JPS62291007A - Superconducting magnet - Google Patents

Abstract

PURPOSE:To enable reducing the thickness of a container member by mechanically or metallurgically jointing a coil support member for supporting a superconducting coil to the container member provided along the direction wherein the electromagnetic force generated by the superconducting coil mutually affects. CONSTITUTION:The mutually attracting electromagnetic force between superconducting coils 7, 8 is affected to an upper plate 3 and a lower plate 4 since the coil support members 11, 12 for supporting each superconducting coil 7, 8 are jointed to the upper plate 3 and the lower plate 4 of container members provided in parallel along the direction wherein the electromagnetic force generated by each superconducting coil 7, 8 mutually affects. In this case, the thickness of all the members of a cryogenic refrigerant container 5, especially that of an inner cylinder 1, can be reduced since the upper plate 3 and the lower plate 4 have high rigidity against the electromagnetic force. This can reduce not only the weight of the cryogenic refrigerant container 5 but also can miniaturize the whole of the cryogenic refrigerant container 5.

Description

[Detailed description of the invention] 3. Detailed description of the invention [Purpose of the invention] (Industrial application field) The present invention relates to an inner cylinder and an outer cylinder arranged vertically in a concentric manner.

It consists of an upper plate and a lower plate that close the upper and lower openings of the inner cylinder and the outer cylinder, and the inner cylinder is sandwiched in the cryogenic refrigerant in the cryogenic refrigerant container that contains the cryogenic refrigerant inside. The present invention relates to a superconducting magnet constructed by disposing at least two superconducting coils facing each other, and particularly relates to a superconducting magnet with an improved coil support structure.

(Prior Art) In recent years, superconducting magnets that use cryogenic coolants such as liquid helium, such as super N-conducting magnets for MRI, have been used in vacuum insulation containers called cryostats. . In other words, this type of superconducting magnet consists of an inner cylinder and an outer cylinder arranged vertically in a concentric manner, and above these inner cylinder and outer cylinder.

The superconducting wire is wound into a cylindrical shape, for example, in a cryogenic refrigerant container that consists of an upper plate and a lower plate that close the lower openings, and contains a cryogenic refrigerant such as liquid helium inside. It consists of two superconducting coils arranged facing each other with an inner tube in between, which are housed in a vacuum insulation container.

FIGS. 3(a) and 3(b) show an example of the structure of a conventional superconducting magnet of this kind in a plan sectional view and a front sectional view, respectively. In FIGS. 3(a) and (b), 1 is a vertically arranged inner cylinder made of a non-magnetic material such as stainless steel, 2 is also made of a non-magnetic material such as stainless steel,
The outer cylinders 3 and 4, which are arranged concentrically with the inner cylinder 1, are also made of non-magnetic material such as stainless steel.
A disc-shaped upper plate and a lower plate are welded to the outer cylinder 2 so as to close the upper and lower openings thereof, and the cryogenic refrigerant container 5 is constituted by these plates.

In addition, liquid helium 6, which is a cryogenic refrigerant, is stored inside the cryogenic refrigerant container 5, and in this liquid helium 6, a superconducting wire is wound into a cylindrical shape, for example.
7.8 superconducting coils.

As shown in the figure, they are placed opposite each other with the inner cylinder 1 interposed therebetween. Furthermore, 9.10 is a coil support member for supporting each of the superconducting coils 7.8, which is metallurgically joined to the inner cylinder 1 constituting a part of the cryogenic refrigerant container 5 by, for example, welding. ing.

The device configured as described above is supported by a support member (usually referred to as a support) in a vacuum insulated container (not shown). The coil support member 9.10 is used to support the electromagnetic force of the superconducting coil 7.8, and to determine the mounting position of the superconducting coil 7.8.

By the way, this type of Super 11 magnet has the following problems. That is, between the two mutually facing superconducting coils 9 and 10 that are immersed in liquid helium 6 in the cryogenic refrigerant container 5, a force that tries to stick to each other, that is, an attractive electromagnetic force acts, so that the two superconducting coils 9 and 10 are immersed in liquid helium 6 in the cryogenic refrigerant container 5, and the two superconducting coils 9 and 10 are immersed in liquid helium 6 in the cryogenic refrigerant container 5. When currents flow in such a way that the magnetic field is It may weigh several tons to several tens of tons. However, in the past, as described above, the coil support members 9 and 10 for supporting each superconducting coil 7.8 are
Joined to the inner cylinder 1 constituting a part of the cryogenic refrigerant container 5,
Since the electromagnetic force is transmitted to the inner cylinder 1, this is to prevent the inner cylinder 1 from being crushed by the large attraction electromagnetic force.

It was necessary to increase the wall thickness of the inner cylinder 1. As a result, not only does the weight of the cryogenic refrigerant container 5 become heavier, but also the entire container becomes larger, and the cryogenic refrigerant container 5 becomes heavier.
A support member with a large cross-sectional area must also be used to support the cryogenic refrigerant container 5 in the vacuum insulation container, which increases the amount of heat intrusion from the room temperature side to the cryogenic side, causing liquid helium There will be a lot of evaporation of 6.

(Problems to be Solved by the Invention) As described above, in the conventional superconducting magnet, the coil support member that supports the superconducting coil is joined to the inner cylinder that constitutes a part of the cryogenic refrigerant container. to transmit electromagnetic force to the inner cylinder.

The wall thickness of the inner cylinder must be made thicker, and as a result, the cryogenic refrigerant container becomes heavier and larger.
There is a problem in that the support member that supports the cryogenic refrigerant container also becomes thicker, and the amount of heat entering the cryogenic refrigerant container l\ increases.

Therefore, in the present invention, the superconducting coil is reliably supported by the coil support member without increasing the wall thickness of the inner cylinder of the cryogenic refrigerant container, and the cryogenic refrigerant container is made easier to open and smaller. An object of the present invention is to provide a superconducting magnet that can reduce the amount of heat intrusion into a low-temperature refrigerant container by making the support member that supports the refrigerant smaller.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention includes an inner cylinder and an outer cylinder arranged vertically in a concentric manner, and on the inner cylinder and the outer cylinder, At least two of the above-mentioned inner cylinders are placed in the cryogenic refrigerant in the cryogenic refrigerant container in which the cryogenic refrigerant is housed, and are composed of an upper plate that closes each lower opening and a lower plate 6. In a superconducting magnet configured by arranging two superconducting films facing each other, a coil support member for supporting each of the superconducting coils is arranged in a container arranged along the direction in which electromagnetic forces generated by the superconducting coils act on each other. To the parts! 1! It is characterized by being joined mechanically or metallurgically.

(Function) In the above-mentioned superconducting magnet, the coil support member for supporting each superconducting coil is joined to the container member arranged along the direction in which the N magnetic force generated by each of the superconducting coils acts on each other. Therefore, the attraction electromagnetic force between the superconducting coils described above is transmitted to the container member arranged parallel to the direction of action of the electromagnetic force with γa. In this case, the container member has extremely high rigidity due to the above-mentioned electromagnetic force acting on its plane, so it is possible to reduce the wall thickness of the container member, which makes the cryogenic refrigerant container smaller. Moreover, it can be made small.

(Example) The present invention will be described below with reference to an example shown in the drawings.

FIG. 1 is a plan sectional view showing an example of the configuration of essential parts of a superconducting magnet according to the present invention, and the same parts as in FIGS. 3(a) and 3(b) are designated by the same reference numerals.

In FIG. 1, 1 is an inner cylinder made of a non-magnetic material such as stainless steel and arranged vertically, 2 is an outer cylinder made of a non-magnetic material such as stainless steel and arranged concentrically with the inner cylinder 1, 3 and 4 is also made of a non-magnetic material such as stainless steel, and these inner cylinders 1. On top of outer cylinder 2.

A disk-shaped upper plate and a lower plate are welded to the cylinder so as to close the lower openings, and constitute the cryogenic refrigerant container 5. Moreover, liquid helium 6, which is a cryogenic refrigerant, is stored inside the cryogenic refrigerant container 5, and two superconducting coils each made of a superconducting wire wound into a cylindrical shape, for example, are contained in the liquid helium 6. 7 and 8 are arranged facing each other with the inner cylinder 1 sandwiched therebetween as shown in FIG. Further, reference numeral 11.12 is a coil support member for supporting each of the superconducting coils 7.8, and each end is connected to the upper plate 3 and the lower plate 4 forming a part of the cryogenic refrigerant container 5.
For example, they are joined metallurgically by welding. Then, the structure configured in this way is placed in a vacuum insulated container (not shown).
It is supported by a support member (usually called a support).

In a superconducting magnet having such a configuration, coil support members 11.12 for supporting each superconducting coil 7.8 are provided.
are connected to the upper plate 3 and the lower plate 4, which are container members arranged in parallel along the direction in which the electromagnetic force generated by each superconducting coil 7.8 acts on each other. 7.8 The mutual attraction electromagnetic force will be transmitted to the upper plate 3 and lower plate 4. In this case, since the upper plate 3 and the lower plate 4 have considerably higher rigidity than a cylinder against the above-mentioned electromagnetic force, even if the wall thickness thereof is relatively smooth, they can be sufficiently supported. That is, the upper plate 3 and the lower plate 4 have high rigidity because they act on their planes, in other words, parallel to the direction in which electromagnetic force acts, and all the members constituting the cryogenic refrigerant container 5, especially the inner cylinder 1, have high rigidity. It becomes possible to make the wall thickness thinner than before. As a result, not only the weight of the cryogenic refrigerant container 5 can be reduced, but also the weight of the cryogenic refrigerant container 5 can be reduced.
The whole can be made smaller. In addition, since the weight of the cryogenic refrigerant container 5 is reduced, it is possible to use a support member with a small cross-sectional area and short dimensions as a supporting member for supporting the cryogenic refrigerant container 5 in the vacuum insulation container. In other words, the amount of heat entering from the room temperature side to the cryogenic side, that is, the cryogenic refrigerant container 5, can be reduced, and the evaporation Rfi of the liquid helium 6 can be significantly reduced.

It should be noted that the present invention is not limited to the embodiments described above, but can be similarly implemented in the following manner.

(a) In the above example, super 1! A coil support member 11.12 for supporting the conductive magnet 7.8 is attached to the upper plate 3.1 of the cryogenic refrigerant container 5. Although they are welded and joined to the lower plate 4, the present invention is not limited thereto. For example, as shown in the plan cross-sectional view of FIG. They are connected to each other by plate-shaped coil support members 13 and 14, and the electromagnetic force is transferred to the coil support members 13 and 14.
．． 14 may be used.

(b) J= In the example, the present invention is applied to a superconducting coil in which a superconducting wire is wound into a cylindrical shape, but the present invention is not limited to this, and the present invention is applicable to a superconducting magnet wound in a predetermined shape of the pond. The present invention can also be applied to the following.

(C) In the above embodiment, the coil support members 11, 12 for supporting the superconducting magnets 1 to 7°8 are placed on the upper plate 3.1 of the cryogenic refrigerant container 5. Although the case has been described in which the lower plate 4 is metallurgically joined by welding, the present invention is not limited to this, and mechanically joining may be performed using, for example, bolt studs.

(d) In the above embodiment, a case was described in which two superconducting coils were arranged facing each other, but the invention is not limited to this, and a case in which an even number of superconducting coils of 2 uA or more, for example, are arranged facing each other, can also be used.
The present invention can be applied in the same way.

<8) In the above embodiment, the inner cylinder 1 configuring the cryogenic refrigerant container 5. Outer cylinder 2, upper plate 3. Although stainless steel is used as the material for the lower plate 4, the material is not limited to this, and any non-magnetic material such as aluminum, manganese, FRP, etc. may be used.

In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention ψ] As explained above, according to the present invention, an inner cylinder, an outer cylinder, and these inner cylinders are arranged vertically in a concentric manner.

It consists of an upper plate and a lower plate that close the upper and lower openings of the outer cylinder, and the inner cylinder is sandwiched between the cryogenic refrigerant container and the cryogenic refrigerant inside. In a superconducting magnet configured by disposing at least two superconducting coils facing each other in such a state, the coil support member for supporting each of the superconducting coils is arranged in a direction in which the electromagnetic force generated by each of the superconducting coils acts on each other. to a container member placed along.

Since the bonding is done mechanically or metallurgically, the superconducting coil can be reliably supported by the coil support member without increasing the wall thickness of the inner cylinder of the cryogenic refrigerant container, making it possible to make the cryogenic refrigerant container smaller and smaller. In addition, it is possible to provide an extremely reliable superconducting magnet that can reduce the amount of heat entering the cryogenic refrigerant container by shortening the support member that supports the cryogenic refrigerant container.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing one example of the actual flow of the present invention, FIG. 2 is a plan sectional view showing another embodiment of the invention, and FIG. 3(a) (
b) is a plan sectional view and a front sectional view showing a conventional superconducting magnet. 1... Inner cylinder, 2... Outer cylinder, 3... Top plate, 4...
Lower plate, 5... Cryogenic refrigerant container, 6... Liquid helium, 7, 8... Superconducting coil, 9, 10... Coil support member, 11゜12.13.14... Coil support Element. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 3 (a)

Claims (3)

[Claims] (1) It consists of an inner cylinder and an outer cylinder arranged vertically in a concentric manner, and an upper plate and a lower plate that close the upper and lower openings of these inner cylinders and outer cylinders, and a cryogenic refrigerant is stored inside. A superconducting magnet configured by disposing at least two superconducting coils facing each other with the inner tube sandwiched in a cryogenic refrigerant in a cryogenic refrigerant container, a coil support for supporting each of the superconducting coils. A superconducting magnet, characterized in that the member is mechanically or metallurgically joined to a container member arranged along a direction in which electromagnetic forces generated by the superconducting coils act on each other. (2) The superconducting magnet according to claim (1), wherein the coil support member is welded to the upper plate and lower plate of the cryogenic refrigerant container. (3) Claim (1) characterized in that the superconducting coils arranged facing each other are connected to each other by a plate-shaped coil support member arranged along the direction of action of electromagnetic force. Superconducting magnet as described in section.