JPH10127602A - Superconducting magnetic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To divide the yoke part of a magnetic shield into small parts and to easily insert a superconducting magnet after assembling the magnetic shield at a site by enabling to incorporate the assembling structure of the super conductive magnet in the magnetic field after assembling. SOLUTION: The superconducting magnet A which generates a uniform magnetic field in a measuring space 3 through the use of superconducting characteristic and is cooled to a temperature showing superconducting characteristic within a cooling container is provided with the magnetic shield B for suppressing the spreading of a leaked magnetic field distributed in its peripheral and external part. At this time the magnetic shield B is constituted of disassembleable iron board 5 and iron yokes 6 to insert the magnet A through between two iron yokes 6 after assembling. The iron yokes 6 are arranged at symmetrical positions at four corners. It is possible that an iron yoke on this side 6A is provided with a small diameter and arranged at a long interval but the iron yoke 6B on a deep side is provided with a large diameter and arranged at a little shorter interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting magnet device for a magnetic resonance imaging device (hereinafter, referred to as an MRI device), and more particularly to a superconducting magnet and a magnetic shield for improving the structure of a superconducting magnet and magnetic shield. The present invention relates to a superconducting magnet device that can be easily assembled with high accuracy after being brought into a use place.

[0002]

2. Description of the Related Art A conventional example of a superconducting magnet apparatus for an MRI apparatus using a magnetic shield made of iron is disclosed in U.S. Pat.
No. 94,810. The structure is shown in FIGS. FIG. 14 is an overall perspective view, and FIG. 15 is a transverse sectional view in a measurement space. In this superconducting magnet device, a uniform magnetic field in the vertical direction is generated in the measurement space 3 by the superconducting coils 1 arranged vertically facing each other. The superconducting coil 1 is usually housed in a cooling vessel 2 and is cooled and held at a temperature exhibiting superconducting characteristics. The upper and lower cooling containers 2 are supported by a support 4 while maintaining an interval (a structure in which the cooling container is supported by the support is hereinafter referred to as a superconducting magnet). Further, a magnetic shield including an iron plate 5 and an iron yoke 6 is provided as a return path of the magnetic flux generated by the superconducting coils 1 arranged vertically. The iron yoke 6 also functions to return the magnetic flux and mechanically support the upper and lower structures. On the side facing the measurement space (uniform magnetic field region) 3 of the iron plate 5 and inside the superconducting coil 1, in order to correct the uniformity of the magnetic field distribution in the measurement space 3, an annular magnetic field distribution correcting ferromagnetic material is used. A piece 7 is arranged.

[0003] The superconducting magnet device for an MRI device having such a structure tends to be larger and heavier as the magnetic field intensity increases. Therefore, in order to deliver a superconducting magnet device to a hospital or the like, it is necessary to disassemble the device at a factory to the extent that it can be disassembled, and to assemble the device on site. Next, the superconducting magnet device is assembled and the building is extended or remodeled so as to be suitable for installation, or the superconducting magnet device is divided and transported to such an extent that the superconducting magnet device can pass through the entrance and the passage of the building. Do assembling in the inside, etc. From the viewpoint of cost, it is more advantageous to carry out the latter divisional loading and assembly.
However, in the case of adopting the method of performing the divided carrying-in and the assembling, easy carrying-in, easy assembling, and high assembling accuracy are required.

[0004] Considering this requirement, a method of carrying in and assembling the above-mentioned conventional apparatus is as follows. First, since the interval between the iron yokes 6 is smaller than the diameter of the superconducting magnet, the iron yoke 6 has to be laterally assembled after assembling the magnetic shield. It is impossible to insert the superconducting magnet from the direction. Therefore, when assembling the device,
(A) The superconducting magnet is mounted on the lower iron plate 5 assembled, and then the iron yoke 6 and the upper iron plate 5 are assembled, or (b) the lower iron plate 5 and the iron yoke 6 are assembled. In this state, a method of inserting a superconducting magnet from above and placing the upper iron plate 5 thereon can be considered.

In this conventional example, an annular magnetic field distribution correcting ferromagnetic piece 7 is fixed to the side of the iron plate 5 of the magnetic shield facing the measurement space 3 for the purpose of correcting the magnetic field distribution in the measurement space 3. ing. For this reason, the superconducting magnet is magnetically shielded.
After the magnetic field distribution correcting ferromagnetic piece 7 must be fixed after being inserted into the field and fixed, the workability is very poor.

[0006]

As described in the above prior art, recent superconducting magnet devices for MRI devices are becoming larger and heavier, and are therefore required to be delivered to places of use such as hospitals. , It is becoming a matter of course to make the parts separately and assemble them locally. However,
In the method of divided loading and assembling on site, even if the magnetic shield is divided into several parts, the magnetic shield is assembled, a superconducting magnet is incorporated therein, and then the upper iron plate 5 or iron yoke is assembled. It was necessary to incorporate the tool 6. Assembling by this method is not an easy operation for a large-sized magnetic shield, and is in parallel with assembling a superconducting magnet having a weak strength, and is a heavy magnetic shield.
Have to assemble the field. In addition, disassembling the superconducting magnet and assembling it on site did not maintain the reproducibility of the magnetic field adjustment in the factory, and required fine adjustment on site.

In order to solve such a problem, according to the present invention, the yoke portion of the magnetic shield is divided into small parts.
It is an object of the present invention to provide a superconducting magnet device that can easily insert a superconducting magnet into a magnetic shield after assembling the magnetic shield on site.

[0008]

A superconducting magnet device according to the present invention, which achieves the above object, comprises a magnetic field source which is made of a material having superconducting characteristics and generates a uniform magnetic field in a finite region in a first direction. Cooling means for housing the magnetic field source, cooling and maintaining the temperature to a temperature exhibiting superconductivity,
A superconducting magnet comprising a supporting means for supporting the cooling means, a plate-shaped ferromagnetic body disposed vertically so as to surround the superconducting magnet, and a magnetic connection between the plate-shaped ferromagnetic substance and In a superconducting magnet device combining a magnetic shield formed by a plurality of columnar ferromagnetic materials to be supported,
After assembling the magnetic shield, the superconducting magnet assembly structure can be inserted and incorporated therein (Claim 1).

In this configuration, the superconducting magnet device is composed of a superconducting magnet and a magnetic shield, and after assembling the magnetic shield, the superconducting magnet can be inserted and incorporated therein. For this reason, when delivering a superconducting magnet device to a hospital, etc., the superconducting magnet device is assembled and adjusted at a factory, then divided into a superconducting magnet assembly structure and components of a magnetic shield. By assembling the shield and inserting the superconducting magnet assembly into the shield, the entire apparatus can be assembled and adjusted. As a result,
Split delivery and on-site assembly are possible, and costs can be reduced.

Further, in the superconducting magnet device of the present invention, the columnar shape of the superconducting magnet assembly is not overlapped with the insertion locus of the superconducting magnet assembly when the superconducting magnet assembly is inserted into the magnetic shield. A ferromagnetic material is provided (claim 2). In this configuration, since the columnar ferromagnetic material does not exist in the passage for inserting the assembly structure of the superconducting magnet into the magnetic shield, the assembly structure of the superconducting magnet can be inserted smoothly.

Further, in the superconducting magnet device of the present invention, the gap between at least two of the columnar ferromagnetic bodies is such that the assembly structure of the superconducting magnet is located inside the magnetic shield. It is larger than the dimension that can be inserted (claim 3). In this configuration, the assembled structure of the superconducting magnet can be inserted into the magnetic shield by passing between the two columnar ferromagnetic materials of the magnetic shield.

Further, in the superconducting magnet device of the present invention, the superconducting magnet is inserted into the magnetic shield at a contact surface between the superconducting magnet and the magnetic shield in the insertion direction of the superconducting magnet. Guide means are provided (claim 4). In this configuration, the guide means for inserting the superconducting magnet into the magnetic shield includes the superconducting magnet and the magnetic shield.
Since the superconducting magnet is provided on the contact surface with the shield, the guide means can insert the superconducting magnet into an appropriate position in the magnetic shield.

As an embodiment of the guide means 1, a contact surface between the superconducting magnet and the magnetic shield is provided with an uneven surface which fits with another contact surface in parallel with the insertion direction of the superconducting magnet. (Claim 5). Further, as another aspect of the guide means, at least one groove is provided on one or both of the contact surfaces between the superconducting magnet and the magnetic shield in parallel with the insertion direction of the superconducting magnet. (Claim 6).

In the superconducting magnet device according to the present invention, after the superconducting magnet is inserted into the magnetic shield, a solid or liquid body containing a ferromagnetic material is embedded in the groove. ). In this configuration, the groove used as the guide means for inserting the superconducting magnet is buried with an object containing a ferromagnetic material, so that the adhesion between the superconducting magnet and the magnetic shield is improved, and the magnetic field in the measurement space is improved. The distribution can be corrected.

Further, in the superconducting magnet device of the present invention, at least one gap is provided at a contact portion between the superconducting magnet and the magnetic shield, and a solid or liquid object containing a ferromagnetic material is provided in the gap. (Claim 8). Also in this case, the same effect as that of the seventh aspect can be obtained.

Further, in the superconducting magnet device of the present invention, a superconducting magnet to which a ferromagnetic piece for correcting a magnetic field distribution is added and integrated with a portion of the superconducting magnet in contact with the magnetic shield, and the ferromagnetic piece is added thereto Is inserted into the magnetic shield (claim 9). In this configuration, a superconducting magnet integrated by adding a ferromagnetic piece for magnetic field distribution correction to the superconducting magnet in advance can be incorporated into the magnetic shield, so that on-site assembly and adjustment for magnetic field distribution correction can be performed. It will be easier.

Further, in the present invention, the superconducting magnet device having the above configuration is applied as a static magnetic field generator of an MRI apparatus.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show a first embodiment of the present invention. The main components of the superconducting magnet device for an MRI device, which is the object of the present embodiment, are basically the same as those described in the related art, so this portion will be described with reference to FIGS.

The superconducting magnet device of this embodiment uses several superconducting coils 1 for generating a uniform magnetic field in the measurement space 3 by utilizing the properties of superconductivity, and a temperature at which the superconducting coils 1 are housed and exhibit superconducting characteristics. Cooling container 2 that cools and holds until
A superconducting magnet A having a connecting pipe 4 for supporting the cooling vessel 2, and a magnetic shield B for suppressing the spread of a leakage magnetic field distributed around the superconducting magnet A. The magnetic shield B is composed of an iron plate 5 and an iron yoke 6, which can be disassembled and have such a structure that the superconducting magnet A can be inserted between the two iron yokes 6 after assembly. Has become.

The arrangement of the superconducting coil 1 is basically the same as that of the conventional example. The superconducting coil 1 is vertically symmetrical with respect to a uniform magnetic field generation area (measurement space) 3 at the center of the apparatus. Accordingly, the upper and lower cooling containers 2 containing both superconducting coils 1 are supported at a predetermined distance by the connecting pipe 4 therebetween. The connecting pipe 4 has a function of mechanically supporting the upper and lower cooling containers 2, but may have a function of thermally connecting the upper and lower cooling containers 2 if necessary. By doing so, the refrigerator can be moved to the upper and lower cooling containers 2
There is no need to provide one unit for each unit, and a single refrigerator can be used for the system. In addition, connecting pipe 4
Is not limited to two on each side, but one on each side.
The number can be increased by three or four.

On the other hand, in order to reduce the leakage magnetic field due to the magnetic flux generated by the superconducting coil 1, a magnetic shield B made of iron is provided on the outer periphery of the device. In the magnetic shield B, the upper and lower sides of the cooling vessel 2 containing the upper and lower superconducting coils 1 are surrounded by iron plates 5, and the upper and lower iron plates 5 are further iron-yoke 6.
Are connected magnetically. This iron yoke 6
Also serves to support the upper and lower iron plates 5. By surrounding the superconducting coil 1 which is the magnetic field generating source with a ferromagnetic material (iron in this embodiment), a magnetic path is formed for the magnetic flux generated outside the superconducting magnet A, and the leakage magnetic field is extended to a distant place. Spreading can be suppressed.

As the ferromagnetic material used here, iron is generally desirable in view of magnetic properties, cost and mechanical strength. Therefore, in the present embodiment, the iron plate 5 and the iron yoke 6
However, a material other than iron can be selected as long as the material shows magnetic ferromagnetism, and the present invention does not limit the ferromagnetic material to iron.

For the sake of explanation in the future, a three-dimensional orthogonal coordinate system having a center point in the center of the superconducting magnet A, that is, a space (measurement space) 3 for generating a uniform magnetic field is defined.
This coordinate system has a Z axis in the vertical direction, an X axis in the horizontal direction in FIG. 1, and a Y axis in a direction orthogonal to the two axes.
A subject placed on a table (not shown) is generally Y
It is inserted into the superconducting magnet device along the axial direction.

In this embodiment, the superconducting magnet A is inserted between two iron yokes 6 along the Y axis. FIG.
And FIG. 2 is a cross-sectional view of the measurement space of the present embodiment,
3 shows a relationship between a superconducting magnet A and a magnetic shield B. In the case of FIG. 1, the iron yoke 6 of the magnetic shield B is arranged symmetrically, and in the case of FIG. 2, the iron yoke 6 is arranged asymmetrically. That is, in FIG. 1, the iron yoke 6 is arranged at the four corners of the rectangular iron plate 5 symmetrically, but in FIG. 2, the iron yoke 6A on the near side has a small outer diameter and X While the iron yoke 6B on the far side has a large outside diameter,
It is arranged away from the X-axis at a slightly smaller interval. In the figure, a superconducting magnet A is inserted from the near side to the far side along the Y axis. The locus of the insertion is shown by a plurality of circular chains. In this embodiment, the shortest distance between the two iron yokes 6 or 6A on the near side constituting the magnetic shield B is set to be larger than the outer diameter of the superconducting magnet A. It can be easily inserted into the central part of the iron plate 5 through between the two iron yokes 6 or 6A. Further, in the configuration of FIG. 2, since the iron yoke 6 is asymmetrically arranged, a wide space is obtained on the near side, which is the insertion opening of the superconducting magnet A.

By arranging the iron yoke 6 of the magnetic shield B as shown in FIG. 1 or 2, it becomes possible to insert the superconducting magnet A after assembling the magnetic shield B. , The magnetic shield B and the superconducting magnet A can be assembled separately. As a whole assembly procedure,
First, the components of the divided magnetic shield B are assembled in a shield room to form a magnetic shield B, and then a superconducting magnet A adjusted at a factory is inserted into the magnetic shield B.

Further, in this embodiment, the contact surface between the iron plate 5 and the superconducting magnet A is a flat surface having no convex portions, so that the horizontal direction (Y
The superconducting magnet A can be inserted from the axial direction). As a result, the structure for fixing the magnetic shield B and the superconducting magnet A is simplified, and the manufacturing is facilitated, so that the cost is reduced. Further, it is very effective to reduce the manufacturing cost if the contact surface between the iron plate 5 and the superconducting magnet A as a flat surface having no convex portions as in this embodiment.

A second embodiment of the present invention is shown in FIGS. 3 is an overall perspective view, FIG. 4 is a front view, and FIG. 5 is a view showing insertion of a superconducting magnet A into a magnetic shield B. In the second embodiment of the present invention, the number of the iron yokes 6 is two, and the iron yoke 6 is further disposed behind the center axis (Z axis) in the vertical direction of the measurement space 3. . In this configuration, the iron plate 5A
Is also asymmetric in the front-rear direction, and the magnetic shield B is opened forward. In this embodiment, as shown in FIG. 5, since the iron yoke 6 does not exist on the insertion trajectory serving as a passage for inserting the superconducting magnet A, the superconducting magnet A
No obstruction is caused when the superconducting magnet A is inserted into the magnetic shield B, and the superconducting magnet A can be easily inserted into the magnetic shield B. In addition, a great sense of openness is obtained for the subject who has entered the measurement space 3, and the subject can be easily accessed from the side during the examination. Therefore, good workability can be obtained when assembling the equipment on site,
The work of inserting the superconducting magnet A, which is weak in strength, into the magnetic shield B becomes safer and more reliable. That is, efficiency in on-site work can be improved.

FIGS. 6 and 7 show a third embodiment of the present invention. FIG. 6 is an overall perspective view, and FIG. 7 is a view showing insertion of the superconducting magnet A into the magnetic shield B. In this embodiment, the entire apparatus has a structure symmetrical in the front-rear direction. The magnetic shield B is provided with iron plates 5B arranged above and below the measurement space 3 and U-shaped iron yokes arranged on both sides of the measurement space 3 to support the iron plate 5B and to be magnetically connected. 6C. The cross section of the iron yoke 6C is rectangular, and the distance between the two iron yokes 6C is such that the superconducting magnet A can be inserted therebetween. By configuring the magnetic shield B in this manner, the superconducting magnet A can be moved from the Y-axis direction to the magnetic shield.
Field B can be easily inserted. Further, by arranging the iron yoke 6C symmetrically in the front-rear direction, the uniform magnetic field generation region corresponding to the measurement space 3 is also symmetrical in the front-rear direction, and the magnetic field distribution can be easily corrected. In addition, if the iron yoke 6C having a cross section composed of a combination of straight lines is used, the manufacturing accuracy can be increased, so that the magnetic shield B can be assembled with high accuracy when dividedly carried in and assembled.

In the above description of the embodiment of the present invention, the iron
Although a cylinder or a square has been illustrated as the arc 6, the present invention is not limited to the shape of the iron yoke 6, but may be a rectangle, an ellipse, a polygon, or the like.
The sectional shape of the iron yoke 6 may be different depending on the position in the Z-axis direction. For example, by changing the sectional size of the corresponding portion of the iron yoke 6 according to the width of each part of the superconducting magnet A. Alternatively, by changing the arrangement of the iron yoke 6, the superconducting magnet A can be easily inserted after assembling the magnetic shield B.

In the first to third embodiments of the present invention, the number of iron yokes 6 is two or four. However, in the present invention, the number of iron yokes 6 is not limited to this. However, there may be a case where three or five or more iron yokes 6 are provided. However, when three or more iron yokes 6 are provided, two superconducting magnets A are inserted into the magnetic shield B so that two superconducting magnets A are inserted on both sides of the portion where the superconducting magnets A are inserted. It is necessary that the shortest distance between the iron yokes 6 is configured to be larger than the maximum diameter of the superconducting magnet A. By arranging the iron yoke 6 in such a manner, the superconducting magnet A can be smoothly inserted after the magnetic shield B is assembled.

FIG. 8 and FIG. 9 show a fourth embodiment of the present invention. FIG. 8 is an overall perspective view of the fourth embodiment, and FIG. 9 is a front view. In this embodiment, the superconducting magnet A and the magnetic shield B
, That is, the contact surface between the upper surface of the superconducting magnet A and the lower surface of the upper iron plate 5 and the lower surface of the superconducting magnet A and the lower iron plate 5
A magnetic shield B is formed by forming a fitting portion having a cross-sectional shape so as to fit each other on the contact surface with the upper surface of the magnetic shield B.
And the superconducting magnet A can be inserted into the magnetic shield B by using the fitting portion as a guide in a direction perpendicular to the cross section where the fitting is performed while the superconducting magnet A and the superconducting magnet A are in close contact with each other. It is. The one shown in FIG. 8 and FIG.
Although this is an example in which the iron yokes 6 are arranged asymmetrically in the front-rear direction, the present invention can be similarly applied to other iron yoke 6 arrangements. In FIG. 8, the superconducting magnet A can be inserted in the Y-axis direction. Therefore, the cross sections that fit each other are formed along the X-axis direction. Irregular surfaces 8A, 8B, 8C and 9A, 9B, 9C are formed on the surfaces of the superconducting magnet A where the cooling container 2 and the iron plate 5A of the magnetic shield B are in contact with each other, and the corresponding convex and concave portions are fitted. Have been combined.
In FIG. 8, five mating concave and convex surfaces are provided at each of the upper and lower positions. Also, the shape of the uneven surface is not limited to the square shape shown in the figure,
It may be triangular or semicircular. These uneven surfaces may be fitted to each other in close contact with each other and serve as a guide when the superconducting magnet A is inserted.

By forming the contact surface between the superconducting magnet A and the magnetic shield B as described above, the superconducting magnet A
The direction in which the superconducting magnet A is inserted into the magnetic shield B is limited to one direction (the Y-axis direction in FIG. 8), that is, the superconducting magnet A can be reliably inserted in one direction. Can be easily and reliably inserted into the position.

FIG. 10 and FIG. 1 show a fifth embodiment of the present invention.
It is shown in FIG. FIG. 10 is an overall perspective view of the fifth embodiment, and FIG.
Is a front view. In the present embodiment, a gap is provided at the contact surface between the superconducting magnet A and the magnetic shield B so that a prismatic solid object can be inserted. This gap is inserted into the superconducting magnet A into the magnetic shield B. After the superconducting magnet A is inserted, a solid object in the form of a prism is inserted into the gap to improve the adhesion between the superconducting magnet A and the magnetic shield A. is there. In FIG. 10, a rectangular groove 9D is provided in a portion of the iron plate 5A of the magnetic shield B in contact with the cooling container 2 of the superconducting magnet A. When the superconducting magnet A is inserted into the magnetic shield B, the rectangular groove 9D is formed in the groove 9D on the contact surface of the cooling vessel 2.
Mating with a square rod (not shown) attached to a portion opposed to, serves as a guide for insertion of superconducting magnet A. In FIG. 10, the groove 9 </ b> D is provided only on the side of the iron plate 5. However, the groove 9 </ b> D may be provided only on the opposite surface of the cooling container 2, or may be provided on both sides of the iron plate 5 and the cooling container 2. Good. In this case, the square rod may be attached to the iron plate 5 side. After inserting the superconducting magnet A,
Remove the square rod and return to the groove 9D. After that, groove 9
By inserting and embedding a solid object 10 in the form of a prism in D, the adhesion between the superconducting magnet A and the magnetic shield B is improved.

In the present embodiment, the object filling the gap of the groove 9D is not limited to a prismatic solid object, but a solid object having a shape suitable for being inserted into the gap, an adhesive or the like. Liquid objects can also be used. At this time, if the object to be inserted into the gap is to be a part of the magnetic shield, it is desirable that the magnetic shield B be made of the same material or a material exhibiting magnetic properties close thereto. Further, a structure in which a non-magnetic material and a ferromagnetic material are combined is used to form a groove 9.
By inserting the groove D, the magnetic characteristics of the magnetic shield B can be corrected, so that the groove 9D can be positively used to increase the uniformity of the magnetic field in the measurement space 3.

FIG. 12 shows a sixth embodiment of the present invention utilizing a gap provided at the contact surface between superconducting magnet A and magnetic shield B in order to correct the magnetic characteristics of the magnetic shield. Here is an example. FIG. 12 shows the lower right part of the vertical sectional view of this embodiment. In this embodiment, a disc-shaped or rod-shaped non-magnetic material 11 having a thickness equivalent to that of the gap is inserted into a gap between the superconducting magnet A and the magnetic shield B. Correction of the magnetic field uniformity of the measurement space 3 is performed by appropriately dispersing and arranging some of the ferromagnetic materials 12 in.

In the fifth and sixth embodiments, an appropriate gap is provided at the contact portion between the superconducting magnet A and the magnetic shield B, and a non-magnetic material in which a ferromagnetic material is added to the gap. Is inserted to adjust the uniformity of the magnetic field in the measurement space 3. However, even in the first to third embodiments, after the superconducting magnet A is inserted into the magnetic shield B, the superconducting magnet is adjusted. If there is a gap in the contact portion between A and the magnetic shield B, a nonmagnetic substance (solid or liquid) to which a nonmagnetic substance or a ferromagnetic substance is added can be embedded in the gap.

FIG. 13 shows a seventh embodiment of the present invention. FIG. 13 shows the lower right part of the vertical sectional view of the seventh embodiment. In this embodiment, the magnetic field distribution correcting ferromagnetic piece 13 is fixed to the superconducting magnet A as an integral unit. Therefore, even when the superconducting magnet A is inserted into the magnetic shield B, since the magnetic field distribution correcting ferromagnetic piece 13 is inserted integrally with the superconducting magnet A, the superconducting magnet A and the magnetic field distribution correcting ferromagnetic piece 13 are inserted. Can be inserted into the magnetic shield B while maintaining the relative positional relationship at the time of assembly.

By using this method, not only the man-hour for assembling the superconducting magnet A and the magnetic field distribution correcting ferromagnetic piece 13 can be reduced, but also the magnetic field distribution correcting ferromagnetic piece 13 is formed together with the superconducting magnet A. Can be added and adjusted at the factory, so that on-site adjustment can be minimized, and the man-hours required for adjustment can be reduced.

[0039]

As described above, according to the present invention, M
The superconducting magnet device for RI devices can be assembled and adjusted at the time of delivery, reducing the number of man-hours, reducing the manufacturing cost due to the simplification of the structure, and utilizing the gap between the superconducting magnet and the magnetic shield. It is possible to provide a superconducting magnet device for an MRI device in which the magnetic field uniformity is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a measurement space according to a first embodiment of the present invention.

FIG. 2 is a structural modification example of the first embodiment of the present invention.

FIG. 3 is an overall perspective view of a second embodiment of the present invention.

FIG. 4 is a front view of a second embodiment of the present invention.

FIG. 5 is a magnetic screen of a superconducting magnet according to a second embodiment of the present invention.
The figure which shows insertion in a field.

FIG. 6 is an overall perspective view of a third embodiment of the present invention.

FIG. 7 is a diagram showing a magnetic shield of a superconducting magnet according to a third embodiment of the present invention;
The figure which shows insertion in a field.

FIG. 8 is an overall perspective view of a fourth embodiment of the present invention.

FIG. 9 is a front view of a fourth embodiment of the present invention.

FIG. 10 is an overall perspective view of a fifth embodiment of the present invention.

FIG. 11 is a front view of a fifth embodiment of the present invention.

FIG. 12 is a diagram showing a lower right part of a longitudinal sectional view of a sixth embodiment of the present invention.

FIG. 13 is a diagram showing a lower right part of a longitudinal sectional view of a seventh embodiment of the present invention.

FIG. 14 is an overall perspective view of a conventional example of a superconducting magnet device.

FIG. 15 is a cross-sectional view of a conventional example of a superconducting magnet device in a measurement space.

[Explanation of symbols]

 Reference Signs List A superconducting magnet B magnetic shield 1 superconducting coil 2 cooling vessel 3 measurement space (uniform magnetic field generation area) 4 connecting pipe 5, 5A, 5B iron plate 6, 6A, 6B, 6C iron yoke 7 ferromagnetic for magnetic field distribution correction Pieces 8A, 8B, 8C, 9A, 9B, 9C Uneven surface 9D Square groove 10 Solid body of prismatic shape 11 Non-magnetic material 12 Ferromagnetic material 13 Ferromagnetic piece for magnetic field distribution correction

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hajime Tanabe 651 Tenwa, Ako City, Hyogo Prefecture Inside Ako Works, Mitsubishi Electric Corporation

Claims (10)

[Claims] 1. A superconducting material, comprising:
A magnetic field source for generating a uniform magnetic field directed in a vertical direction in a finite area, cooling means for housing the magnetic field source, cooling and holding the temperature to a temperature showing superconducting characteristics, and supporting means for supporting the cooling means. A superconducting magnet provided, plate-like ferromagnetic members arranged vertically so as to surround the superconducting magnet, and a plurality of columnar ferromagnetic members magnetically connecting and supporting the plate-like ferromagnetic material And a magnetic shield formed by combining the magnetic shield with the magnetic shield, wherein after assembling the magnetic shield, it is possible to insert and assemble the superconducting magnet assembly into the magnetic shield. Superconducting magnet device. 2. A superconducting magnet device according to claim 1, wherein said superconducting magnet assembly structure is inserted into said magnetic shield so as not to overlap an insertion locus of said superconducting magnet assembly structure. A superconducting magnet device, wherein the columnar ferromagnetic material is arranged. 3. The superconducting magnet device according to claim 1, wherein a gap between at least two of the columnar ferromagnetic members is formed by the magnetic shield of the superconducting magnet assembly structure. A superconducting magnet device characterized in that it is larger than a dimension that can be inserted inside. 4. The superconducting magnet device according to claim 1, wherein said superconducting magnet is provided inside said magnetic shield at a contact surface between said superconducting magnet and said magnetic shield in the insertion direction of said superconducting magnet. A superconducting magnet device comprising a guide means for insertion. 5. The superconducting magnet device according to claim 4, wherein said guide means is provided on a contact surface between said superconducting magnet and said magnetic shield in parallel with the direction of insertion of said superconducting magnet, and the other contacting means. A superconducting magnet device, characterized in that the surface is an uneven surface fitted with the surface. 6. A superconducting magnet device according to claim 4, wherein said guide means is provided on one or both of the contact surfaces between said superconducting magnet and said magnetic shield in parallel with the direction of insertion of said superconducting magnet. A superconducting magnet device comprising at least one groove provided. 7. The superconducting magnet device according to claim 6, wherein a solid or liquid body containing a ferromagnetic material is embedded in the groove after inserting the superconducting magnet into the magnetic shield. Superconducting magnet device. 8. The superconducting magnet device according to claim 1, wherein at least one gap is provided at a contact portion between the superconducting magnet and the magnetic shield, and the gap includes a ferromagnetic material. A superconducting magnet device comprising a solid or liquid object. 9. The superconducting magnet device according to claim 1, wherein a ferromagnetic piece for correcting a magnetic field distribution is added to a portion of said superconducting magnet in contact with said magnetic shield to be integrated with said superconducting magnet. A superconducting magnet device, wherein a superconducting magnet to which a ferromagnetic piece is added is inserted into the magnetic shield. 10. A magnetic resonance imaging apparatus using the superconducting magnet apparatus according to claim 1 as a static magnetic field generator.