JPH07283021A - Electromagnet unit - Google Patents

Abstract

PURPOSE:To obtain a high performance electromagnet unit which can be operated easily while reducing the leakage field and the imbalance of electromagnetic force. CONSTITUTION:The electromagnet unit comprises a superconducting coil 11 generating a magnetic field, a vessel 12 for housing the superconducting coil, a vacuum vessel 14 for defining a vacuum space and supporting the coil vessel while insulating thermally, a yoke 21 disposed around the vacuum vessel, and at least one ferromagnetic piece 13, 30, 33, 38 fixed appropriately to the outside of the yoke. Furthermore, the electromagnet unit may comprises electromagnetic force measuring units 32, 37, a regulation mechanism 38, and a field measuring element. This structure allows monitoring and regulation of imbalance in the electromagnetic force between the superconducting coil and the yoke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet device, and more particularly to a superconducting electromagnet device such as a superconducting electromagnet for generating a highly uniform and strong magnetic field relating to high energy physics such as an accelerator and a charged particle storage ring. . The present invention is particularly effective when applied to a superconducting electromagnet device, but can also be used for a normal electroconducting magnet device.

[0002]

2. Description of the Related Art FIG. 19 shows a "vacuum" (Japan Vacuum Association) 1
989 is a plan sectional view showing a central portion of a vertically symmetrical structure showing a conventional superconducting small SR ring described in Vol. 32, No. 6, 1989, p. 545, showing an example of a conventional superconducting electromagnet device, 20 is a sectional view taken along line XX-XX in FIG.

In FIGS. 19 and 20, superconducting electromagnet devices are vertically symmetrically arranged at regular intervals to generate a magnetic field, a superconducting coil 1, a coil container 2 for accommodating the superconducting coil 1, and a coil container 2. And a vacuum container 4 which accommodates the above in a vacuum space and supports it adiabatically. The superconducting electromagnet apparatus is further provided with a vacuum chamber 7 provided in the vacuum container 4 for passing the bridging particles, and radiated light tangentially emitted from the charged particles moving along the trajectory S in the vacuum chamber 7. And a beam line 8 for taking out to the outside. The coil container 2 is connected and supported by a support 5, and the vacuum container 4 is arranged so as to cover the outside thereof substantially, and is supported by a yoke 10 made of a ferromagnetic material such as iron and allowing a magnetic field to pass therethrough. The yoke 10 is provided with a notch-shaped emission light port 9 which extends through the yoke 10 and allows the emission light beam line 8 to pass therethrough.

In such a superconducting electromagnet apparatus, when a current is passed through the superconducting coil 1 to generate a magnetic field in the vacuum chamber 7 and charged particles are allowed to pass through the magnetic field, the traveling direction is deflected by the Loret force. Then, the charged particles rotate in the vacuum chamber 7 in a circular orbit S. At this time, since the charged particles receive a force in the radial direction, radiated light is generated in the tangential direction of the charged particle beam orbit, which is a direction perpendicular to the force, and this radiated light is extracted to the outside through the radiated light beam line 8.

In order to bend the high-energy charged particles along the circular orbit S having a predetermined small radius, a high magnetic field of high homogeneity is required, but when the high magnetic field is generated, high leakage to the outside of the superconducting coil 1 occurs. Since a magnetic field is generated, a yoke 10 made of a ferromagnetic material such as iron is arranged so as to cover the vacuum container 4 in order to shield this leakage magnetic field. Here, in order to obtain high homogeneity of the magnetic field, the magnetic components such as the superconducting coil 1 and the yoke 10 are usually arranged symmetrically.

Further, when a magnetic field is generated by the superconducting coil 1, a strong Maxwell force acts between the superconducting coil 1 and the yoke 10, and an electromagnetic force attracting each other is applied to the superconducting coil 1 and the yoke 10. An electromagnetic force attracting each other in the vertical direction and an electromagnetic force repelling each other in the radial direction are generated between each other. At this time, the coil container 2 connected by the support 5 receives the force in the direction in which the electromagnetic force is large due to the vector sum of the various electromagnetic forces described above.

[0007]

In the superconducting electromagnet apparatus as described above, the positional relationship between the superconducting coil 1 and the yoke 10 is usually arranged symmetrically in the vertical and radial directions. There is a problem that asymmetry occurs and an unbalanced electromagnetic force is generated due to the number of eight, the arrangement of charged particle injection devices, the manufacturing error of the superconducting coil 1 and the yoke 10, the installation error between the superconducting coil 1 and the yoke 10, and the like. It was Further, if the beam lines 8 and the like are installed symmetrically, a plurality of radiated light ports 9 will be arranged in unnecessary places, and there is a problem that the leakage magnetic field to the outside increases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electromagnet device which solves the problems of the above-mentioned conventional electromagnet device, in particular, the leakage magnetic field to the outside is small, and the unbalanced electromagnetic force can be suppressed as much as possible. It is an object of the present invention to provide a high performance superconducting electromagnet device which is easy to operate.

[0009]

According to a first aspect of the present invention, there is provided an electromagnet device, which includes a coil that generates a magnetic field, a coil container that houses the coil, a yoke that surrounds the coil container, and an outside of the yoke. And at least one ferromagnetic piece.

In the electromagnet device according to the second aspect, the coil is a superconducting coil, the coil container is housed between the coil container and the yoke, and a vacuum space is formed to adiabatically support the coil container. Is equipped with.

According to the electromagnet apparatus of the third aspect, the yoke is provided with the port, and the ferromagnetic piece has a volume substantially corresponding to the volume of the port, and is attached near the port.

According to the fourth aspect of the electromagnet device, the electromagnetic force measuring device acting between the superconducting coil and the yoke is provided.

According to the electromagnet device of the fifth aspect, the superconducting coil for generating a magnetic field, the coil container for accommodating the superconducting coil, the coil container for accommodating the coil container, forming a vacuum space, and supporting the coil container adiabatically. A vacuum container, a yoke surrounding the vacuum container, and an electromagnetic force measuring device acting between the superconducting coil and the yoke.

According to the electromagnet apparatus of the sixth aspect, the heat insulating support for thermally supporting the superconducting coil in the vacuum container is provided, and the electromagnetic force measuring device is provided on the heat insulating support.

According to the seventh aspect of the electromagnet device, the adjusting mechanism for adjusting the relative position between the superconducting coil and the yoke is provided.

According to the eighth aspect of the present invention, there is provided a magnetic field measuring element provided inside the vacuum container for measuring the magnetic field inside the vacuum container.

According to the electromagnet device of the present invention, a superconducting coil for generating a magnetic field, a coil container for accommodating the superconducting coil, a coil container are accommodated, a vacuum space is formed, and the coil container is adiabatically supported. A vacuum container, a yoke that surrounds the vacuum container, and a magnetic field measuring element that is provided in the vacuum container and measures the magnetic field in the vacuum container.

According to the tenth aspect of the electromagnet apparatus, the superconducting coil is a superconducting coil for deflecting the charged particles, and the superconducting coil includes a vacuum chamber for passing the charged particles along a predetermined orbit, and the magnetic field measuring element includes the charged particles. It is provided at a position deviated from the particle orbit.

[0019]

According to the electromagnet device of the present invention, a coil for generating a magnetic field, a coil container for accommodating the coil, a yoke arranged so as to surround the coil container, and at least one ferromagnet mounted outside the yoke. With the body piece, the ferromagnetic body piece can be appropriately arranged outside the yoke to adjust the magnetic field distribution, and the unbalanced electromagnetic force acting on the coil can be minimized.

Since the electromagnet device according to the second aspect includes at least one ferromagnetic piece attached to the outside of the yoke, the ferromagnetic piece is appropriately arranged on the outside of the yoke so that the superconducting coil and the superconducting coil are formed. The unbalanced electromagnetic force acting between the yoke and the yoke can be adjusted.

According to the electromagnet device of the third aspect, the unbalanced electromagnetic force acting between the superconducting coil and the yoke can be easily adjusted corresponding to various ports.

According to the electromagnet device of the fourth aspect, the electromagnetic force acting between the superconducting coil and the yoke can be easily measured.

According to the electromagnet device of the fifth aspect, the electromagnetic force acting between the superconducting coil and the yoke can be easily and accurately measured.

According to the electromagnet device of the sixth aspect, the electromagnetic force acting on the heat insulating support can be accurately and easily measured.

According to the electromagnet device of the present invention, the electromagnetic force acting between the superconducting coil and the yoke is accurately measured, the relative position between the superconducting coil and the yoke is accurately adjusted, and the electromagnetic force between them is adjusted. The electromagnetic force of can be minimized.

According to the electromagnet device of the eighth aspect, it is possible to improve the homogeneity of the magnetic field in the vacuum container and reduce the unbalanced electromagnetic force.

According to the ninth aspect of the electromagnet device, the uniformity of the magnetic field can be improved and the unbalanced electromagnetic force can be reduced.

According to the electromagnet apparatus of the tenth aspect, the measurement result of the magnetic field measuring element and the analysis result are combined to remotely measure the magnetic field on the charged particle orbit, so that the movement of the charged particle is not disturbed. It is possible to facilitate the remote measurement of the magnetic field at the same time as the accelerated accumulation of charged particles.

[0029]

【Example】

Example 1. The electromagnet device of the present invention shown in FIGS.
Basically, the superconducting electromagnet apparatus has the same structure as the conventional circular solenoid type superconducting electromagnet apparatus shown in FIGS. 19 and 20, but the details thereof are omitted and shown schematically.
1 shows a schematic plan sectional view thereof, and FIGS. 2 to 4 show schematic side sectional views thereof. The electromagnet device of the present invention includes a circular superconducting coil 1 for generating a magnetic field, and the superconducting coil 1.
A coil container 2 for accommodating the coil container 2, a vacuum container 4 for accommodating the coil container 2 and forming a vacuum space for adiabatically supporting the coil container 2, and a yoke 10 surrounding the vacuum container 4. There is. This superconducting electromagnet device has a plane of rotational symmetry A
It has -A and a plane of symmetry BB.

The superconducting coil 1 is one in which two large and small circular coils are concentrically arranged and housed in a disc-shaped coil container 2, but two superconducting coils are supported by a support 5 with an axial interval therebetween. Is. The coil container 2 containing the superconducting coil 1 is adiabatically supported and housed in a vacuum container 4 forming a vacuum space as described later. The vacuum container 4 is supported by being surrounded by a yoke 10.

In such a superconducting electromagnet apparatus, when an electric current is passed through the superconducting coil 1, a magnetic field shown by magnetic force lines L in FIGS. 2 and 3 is generated, and the magnetic force lines L surround the vacuum container 4. Pass through the yoke 10. Electromagnets applied to high energy physics such as charged particle accelerators and storage rings require a high magnetic field, so the magnetic field must be increased by the yoke 10. When a high magnetic field is generated, a strong Maxwell stress acts between the superconducting coil 1 and the yoke 10 to generate a large electromagnetic force attracting each other between the superconducting coil 1 and the yoke 10. At the same time, an electromagnetic force attracting in the vertical direction and a repulsive electromagnetic force in the radial direction are generated between the two superconducting coils 1. These electromagnetic forces are combined with each other, and the coil container 2 connected by the support 5 is pulled to the larger combined electromagnetic force.

FIG. 2 is a diagram showing the distribution of lines of magnetic force obtained when the respective constituent elements are ideally symmetrically arranged with respect to the vertical symmetry plane BB in such a superconducting electromagnet apparatus. Since the lines of magnetic force L are vertically symmetrical, the electromagnetic force is balanced in the vertical direction and the vertical force does not act.

FIG. 3 is a diagram showing the distribution of magnetic force lines obtained when the respective constituent elements are not symmetrical with respect to the vertical symmetry plane BB and are arranged asymmetrically in the vertical direction.
Is asymmetrical in the vertical direction, the electromagnetic force is a downward unbalanced electromagnetic force acting between the superconducting coil 1 and the yoke 10. In such a superconducting electromagnet apparatus, since the superconducting coil 1 is housed in the vacuum container 4 and the installation state cannot be seen, the superconducting coil 1 may be asymmetrically arranged as shown in the drawing.

According to the electromagnet apparatus of the present invention, as shown in FIG. 4, at least one ferromagnetic piece 3 attached to the outside of the yoke 10 by a known suitable fixing means such as welding or bolts is provided. By appropriately selecting the number, volume, shape, arrangement, etc. of the ferromagnetic pieces 3 and attaching them to the outside of the yoke 10, the unbalanced electromagnetic force acting between the superconducting coil and the yoke is adjusted. It can be almost eliminated.
That is, in FIG. 4, since the superconducting electromagnet apparatus of the present invention has the ferromagnetic piece 3 attached to the upper surface of the yoke 10, that is, the outer surface of the yoke 10 opposite to the direction of action of the unbalanced electromagnetic force,
Otherwise, where the magnetic field distribution is as shown in FIG. 3, the asymmetry of the lines of magnetic force L is relaxed, the bias of the magnetic field distribution is almost eliminated, and the unbalanced electromagnetic force can be adjusted to the minimum. Further, it is possible to suppress the spread of the leakage magnetic field to the outside. Furthermore, if the ferromagnetic piece 3 is divided into a plurality of pieces, an arbitrary amount can be attached to a free position of the electromagnet, so that the unbalanced electromagnetic force can be adjusted with higher accuracy.

Example 2. 5 to 9 show an electromagnet apparatus according to another embodiment of the present invention, in which the present invention is applied to a superconducting electromagnet apparatus having a 180 ° deflection angle used in a racetrack type SR ring. 5 is a perspective view of the superconducting electromagnet apparatus, FIG. 6 is a sectional plan view, and FIG. 7 is a sectional side view. This superconducting electromagnet device is a superconducting coil 1 that generates a magnetic field.
1 (FIG. 7), a coil container 12 that houses the superconducting coil 11, a vacuum container 14 that houses the coil container 12, forms a vacuum space and adiabatically supports the coil container 12, and encloses the vacuum container 4. And a yoke 21 arranged in. This superconducting electromagnet device has a left-right symmetry plane AA (FIG. 6) and a top-bottom symmetry plane BB (FIG. 7).

The superconducting coil 11 has a banana shape in which two large and small arc-shaped coils are concentrically arranged and the ends thereof are connected to each other. Two pieces are housed in a fan-shaped plate-shaped coil container 12 in the axial direction. It is supported by the support 15 with a space between the two. A vacuum chamber 17 is provided between the superconducting coils 11 as described above, in which charged particles are deflected along the trajectory S and radiate light in a tangential direction of the trajectory S. The coil container 12 accommodating the superconducting coil 11 is adiabatically supported and accommodated in a vacuum container 14 forming a vacuum space, as will be described later. The vacuum container 14 is surrounded and supported by the yoke 21.

As is apparent from FIGS. 6 and 7, the yoke 21 is provided with a plurality of types of ports at various positions, impairing the magnetic symmetry of the superconducting electromagnet apparatus. According to this, the ferromagnetic piece having a volume substantially corresponding to the volume of the port provided in the yoke 21 is provided to the yoke 21.
Since it is attached to the vicinity of the port outside of, the unbalanced electromagnetic force acting between the superconducting coil 11 and the yoke 21 can be easily adjusted corresponding to various ports.

That is, in FIG. 6 and FIG. 7, the yoke 2
1 is a semicircular top plate 22, a bottom plate 23, and a cylindrical side plate 24.
And a flat back plate 25, and as a whole, substantially completely covers and supports the vacuum container 14 provided inside thereof. On the side plate 24 of the yoke 21 as described above, in order to take out radiation light generated when the charged particles are deflected along the trajectory S by the superconducting coil 11, the yoke 21 is extracted.
An opening or radiant light port 26 is provided on the outer periphery of the. The synchrotron radiation port 26 is a through-hole having a shaft center 27 that is tangential to the trajectory S of the charged particles, and extends along the shaft center 27 from the vacuum chamber 17 to guide the synchrotron light therethrough. A synchrotron radiation beam line 28 that extends in an airtight manner through the vacuum container 14 extends.

In the example shown in FIG. 6, a strong material made of a ferromagnetic material such as iron is provided by an appropriate fixing means such as bolts or welding so as to substantially surround the radiation light ports 26 on the outer surface of the yoke 21. The magnetic piece 13 is fixed. These ferromagnetic pieces 13 may be integrated with each other, each of them may have an annular shape, or may have a combination of appropriate shapes and numbers. Each of these ferromagnetic pieces 13 is configured to have a volume substantially corresponding to the volume of the radiation light port 26 which is an opening, and compensates for the loss of the magnetic material at the position of the radiation light port 26. is there. Due to the presence of the ferromagnetic piece 13, the unbalanced electromagnetic force in the horizontal plane corresponding to the emitted light port 26 can be easily and accurately adjusted as needed.

A supply port 27 is provided on the top plate 22 of the yoke 21.
Is provided. The supply port 27 is for passing through a refrigerant supply pipe 29 extending from the coil container 12 and connected to an external refrigerant tank 28. The vacuum container 14 also surrounds the refrigerant supply pipe 29 extending from the coil container 12, extends through the inside of the supply port 27, and further surrounds the refrigerant tank 28. The supply port 27 is used not only for supplying the refrigerant through the refrigerant supply pipe 29, but also for taking in and out other parts and materials.

A yoke 21 is provided around the supply port 27.
A ferromagnetic material piece 30 made of a ferromagnetic material such as iron is fixed by suitable fixing means such as bolts or welding so as to substantially surround them on the outer surface of the. These ferromagnetic pieces 30 may be an integral annular ring as in the illustrated example, or may be a combination of portions having an appropriate shape and number. The ferromagnetic piece 30 is configured to have a volume substantially corresponding to the volume of the supply port 27 which is an opening, and compensates for the loss of the magnetic material at the position of the supply port 27. Due to the presence of the ferromagnetic piece 30, the vertical unbalanced electromagnetic force corresponding to the supply port 27 can be easily and accurately adjusted as needed. In addition, the addition of the ferromagnetic piece 30 increases the volume of the yoke 21, so that the leakage magnetic flux to the outside can be reduced.

The superconducting electromagnet apparatus is also provided with a mounting port 32 which is an opening for mounting the superconducting coil 11 through the heat insulating support 31 on the top plate 22 of the yoke 21. One end of the heat insulating support 31 extending in the vertical direction is supported on the top plate 22 by being covered with an extension extending above the top plate 22 and extending from the vacuum container 14, and the other end of which has the superconducting coil 11 inside. It is connected to and supports the housed coil container 12. The heat insulating support 31 also acts between the yoke 21 and the superconducting coil 11,
An electromagnetic force measuring device 36, which is a load sensor for measuring the load due to the electromagnetic force applied to the heat insulating support 31, is attached.

As with the previous port, the mounting port 32
A ferromagnetic material piece 33 made of a ferromagnetic material such as iron is fixed to the periphery of the yoke 21 by an appropriate fixing means such as bolts or welding so as to substantially surround them with the outer surface of the yoke 21. These ferromagnetic pieces 33 may be an integral annular shape as in the illustrated example, or may be a combination of parts of appropriate shapes and numbers. The ferromagnetic piece 33 is configured to have a volume substantially corresponding to the volume of the mounting port 32 that is an opening, and compensates for the loss of the magnetic material at the position of the mounting port 32. Due to the presence of the ferromagnetic piece 33, the vertical unbalanced electromagnetic force corresponding to the mounting port 32 can be easily and accurately adjusted. In addition, the addition of the ferromagnetic piece 33 increases the volume of the yoke 21 and can reduce the leakage magnetic flux to the outside.

The yoke 21 of the superconducting electromagnet apparatus also has a mounting port 35 which is an opening for mounting the heat insulating support 34 supporting the superconducting coil 11 in the back plate 25 of the yoke 21. One end of the heat insulating support 34 that extends in the horizontal direction is supported on the back plate 25 while being covered by an extension that extends rearward from the back plate 25 and extends from the vacuum container 14, and the other end is inside the superconducting coil. It is connected to a coil container 12 accommodating 11 and supports it.
Also attached to the heat insulating support 34 is an electromagnetic force measuring device 37 which is a load sensor for measuring a load due to an electromagnetic force applied to the heat insulating support 34.

As with the previous port, the mounting port 35
A ferromagnetic material piece 38 made of a ferromagnetic material such as iron is fixed to the periphery of the back plate 25 of the yoke 21 by a suitable fixing means such as bolts or welding so as to substantially surround them with the outer surface of the back plate 25 of the yoke 21. There is. These ferromagnetic pieces 38 may be an integral annular ring as in the illustrated example, or may be a combination of portions having an appropriate shape and number. The ferromagnetic piece 38 is configured to have a volume substantially corresponding to the volume of the mounting port 35, which is an opening, and compensates for the loss of the magnetic material at the position of the mounting port 35. Due to the presence of the ferromagnetic piece 38, the horizontal unbalanced electromagnetic force corresponding to the mounting port 35 can be easily and accurately adjusted. Also,
The addition of the ferromagnetic piece 38 increases the volume of the yoke 21 and can reduce the leakage magnetic flux to the outside.

8 and 9 are schematic diagrams and graphs for explaining the action of the ferromagnetic piece 33 in the superconducting electromagnet device of the present invention. In FIG. 8, the top plate 22 of the yoke 21 is provided with a mounting port 32 which is an opening for mounting the superconducting coil 11 through the heat insulating support 31. In addition, the heat insulating support 31 extending in the vertical direction
One end of the heat insulating support 31 is supported on the top plate 22 by being covered with an extension extending from the vacuum container 14 so as to project above the top plate 22, and the other end of the heat insulating support 31 is provided inside the superconducting coil 11.
Is connected to and supports the coil container 12 in which is stored. The heat insulating support 31 is also provided with an electromagnetic force measuring device 36 which is a load sensor that acts between the yoke 21 and the superconducting coil 11 and measures the load due to the electromagnetic force applied to the heat insulating support 31. There is. Mounting port 3
An annular ferromagnetic piece 33 having a volume corresponding to the volume of the mounting port 32 is substantially fixed around the mounting port 32 by the outer surface of the yoke 21 around the periphery of the yoke 2.

In such a superconducting electromagnet device, the unbalanced electromagnetic force Fz applied to the heat insulating support 31 is measured by the electromagnetic force measuring device 36 while changing the current I flowing through the superconducting coil 11, and as shown in FIG. I got the result. In FIG. 9, the horizontal axis represents the current I (A) applied to the superconducting coil 11, the vertical axis represents the unbalanced electromagnetic force Fz (kg), and the broken line curve A represents the current in the apparatus of FIG. When the ferromagnetic piece 33 of the present invention is not used, the solid curve B represents the case where the ferromagnetic piece 33 of the present invention is used in the superconducting electromagnet apparatus of FIG. As is clear from this graph, the unbalanced electromagnetic force Fz in the case where the ferromagnetic piece 33 is attached is smaller than that in the case where the ferromagnetic piece 33 is not provided, and particularly, it decreases to about 50% at 350A. From this, the unbalanced electromagnetic force is significantly reduced by optimally adjusting the number and arrangement of the ferromagnetic pieces 33,
Obviously, it can be substantially zero. Further, the addition of the ferromagnetic piece 33 is equivalently to increase the volume of the yoke 21, and also to reduce the leakage magnetic flux to the outside.

Example 3. In a superconducting electromagnet apparatus according to another embodiment of the present invention shown in FIG. 10, the heat insulating support 31 is provided with an electromagnetic force measuring device 36 and an adjusting mechanism 38 for adjusting the relative position between the superconducting coil 11 and the yoke 21. Therefore, the electromagnetic force Fz acting between the superconducting coil 11 and the yoke 21 is accurately measured, the relative position between the superconducting coil 11 and the yoke 21 is adjusted based on the measurement result, and the force between them is adjusted. The electromagnetic force Fz can be minimized. The adjusting mechanism 38 is a position adjusting mechanism which is provided on the upper end of the heat insulating support 31 and is supported with respect to the yoke 21 by a tubular support structure 39 which is also a part of the vacuum container. In the illustrated example, the heat insulating support member 40 is provided. Is formed of a screw member 42 that extends from the upper end of and is screwed into a nut 41 provided on the support structure 39. 3 on the outer circumference of the cylindrical heat insulating support member 40.
A tubular support structure 3 provided with a book O-ring 43
An airtight seal is formed between the inner surface and the inner surface of 9. Nut 41
The heat insulating support 31, and hence the superconducting coil 11, can be moved up and down with respect to the yoke 21 by rotating.

In FIG. 10, the line BB is the magnetic symmetry plane of the superconducting electromagnet apparatus, and H is up to the ideal symmetry point where the superconducting coil 11 should be installed with respect to the magnetic symmetry plane BB. From the magnetic symmetry plane BB, ε is an initial installation error of the superconducting coil 11, fz ₁ is an electromagnetic force generated in the heat insulating support 31 when a current is applied to the superconducting coil 11,
x ₁ is a superconducting coil 11 when the electromagnetic force fz ₁ is received
Is the displacement of.

Since the superconducting coil 11 is installed in the vacuum vessel 14, it is difficult to externally measure the position of the superconducting coil 11 with respect to the magnetic symmetry plane BB during the assembly work of the superconducting electromagnet apparatus. In many cases, an initial installation error ε is generated at the position of the coil 11, resulting in the state shown in FIG. 10. When the superconducting coil 11 is energized in this state, the unbalanced electromagnetic force fz ₁ acts between the superconducting coil 11 and the yoke 21, and the heat insulating support 31 that supports the coil container housing the superconducting coil 11 is applied. This unbalanced electromagnetic force fz ₁ is applied. Due to this force, the heat insulating support 31 contracts by x ₁ according to the spring constant of the structure, and the superconducting coil 11 is also displaced by x ₁ .

Assuming that the spring constant of the unbalanced electromagnetic force is kf, the following relationship is established among the unbalanced electromagnetic force fz ₁ , initial installation error ε, elongation x ₁ , and spring constant kf.

Fz ₁ = kf (ε + x ₁ ) Next, a certain fixed value for the initial installation error ε, for example, 1 mm
When the electromagnetic force fz ₂ and the displacement x ₂ when only eccentricity is measured, the formula of fz ₂ = kf (ε + x ₁ + x ₂ ) is established, where fz ₁ , x ₁ , fz ₂ , x ₂ are measured. The two unknowns ε and kf can be easily obtained from the above two equations because they are known values.

As described above, the initial installation error ε with respect to the magnetic symmetry plane BB of the superconducting coil 11 can be accurately and easily obtained, and using this value, the position of the superconducting coil 11 with respect to the yoke 21 is adjusted by the adjusting mechanism 38. By adjusting, the unbalanced electromagnetic force can be made substantially zero.

The above-mentioned superconducting coil 11 and yoke 21.
An adjusting mechanism similar to the adjusting mechanism 38 for adjusting the relative position between the heat insulating support 34, which is horizontally attached to the back plate 25 of the yoke 21 shown in FIGS. 6 and 7 and supports the superconducting coil 11, and When used in combination with the electromagnetic force measuring device 37 provided on the heat insulating support 34, the horizontal or radial position of the superconducting coil 11 with respect to the yoke can be adjusted in the same manner as the embodiment described with reference to FIG. , The radial unbalanced electromagnetic force can be reduced.

Example 4. 11 and 12 schematically show still another embodiment of the superconducting electromagnet device of the present invention. In this superconducting electromagnet device, a magnetic symmetry plane B- It is provided in two parallel planes apart from B and is provided with a magnetic field measuring element 44 for measuring a magnetic field at a position close to the trajectory of charged particles in the vicinity of the vacuum chamber 17 but deviated from the trajectory. . In the example shown, the magnetic field measuring element 44 is fixed to two mutually opposing surfaces of the coil container 12, which are arranged on both sides of the magnetic symmetry plane BB, that is, each outer surface facing the vacuum chamber 17. And a plurality of magnetic field measuring elements 44 provided at symmetrical positions with respect to the magnetic symmetry plane BB. Of course, the magnetic field measuring element 44 may be attached to the outer surface of the vacuum chamber 17, and the same effect is obtained. The magnetic field measuring elements 44 may be known magnetic sensors, and are arranged in three rows along the semicircular orbit S of the charged particles as best understood from FIG.

According to such a superconducting electromagnet apparatus, since the magnetic field measuring element symmetrically attached to the coil container 12 or the vacuum chamber 17 is provided, the asymmetry of the magnetic field can be easily and accurately monitored. It is possible to improve the homogeneity of the magnetic field and reduce the unbalanced electromagnetic force.

That is, in order to move the charged particles on a predetermined orbit in the superconducting electromagnet apparatus, it is required that the magnetic field applied to the charged particles be extremely uniform. Therefore, the magnetic field generated by the superconducting coil 11 must be vertically symmetrical with respect to the magnetically symmetrical plane BB, and the superconducting coil 11 and the yoke 21 are magnetically symmetrical. Further, the breaking of the symmetry between the superconducting coil 11 and the yoke 21 causes the generation of a large unbalanced electromagnetic force.

If the coil container 12 is magnetically symmetrically arranged, the magnetic field measuring elements 44 are also arranged magnetically symmetrically. Therefore, the magnetic field measuring elements at symmetrical positions are arranged. The magnetic field output measured by 44 always has the same value without depending on the value of the current flowing through the superconducting coil 11. However, in practice, it is practically difficult to geometrically dispose the yoke 21 due to the manufacturing accuracy and initial installation error of the superconducting coil 11 and the yoke 21. Therefore, by comparing the outputs of these magnetic field measuring elements 44 and knowing the asymmetry of the superconducting coil 11 and the yoke 21,
It is possible to adjust the position of the coil container 12 through the heat insulating support 31 so that the generation of the unbalanced electromagnetic force is minimized within the range allowed by the magnetic field uniformity.

In this embodiment, the magnetic field measuring element 44
Can easily and accurately monitor the asymmetry with respect to the magnetic symmetry plane B-B as shown in FIG. 11, so that the unbalanced electromagnetic force mainly acting in the radial direction can be adjusted with high accuracy and the magnetic field The unbalanced electromagnetic force can be reduced by improving the uniformity. Further, the magnetic field measuring element 44 can also measure the asymmetry with respect to the magnetic symmetry plane AA as shown in FIG. 12, and adjusts the unbalanced electromagnetic force acting mainly in the axial direction with high accuracy to improve the homogeneity of the magnetic field. The unbalanced electromagnetic force can also be reduced.

Further, according to this superconducting electromagnet apparatus, a vacuum chamber for passing charged particles deflected by the superconducting coil along a predetermined orbit is provided, and the magnetic field measuring element 44 is provided.
Is provided at a position deviated from the orbit of the charged particle, the movement of the charged particle is hindered by remotely measuring the magnetic field on the orbit by combining the measurement result of the magnetic field measuring element 44 and the analytical solution. Without this, it is possible to easily perform the remote measurement of the magnetic field at the same time as the accelerated accumulation of the charged particles, and the accelerated accumulation of the charged particles can be facilitated.

As an example of the superconducting electromagnet apparatus equipped with the magnetic field measuring element 44, the superconducting electromagnet apparatus having the deflection angle of charged particles of 180 degrees has been described. As shown in FIG. 1, the circular superconducting electromagnet apparatus has a deflection angle of 360 degrees. Also in this case, the asymmetry of the magnetic field can be measured by arranging the magnetic field measuring element 44 at a plurality of positions symmetrical with respect to the center of the circle, and the same effect as described above can be obtained.

Example 5. In the embodiment shown in FIG. 13, the coil container 12 to which the magnetic field measuring element 44 is attached is shown.
Are supported by an insulating support 31 having an electromagnetic force measuring device 36, and the upper end of this insulating support 31 is lifted by a hydraulic jack 45 with respect to the yoke 21 via an adjusting mechanism 46. Supported by. Also in this case, a vacuum container (not shown) and the insulating support 31 are hermetically sealed by an O-ring as shown in FIG. In this embodiment, the superconducting coil 11 and the yoke 2 are monitored while the magnetic field measuring element 44 monitors the asymmetry of the magnetic field while the superconducting coil 11 is energized.
It is possible to adjust the relative position between the superconducting electromagnet and the superconducting electromagnet, and to easily realize a superconducting electromagnet device having a high magnetic field uniformity and a small unbalanced electromagnetic force. In addition, the magnetic field measuring element 4
4 and the electromagnetic force measuring device 36 can be used together, and the adjustment work becomes easier and more accurate.

Example 6. In the embodiment of the superconducting electromagnet apparatus schematically shown in FIG. 14, a plurality (for example, three) of magnetic field measuring elements 47 are arranged in the radial direction x,
One coil container 12 of the two coil containers 12
Of the outer surface facing the vacuum container 17. The magnetic field measuring element 47 is thus arranged in the vacuum chamber 17
It is arranged in the vicinity of the orbit S through which the charged particles 48 pass in the x direction, which is perpendicular to the direction of the orbit S. In order for the charged particles 48 to be accelerated and accumulated while moving along a predetermined orbit S, it is required that the magnetic field distribution in the x direction of the magnetic field applied to the charged particles 48 is highly uniform. As described above, the superconducting coil 11 is in the vacuum container 14 surrounded by the yoke 21, and the relative positional relationship between the superconducting coil 11 and the yoke 21 is changed from the ideal position due to manufacturing error or installation error of the superconducting coil 11. The magnetic field acting on the charged particles 48 is deteriorated, and the uniformity of the magnetic field acting on the charged particles 48 in the x direction deteriorates.
May deviate from the orbit S.

In this embodiment, the magnetic field measuring element 47
Are provided at positions sufficiently close to the trajectory S of the charged particles 48, the magnetic field distribution on the trajectory S and the magnetic field distribution at the installation position of the magnetic field measuring element 47 are substantially equal. Therefore, by measuring the magnetic field distribution at that position by the magnetic field measuring element 47, the magnetic field distribution in the x direction on the trajectory S of the charged particles 48 can be obtained, and the charged particles 48 are accelerated and accumulated and in real time. The magnetic field distribution in the x direction on the trajectory S can be obtained without hindering the passage of the magnetic field. Depending on the magnetic field distribution thus measured, the charged particles 48 are adjusted by adjusting the non-uniformity of the magnetic field distribution in the x direction using a beam adjusting device (not shown) outside the superconducting electromagnet apparatus. Accelerating and accumulating can be performed more easily.

Example 7. In the embodiment shown in FIG. 15, a plurality of magnetic field measuring elements 49, 50 and 51 are charged particles 4.
It is arranged in the z direction in the vicinity of the trajectory S of 8 and the magnetic field distribution in the z direction can be monitored in this case as well. These magnetic field measuring elements 49, 50, 51 are arranged such that the magnetic field measuring element 49 is provided on the upper surface of the vacuum chamber 17 and the vacuum chamber 17 of the coil container 12 is provided.
The magnetic field measuring element 50 on the side facing the
A magnetic field measuring element 51 is arranged on the opposite side of the vacuum chamber 17 from the trajectory S of the charged particles 48 in the z direction.

Example 8. In the embodiment shown in FIG. 16, a plurality of magnetic field measuring elements 50 are deviated from the trajectory S of the charged particles 48, but along the trajectory S, that is, aligned in the S direction, on the coil container 12. It is arranged. According to this embodiment, the magnetic field distribution in the S direction can be accurately obtained and adjusted by a beam adjusting device (not shown) outside the superconducting electromagnet apparatus to reduce the non-uniformity of the magnetic field distribution in the S direction. it can.

Example 9. 17 and 18 are diagrams schematically showing yet another embodiment of the superconducting electromagnet apparatus of the present invention and a graph showing the operation thereof. In this superconducting electromagnet apparatus, the trajectory of charged particles 48 in the vicinity of the vacuum chamber 17 is shown. A magnetic field measuring element 53 such as a known magnetic sensor for measuring a magnetic field at a position which is close to S but deviates from the trajectory S is provided, and the magnetic field measuring element 53 is arranged in the vicinity of the vacuum chamber 17. Only one is mounted on the surface of the coil container 12 that faces the vacuum chamber 17. At this time,
Since the outer wall of the coil container 12 and the orbit S of the charged particles 48 are sufficiently close to each other, the ratio of the magnetic field intensity on the orbit S of the charged particles 48 to the magnetic field intensity at the position of the magnetic field measuring element 53 is determined by the energization current of the superconducting coil 11. Is almost constant. In the graph of FIG. 12, the horizontal axis represents the energizing current i (A) to the superconducting coil 11.
Taken up and expressed by taking the ratio α (B ₄₅ / B _S) to the magnetic field strength B _S on the charged particle orbit S of the magnetic field strength B ₄₅ in the coil container 12 outer wall was measured by a magnetic field measuring element 53 on the vertical axis, It is an analysis result and a measurement result by this example. As is clear from FIG. 12, both the analysis result and the actual measurement result are shown in FIG.
The magnetic field strength B ₄₅ measured at 3, the ratio of magnetic field strength B _S on the charged particle orbit _{S α (B 45 / B S} ) is found to be constant regardless of the energizing current i.

From this, by multiplying the value of the magnetic field strength measured by the magnetic field measuring element 53 installed at a position distant from the track S by the above-mentioned ratio α previously obtained by analysis, It is possible to accurately estimate the magnetic field strength remotely. Further, the magnetic field required for the operation of the charged particles 48 can be accurately obtained in real time during the accelerated accumulation operation of the charged particles 48 without hindering the passage of the charged particles 48.

Although only one magnetic field measuring element 53 is provided in this embodiment, a plurality of magnetic field measuring elements are arranged at various positions as shown in FIGS. 11 to 16 to simultaneously obtain magnetic field strength and magnetic field distribution. You can also Further, by averaging the values of the plurality of magnetic field strengths obtained by the plurality of magnetic field measuring elements, the magnetic field strength on the track S can be obtained with higher accuracy.

Although the present invention has been described along with a number of embodiments, these embodiments can be combined and applied to an electromagnet device or a superconducting electromagnet device.

[0071]

According to the electromagnet device of the first aspect of the present invention, a coil that generates a magnetic field, a coil container that houses the coil, a yoke that surrounds the coil container, and at least one attached to the outside of the yoke are provided. Since the ferromagnetic material piece is provided, the unbalanced electromagnetic force acting between the coil and the yoke can be adjusted by appropriately disposing the ferromagnetic material piece outside the yoke.

In the electromagnet apparatus according to the second aspect, the coil is a superconducting coil, the coil container is housed between the coil container and the yoke, and a vacuum space is formed to adiabatically support the coil container. By appropriately disposing the ferromagnetic piece outside the yoke, the unbalanced electromagnetic force acting between the superconducting coil and the yoke can be adjusted.

According to the electromagnet device of the third aspect, the yoke is provided with the port, and the ferromagnetic material piece has a volume substantially corresponding to the volume of the port and is mounted near the port. The unbalanced electromagnetic force acting between the superconducting coil and the yoke corresponding to various ports can be easily adjusted.

According to the electromagnet apparatus of the fourth aspect, since the electromagnetic force measuring device acting between the superconducting coil and the yoke is provided, the electromagnetic force acting between the superconducting coil and the yoke can be easily measured. it can.

An electromagnet device according to a fifth aspect of the present invention includes a superconducting coil for generating a magnetic field, a coil container for accommodating the superconducting coil, a coil container for accommodating the coil container, a vacuum space for adiabatically supporting the coil container. Since the container, the yoke arranged to surround the vacuum container, and the electromagnetic force measuring device acting between the superconducting coil and the yoke are provided, the electromagnetic force acting between the superconducting coil and the yoke can be easily measured. .

According to a sixth aspect of the present invention, an electromagnet device includes a heat insulating support for adiabatically supporting the superconducting coil in the vacuum container, and an electromagnetic force measuring device provided on the heat insulating support and acting between the superconducting coil and the yoke. Since it is provided, the electromagnetic force acting on the heat insulating support can be measured accurately and easily.

Since the electromagnet device according to claim 7 is provided with the adjusting mechanism for adjusting the relative position between the superconducting coil and the yoke, the electromagnetic force acting between the superconducting coil and the yoke is accurately measured to obtain the superconducting coil. The relative position between the yoke and the yoke can be precisely adjusted to minimize the electromagnetic force between them.

According to the electromagnet device of the eighth aspect, since the magnetic field measuring element provided in the vacuum container is provided, the asymmetry of the magnetic field can be easily and accurately monitored, and the homogeneity of the magnetic field can be improved. It is possible to improve and reduce the unbalanced electromagnetic force.

According to a ninth aspect of the present invention, an electromagnet device includes a superconducting coil for generating a magnetic field, a coil container for accommodating the superconducting coil, a coil container for accommodating the coil container, a vacuum space for adiabatically supporting the coil container. Since it comprises a container, a yoke arranged around the vacuum container, and a magnetic field measuring element attached to the outside of the coil container or the vacuum container,
The asymmetry of the magnetic field can be easily and accurately monitored, the homogeneity of the magnetic field can be improved, and the unbalanced electromagnetic force can be reduced.

According to the electromagnet apparatus of the tenth aspect, the superconducting coil is a superconducting coil for deflecting the charged particles, the vacuum chamber is provided for passing the charged particles along a predetermined trajectory, and the magnetic field measuring element is used for the magnetic field measuring element. Since it is provided at a position deviated from the trajectory of the charged particle, the measurement result of the magnetic field measuring element and the analytical solution are combined to remotely measure the magnetic field on the trajectory, so that the movement of the charged particle is not hindered. The remote measurement of the magnetic field can be facilitated at the same time as the accelerated accumulation of the charged particles, and the accelerated accumulation of the charged particles can be facilitated.

[Brief description of drawings]

FIG. 1 is a schematic sectional plan view showing a superconducting electromagnet device of the present invention.

FIG. 2 is a schematic cross-sectional side view showing a state of a magnetic field in the superconducting electromagnet device of FIG.

3 is a schematic cross-sectional side view showing a state of a magnetic field when the superconducting electromagnet apparatus of FIG. 2 is asymmetric.

FIG. 4 is a schematic cross-sectional side view showing a state of a magnetic field when the ferromagnetic piece of the present invention is applied to the superconducting electromagnet device of FIG.

FIG. 5 is a perspective view showing another embodiment of the superconducting electromagnet apparatus of the present invention.

6 is a schematic cross-sectional plan view of the superconducting electromagnet device of FIG.

7 is a schematic cross-sectional side view of the superconducting electromagnet apparatus of FIG.

FIG. 8 is a schematic sectional side view showing a ferromagnetic piece applied to a mounting port of the superconducting electromagnet apparatus of the present invention.

9 is a graph showing the effect of a ferromagnetic piece by the electromagnetic force measuring device of FIG.

FIG. 10 is a schematic sectional side view showing a position adjusting mechanism of the superconducting electromagnet device of the present invention.

FIG. 11 is a schematic sectional side view showing a magnetic field measuring element of a superconducting electromagnet device of the present invention.

12 is a schematic cross-sectional plan view of the superconducting electromagnet apparatus of FIG.

FIG. 13 is a schematic sectional side view showing an adjusting device for a superconducting electromagnet device according to the present invention.

FIG. 14 is a schematic cross-sectional view showing an example of a magnetic field measuring element of the superconducting electromagnet device of the present invention.

FIG. 15 is a schematic sectional view showing an example of a magnetic field measuring element of the superconducting electromagnet device of the present invention.

FIG. 16 is a schematic cross-sectional view showing an example of a magnetic field measuring element of the superconducting electromagnet device of the present invention.

FIG. 17 is a schematic sectional view showing an example of a magnetic field measuring element of the superconducting electromagnet device of the present invention.

FIG. 18 is a graph showing the ratio of the actual measurement result and the analysis result of the magnetic field in the superconducting electromagnet apparatus of FIG. 17, with respect to the superconducting coil current.

FIG. 19 is a schematic plan view of a conventional superconducting electromagnet device.

FIG. 20 is a schematic sectional side view of a conventional superconducting electromagnet device.

[Explanation of symbols]

1, 11 Coil (superconducting coil), 2, 12 Coil container, 3, 13, 30, 32, 38 Ferromagnetic material piece, 1
0, 21 yoke, 14 vacuum container, 26, 27, 3
2, 35 ports, 26 radiant light port, 27 carrier port, 32 mounting port, 36, 37 electromagnetic force measuring device, 38 adjusting mechanism, 44, 47 to 53 magnetic field measuring element.

Front page continuation (72) Inventor Kao Senoo 8-1-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric Corporation Central Research Laboratory (72) Inventor Masao Morita 8-1-1 Tsukaguchihonmachi, Amagasaki Mitsubishi Electric Corporation Inside the Central Research Institute (72) Inventor Oguru Kouji 8-1-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric Corporation Central Research Institute (72) Inventor Shunji Yamamoto 8-1-1 Tsukaguchihonmachi, Amagasaki Mitsubishi Electric Corporation Central (72) Inventor Shiro Nakamura 8-1-1 Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Corporation Central Research Laboratory (72) Inventor Tadatoshi Yamada 8-1-1 Tsukaguchi Honmachi Amagasaki City Central Research Institute Mitsubishi Electric Corporation

Claims (10)

[Claims] 1. A coil that generates a magnetic field, a coil container that houses the coil, a yoke that surrounds the coil container, and at least one ferromagnetic piece that is attached to the outside of the yoke. An equipped electromagnet device. 2. The coil is a superconducting coil, and the coil container is housed between the coil container and the yoke, and a vacuum container is provided which forms a vacuum space and adiabatically supports the coil container. The electromagnet device according to claim 1. 3. The yoke according to claim 1 or 2, wherein the yoke has a port, and the ferromagnetic piece has a volume substantially corresponding to the volume of the port and is mounted in the vicinity of the port. Electromagnet device. 4. The electromagnet device according to claim 2, further comprising an electromagnetic force measuring device acting between the superconducting coil and the yoke. 5. A superconducting coil that generates a magnetic field, a coil container that houses the superconducting coil, a vacuum container that houses the coil container, forms a vacuum space, and adiabatically supports the coil container, An electromagnet device comprising: a yoke arranged so as to surround a vacuum container; and an electromagnetic force measuring device acting between the superconducting coil and the yoke. 6. The superconducting electromagnet apparatus according to claim 5, further comprising an adiabatic support for adiabatically supporting the superconducting coil in the vacuum container, wherein the electromagnetic force measuring device is provided on the adiabatic support. 7. The electromagnet device according to claim 5, further comprising an adjusting mechanism for adjusting a relative position between the superconducting coil and the yoke. 8. The electromagnet device according to claim 2, further comprising a magnetic field measuring element that is provided inside the vacuum container and that measures a magnetic field inside the vacuum container. 9. A superconducting coil that generates a magnetic field, a coil container that houses the superconducting coil, a vacuum container that houses the coil container, forms a vacuum space, and adiabatically supports the coil container, An electromagnet device comprising: a yoke that surrounds a vacuum container; and a magnetic field measuring element that is provided in the vacuum container and measures a magnetic field in the vacuum container. 10. The superconducting coil is a superconducting coil for deflecting charged particles, comprising a vacuum chamber for passing the charged particles along a predetermined orbit, wherein the magnetic field measuring element is deviated from the orbit of the charged particles. The electromagnet device according to claim 9, which is provided at a different position.