JPH02183956A - Deflecting electromagnet for charged particle device - Google Patents

Abstract

PURPOSE:To almost dispense with the electromagnetic force support in the coil diameter direction by making the distance between an inner diameter side coil and an inside return yoke smaller than the distance between an outer diameter side coil and an outside return yoke. CONSTITUTION:The distance t1 between an inner diameter side coil 2 and an inside return yoke is made shorter than the distance t2 between an outer diameter side coil and an outside return yoke, thus the Maxwell stresses applied to respective coils can be balanced. No support material supporting the coils 2 and 3 is required, and the insertion of a structure and the design of coils are facilitated. The distance t3 between the coils 2 and 3 and the return yoke 1 and the distance t4 between the coils 2 and 3 and the vertical coil symmetrical faces are made equal, thus the electromagnetic forces of the above two coils can be balanced. No support material supporting the coils 2 and 3 is required, and the insertion of a structure and the design of coils can be facilitated.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a bending electromagnet for a charged particle device used to bend the traveling direction of charged particles, and particularly relates to an improvement in the electromagnetic force of the coil portion thereof. .

[Prior art 1] Fig. 9 shows, for example, the conventional banana 5 shown in Japanese Patent Application No. 110822/1982 entitled ``For charged particle devices - t5a stone''.
10 is a plan view showing the 1s direction electromagnet device, and FIG.
It is a sectional view taken along the line XX in the figure. Further, FIGS. 11 and 12 are a plan view and a sectional view taken along the line ■-■ of a banana-shaped 1f magnet device according to another conventional example. In the figure, (1
) is the return yoke, (2) is the inner diameter side coil winding, (3
) is the outer diameter side coil winding, (4) is the coil winding (2),
(3) is an aperture interposed between them, (5) is a banana-shaped coil, and (7) is a current direction. usually.

The configuration of the device shown in FIGS. 9 and 10 consists of a coil (2) (
3) is a case where a normal conducting coil is used, and the configuration of the apparatus shown in FIGS. 11 and 12 is a case where the coils (2) and (3) are superconducting coils.

Next, the operation will be explained. Bending electromagnets are used to bend charged particles using the Lorentz force caused by a magnetic field. When current is applied to coils (2) and (3),
A magnetic field is generated in the aperture (4).
4) When the charges 11t and g1 pass through the inside, the charged particles receive the Lorentz force and bend their traveling direction.By the way, when a magnetic field is generated in the aperture (4), the coils (2) and (3B: return yoke Maxwell's stress acts between (1) and the direction of the force is 1rll, IE''21 stress acts in the vertical direction of the coil as shown in Figure 13, and they either pull each other or the coil returns. It is attracted to the yoke (1).Also, lF”31. +
1'4+, the inner diameter side coil (2) is directed toward the inner return yoke, and the outer diameter side coil (3) is directed toward the outer return yoke. At this time, since the coils (2) and (3) are a pair of banana coils, they will be pulled in the direction of the stronger stress.

Here, the return yoke (1) is a yoke through which the return of the magnetic field passes, and is usually made of iron.

[Problem to be Solved by the Inventionj] Since the conventional bending electromagnet for charged particle devices is configured as described above, the Maxwell's stress applied to the coil is extremely large. It is necessary to attach the coil to the yoke, which poses problems such as the inability to insert a structure between the coil and the return yoke. ,H'
At a stress of 31,11°41, the stress IF51 in the direction of the outer diameter of the coil was extremely large.

Furthermore, when a superconducting coil is used as the coil, a cryostat for cooling the coil is required between the coil and the return yoke. For this reason, conventional devices require extremely large supports to support the coils, which poses the problem of extremely large amounts of heat entering the cryo.

This invention was made to solve the above-mentioned problems, and it balances the stress applied to the coils (2) and (3), and is suitable for charged particle devices that require almost no electromagnetic force support in the coil radial direction. The purpose is to stop the bending electromagnet device.

Another object of the present invention is to provide a deflection electromagnet device for a charged particle device that balances the force between the upper and lower coils and the force that the coil is attracted to the return yoke, and that hardly requires an electromagnetic force support in the vertical direction of the coil.

[Means for Solving the Problems 1] A bending electromagnet for a charged particle device according to the present invention includes a coil consisting of an inner diameter coil winding and an outer diameter coil winding, and a return yoke surrounding this coil. The distance between the coil and the inner return yoke is configured to be smaller than the distance between the outer diameter side coil and the outer return yoke.

In addition, it consists of an inner diameter coil winding and an outer diameter coil winding,
Each of the coil windings includes a coil arranged to face each other symmetrically with an aperture in between, and a return yoke surrounding the coil, and the distance between the coil winding and the return yoke and the distance between the coil winding and the coil The distance between the plane of symmetry and the plane of symmetry is made substantially the same.

[Operation j] In this invention, the respective stresses acting between the coil and the return yoke are balanced by making the distance between the inner diameter side coil and the inner return yoke shorter than the distance between the outer diameter side coil and the outer return yoke. be able to. This eliminates the need for coil support materials, making it easier to insert structures and design coils.In addition, the stress caused by the upper and lower coils attracting each other, and the stress caused by the coils being attracted to the upper return yoke, are reduced by the upper and lower coils. Balance can be achieved by making the distance between the coil symmetry plane and the distance between the coil and the upper return yoke substantially equal. This eliminates the need for almost any coil support material, making it easier to insert the structure and design the coil.

[Example 1] Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.
The figure shows the deflection for charged particles tt! according to an embodiment of the present invention. 1
It is a sectional view showing a stone, and in the figure, (1) is a return yoke, (2) is a coil winding on the inner diameter side, (3) is a coil winding on the outer diameter side, and (4) is an aperture through which the beam passes.

In this example, the distance g (tl) between the inner diameter side coil winding (2) and the inner return yoke (1) is 180M, and the distance between the outer diameter side coil winding (3) and the outer return yoke (1) is 180M. t2) is 300ag, upper and lower return yoke width is 65
0 tm, inner return yoke width 100m, outer return yoke width 450M, coil cross section 120M x 1
20 tm.

Bending electromagnets are used to bend charged particles using the Lorentz force caused by a magnetic field. When current is applied to the coils (2) and (3), a magnetic field is generated in the aperture (4). When a charged particle passes through the aperture (4), it is subjected to a Lorentz force and its progress is bent.

The return yoke (1) is a yoke through which the return of the magnetic field passes, and is usually made of iron.

By the way, when a magnetic field is generated in the aperture (4), Maxwell's stress acts between the coils (2), (3) and the return yoke. The direction of the force is that the inner diameter coil (2) is pulled inward of the turn yoke (1), and the outer diameter coil is pulled toward the outer return yoke. At this time Koi tv (2) +
Since (3) is a pair of banana coils, it will be pulled in the direction of stronger stress. In fact, since the force in the outward direction where the radius of curvature is long is strong, the carp/v(2)I(3) is drawn toward the outer return yoke (1).

When inserting a structure between the coils (2), (3) and the return yoke (1), it is necessary to provide a gap between the coils (2), (3) and the return yoke (1). At that time, a support is required to support the coil due to the difference in stress as described above.However, in the above embodiment, the distance between the inner diameter side coil (2) and the inner return yoke (tx) is
Outer diameter side coil (3)/outer return yoke Ii5 distance 4
By making (+, 2) j shorter, the Maxwell's stress acting on each coil can be balanced.

Therefore, a gap can be created between the coils (2), (3) and the return yoke (1) without the need for supporting materials to support the coils (2), (3). 3) and the return yoke (1). Moreover, the design of the coil becomes easy.

As an example of stress and ratio according to this example, tl=250y,
The stress when t2=200 am is shown in the table below.

When the current density K passed through the coil is 2000 A and E, the central magnetic field (T) of the aperture (4), the force applied to the outer diameter side coil 11i' l l (ton/rad),
Force applied to the inner coil tr21 (tOn/rad)
, the above force difference IE"11-IF"21 (tOn/,
The values of d) were determined for each example and comparative example.

According to the clothes mentioned above, lF+I -lE"21 was 7.63 ton/rad in the comparative example, while it was 60 t in the example 5.
on/rad, and it can be seen that it is effective in balancing the difference in Maxwell's stress.

FIG. 2 is a sectional view showing a magnet for deflecting charged particles according to an embodiment of the present invention, and (8) is a plane of symmetry of the coil. In this example, the distance M (t4) between the coil windings (2), (3) and the plane of symmetry of the coil (8), and the distance between the coil windings (2), (3) and the return yoke (1). The distance between them (t3) is made substantially the same, for example, t3=7
9a*, t4=79B, upper and lower return yoke width 450m
, inner return yoke width Loom, outer return yoke width 450mm, coil cross section 120H x 120mm. When a magnetic field is generated in the aperture (4), an electromagnetic force that attracts the upper and lower coils to each other and an electromagnetic force that draws the coil to the return yoke are generated. At this time, the coils (2) and (3) will be drawn toward the direction where the electromagnetic force is stronger. When actually inserting a structure between coils (2), (3) and return yoke (1), coil (2),
It is necessary to provide a gap between (3) and return yoke (1). In this case, a support is required to support the coil. However, in the above embodiment, the coils (2), (3
) and the distance t3 between the return yoke (1) and the coil (2)
By making the distance 4 t4 between , (3) and the plane of symmetry of the upper and lower coils equal, the two electromagnetic forces described above can be balanced.

Therefore, there is no need for supporting materials to support the coils (2), (3) and the return yoke (
A gap can be provided between the coil (2) and the coil (2).
), (3) and the return yoke (1) may be inserted, and the design of the coil may be modified.

In Figure 7, t"" is 79m, and t3 = 50.79.10
This is a graph showing a comparison of electromagnetic force at 0 m, and the horizontal axis is t3.
-), and the vertical axis indicates the outward electromagnetic force (Kg/rad), as shown in F in FIG. In this example,
The electromagnetic force is balanced by setting t3=79am and t4=79am.

In the above embodiment, the case where t3 = t4 was described, but the case is not limited to this. By balancing the attraction force between the upper and lower coils and the attraction force between the iron core and the coil, the attraction force between the upper and lower coils can be reduced to almost 0. By doing so, it is possible to eliminate the support between the upper and lower coils. Therefore, it is not necessary that t3=t4 as in the above embodiment, and t3 and t4 may be determined in a relationship such that the attraction force between the upper and lower coils is minimized. For example, according to FIG. 7, when t3 is slightly larger than t4, the electromagnetic force between the upper and lower coils becomes 0.

As an application field of the bending electromagnet for charged particle devices according to the present invention, for example, SOR light (5yhcrotron 0rh
There is a generator for ital Radiation. SOR light is light with a wavelength of 10λ that is generated in the tangential direction of the orbit when the orbit of an electron is deflected by a magnetic field. In explaining this invention, the vacuum chamber for extracting SOR light is not mentioned;
In order to take out the SOR light, a linear through hole may be provided in the return yoke on the outer diameter side, and the SOR light may be taken out to the outside of the electromagnet through this hole.

In the above embodiment, one pair of banana-shaped coils is shown, but two or more pairs of banana-shaped coils may be used, and the same effects as in the above embodiment can be achieved. Also, in Figures 3 and 4, tl = 180mg and t2 in Figure 1.
= 300am, upper and lower return yoke width 650m, inner diameter return yoke width 100m, outer diameter return yoke width 4
This is an example in which the length is 50M, and the same effects as in the above example can be achieved. Alternatively, as shown in FIGS. 5 and 6, a D-shaped electromagnet having a coil (6) with an iron core may be used.

In this case as well, the same effects as in the above embodiment can be achieved. Further, there may be three or more pairs of D-shaped coils, and in this case, the same effect as in the above embodiment can be achieved.Furthermore, when superconducting coils are used for coils (2) and (3), coil support Since the material only needs to receive the electromagnetic force from the fan core at the mounting position of the coil, the support can be extremely small, and therefore the intrusion of heat into the coil can be minimized. Figure 1, 2nd
As shown in the figure, the balance of the electromagnetic force in the radial direction of the coil and the balance of the electromagnetic force in the vertical direction are carried out separately, but at the same time, the balance of the electromagnetic force in the radial direction and the vertical direction of the coil is carried out separately. It can also be configured to balance the magnetic force.

[Effect of the Invention 1 As described above, according to the present invention, in the deflection electromagnetic force for a charged particle device comprising a coil consisting of an inner diameter coil winding and an outer diameter coil winding, and a return yoke surrounding this coil, By configuring the distance between the inner diameter side coil and the inner return yoke to be smaller than the distance between the outer diameter side coil and the outer return yoke, the McNuwell stress acting on the inner diameter side and outer diameter side coils is balanced, and the coil diameter This has the effect of making it possible to obtain a deflection magnet for a charged particle device, which can almost eliminate the need for a directional electromagnetic force support.

In addition, it consists of an inner diameter coil winding and an outer diameter coil winding,
The coils are arranged so that each of these coil windings is symmetrically opposed to each other with an aperture in between.
In a deflecting electromagnet for a charged particle device equipped with a return yoke surrounding V, the distance between the coil winding and the return yoke and the distance between the coil winding and the plane of symmetry of the coil are made substantially the same. , work on the coil! This has the effect of making it possible to balance the magnetic force and to obtain a deflection magnet for a charged particle device, which makes it almost unnecessary to support the "W electromagnetic force in the vertical direction of the coil."

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a deflection electromagnet for a charged particle device according to an embodiment of the present invention, and FIG. 3 is a plan view showing an embodiment of the pond, FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3, and FIG. 5 is a diagram showing a charged particle device according to still another embodiment of the present invention. A plan view showing the bending electromagnet, Fig. 6 is a sectional view taken along the line Vl-VI of Fig. @5, and Fig. 7
The figures relate to another embodiment, a graph showing 1M and magnetic force versus the distance between the coil and the return yoke, Fig. 8 is an explanatory diagram thereof, Fig. 9 is a plan view showing a conventional deflection electromagnet for a charged particle device, and Fig. 10 is a sectional view taken along the line X-X in FIG. 9, FIG. 11 is a plan view showing another example of a conventional deflection electromagnet for a charged particle device, and FIG. FIG. 13 is an explanatory diagram showing the force applied to a conventional electromagnet. In the figure, (1) is a return yoke, (2) is a coil winding on the inner diameter side, (3) is a coil winding on the outer diameter side, and (4) is an aperture. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Figure 8■ Figure 4 Figure 1 Figure 2 Inside? 7th line A 7th line 3 77th fill 4th line 4 :7 h0-+mer Figure 2 Figure 5 VJ Figure 6 Figure 8 Figure 11-xII Figure 12 Figure 9 X Figure 10 Figure 13

Claims (2)

[Claims] (1) In a deflecting electromagnet for a charged particle device that includes a coil consisting of an inner diameter coil winding and an outer diameter coil winding, and a return yoke surrounding this coil, the distance between the inner diameter side coil and the inner return yoke is A deflecting electromagnet for a charged particle device, characterized in that the distance is smaller than the distance between the outer diameter side coil and the outer return yoke. (2) Consists of an inner coil winding and an outer coil winding,
In this deflecting electromagnet for a charged particle device, the deflection electromagnet for a charged particle device includes a coil arranged so that each of the coil windings faces symmetrically with an aperture interposed therebetween, and a return turret surrounding the coil, between the coil winding and the return yoke. A deflecting electromagnet for a charged particle device, characterized in that a distance between the coil winding and a plane of symmetry of the coil is substantially the same.