducting wires to each other between different turns,
The superconducting wire is a member obtained by sintering a superconducting material and a member having a superconducting transition temperature of 25K or more,
The adhesive is a superconducting magnet device having a curing temperature lower than a firing temperature of the superconducting wire and a softening temperature higher than a firing temperature of the superconducting wire. The superconducting magnet device according to claim 1,
A cylindrical portion disposed on the inner diameter side of the superconducting coil;
A flange portion projecting in an annular shape from the tubular portion;
With
The superconducting coil is a superconducting magnet device supported from the flange portion and the cylindrical portion. The superconducting magnet device according to claim 2,
A superconducting magnet device in which the flange portion is detachably attached to the cylindrical portion. The superconducting magnet device according to claim 3,
A superconducting magnet apparatus having a fastener that fastens the flange portion to the cylindrical portion from an axial direction of the cylindrical portion. The superconducting magnet device according to claim 4,
The said fastener is a superconducting magnet apparatus which has an elastic part which applies a press to the said axial direction with respect to the said flange part. The superconducting magnet device according to any one of claims 3 to 5,
The flange portion is a superconducting magnet device having a portion formed of a material having a higher thermal conductivity than the cylindrical portion. A superconducting magnet device according to any one of claims 2 to 6,
A heat transfer cooling member installed between the flange and the superconducting coil;
A heat transfer path member connecting the heat transfer member and the refrigerator;
A superconducting magnet device. A magnetic resonance imaging apparatus comprising the superconducting magnet apparatus according to any one of claims 1 to 7 as a static magnetic field apparatus.

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