JP2000051178A - Superconductive magnet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To significantly reduce working time by making it easy to provide a magnetic body for a compensating magnetic field to compensate the nonuniformity of the main magnetic field. SOLUTION: This superconductive magnet device is composed of a superconductive magnet 1 which generates a main magnetic field to be applied to a subject held in a measurement space inside the device, a cryostat 2 which coaxially surrounds and cools the superconductive magnet 1, and a magnetic body for compensating magnetic field which is held at the inside area of the superconductive magnet 1 and compensates the nonuniformity of the main magnetic field. The magnetic body for compensating magnetic field is a magnetic body piece S', which is made of iron powder mixed with an epoxy resin for fixing and is adhered to multiple specified points at the measuring face of the cryostat 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION An NMR apparatus is a nuclear magnetic resonance phenomenon (NMR) such as an NMR-CT (nuclear magnetic resonance imaging apparatus) for imaging a tomogram of a human body and an apparatus for analyzing the bonding state of organic compounds. Magnetic Resonance)
It is a device for observing and measuring. The present invention relates to a superconducting magnet apparatus for an NMR apparatus, and more particularly, to a superconducting magnet apparatus having a magnetic body for magnetic field correction for correcting non-uniformity of a main magnetic field by a superconducting magnet and obtaining high magnetic field uniformity. is there.

[0002]

2. Description of the Related Art A superconducting magnet apparatus for an NMR apparatus is required to have a very high magnetic field uniformity in a measurement space, that is, a uniform magnetic flux density, no gradient, and a very small spatial change in magnetic flux density. . Therefore, in order to realize such a high uniformity of the magnetic field, the coil shape and the current density of the superconducting magnet that generates the main magnetic field are devised at the design stage. However, the desired magnetic field uniformity cannot be obtained due to the difficulty in obtaining the manufacturing accuracy as designed or the influence of a magnetic substance that becomes a disturbance, such as a reinforcing bar of a reinforced concrete building, which is present at the device installation location. Sometimes. For this reason, in the superconducting magnet device, for example, a large number of magnetic material pieces each composed of a nickel piece or an iron piece having a size of several millimeters square are used as magnetic field correcting magnetic bodies for correcting non-uniformity of the main magnetic field due to the superconducting magnet. Are arranged. This small magnetic piece is called a magnetic shim.

FIG. 9 is a schematic structural explanatory view showing a conventional superconducting magnet device, in which a quarter of the whole is cut away to show the inside of the device. In FIG. 1, reference numeral 1 denotes a cylindrical superconducting magnet for generating a main magnetic field applied to the object T, and reference numeral 3 denotes a three-dimensional annular liquid helium container made of copper. The superconducting magnet 1 is disposed in a liquid helium container 3 immersed in liquid helium (not shown) for cooling and operating the magnet 1 to the superconducting operating temperature. Reference numeral 4 denotes a vacuum container which has a three-dimensional annular shape and surrounds the liquid helium container 3 containing the superconducting magnet 7. The vacuum vessel 4 has an inner cylinder 4a made of copper, and the other parts are made of stainless steel. The vacuum heat insulating space formed between the vacuum container 4 and the liquid helium container 3 prevents heat radiation from room temperature to the liquid helium.

In this embodiment, the liquid helium container 3 and the vacuum container 4 constitute a cryostat (cryogenic constant temperature device) 2 which surrounds the superconducting magnet 1 concentrically and keeps it cool. The DUT T is arranged in a measurement space at room temperature formed in the inner region of the superconducting magnet 1. A large number of magnetic pieces S are arranged on the surface of the vacuum vessel inner cylinder 4a on the outside of the vessel to correct the non-uniform component of the main magnetic field.

The operation of disposing the magnetic piece S will be described. In the case of this example, the outer dimensions of the superconducting magnet 1: an inner diameter of 92 m
m, outer diameter 220 mm, axial length 370 mm, outer dimensions of vacuum vessel 4 (outer dimensions of cryostat): inner diameter 54 mm, outer diameter 600 mm, axial length 800 mm, superconducting magnet 1 used to measure the center of the magnet A high uniformity magnetic field of 7 Tesla (equivalent to a proton nuclear magnetic resonance frequency of 300 MHz) is generated in the space, and a thickness of 0.2 mm ×
A magnetic material piece S made of nickel foil and having a rectangular shape and a width of 2 mm and a length of 4 mm was attached to 130 positions using tweezers with an instant adhesive (epoxy resin or the like). The position where these magnetic pieces S were attached was determined by simulation calculation, and this attaching work required about 20 hours.

[0006] Thus, the superconducting magnet 1 for generating a main magnetic field to be applied to the object T arranged in the measurement space formed in the inner region, and surrounding the superconducting magnet 1 concentrically therewith. A superconducting magnet device comprising a cryostat 2 to be kept cool and a number of magnetic pieces S arranged in the inner region of the superconducting magnet 1 and on the wall surface of the cryostat 2 at the room temperature measurement space is configured.

[0007]

In the above-described conventional superconducting magnet apparatus, a large number of magnetic material pieces S each having a size of several millimeters square as a magnetic material for magnetic field correction are several tens of millimeters of the cryostat 2. Since it has a structure in which it is attached to each required position on the wall of the measurement space having a small diameter and a cylindrical surface, there is a problem that it takes a long time to attach these magnetic pieces S.

SUMMARY OF THE INVENTION An object of the present invention is to provide a superconducting magnet apparatus in which a magnetic field correcting magnetic body for correcting non-uniformity of a main magnetic field can be easily provided, and the time required for the work can be greatly reduced. Is to provide.

[0009]

According to a first aspect of the present invention, there is provided a superconducting magnet for generating a main magnetic field to be applied to an object to be measured disposed in a measurement space formed in an inner region. A cryostat that surrounds the superconducting magnet concentrically and cools it, and a magnetic body for magnetic field correction disposed in an inner region of the superconducting magnet and correcting non-uniformity of the main magnetic field. In the superconducting magnet apparatus, the magnetic material for magnetic field correction is a magnetic material piece formed by adhering a mixture of a magnetic powder and a high-viscosity liquid for fixation at a required amount to each required position. It is configured as a magnet device.

According to a second aspect of the present invention, there is provided a superconducting magnet for generating a main magnetic field to be applied to an object to be measured disposed in a measurement space formed in an inner region, and surrounding the superconducting magnet concentrically with the superconducting magnet. A cryostat, and a superconducting magnet device, which is disposed in an inner region of the superconducting magnet and includes a magnetic field correcting magnetic body for correcting non-uniformity of the main magnetic field.
A cylindrical substrate made of a non-magnetic material is disposed concentrically with the superconducting magnet in an inner region of the superconducting magnet, and a magnetic material piece is attached to each required position on the surface of the cylindrical substrate as the magnetic field correcting magnetic material. This is configured as a superconducting magnet device.

According to a third aspect of the present invention, there is provided a superconducting magnet for generating a main magnetic field applied to an object to be measured arranged in a measurement space formed in an inner region, and surrounding the superconducting magnet concentrically with the superconducting magnet. A cryostat, and a superconducting magnet device, which is disposed in an inner region of the superconducting magnet and includes a magnetic field correcting magnetic body for correcting non-uniformity of the main magnetic field.
The superconducting magnet, wherein the magnetic field compensating magnetic body is formed of a cylindrical magnetic material from which respective required portions are removed, and the cylindrical magnetic body with a window portion is arranged concentrically with the superconducting magnet. It is configured as a device.

The superconducting magnet device according to the first invention comprises:
As a magnetic material for magnetic field correction, a magnetic material piece is provided by, for example, adhering a required amount of a mixture of a magnetic material powder and a viscous liquid for solidification that solidifies at room temperature to each required position on a measurement space wall surface of a cryostat, for example. Of structure. Therefore,
As compared with a conventional apparatus in which a large number of magnetic pieces each having a size of several mm square are attached one by one, the operation of providing the magnetic material for magnetic field correction is simpler and easier.

A superconducting magnet device according to a second aspect of the present invention is a superconducting magnet device in which a magnetic substrate is attached to each required position of a cylindrical substrate made of a non-magnetic material as a magnetic material for magnetic field correction and inserted into an inner region of the superconducting magnet. It is of the structure arranged. Therefore, unlike the conventional device, it is not necessary to directly attach the magnetic piece to the wall of the cryostat, and the lightweight and short cylindrical board can be freely handled when the magnetic piece is attached. By attaching each magnetic piece to the surface, or forming the magnetic piece attached to each required position on the flat plate into a cylindrical shape, it is easy to attach the magnetic piece to the cylindrical substrate. it can. In the superconducting magnet device according to the second aspect of the present invention, instead of sticking a magnetic piece such as a nickel foil to a required position of a cylindrical substrate, a mixture of a magnetic powder and a high-viscosity liquid for fixing is required. In the case where the magnetic material pieces are provided by attaching a large amount, the operation of providing the magnetic material for magnetic field correction becomes easier.

In the superconducting magnet device according to the third aspect of the present invention, the magnetic material for correcting the magnetic field includes a cylindrical magnetic member with a window formed by removing each required position in a required shape in order to correct unevenness of the main magnetic field. It has a structure in which the body is inserted and disposed in the inner region of the superconducting magnet. Thus, in this apparatus, the cylindrical magnetic body with a window can be easily manufactured by, for example, forming a flat magnetic material punched by a punch into a cylindrical shape.

Further, in the superconducting magnet device according to the second and third aspects of the present invention, in which the magnetic material for magnetic field correction is arranged inside the cryostat, the magnetic material for magnetic field correction is not affected by a temperature change in the measurement space. Since the temperature of the magnetic body can be kept substantially constant, there is an advantage that a highly uniform magnetic field can be generated in the measurement space with good stability.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic structural explanatory view of a superconducting magnet device according to an embodiment of the first invention, wherein a quarter of the whole is cut away to show the inside of the device. Here, the superconducting magnet 1 and the cryostat 2 in each of the following embodiments have the same shape and the same dimensions as those of the conventional superconducting magnet device shown in FIG. 9, and are denoted by the same reference numerals as in FIG. The description is omitted.

As shown in FIG. 1, in the superconducting magnet apparatus according to this embodiment, a cryostat 2 is used as a magnetic field correcting magnetic body for correcting non-uniformity of the main magnetic field caused by the superconducting magnet 1.
In the measurement space wall surface, specifically, at each required position on the outer surface of the inner cylinder 4a of the vacuum vessel 4 constituting the cryostat 2, a magnetic substance piece S 'made of a magnetic substance powder and a high-viscosity liquid for fixing is provided. Is arranged. These magnetic pieces S ′ were prepared by uniformly mixing a mixture of iron powder having an average particle diameter of 70 μm as a magnetic powder and an EPON-based epoxy resin as a high-viscosity liquid that solidifies by a chemical reaction at room temperature. It is formed by adhering one droplet at each required position by a mixed liquid ejecting device 7 capable of ejecting one droplet at a time. The weight ratio of the iron powder to the mixed solution is 30%, and the ejection device 7 ejects 60 mg of the mixed solution per one drop. Therefore, each magnetic piece S ′ has a magnetic field correction by 18 mg of the iron piece. ing. In addition, a sty cast may be used in addition to the EPON-based epoxy resin.

The positions at which these magnetic material pieces S 'are provided are determined by simulation calculations in order to correct the non-uniform magnetic field component, and are 170 in this example. As a result, the correction effect according to the simulation calculation is obtained,
A highly uniform magnetic field could be generated in the measurement space. As described above, since the magnetic material pieces S 'are formed by adhering the mixed solution of the iron powder and the fixing epoxy resin, the magnetic field is smaller than that of the conventional device in which the magnetic material pieces are attached one by one. The work of providing the magnetic material for correction is simple, and the work time can be greatly reduced.

FIG. 2 is a schematic structural explanatory view of a superconducting magnet device according to an embodiment of the second invention, wherein a quarter of the whole is cut away to show the inside of the device.

As shown in FIG. 2, the superconducting magnet apparatus according to the present embodiment has a magnetic piece made of iron powder and fixing epoxy resin as magnetic bodies for magnetic field correction at each required position of a cylindrical substrate 5 made of a nonmagnetic material. The vacuum vessel 4 with the S 'attached
The superconducting magnet 1 is inserted into a measurement space at room temperature at the inside and is arranged concentrically with the superconducting magnet 1. The cylindrical substrate 5 made of a non-magnetic material is made of copper in this example and has a thickness of 1 mm and an inner diameter of 5 mm.
The length is 1 mm and the axial length is 200 mm. As in the case of FIG. 1, a mixed solution of iron powder and epoxy resin is adhered to 170 locations on the inner peripheral surface of the cylindrical substrate 5 by the mixed solution jetting device 7 to remove the magnetic material pieces S ′. It is then provided in a measuring space inside the vacuum vessel 4. In the case of this example, the cylindrical substrate 5 is shorter and lighter than the cryostat 2, and the relative position of the cylindrical substrate 5 and the ejection device 7 can be easily controlled. Thus, the magnetic piece S ′ could be provided more easily. In addition, the correction effect was the same as the simulation calculation. In the present example, the magnetic piece S ′ is provided on the inner peripheral surface of the cylindrical substrate 5. However, the present invention is not limited to this, and the magnetic piece S ′ may be provided on the outer peripheral surface or both surfaces of the cylindrical substrate 5. Good.

FIG. 3 is a schematic explanatory view of a superconducting magnet device according to another embodiment of the second invention, in which a quarter of the whole is cut away to show the inside of the device. FIG. 2
The difference from the superconducting magnet device of the first embodiment resides in the magnetic piece.

As shown in FIG. 3, the superconducting magnet device according to the present embodiment has a structure in which a magnetic material piece S made of nickel foil is attached as a magnetic material for magnetic field correction at each required position of a cylindrical substrate 5 made of copper. The superconducting magnet 1 is inserted into a room temperature measurement space inside the vacuum vessel 4 and arranged concentrically with the superconducting magnet 1. 130 of the outer peripheral surface of the same cylindrical substrate 5 as that of FIG.
A piece of magnetic material S made of nickel foil having a thickness of 0.2 mm, a width of 2 mm, and a length of 4 mm is stuck to the position of the spot with an instant adhesive using tweezers in the same manner as that used in the conventional apparatus of FIG. 9 described above. After that, it is arranged in a measuring space inside the vacuum vessel 4.

In the case of this embodiment, the time required for the work of attaching the magnetic material pieces S is about 12 hours, and the structure in which the magnetic material pieces S are directly attached to the wall of the measurement space of the cryostat 2 as shown in FIG. In the conventional apparatus shown in FIG. 1, the pasting operation was performed in a narrow and difficult state, which required about 20 hours, which was significantly reduced. In addition, a correction effect according to the simulation calculation was obtained. In the conventional apparatus, the correction effect of about 7
About 0% is obtained, and it is considered that this error is caused by a positional shift of the sticking position caused by the sticking operation.

FIG. 4 is a schematic explanatory view of a superconducting magnet device according to another embodiment of the second invention, in which a quarter of the whole is cut away to show the inside of the device. FIG. 3
The difference from the superconducting magnet device is that a cylindrical substrate 5 ′ to which the magnetic pieces S are attached is disposed inside the cryostat 2.

As shown in FIG. 4, the superconducting magnet apparatus according to the present embodiment is provided in the liquid helium container 3 constituting the cryostat 2 in the inner region of the superconducting magnet 1 at each required position of the copper cylindrical substrate 5 ′. The superconducting magnet 1 has a structure in which a magnetic material piece S made of nickel foil is adhered and arranged concentrically with the superconducting magnet 1. According to this superconducting magnet device, there is an advantage that the operation of providing the magnetic material pieces S is easier than that of the conventional device of FIG. 9, and that a highly uniform magnetic field can be generated with high stability in the measurement space.

That is, for example, in the superconducting magnet device shown in FIG. 3 in which the magnetic piece is located in the measurement space at room temperature, when the measurement is performed by changing the temperature of the object to be measured, the temperature of the magnetic piece changes due to the influence. I do. As a result, the magnetization characteristic of the magnetic piece changes due to the temperature change. (The change ratio of the saturation magnetization Is of iron, which is a representative of the magnetic material, to the temperature change is 300 K (27 ° C.), which is room temperature. About 70ppm
/ K), the magnetic field correction effect may deteriorate, and a required high uniform magnetic field may not be obtained in the measurement space.

On the other hand, in the superconducting magnet device of FIG.
Since the cylindrical substrate 5 ′ with the magnetic piece S is disposed in the liquid helium container 3, the temperature of each magnetic piece S is the temperature of the liquid helium contained in the container 3. .
It is 2K and substantially constant. As a result, even when the measurement was performed while changing the temperature of the measurement space from room temperature to 100 ° C., a highly uniform magnetic field could be generated stably without fluctuating. At this time, even if it is disposed in the liquid helium container 3, the magnetic material pieces S adhered with the instant adhesive do not peel off or displace. In the case where the cryostat has a liquid helium container and a liquid nitrogen container (77K) or a gas cooling container (about 40K) surrounding it, the cylindrical substrate 5 'with the magnetic piece S is attached to the liquid helium container. Inside the liquid nitrogen container or the gas cooling container, the temperature of the magnetic material pieces S can be substantially reduced without being affected by the temperature change of the measurement space. Can be kept constant.

In the present embodiment, the cylindrical substrate 5 'on which the magnetic piece S made of nickel foil is adhered is provided inside the cryostat 2, but the present invention is not limited to this. A structure in which a cylindrical substrate 5 'to which a magnetic piece S' made of a fixing epoxy resin is attached may be provided.

FIG. 5 is a schematic explanatory view of a superconducting magnet device according to another embodiment of the second invention, in which a quarter of the whole is cut away to show the inside of the device. FIG. 3
The difference from the superconducting magnet device of the first embodiment resides in a cylindrical substrate 5 ″ to which the magnetic piece S is attached.

As shown in FIG. 5, the superconducting magnet device according to the present embodiment is a superconducting magnet device in which a magnetic material piece S made of nickel foil is attached to each required position of a non-magnetic material, in this example, a copper flat plate with an instant adhesive. A structure in which a cylindrical substrate 5 ″ formed into a cylindrical shape and each of the magnetic substance pieces S is attached to the outer peripheral surface thereof is inserted into a measurement room at room temperature inside the vacuum vessel 4 and arranged concentrically with the superconducting magnet 1. The dimension of the flat plate is 0.5 mm in thickness and 160 mm × 200 mm. In the case of this example, the operation time of sticking the magnetic piece S to the flat plate is about 8 hours, which is smaller than that of the cylindrical body. Fig. 3
The time was shortened as compared with the device of the above. In addition, a correction effect according to the simulation calculation was obtained. In the present example, the magnetic piece S is provided on the outer peripheral surface of the cylindrical substrate 5 ″ (the side facing the inner cylinder 4a of the vacuum vessel 4), but is not limited thereto. May be provided on the inner peripheral surface or both surfaces. Further, instead of the magnetic piece S, a magnetic piece S ′ made of iron powder and an epoxy resin for fixing is used.
It may be.

FIG. 6 is a schematic structural explanatory view of a superconducting magnet device according to an embodiment of the third invention, wherein a quarter of the whole is cut away to show the inside of the device.

As shown in FIG. 6, the superconducting magnet device according to the present embodiment has a window portion as a magnetic material for magnetic field correction made of a cylindrical magnetic material whose required positions are punched out in a required shape for magnetic field correction. The cylindrical magnetic body 6 is inserted into a measurement space at room temperature inside the vacuum vessel 4 and is disposed concentrically with the superconducting magnet 1. The cylindrical magnetic body 6 with a window portion is made of a magnetic material such as nickel in this example, and has dimensions before punching of a thickness of 0.5 mm, an inner diameter of 53 mm, and an axial length of 200 mm.
mm. The window (hole) 6a has a rectangular shape of 2.0 × 4.0 mm.
The windows 6a were provided at zero positions. The positions of these windows 6a are determined by simulation calculations in order to correct the non-uniform magnetic field component.

In the case of this embodiment, the time required for punching these windows 6a is about 4 hours, and a magnetic material piece S of nickel foil is applied to each required position of the copper cylindrical substrate 5 in FIG. The punching work itself is simpler than that of the structure that is pasted in about 12 hours.
In addition, the work efficiency was good, so that the time was greatly reduced. In addition, a correction effect according to the simulation calculation was obtained.

FIG. 7 is a schematic explanatory view of a superconducting magnet device according to another embodiment of the third invention, in which a quarter of the whole is cut away to show the inside of the device. FIG. 6
The difference from the superconducting magnet device of the first embodiment resides in that a cylindrical magnetic body 6 ′ with a window is disposed inside the cryostat 2.

As shown in FIG. 7, in the superconducting magnet apparatus according to the present embodiment, a cylindrical magnetic body 6 ′ having a window is concentrically arranged with the superconducting magnet 1 in the liquid helium container 3 inside the superconducting magnet 1. It is of the structure arranged. According to the superconducting magnet device, the operation of providing the magnetic field correcting magnetic body is easier than the conventional device, and the temperature of the cylindrical magnetic body with window 6 ′ can be kept substantially constant. There is an advantage that a highly uniform magnetic field can be generated in the measurement space with good stability.

FIG. 8 is a schematic explanatory view of a superconducting magnet device according to another embodiment of the third invention, in which a quarter of the whole is cut away to show the inside of the device. FIG. 6
The difference from this superconducting magnet device lies in the structure of the cylindrical magnetic body 6 ″ with a window.

As shown in FIG. 8, the superconducting magnet apparatus according to the present embodiment is formed by forming a nickel plate having windows 6 "a at respective required positions into a cylindrical shape, and forming the cylindrical magnet with the windows. The body 6 ″ has a structure in which the body 6 ″ is inserted into a measurement space at room temperature inside the vacuum vessel 4 and is disposed concentrically with the superconducting magnet 1. The dimensions of the flat plate are 160 mm × 200 mm with a thickness of 0.5 mm. The window 6 "a has a rectangular shape of 2.0 × 4.0 mm and is provided at 120 positions by punching with a punch. In the case of this example, the time required for punching the window 6a with this flat plate is used. Is about 2 hours, and since the punching work is easier with a flat plate than with a cylindrical body, the working time can be reduced by half as compared with the apparatus shown in FIG. It should be noted that the cylindrical magnetic body 6 ″ with a window may be provided in the liquid helium container 3.

[0038]

As described above, in the superconducting magnet apparatus according to the first aspect of the present invention, as a magnetic field compensating magnetic body, for example, a magnetic substance powder and a high-viscosity liquid for fixing are placed at each required position on the wall of a measurement space of a cryostat. A magnetic material piece is provided by adhering a required amount of a mixture of the material, compared to a conventional device that attaches a large number of magnetic material pieces with a size of about several mm square one by one. Thus, the magnetic piece can be easily provided. The work is easy and the work time can be greatly reduced, and the cost of the superconducting magnet device can be reduced.

Further, the superconducting magnet device according to the second aspect of the present invention provides a superconducting magnet device in which a magnetic piece is attached as a magnetic material for magnetic field correction at each required position on a cylindrical substrate made of a non-magnetic material. It is intended to be arranged.
Thus, in the device, unlike the conventional device, there is no need to directly attach the magnetic piece to the cryostat wall surface,
Since the cylindrical substrate can be handled freely when attaching the magnetic material pieces, each magnetic material piece can be attached to the outer peripheral surface of the cylindrical substrate which is easy to attach, or the magnetic material piece attached to each required position on the flat plate into a cylindrical shape By molding, the magnetic piece can be easily attached to the cylindrical substrate.

In the superconducting magnet device according to the third aspect of the present invention, a cylindrical magnetic body with a window, which is obtained by removing each required portion in a required shape, is provided in the inner region of the superconducting magnet as a magnetic field correcting magnetic body. It is something to do. Thus, in this apparatus, the cylindrical magnetic body with a window can be easily manufactured by, for example, forming a flat magnetic material punched by a punch into a cylindrical shape.

Therefore, according to the superconducting magnet device according to the first, second and third aspects of the present invention, the operation of providing the magnetic material for magnetic field correction is easier than the conventional device, and the operation time can be greatly reduced. The cost of the superconducting magnet device can be reduced. In the superconducting magnet device according to the second and third aspects of the present invention, the magnetic body for magnetic field correction is arranged inside the cryostat, so that the magnetic body for magnetic field correction is not affected by a temperature change in the measurement space. Since the temperature can be kept substantially constant, there is an advantage that a highly uniform magnetic field can be generated with high stability in the measurement space.

[Brief description of the drawings]

FIG. 1 is a schematic structural explanatory view of a superconducting magnet device according to an embodiment of the first invention, in which a quarter of the whole is cut away to show the inside of the device.

FIG. 2 is a schematic structural explanatory view of a superconducting magnet device according to an embodiment of the second invention, in which a quarter of the whole is cut away to show the inside of the device.

FIG. 3 is a schematic structural explanatory view of a superconducting magnet device showing another embodiment of the second invention.

FIG. 4 is a schematic structural explanatory view of a superconducting magnet device showing another embodiment of the second invention.

FIG. 5 is a schematic structural explanatory view of a superconducting magnet device showing another embodiment of the second invention.

FIG. 6 is a schematic structural explanatory view of a superconducting magnet device according to an embodiment of the third invention, in which a quarter of the whole is cut away to show the inside of the device.

FIG. 7 is a schematic structural explanatory view of a superconducting magnet device showing another embodiment of the third invention.

FIG. 8 is a schematic structural explanatory view of a superconducting magnet device showing another embodiment of the third invention.

FIG. 9 is a schematic structural explanatory view showing a conventional superconducting magnet apparatus, and is a diagram in which a quarter portion of the whole is cut out to show the inside of the apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Superconducting magnet 2 ... Cryostat 3 ... Liquid helium container 4 ... Vacuum container 5, 5 ', 5 "... Cylindrical substrate 6, 6', 6" ... Cylindrical magnetic body 6a, 6 'with a window part
a, 6 "a: window 7: mixed liquid jetting device T: object to be measured S: magnetic piece made of nickel foil S ': magnetic piece made of iron powder and epoxy resin for fixing

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Mamoru Hamada 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Japan Magnet Technology Co., Ltd. F-term (reference) 4C096 AA01 AB32 AB45 AD02 AD08 CA02 CA22 CA52

Claims (6)

[Claims] A superconducting magnet for generating a main magnetic field to be applied to an object to be measured arranged in a measurement space formed in an inner region;
A superconducting magnet comprising: a cryostat that surrounds the superconducting magnet concentrically therewith and keeps it cool; and a magnetic field correction magnetic body disposed in an inner region of the superconducting magnet and for correcting non-uniformity of the main magnetic field. In the apparatus, the magnetic material for magnetic field correction is a magnetic material piece formed by adhering a required amount of a mixture of a magnetic material powder and a high-viscosity liquid for fixation at required positions. . 2. A superconducting magnet for generating a main magnetic field applied to an object to be measured disposed in a measurement space formed in an inner region,
A superconducting magnet comprising: a cryostat that surrounds the superconducting magnet concentrically therewith and keeps it cool; and a magnetic field correction magnetic body disposed in an inner region of the superconducting magnet and for correcting non-uniformity of the main magnetic field. In the apparatus, a cylindrical substrate made of a non-magnetic material is disposed concentrically with the superconducting magnet in an inner region of the superconducting magnet, and a magnetic material is provided at each required position on the surface of the cylindrical substrate as the magnetic material for magnetic field correction. A superconducting magnet device having a piece attached thereto. 3. A method according to claim 1, wherein each of said magnetic material pieces is formed by adhering a mixture of a magnetic material powder and a highly viscous liquid which solidifies in air to the surface of said cylindrical substrate. 3. The superconducting magnet device according to 2. 4. The superconducting magnet device according to claim 2, wherein the cylindrical substrate to which each of the magnetic substance pieces is attached is disposed inside the cryostat. 5. A superconducting magnet for generating a main magnetic field applied to an object to be measured arranged in a measurement space formed in an inner region,
A superconducting magnet comprising: a cryostat that surrounds the superconducting magnet concentrically therewith and keeps it cool; and a magnetic field correction magnetic body disposed in an inner region of the superconducting magnet and for correcting non-uniformity of the main magnetic field. In the apparatus, the magnetic material for magnetic field correction is a cylindrical magnetic material in which each required position portion is removed, and the cylindrical magnetic material with a window portion is arranged concentrically with the superconducting magnet. Superconducting magnet device. 6. The superconducting magnet device according to claim 5, wherein the cylindrical magnetic body with a window is disposed inside the cryostat.