JPS62232106A - Superconducting electromagnet - Google Patents

Abstract

PURPOSE:To enable application control and the like while observing the application of a magnetic field to an object by providing a through hole at the center where no coil wire material exists. CONSTITUTION:A superconducting electromagnet has a base plate on which a saddle type coil 2 is mounted and a cryostat 6 in a nearly semicircular section. A through hole 8 is provided at the center of the electromagnet where no coil wire material exists. The one end of the through hole 8 is opened toward a recession 7 5a from the wall 5a the curvature radius of which is smaller of an outer container 5 and the other end is opened toward outer space at the opposite side of the recession 7 from the wall 5b the curvature radius of which is larger of the outer container 5. The through hole 8 has a pipe 9 fixed in airtight between the walls 5a, 5b and a pipe 10 fixed in airtight against the walls 3a, 3b of an inner container 3 outside of the pipe 9. A heat insulating layer 4' connected to a heat insulating layer 4 is provided between the both pipes 9, 10. The shape of the through hole 8 is not especially limited and may be made for easy observation against the size or the shape of an object.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a superconducting electromagnet for generating a high magnetic field, specifically,
The present invention relates to an improvement in an electromagnet that employs a saddle-shaped coil and has a generally semicircular or U-shaped end view including the cryostat in order to facilitate the application of a magnetic field to an object.

[Technical background]

A well-known solenoid coil is used to apply a magnetic field to the object (
The method of applying a magnetic field to an object (hereinafter referred to simply as an object) is as follows:
? ``There are strict restrictions on the use of magnets, and there are cases where the generated magnetic field cannot be used efficiently, so as a solution to this problem, the inventors of the present invention designed the object by having the horse straddle the saddle. It can be placed around objects, and a single electromagnet can apply a magnetic field even to objects that are long in the -axis direction.
Furthermore, they have recently applied for a patent for a superconducting magnet that allows objects to be placed in the magnetic field space where the magnetic flux density is highest. The electromagnet is shown in FIGS. 3 and 5.

As shown in FIG. 4, the electromagnet shown in FIG. It has a structure in which a cryostat (generally liquid helium) for cooling the coil is housed in a semicircular cryostat b with an end face 1M surrounded by an outer container 5.

On the other hand, in the electromagnet shown in FIG. 5, the base plate 1 that straddles the saddle-shaped coil has a U-shape when viewed from the end, and the saddle-shaped coil placed on the base plate has a U-shape when viewed from the end like the base plate. It has a structure in which it is housed together with a cryogen in a cryostat 6 that forms a In both electromagnets, the peripheral wall 3a of the inner container 3 on the side with a smaller radius of curvature is formed by the base plate 1, but it is formed from another wall material having a similar shape to the base plate, and a base plate is placed on top of it. Sometimes it is fixed by straddling it.

[Problem that the invention seeks to solve]

In the above-mentioned electromagnet, a magnetic field is applied by placing the object A within the four parts 7 formed on the outer wall of the cryostat, but when the electromagnet is used horizontally as shown in the figure, from the upper side, When the electromagnet is rotated 90 degrees from the state shown in the figure so that the end face is horizontal and used vertically, even if you try to observe the object from the front side (in both cases from the X point side in the figure), the observation point Since the magnetic field is blocked by the electromagnet, this cannot be done, which poses a problem in that it interferes with visual observation or observation of the applied state of the magnetic field using a TV camera or the like.

This invention aims to solve these problems.

[Means for solving problems]

In order to eliminate the above-mentioned problems, the present invention uses a saddle-shaped coil and has a substantially semicircular or U-shaped end view shape as a whole including the cryostat. In the center of the electromagnet, which does not exist, a through hole was provided to allow the magnetic field application part to be opened halfway through the outer wall of the cryostat, allowing the object to be observed from around the electromagnet through the hole.

〔Example〕

FIGS. 1 and 2 show an example of a superconducting electromagnet of the present invention. This electromagnet is an improved version of the electromagnet shown in FIG. 3 in which the base plate that straddles the saddle-shaped coil 2 and the cryostat 6 are formed into semicircular end faces. In the center, one end is the outer container 5
The peripheral wall 5a having a small radius of curvature opens to the fourth part 7, and the other end opens from the peripheral wall 5b of the outer container 5 having a large radius of curvature to a space on the opposite side to the fourth part 7.

The through hole 8 may be created by airtightly fixing the pipe 9 between the peripheral walls 5a and 5b, and airtightly connecting the edge of the vibrator insertion hole of the inner container 3 in the middle of the pipe, but in this case, Inner container 3 containing cryogen only through pipe 9
Since the inner chamber of the inner chamber is in contact with the atmosphere and the evaporation loss of the refrigerant increases due to the intrusion of external heat, the pipe is fixed airtight to the outer circumference of the pipe 9 to the peripheral walls 3a and 3b of the inner container 3, as shown in the figure. 10, and a heat insulating layer 4' continuous to the heat insulating layer 4 is preferably interposed between both pipes 9 and 10.

Note that the shape of the through hole 8 is not particularly limited. It is sufficient if the shape is easy to observe in light of the size and shape of the object.

Since the same structure can be adopted for the electromagnet shown in FIG. 5 and a through hole can be provided therein, a specific example thereof will not be mentioned.

〔effect〕

As mentioned above, since the electromagnet of the present invention has a through hole in the central part where the coil wire is not present, it is possible to control the magnetic field application while observing the application status of the magnetic field to the object. The above effect can be obtained, and this effect brings particularly great advantages to single crystal growth apparatuses and the like.

In other words, when producing a single crystal, a magnetic field is applied to the molten crystal material in a crystal growth furnace to eliminate the polarity of the material, but seeding is required as in the case of single crystal growth. In such cases, or when it is necessary to observe the growth status, internal observation with the naked eye or a TV camera is essential. However, if the magnet 7 does not have a through hole, there will be cases where observation cannot be performed. In addition, in the case of single crystal growth equipment,
It is conceivable that the inside of a crystallization furnace made of quartz glass or the like can be visually observed from an oblique outside where it is not disturbed by electromagnets, or observed with a TV camera, but since the oblique image is distorted, it is difficult to ensure accurate seeding. No adverse effect on magnetic field application control.

On the other hand, if the electromagnet of the present invention is used, the magnetic field applying section can be observed from the perpendicular direction through the through hole, and the above-mentioned disadvantages can be eliminated.

[Brief explanation of drawings]

11QI is a sectional view showing an example of the superconducting electromagnet of the present invention, FIG. 2 is a plan view thereof, and FIGS. FIG.

Claims (1)

[Claims] A saddle-shaped coil is placed over a base plate having a substantially semicircular or U-shaped end view, and this coil is surrounded by an outer container via a heat insulating layer, and a part of the peripheral wall of the inner container is connected to the base plate. Alternatively, in a superconducting electromagnet housed in a cryostat that is approximately semicircular or U-shaped in end view and formed by wall materials of a similar shape, the magnetic field application part is placed in the center of the electromagnet where no coil wire is present, and the magnetic field application part is placed on the outer wall of the cryostat. A superconducting electromagnet characterized by having a through hole that opens in the middle.