JPH05288900A - Deflecting electromagnet device for parting direction of beam - Google Patents

Abstract

PURPOSE:To make a deflecting electromagnet device for parting a beam be small in size and light in weight and to reduce an exciting power. CONSTITUTION:An electromagnet 18 having a track 12 in one direction of deflection, an electromagnet 19 including a track in a different direction of deflection from the one of the electromagnet 18, a jack 20 moving these electromagnets 18 and 19, and a vessel 21 having an incidence port 7 and emission ports 8 to 10 of a beam and keeping the tracks vacuum, are provided. For switching the direction of deflection, the electromagnet having the direction of deflection needed is moved to the emission port needed. The area of a magnetic pole of the electromagnet is reduced, an electromagnet device is made small in size and light in weight accordingly and power-saving is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflecting electromagnet device for diverting the direction of a charged particle beam, which is used in, for example, experimental nuclear physics or medical field.

[0002]

2. Description of the Related Art For convenience of explanation of the prior art, first, referring to a beam distribution explanatory view of FIG. 13, for example, a deflection electromagnet device for beam distribution in an experimental beam irradiation system is described.
Explain how it is used. In the figure, 4 is an electromagnet, which comprises an entrance 7 (hereinafter referred to as an entrance) for a charged particle beam (hereinafter referred to as a beam), a right exit 8, a straight exit 9, and a left exit 10. ing. 11
˜14 are beam trajectories shown for explanation, 11 is an incident beam orbit passing through the entrance 7, 12 is a right exiting beam orbit passing through the right exit 8, 13 is a straight beam going through the straight exit 9, 14 Indicates a left output beam trajectory passing through the left output port 10. Reference numeral 16 denotes a beam irradiation target, and 17 is another deflecting device, a beam squeezing device, a diffusing device or the like (hereinafter referred to as another device) used in the irradiation system. Although not shown in the figure, all the beam trajectories 11 to 14 pass through the inside of a pure duct.

In an experiment conducted using the irradiation system shown in FIG. 13, it is inconvenient to irradiate the irradiation target 16 with a beam from one direction, and it may be necessary to switch the irradiation direction. Although it is possible to change the apparent irradiation direction by changing the direction of the irradiation target 16 itself, there are cases where the irradiation target 16 cannot be moved. In such a case, the system may be configured so that the direction of the beam is distributed to the right, left, or straight by the electromagnet 4, and the beam reaches the irradiation target 16 from any different direction by using another device 17. For example, the beam can be easily emitted from either direction when needed. The sorting electromagnet device is used in this way.

Next, FIGS. 10 to 12 show an example of a conventional deflection electromagnet device for diverting the direction of a charged particle beam (hereinafter referred to as a beam). 10 to 12 are similar to those shown in the "Medical Accelerator Design Report" (issued in July 1988) issued by the University of Tsukuba Particle Beam Medical Science Center. 10 is a top view, FIG. 11 is a front view, and FIG. 12 is an exploded view showing the internal structure. In the figure 4, 7 ~
Since 14 is the same as that in FIG. 13, its explanation is omitted.

The above-mentioned electromagnet 4 is composed of the following. That is, two magnetic poles 1 arranged to face each other across a small gap, an exciting coil 2 (hereinafter referred to as a coil) wound around the magnetic pole 1, and two magnetic poles 1 are magnetically connected to each other. And the gap 5 between the two magnetic poles 1 (hereinafter,
(Referred to as the magnetic pole gap) and a hollow duct 6 through which the beam is passed while keeping the inside of the vacuum duct, and the above-mentioned entrance 7 for connecting to the beam trajectory of another device 17 provided in the vacuum duct 6
And a right exit 8, a straight exit 9, and a left exit 10.

Reference numeral 15 denotes a magnetic path for returning to the first described magnetic pole 1 through one magnetic pole 1, magnetic pole gap 5, another magnetic pole 1, and yoke 3 for the sake of explanation. Although FIG. 12 shows the yoke 3 separated into two pieces, it may be integrated or may be divided into more parts for the convenience of manufacturing.

Next, the operation will be described with reference to FIGS. By passing a direct current through the coil 2, magnetic lines of force are induced along the magnetic path 15 and a magnetic field is generated in the magnetic pole gap 5. If the direction of the electric current is reversed, the direction of the magnetic field is also reversed. Since this magnetic field is uniformly generated inside the air duct 6, when the incident beam 11 enters the air duct 6 from the entrance 7, the incident beam is deflected and the strength of the magnetic field is moderate. For example, depending on the direction of the magnetic field, either the right exit port 8 or the left exit port 10 may be moved to the right exit beam trajectory 12
Alternatively, the light is emitted along the left emission beam trajectory 14. If no current is passed through the coil 2, no magnetic field is generated and the incident beam 1
1 travels straight without being deflected, and is emitted from the straight exit port 9 along the straight beam trajectory 13.

As described above, depending on the presence / absence of the current to the coil 2 or the direction of the current, in the beam irradiation system of FIG. 13, the beam is divided into the right exit beam trajectory 12, the straight exit beam trajectory 13, and the left exit beam trajectory 14. You can sort to either. In addition, the polarity of the charge of the charged particles is described as one kind in the description here.

The size of the magnetic pole 1 in FIG. 10 needs to be a size including the incident beam orbit 11, the right outgoing beam orbit 12 and the left outgoing beam orbit 14. Although the magnetic poles in the vicinity of the straight beam exit 9 of the straight beam trajectory 13 are unnecessary, it is difficult to make the center of the magnetic poles chipped off in the electromagnet manufacturing technology, and therefore all of these are generally used. A large area magnetic pole including the orbit is used. In order to prevent the magnetic flux density of the yoke 3 from becoming excessive, it is necessary to make the cross-sectional area of the yoke 3 wide according to the area of the magnetic pole 1.
If the area is large, the yoke 3 also becomes large, and the size and weight of the electromagnet 4 become large. Further, since the coil 2 needs to have a size that surrounds the wide magnetic pole 1, the larger the area of the magnetic pole 1, the greater the power consumption of the coil 2.

[0010]

Since the conventional deflecting electromagnet device for beam direction distribution is constructed as described above, the beam orbit used at a certain time is always one, but the magnetic pole of the magnetic pole is always used. Since the area is configured to include all trajectories, the magnetic pole area will be large,
According to this, the yoke section becomes larger, the coil becomes larger, and the size and weight become huge, and the electromagnet manufacturing cost, transportation cost, installation work cost, power supply device and power consumption cost are also large. There was a problem.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a beam deflecting electromagnet device in which all of the electromagnet size and weight and the coil power consumption are reduced. Is.

[0012]

According to a first aspect of the present invention, there is provided a deflection electromagnet device for beam direction distribution, which comprises a moving mechanism for an electromagnet, and when the deflection direction is switched, a necessary exit port of the electromagnet is at a predetermined position. It can be moved so as to come to the air, and is equipped with a container that can keep all the beam trajectories clean even during this movement.

As a second invention, the magnetic poles of the electromagnet are
It is designed to move on the surface of the yoke of the electromagnet.

[0014]

In the beam deflecting deflecting electromagnet device according to the first aspect of the present invention constructed as described above, the electromagnet can be moved to move the emission port to be used to a predetermined position.
One magnetic pole can include only one beam trajectory, and the magnetic pole area can be reduced. This reduces the size and weight of the electromagnet. Further, since only the coil corresponding to the orbit to be used need be excited, the coil exciting power can be reduced.

In the second aspect of the invention, since the magnetic poles can be moved in the required orbital direction, the magnetic poles can be of a small area in conformity with the form in which all orbits are accumulated. This reduces the size and weight of the electromagnet, reduces the size of the coil, and reduces the coil excitation power.

[0016]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of a deflecting electromagnet device for beam direction distribution according to a first embodiment of the present invention, FIG. 2 is a top view of the same, and FIG. 3 is a view for explaining a structure of an electromagnet used in the first embodiment. It is a partially exploded view. 5 to 5 in FIGS.
Since 14 is the same as the conventional example, description thereof will be omitted. The magnetic pole 1, the coil 2, the yoke 3, and the electromagnet 4 composed of them are smaller than conventional ones. Reference numeral 18 is a right magnet, which is composed of two opposing magnetic poles 1, 2 coils 2 and yoke 3, and 19 is a left magnet, the configuration of which is the right magnet 1.
Although the same as No. 8, the bending direction of the magnetic pole 1 is bent leftward symmetrically with the right magnet 18. Reference numeral 20 denotes a jack movable up and down. A left magnet 19 is mounted on the jack 20, and a right magnet 18 is mounted thereon. 21 is jack 2
0, a right magnet 18, and a left magnet 19 are empty containers. The empty container 21 is provided with an entrance 7, a right exit 8, a straight exit 9, and a left exit 10 at the same height.

The structures of the right magnet 18 and the left magnet 19 of the first embodiment will be described with reference to FIG. FIG. 3 shows the structure of the right magnet 18. Since the right magnet 18 is used only for deflection of the right bend, the width of the magnetic pole 1 of the right magnet 18 is such that the width of one particle trajectory is from the incident beam trajectory 11 to the right exit beam trajectory 12.
It is the minimum width necessary to give a stable magnetic field to one orbit leading to. The same applies to the left magnet 19 except that the bending direction is opposite. Even if the area of the magnetic pole 1 of the right magnet 18 and the area of 1 of the magnetic pole of the left magnet 19 are matched,
The area of the magnetic pole 1 of the conventional electromagnet 4 is smaller than the area of the straight magnetic beam trajectory. Since the area of the magnetic pole 1 is small, the cross-sectional area of the yoke 3 can be small, and the coil is also small, and the weight of the right magnet 18 and the weight of the left magnet 19 are smaller than the weight of the conventional electromagnet 4.

By moving the jack 20 up and down, both the right magnet 18 and the left magnet 19 move up and down. The right magnet 18 and the left magnet 19 have their incident trajectories 11 parallel to each other,
In addition, the jacks 20 are arranged so as to vertically overlap with each other along the vertical movement direction of the jack 20. Therefore, by adjusting the height of the jack 20 to an appropriate level, the height of the entrance 7 can be controlled by either the right magnet 18 or the left magnet 19. The position of the incident beam trajectory 11 can also be adjusted.

When the position of the incident beam orbit 11 of the right magnet 18 is aligned with the entrance 7, the right outgoing beam orbit 12 is aligned with the position of the right exit 8, so that the right magnet 18 is at this time.
When a current is applied to the coil 2 of the device in a predetermined direction, the particles are swung to the right through the entrance 7 and the right exit 8, while the left magnet 19
When the position of the incident beam orbit 11 is aligned with the entrance 7, the outgoing beam orbit 14 is aligned with the position of the left exit 10. Therefore, at this time, if a current is applied to the coil 2 of the left magnet 19 in a predetermined direction. Particles can be swung to the left through the entrance port 7 and the left exit port 10.

When the particles are emitted from the straight emission port 9, it is not necessary to pass the current through the coils 2 of the right magnet 18 and the left magnet 19 because there is no need for deflection. Right magnet 18 so as not to obstruct the passage of
Either the magnetic pole gap 5 of the left magnet 19 is set to the height of the entrance 7 and the straight exit 9. As described above, the particles can be distributed by adjusting the vertical position of the jack 20 and controlling the current to the coil 2.

Even if the jack 20 is moved, the inside of the container 21 is always kept empty, so that the empty space is not broken during the switching operation of the distribution direction of the track.

As described above, the magnetic fields of the right magnet 18 and the left magnet 19 are used only for right bending and left bending, respectively. Therefore, the width of the magnetic pole 1 is required for the right bending trajectory and the left bending trajectory, respectively. The width can be minimized, and the area of the magnetic pole 1 can be small.

Example 2. 4 and 5 show Embodiment 2 of the present invention.
FIG. 4 is a view showing a deflecting electromagnet device for beam direction distribution according to FIG. 4, FIG. 4 is a top view, and FIG. In the figure, 2
Reference numeral 2 denotes a container (hereinafter, referred to as a right bent duct) including the right outgoing beam orbit 12 inserted in the magnetic pole gap 5 of the right magnet 18.
3 is a container (hereinafter, referred to as a left bent duct) including a left outgoing beam orbit 14 and a straight outgoing beam orbit 13 inserted in the magnetic pole gap 5 of the left magnet 19, and 24 is a right bent duct 22 and a right outgoing port 8. It is a container made of a flexible metal bellows to be connected (hereinafter referred to as a right emitting bellows).

Reference numeral 25 denotes a bellows-like container (hereinafter referred to as a straight-moving bellows) which connects the straight-moving beam orbit of the left-turning duct 23 and the straight-moving emitting port 9 to each other.
Is a container made of bellows similar to the above connecting the part corresponding to the left outgoing beam trajectory of the left bent duct 23 and the left outgoing port (hereinafter referred to as left outgoing bellows), and 27 is the right bent duct 22.
Corresponding to the incident beam trajectory 11 of the left curved duct 2
A container made of the same bellows as described above (hereinafter referred to as an entrance bellows) is connected to both the part corresponding to the three-incidence beam trajectory 11 and the entrance port 7. 4 and 5, objects that should support the entrance 7, the right exit 8, the straight exit 9, and the left exit 10 are not shown, but these are other devices (not shown) on the particle orbit. Is connected to and is stuck

In FIG. 5, the jack 20 is lifted and the left magnet 1
9 shows a state in which the incident beam orbit 11 and the left exit beam orbit 14 of the beam 9 and the left exit beam 10 and 14 respectively face each other.
Is also a position facing the straight-ahead exit port 9, and is a position where the incident beam orbit 11, the straight-ahead beam orbit 13 and the left exit beam orbit 14 are used. Right emitting bellows 2
4. The straight-moving output bellows 25, the left-side output bellows 26, and the input-side bellows 27 can be freely bent or expanded / contracted, and the inside is always kept empty even if the right magnet 18 and the left magnet 19 move up and down. .. Also, the bellows 24, 25,
Particles 26 and 27 are respectively held as linear orbits by a proper supporting member (not shown) so as not to bend due to slackening when they come to a position to be used,
It has a structure that does not hinder the progress of particles.

1 to 5 of the first and second embodiments, the right magnet 18 and the left magnet 19 are arranged one above the other,
The jacks 20 that move up and down are used to move these magnets, but either magnet may be placed on the top and bottom.
Alternatively, both magnets may be arranged side by side and a carriage for horizontal movement may be used for movement. Also, three or more types of magnets having different deflection angles may be used. Although the straight beam trajectory 13 is included in the left-turning duct 23 of the second embodiment, the straight beam trajectory may be included in the right-turning duct 22.

Example 3. 6 and 7 show Embodiment 3 of the present invention.
FIG. 6 is a top view, FIG. 7 is a side view,
Each of them shows a partial cross section. In the figure, 28 is a magnet having only a left-turning orbit. Reference numeral 29 denotes a rotary bearing that supports the magnet 28. The axis of rotation of the magnet 29 coincides with the incident beam orbit 11 and is provided at a position where the magnet 28 can rotate stably. Reference numeral 30 denotes a drive device for rotationally driving the magnet 28, which is provided with a straight advancing orbit duct 31 by penetrating the central axis of its rotation, and a straight advancing exit 9 being provided at the outlet thereof. The materials and arrangement of the rotary bearing 29 and the driving device 30 are considered so as not to disturb the magnetic field of the magnetic pole gap 5. For the sake of explanation, reference numeral 32 shows the case where the magnet 28 is rotated by about 180 ° from the state shown by the solid line in FIG. The drive device 30 penetrating the container 21 is
The rotary bearing 29 has a structure that maintains airtightness.

Since the magnet 28 has only one orbit, it is smaller and lighter than the conventional electromagnet 4. Also, the power consumption of the coil 2 is small. To turn the beam to the right, drive the magnet 28 to the flip position 32,
By aligning the exit beam trajectory with the right exit,
It can be used as the right emission beam trajectory 12.
The current flowing through the coil 2 is always in the same direction regardless of whether the deflection direction is right or left. When the beam travels straight, regardless of the position of the magnet 28, it suffices not to pass a current through the coil 2. In this embodiment, the container 21 is provided with only two outlets, but for example, the magnet 28 has 90
An output port may be provided at each rotation position, and the number of magnets to be used may be one regardless of the number of deflection directions.

In FIGS. 6 and 7 of the third embodiment, the container 21 is fixed and only the magnet 28 is rotated. However, even if the container 21 rotates around the magnet 28,
It is sufficient that the bearing 29 and the inlet / outlet port are kept airtight. Although the container 21 is illustrated as covering the outside of the magnet 28, the left duct 23 is provided in the magnetic pole gap 5 without using the container 21, and the bellows 25 and 26 shown in FIG. You can also keep it.
In this case, the movement range of the magnet 28 is restricted within the range in which the length of the bellows 25 and 26 is sufficient. The bending direction of the magnet 28 may be opposite to that shown in FIG.

Example 4. 8 and 9 show Embodiment 4 of the present invention.
FIG. 8 is an exploded view showing the structure, and FIG. 9 is a diagram for explaining the size of magnetic poles. In the figure, numeral 33 is a magnetic pole rotating shaft for rotating the magnetic pole 1 on the surface of the yoke 3. The magnetic pole 1 is in contact with the yoke 3, and the magnetic pole rotation shaft 33 is the center, and the right emission port 8
The structure is such that the coil 2 swings left and right from the position corresponding to the position 1 to the position corresponding to the left emission port 10.
Rotate and move with. Reference numeral 34 is a drive device for rotating the magnetic pole 1 via the magnetic pole rotation shaft 33. In FIG. 8, magnetic pole 1
Shows the case where the position is corresponding to the left emission port 10.

The size of the magnetic pole 1 of the fourth embodiment will be described with reference to FIG. In the fourth embodiment, one magnetic pole 1 deflects in both the right-deflecting deflection and the left-deflecting deflection. To prevent the area of the magnetic pole 1 from increasing, the trajectories in both directions overlap on the magnetic pole 1. The overlapping of trajectories is such that the area within the envelope that encloses all overlapping trajectories is minimized. That is, in FIG. 9, the distance 35 at the central portion where the right output beam orbit 12 and the left output beam orbit 14 intersect, the distance 36 at the end of the magnetic pole 1 on the side where both the outputs are output, and both the deflections At this time, the width of the magnetic pole 1 can be minimized when the incident beam 11 and the distance 37 at the incident end of the magnetic pole 1 are overlapped so that the three distances are substantially equal.

When the magnetic pole 1 is at the position shown in FIG.
The left emission beam orbit 14 is used, and when the right emission beam orbit 12 is used, the magnetic pole 1 is moved to a position corresponding to the right emission port 8 and the direction of the current flowing through the coil 2 is reversed.

In this embodiment, since the magnetic poles having a narrow width corresponding to the one in which the left and right deflection trajectories are overlapped are used,
Since the magnetic pole area is small and the cross-sectional area of the yoke 3 is small accordingly, and the coil may be small, the size, weight and power consumption can be reduced.

[0034]

As described above, according to the first aspect of the present invention, the moving device for the electromagnet can move the exit of the electromagnet to the position necessary for deflection, so that the magnetic pole has a small area including one orbit. Since the magnetic pole area does not necessarily include a straight track, the total magnetic pole area of the deflection electromagnet is small, and the yoke cross-sectional area is correspondingly small, which is small and lightweight. In addition, the coil is small, and since only the coil in the necessary deflection direction needs to be excited, there is an effect that the coil power consumption can be small.

Further, it is necessary to move the magnet having the magnetic poles matching the deflection direction to be used to the required exit port. At this time, since the beam orbit is always maintained by the empty container, the beam trajectory is kept empty. Never breaks.

According to the second invention, since the magnetic pole area is small, it is possible to reduce the size and weight of the electromagnet and reduce the power consumption of the coil as in the first invention. Further, since the portion to be moved is only the magnetic pole portion, there is an effect that the movement is easy and the structure of the empty container is simple because the empty container has no movable part, and the manufacturing is easy.

[Brief description of drawings]

FIG. 1 is a side sectional view of a first embodiment of the present invention.

FIG. 2 is a top view of the first embodiment of the present invention.

FIG. 3 is a partially exploded view of the first embodiment of the present invention.

FIG. 4 is a top view of the second embodiment of the present invention.

FIG. 5 is a side view of a second embodiment of the present invention.

FIG. 6 is a top view of the third embodiment of the present invention.

FIG. 7 is a side view of a third embodiment of the present invention.

FIG. 8 is an exploded view of a fourth embodiment of the present invention.

FIG. 9 is an explanatory diagram of Embodiment 4 of the present invention.

FIG. 10 is a top view showing an example of a conventional beam direction distribution electromagnet device.

11 is a front view of the conventional electromagnet device of FIG.

12 is an exploded view of the conventional electromagnet device of FIG.

FIG. 13 is a diagram for explaining distribution of particle beams.

[Explanation of symbols]

 1 Magnetic pole 2 Coil 3 Yoke 7 Entrance 8 Right exit 9 Straight exit 10 Left exit 11 Incident beam orbit 12 Right exit beam orbit 13 Straight ahead beam orbit 14 Left exit beam orbit 20 Jack 21 Empty container 33 Magnetic pole rotation axis

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruji Matsuzaki 1-2-1 Wadazakicho, Hyogo-ku, Kobe Sanritsu Electric Co., Ltd. Kobe Works

Claims (2)

[Claims] 1. An orbit across which charged particles are incident,
Magnetic poles arranged on both sides, a yoke that magnetically couples the magnetic poles to each other, a coil that magnetizes the magnetic pole and the yoke, a particle entrance that is between the magnetic poles and that the charged particles enter, and a particle that exits In a deflecting electromagnet device for beam direction distribution, which is composed of a hollow container having an emission port and forming a particle orbit and which emits the charged particles from the emission port to a predetermined emission position, A deflection electromagnet device for beam direction distribution, comprising a moving mechanism for moving to a predetermined emission position, and a container for keeping all the particle trajectories generated by this movement empty. 2. across the orbit where charged particles are incident,
Magnetic poles arranged on both sides, a yoke that magnetically couples the magnetic poles to each other, a coil that magnetizes the magnetic pole and the yoke, a particle entrance that is between the magnetic poles and that the charged particles enter, and a particle that exits In a deflection electromagnet device for beam direction distribution, which is composed of a hollow container having an emission port and forming a particle orbit, and ejects and distributes the charged particles from the emission port to a predetermined emission position, the magnetic poles are connected to each other. A deflection electromagnet device for beam direction distribution, which is designed to move on the surface of iron.