JP2017084595A - Deflection electromagnet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact deflection electromagnet device generating a stable magnetic field.SOLUTION: In a deflection electromagnet device for deflecting a passing charged particle beam, a pair of yokes 5A, 5B are arranged oppositely in the vertical direction via a gap through which a charged particle beam passes. The yokes include a pair of coils 41A, 41B having main poles 1A, 1B, and side poles 21A, 21B, 22A, 22B and generating a magnetic field in the poles, and a pair of coils 51A, 51B coaxial with the coils 41A, 41B on the outer peripheral side thereof. The upper yoke 5A and lower yoke 5B are couped by means of a nonmagnetic support member.SELECTED DRAWING: Figure 5

Description

The present invention relates to a deflection electromagnet apparatus used for a storage ring, a synchrotron radiation light ring, or the like.

  There is a technique for generating synchrotron radiation by applying a periodic motion in a direction perpendicular to the traveling direction of a charged particle beam such as an electron beam or a proton beam. In order to apply periodic motion to the charged particle beam, an insertion light source is installed on the beam trajectory of a beam duct (vacuum vessel) through which the charged particle beam passes. A magnetic field is generated by a deflecting electromagnet device provided in the insertion light source, and the charged particle beam passing through the beam duct is deflected to generate radiation light. There is a technique for generating a stronger magnetic field and generating short-wavelength radiation by using a wiggler as an insertion light source.

  Patent Document 1 aims to provide a deflecting electromagnet device and an insertion light source device that can be miniaturized. As a solving means, “a deflecting electromagnet device is disposed below a first yoke of a magnetic body and below this first yoke. And a magnetic second yoke connected to the first yoke by a non-magnetic support member, the first yoke including a first return pole, a first main pole, and a second return pole. The second yoke includes a third return pole, a second main pole, and a fourth return pole, and a first coil that generates a magnetic field is provided on the first main pole, and a second coil that generates a magnetic field. Is provided on the second main pole, the first return pole and the third return pole, the first main pole and the second main pole, and the second return pole and the 4 return pole, disclose respectively, characterized in that the charged particle beam are arranged on opposite sides while the gap to pass "the.

JP 2011-34818 A

  The deflecting electromagnet device disclosed in Patent Document 1 has a system in which three deflecting electromagnets are arranged along a straight direction of a charged particle beam. The approach to miniaturization disclosed in Patent Document 1 is based on an arrangement system in which three independent deflection electromagnets are arranged. Accordingly, the present invention has an object to provide a deflecting electromagnet apparatus that can be made more compact by examining an arrangement system of a deflecting electromagnet that has been assumed.

The present invention includes various embodiments in order to solve the above-mentioned problem, and an example thereof is “a pair of yokes arranged to be vertically opposed to each other, a beam duct installed between the pair of yokes,
A non-magnetic support member for supporting the pair of yokes,
The yoke protrudes at least toward the beam duct and is disposed along the longitudinal direction of the beam duct. The first magnetic pole, the second magnetic pole, the third magnetic pole, and the second magnetic pole And a second coil that includes both the first magnetic pole and the third magnetic pole on the inner diameter side ”.

  Or “in a bending electromagnet apparatus comprising: a pair of yokes arranged vertically opposite to each other; a beam duct installed between the pair of yokes; and a nonmagnetic support member that supports the pair of yokes. The yoke protrudes at least toward the beam duct and is disposed along the longitudinal direction of the beam duct. The first magnetic pole, the second magnetic pole, and the third magnetic pole, and the second magnetic body A first coil wound around a pole; a second coil having a coil surface along a side surface of the first magnetic pole; and a third coil having a coil surface along a side surface of the third magnetic pole; The second coil and the third coil are provided outside the first magnetic pole and the third magnetic pole in the longitudinal direction of the beam duct. And wherein when ".

  The present invention can provide a deflecting electromagnet device that can be made compact.

It is the conceptual diagram which looked at the arrangement | positioning of the wiggler which is a kind of insertion light source and is comprised from 3 poles from the upper part. It is an AA arrow line view of the wiggler of FIG. It is a conceptual diagram of the BB arrow line view of an example of the wiggler of FIG. It is a conceptual diagram of the BB arrow line view in the different aspect of the wiggler of FIG. It is the conceptual diagram which looked at the deflection | deviation electromagnet apparatus which is the 1st Example of this invention from the direction perpendicular | vertical to a deflection surface. 1 is a perspective view showing a bending electromagnet device according to a first embodiment of the present invention. It is a figure which shows the shift | offset | difference from the ring orbit of a beam orbit by the magnetic field analysis result of the magnetic field intensity with respect to the distance from a magnetic field center, and the said magnetic field. It is the conceptual diagram which looked at the deflection | deviation electromagnet apparatus which is the 2nd Example of this invention from the direction perpendicular | vertical to a deflection | deviation track | orbit. It is the conceptual diagram which looked at the deflection electromagnet apparatus which is the 3rd Example of this invention from the direction perpendicular | vertical to a deflection | deviation track | orbit.

  In describing the present invention, the basic mechanism of the wiggler will be described first, and then the features of the present invention will be described in detail. The wiggler refers to a deflection electromagnet device used as an insertion light source.

  FIG. 1 is a conceptual diagram showing an example of a wiggler used as an insertion light source. The wiggler (deflecting electromagnet device 11) of FIG. 1 is configured by arranging a first deflecting electromagnet 2A, a second deflecting electromagnet 1 and a third deflecting electromagnet 2B along a straight portion of the beam duct 7. In FIG. 1, the support structure, connection lines, and the like are omitted.

  The charged particle beam travels from left to right in FIG. The wiggler is installed on the ring orbit 3 of the synchrotron or storage ring. When observing the radiated light, the radiated light is generated by abruptly bending the trajectory of the charged particle beam that circulates around the ring orbit 3 to generate the deflection trajectory 9. The charged particle beam rapidly deflected while passing through the wiggler is restored to the original ring orbit when exiting the wiggler.

  The deflection electromagnet 2A generates a magnetic field that deflects the incident charged particle beam. The deflection electromagnet 1 is provided for the purpose of generating radiated light. A magnetic field stronger than the deflection electromagnet 2A and having the opposite direction is generated. The deflection electromagnet 2B generates a magnetic field in the same direction as the deflection electromagnet 2A. When the charged particle beam passes through the magnetic field formed by each deflection electromagnet, the charged particle beam travels like a deflection trajectory 9. The reason can be explained as follows.

  The charged particle beam incident on the wiggler is first deflected by the magnetic field generated by the deflection electromagnet 2A. In the example shown in FIG. 1, when passing through the deflecting electromagnet 2 </ b> A, a motion component from top to bottom is added to the charged particle beam.

  The deflection electromagnet 1 generates a strong magnetic field in the opposite direction to the deflection electromagnet 2A. If the direction component perpendicular to the ring orbit 3 is called a deflection component, the deflection electromagnet 1 has a role of inverting the deflection component of the incident charged particle beam and entering the deflection electromagnet 2B. The charged particle beam incident on the deflection electromagnet 2B cancels the deflection component imparted by the deflection electromagnet 1 and exits along the remaining straight component.

  As a result of each deflecting electromagnet generating a magnetic field in this way, the charged particle beam passing through the wiggler draws a deflection trajectory 9 shown in FIG. If these deflection electromagnets are not operated, the charged particle beam travels straight after entering the wiggler and no radiated light is generated.

  FIG. 2 is a cross-sectional view of the wiggler shown in FIG. The deflecting electromagnet apparatus 11 used as a wiggler often has such a system.

  The deflection electromagnet device 11 includes main poles 1A and 1B and side poles 21A, 22A, 21B, and 22B that define a path (magnetic path) of a magnetic field. The deflection electromagnet apparatus 11 includes coils 41A, 41B, 42A, 42B, 43A, and 43B for generating a magnetic field. Further, yokes 5A and 5B to which these components are fixed are provided.

  The coil 41A is wound around the main pole 1A. Similarly, the coil 41B is wound around the main pole 1B, the coil 42A is wound around the side pole 21A, the coil 43A is wound around the side pole 22A, the coil 42B is wound around the side pole 21B, and the coil 43B is wound around the side pole 22B.

  The deflecting electromagnet apparatus 11 has a symmetric structure with respect to the deflection surface of the charged particle beam, and for each configuration provided in the above-described deflecting electromagnet apparatus 11, the reference numerals with A and B correspond. There is a relationship.

  The yokes 5 </ b> A and 5 </ b> B are members that support the coils, the main poles, and the side poles, and are supported by the support members 8. The material of the support member 8 is a non-magnetic material and is made of, for example, stainless steel. Further, the support mode of each yoke is a two-side support mode in which two support members 8 are arranged so as to surround the coils 41A and 41B as shown in FIG. 3, and a single support member 8 as shown in FIG. Any of the aspects of the one side support which arrange | positions may be sufficient.

  Next, the magnetic field generated by the deflection electromagnet apparatus 11 will be described with reference to FIG.

  The deflection electromagnet apparatus 11 includes a plurality of coils, and these function as a magnetomotive force source. The sign of + or − attached in the vicinity of each coil indicates the direction of current in the coil cross section. The current flowing through the coils 41A and 41B is opposite to the current flowing through the adjacent coils 42A, 42B, 43A and 43B. In addition, these directions are examples and these may reverse. However, it is the same that the direction of the magnetic field generated near the center is opposite to the direction of the magnetic field generated on both sides thereof.

  The coils 41A and 41B generate a magnetic field (lines of magnetic force 6) in the gap between the upper main pole 1A and the lower main pole 1B. In FIG. 2, the magnetic field generated between the main poles is a unidirectional magnetic field from the lower main pole 1B to the upper main pole 1A. Further, the coil 42A and the coil 42B generate a unidirectional magnetic field from the side pole 21A toward the side pole 21B. The coils 43A and 43B generate a unidirectional magnetic field from the side pole 22A toward the side pole 22B.

  The correspondence between each coil and FIG. 1 is as follows. The main poles 1A and 1B and the coils 41A and 41B correspond to the deflection electromagnet 1. The side poles 21A and 21B and the coils 42A and 42B correspond to the bending electromagnet 2A. The side poles 22A and 22B and the coils 43A and 43B correspond to the bending electromagnet 2B.

  The main magnetic circuit of the deflection electromagnet device 11 is a path indicated by a magnetic force line 6 indicated by a dotted line in FIG. That is, the magnetic lines of force 6 are loops with the main poles and the side poles as inlets or outlets, and are closed inside the yokes 5A and 5B. When a charged particle beam is incident on such a deflecting electromagnet apparatus 11, the charged particle beam is deflected by a magnetic field created on the ring orbit 3. Since the support member 8 is a non-magnetic material and has a large magnetic resistance, the magnetic circuit connecting the upper and lower yokes 5A and 5B via the support member 8 in the deflection electromagnet apparatus 11 does not become a main magnetic circuit.

  As described above, the deflection electromagnet device 11 is configured by a system in which three deflection electromagnets are arranged along the ring track 3 in order to form the magnetic field distribution described above. Since a coil is individually installed for each pole, a certain distance is required between the poles in the direction of the ring track 3, so that the size of the device is likely to increase.

  By the way, the charged particle beam always travels in a substantially vacuum duct called a beam duct. Therefore, the beam duct is required to have a shape and a size that can cover from the incident axis to the farthest point reached by deflection. In the case of FIG. 1, the shape and size capable of including the deflection track 9 are required.

  Therefore, if the beam duct can be reduced in size, the deflection electromagnet device 11 can be further reduced in size, but there are the following problems.

  As described above, the deflecting electromagnet device 11 requires a certain distance in the direction of the ring track 3 due to the device system. On the other hand, when the distance from the entrance to the exit of the charged particle beam is increased, the degree to which the charged particle beam is separated from the ring trajectory 3, that is, the amplitude of the deflection trajectory 9 is increased. In addition, when no light is emitted, the deflection electromagnet device 11 is not excited, and the charged particle beam passes on the ring orbit 3. As a result, it is necessary to configure the beam duct 7 in consideration of the deflection trajectory 9 and the beam trajectory when the beam is not deflected, and the beam duct is easily increased in size.

  Accordingly, the present inventor has reviewed the arrangement system of the deflection electromagnet apparatus and devised a new system capable of reducing the size of the deflection electromagnet apparatus and the beam duct, which will be described in detail.

  A deflecting electromagnet apparatus 100, which is a preferred first embodiment of the present invention, will be described with reference to FIG. In FIG. 5, the charged particle beam travels from the left to the right, with the left side being the upstream and the right side being the downstream. The charged particle beam passes through the beam duct 7 and travels on the surface including the ring orbit 3, that is, on the deflection surface 10.

  The deflection electromagnet apparatus 100 according to the present embodiment includes, in order from the upstream in the traveling direction of the charged particle beam along the longitudinal direction of the beam duct 7 through which the charged particle beam passes, side poles 21A and 21B, which are first magnetic poles, Main poles 1A and 1B, which are two magnetic poles, and side poles 21B and 22B, which are third magnetic poles, are arranged. Each of the poles constituting the first magnetic pole, the second magnetic pole, and the third magnetic pole is arranged with the deflecting surface 10 interposed therebetween to form a gap, and the beam duct 7 is installed in the gap. The Each pole is installed on the yoke and becomes a structure projecting from the yoke toward the beam duct 7.

  Each pole portion is provided with a coil formed of a magnetic material. As the first coil, the coil 41A is wound around the main pole 1A, and the coil 41B is wound around the main pole 1B. The coil 51A having the side pole 21A and the side pole 22A on the inner diameter side is wound, and the coil 51B having the side pole 21B and the side pole 22B on the inner diameter side is installed as the second coil. The installation positions of the coils 41A and 41B in the vertical direction are preferably equal to the coils 51A and 51B, but may be different.

  FIG. 6 is a perspective view of the bending electromagnet device 100. In addition, although the member to which the code | symbol B was mainly shown on drawing of a perspective view was shown, the member to which the code | symbol A was attached | subjected about the deflection surface 10 is arrange | positioned. Further, the deflection surface 10 includes a ring orbit 3 that is a trajectory of the charged particle beam in the straight traveling direction, and is a plane having the same distance to the main pole 1A and the main pole 1B. When viewed from the perspective direction of the perspective view, the rear region of the beam duct 7 is originally a structure that cannot be seen, but the beam duct 7 is shown as a transparent member for the sake of simplicity of explanation.

  As shown in FIG. 6, the coil 41B and the coil 51B are both racetrack-shaped coils. The coil 51B is larger than the coil 41B, and the coil 41B is configured to fit inside the coil 51B. Also. It is desirable that the long axis of the coil 41B and the long axis of the coil 51B are arranged to coincide.

  Side poles 21B and 22B are installed between the coil 41B and the coil 51B. The side poles 21B and 22B correspond to a part of a member formed by processing or assembling a magnetic body in a substantially racetrack shape.

  The main pole 1B is installed on the inner diameter side of the coil 41B. Since the coil 41B is installed on the outer peripheral side of the main pole 1B and the coil 44B is installed close to the outer peripheral side of the side pole 21B and the side pole 22B, the magnetic force generated by the coil 41B and the coil 44B is efficiently desired. Can be led in the direction of

  The main pole 1B is a columnar member having an elliptical cross section. Like a side pole, it is formed of a magnetic material, and for example, pure iron or silicon steel is used. A laminated body of other electromagnetic steel sheets may be used instead of silicon steel. Further, it is desirable that the direction of the major axis of the cross section of the main pole 1B and the direction of the major axis of the substantially racetrack shape including the side pole as a part coincide with each other.

  More preferably, the major axis of the coil 41B, the major axis of the coil 51B, the major axis of the cross section of the main pole 1B, and the major axis of the racetrack-shaped member partially including the side poles are aligned with each other. The member is arranged. Further, it is desirable that the ring trajectory 3 of the charged particle beam is orthogonal to these long axes.

  In a racetrack-shaped member partially including the side poles 21B and 22B, the size of each side pole is approximately the same as the length of the major axis of the main pole 1B. Due to the above dimensions and the arrangement relationship between the long axis and the ring orbit 3, the intensity of the magnetic field distribution is approximately equal in the plane of the deflecting surface 10 and in the direction orthogonal to the straight beam traveling direction (ring orbit 3). Become. In other words, since the magnetic field distribution in the orthogonal direction of the beam is uniform within an allowable range, the disturbance of the magnetic field experienced by the charged particle beam can be suppressed as a result.

  Note that the side poles 21B and 22B do not form a part of a substantially racetrack shape but may be a simple flat plate member. In that case, it is only necessary that the two side poles be arranged like a wall separating at least the linear portion of the coil 41B and the linear portion of the coil 51B. Moreover, it is desirable to install a side pole so that it may become parallel to the long axis of the main pole 1B.

  The structure other than each coil and each pole portion will be described.

  The yokes 5A and 5B are made of a magnetic material and are also called yokes. The support member 8 is a nonmagnetic material. The effect of forming the support member 8 from a non-magnetic material is as described above. The beam duct 7 is placed in the center, the yoke 5A is disposed at the upper part, and the yoke 5B is disposed at the lower part. The pair of yokes are fixed to each other by a support member 8. Further, as shown in FIG. 5, a main pole 1A and side poles 21A, 22A are installed on the yoke 5A. A main pole 1B and side poles 21B and 22B are attached to the yoke 5B. Each pole forms a gap in the vertical direction, and a beam duct 7 is installed in this gap.

  The mode of support by the support member 8 is the same as the example shown in FIG. When viewed from the charged particle beam incident on the deflecting electromagnet apparatus 100 (as viewed from the side poles 21A and 21B arranged on the upstream side in the beam traveling direction), the upper and lower yokes support the support member 8 so as to have a C shape. Fixed by. By adopting a C-shaped shape, the installation space can be reduced as compared with an H-shaped electromagnet as shown in FIG. Further, when the electromagnet is moved for maintenance or the like, an effect such as no need to remove the beam duct 7 can be obtained.

  In the above description, the main pole 1A, the side poles 21A and 22A, and the yoke 5A are independent members, and each is assembled. However, these may be integrally formed. The same applies to members denoted by reference symbol B.

  Next, the role of each coil and pole will be described. In addition, about each coil and each pole member, the structure which attached | subjected the code | symbol A corresponding to what was attached | subjected the code | symbol B is arrange | positioned in plane symmetry regarding the deflection surface 10. FIG.

  First, functions of the side poles 21A and 21B, the side poles 22A and 22B, and the coils 51A and 51B installed on the outer periphery will be described.

  The magnetic field generator having the pole portion and the coil has a role of generating a magnetic field for returning the charged particle beam to the ring orbit 3. This magnetic field is generated when current flows in the same direction through the coils 51A and 51B. In the example of FIG. 5, the current is passed clockwise as viewed from the upper side in the vertical direction of the bending electromagnet apparatus 100.

  The magnetic field generator having the main poles 1A and 1B, the coils 41A, and the coils 41B deflects the charged particle beam so as to suddenly deviate from the ring trajectory 3, and generates a magnetic field that forms the deflection trajectory 9. This generates emitted light. The magnetic field forming the deflection trajectory 9 is generated when currents in the same direction are applied to the coils 41A and 41B. In the example of FIG. 5, the current is passed counterclockwise as viewed from the upper side in the vertical direction of the bending electromagnet apparatus 100. In addition, the electric current supplied to the coils 41A and 41B is opposite to the electric current supplied to the coils 51A and 51B. Note that the direction of current application may be opposite. However, the current flowing in the coils 41A and 41B and the current flowing in the coils 51A and 51B must be in opposite directions.

  Next, the path of the magnetic field formed by the arrangement of the coil and pole described above will be described.

  A magnetomotive force is generated when a current is applied to the upper coils 41A and 51A. As shown in FIG. 5, a magnetic field (line of magnetic force 6) passing through the main pole 1A, the side poles 21A and 22A, and the yoke 5A is generated. Generated. Similarly, a magnetomotive force is generated when current is passed through the lower coils 41B and 51B, and a magnetic field passing through the main pole 1B, the side poles 21B and 22B, and the yoke 5B is generated.

  More specifically, when a current is passed through the coils 41A and 41B, a magnetic field from the main pole 1B toward the main pole 1A is formed as shown in FIG. The magnetic field entered from the main pole 1A travels inside the yoke 5A and travels from the side poles 21A and 22A to the lower side poles 21B and 22B. The magnetic field entered from the side poles 21B and 22B travels inside the yoke 5B and travels from the main pole 1B to the main pole 1A.

  The reason why the magnetic field lines 6 pass between the upper and lower main poles or between the upper and lower side poles is that the distance passing through the atmosphere is the shortest through these portions. In other words, this path is formed because the integrated value of the magnetoresistance is smaller than when other paths are taken.

  The current passed through the coils 51A and 51B forms a magnetic field from the side pole 21A and the side pole 22A toward the side poles 21B and 22B. At this time, it seems that a magnetic field from the main pole 1A to the main pole 1B is formed, but this does not occur. There is an opposite magnetic field formed by the coils 41A and 41B between the two main poles, and this magnetic field is stronger than the magnetic field generated by the coils 51B and 51A. Therefore, a magnetic field from the main pole 1A toward the main pole 1B is not generated. The magnetic field lines of the magnetic field formed by the coils 51A and 51B are pushed around the main poles 1A and 1B by the magnetic field derived from the coils 41A and 41B, and become magnetic fields directed from the side poles 21A and 22A to the side poles 21B and 22B.

  The magnetic field that has entered the side poles 21B and 22B travels inside the yoke 5B and travels from the main pole 1B to the main pole 1A. The magnetic field entering the main pole 1A travels through the yoke 5A and reaches the side poles 21A and 22A again. In this way, a magnetic field as indicated by the magnetic lines of force 6 is also formed by the coils 51A and 51B.

  Further, since the support member 8 that connects the yokes 5A and 5B is made of a non-magnetic material, the magnetic resistance is magnetic (particularly the yokes 5A and 5B, the main poles 1A and 1B, the side poles 21A, 22A, and 21B, 22B). The magnetic circuit has the property of being closed by a magnetic path with a small magnetic resistance. Accordingly, the magnetic pole travels from the main pole 1A to the main pole 1B through the support member 8 which is a nonmagnetic material and travels from the main pole 1A to the inside of the yoke 5A, and passes through the side poles 21A and 22A. , 22B, and the magnetic path of the magnetic path reaching the main pole 1B through the inside of the yoke 5B is small, so that a magnetic circuit as shown in FIG. 5 is formed.

  The magnetic field analysis result regarding the bending electromagnet apparatus 100 of the present embodiment is shown in FIG. The graph shown on the left side in FIG. 7 shows the installation positions of the main pole and the side pole in each of the new and old systems, and the graph shown on the right side shows the deflection trajectory 9 of the charged particle beam for each of the new and old systems.

  First, the graph shown on the left side of FIG. 7 will be described. The horizontal axis of this graph indicates the position on the ring track 3. The zero point on the horizontal axis is the intersection of the major axis of the main poles 1A and 1B and the ring track 3, that is, the center in the ring track direction of the deflection electromagnet apparatus 100. The vertical axis indicates the magnetic field on the ring orbit 3 experienced by the charged particle beam. The magnetic field on the ring orbit 3 approximated a one-dimensional magnetic field formed on the ring orbit 3 by the main pole and the side pole. This magnetic field is a magnetic field acting perpendicularly to the ring orbit 3. In addition, a magnetic field for deflecting the charged particle beam and generated between the main poles is a positive magnetic field, and a magnetic field for returning the charged particle beam to the ring orbit and generated between the side poles is a negative magnetic field. . An empirical magnetic field of zero indicates that the charged particle beam has returned from the deflection trajectory 9 to the ring trajectory 3.

  The graph shown in the upper left part of FIG. 7 shows the case of the old system shown in FIG. 2, and the graph shown in the lower part shows the case of the new system shown in FIG. The old system assumed that the three racetrack coils were arranged so that the central axes were all parallel, and the magnetic field distribution was calculated.

  In the old system shown in FIG. 2, for example, a portion where the + current of the coil 43A flows is immediately adjacent to a portion where the + current flows through the coil 41A. That is, there are at least two coil widths through which + current flows, and the length of the bending electromagnet device 11 in the ring orbit 3 direction is increased correspondingly. As a result, the distance from the main pole 1A that forms a positive magnetic field to the side pole 22A that forms a negative magnetic field becomes longer.

  In contrast to the old system, in the new system shown in FIG. 5, the coil 41A does not have a coil in which + current flows in the same direction on the side of the portion in which + current flows. The distance to is shortened. That is, the deflection electromagnet apparatus 100 of the present embodiment can bring the side pole 22A closer to the center of the deflection electromagnet apparatus 100, and the region where the negative magnetic field is formed on the ring track 3 is made closer to the center of the deflection electromagnet apparatus 100. Yes. Although the relationship between the main pole 1A and the side pole 22A is shown in FIG. 7, the relationship between the main pole 1A and the side pole 21A is also the same, and the same applies to each coil and pole denoted by reference character B. is there.

  From the analysis result shown on the left side of FIG. 7, in the new system of deflection electromagnet apparatus 100, the side poles 21 </ b> A and 22 </ b> A (21 </ b> B and 22 </ b> B) can be arranged near the center of the deflection electromagnet apparatus 100. By comparison, it can be seen that a magnetic field rising steeply from the negative region to the positive region is formed, and the charged particle beam is deflected to reach the central magnetic field point 0.

  A calculation example in which the beam trajectory is calculated using the magnetic field distribution shown on the left side of FIG. 7 for a specific deviation from the ring trajectory 3 is shown on the right side of FIG. From this calculation result, it can be seen that the new system can reduce the deviation of the charged particle beam from the ring orbit 3, that is, the amplitude of the deflection orbit 9, by about 14% compared to the old system. Here, although the deviation from the ring orbit depends on the beam storage energy, a 2.5 GeV storage ring was assumed in this study.

  According to the present embodiment, a pair of yokes arranged vertically opposite to each other has a main pole and a side pole, and the support member that connects and supports the upper yoke and the lower yoke is formed of a non-magnetic material. Therefore, a magnetic field having an opposite direction is efficiently generated on the ring orbit 3 of the charged particle beam. In other words, the direction of the magnetic field generated between the main pole 1A and the main pole 1B (the gap portion and the region through which the charged particle beam passes) is set between the side poles 21A and 22A (the gap portion and the charged particle beam). The direction of the magnetic field generated in the region through which the charged particle beam passes) and the direction of the magnetic field generated between the side poles 21B and 22B (the region through which the charged particle beam passes). It is configured so that the magnetic field is formed closer than the old system.

  Thus, since the deflection | deviation electromagnet apparatus 100 of a present Example can narrow the area | region for deflecting a charged particle beam, the whole magnitude | size of the deflection | deviation electromagnet apparatus 100 can be made small. In addition, since the difference (distance) between the trajectory and the ring trajectory when the charged particle beam is deflected can be shortened, the beam duct 7 can also be designed smaller than the old system.

  Further, since the deflection electromagnet device 100 can be downsized, the installation space can be suppressed. Moreover, if the beam duct 7 is formed in the same size as the conventional one, the radiation power applied to the inside of the beam duct 7 can also be reduced. Further, it is possible to obtain effects such as downsizing the cooling system of the beam duct 7. Further, the manufacturing cost can be reduced by downsizing the deflection electromagnet device 100.

  As described in the first embodiment, the deflection electromagnet device can be reduced in size by reviewing the coil arrangement system. A system different from that of the first embodiment will be described with reference to FIG. 8 as a deflecting electromagnet apparatus according to a second preferred embodiment of the present invention.

  As shown in FIG. 8, the deflecting electromagnet apparatus 100 of the present embodiment includes a side pole that is a first pole portion in order from the upstream side in the traveling direction of the charged particle beam along the beam duct 7 through which the charged particle beam passes. 21A and 21B, main poles 1A and 1B as second pole portions, and side poles 22A and 22B as third pole portions are arranged. Each pole is formed by fixing or machining with respect to the upper yoke 5A or the lower yoke 5B, and the yoke 5A and the yoke 5B are supported by a support member 8 formed of a nonmagnetic material.

  The difference from the first embodiment is that the coil system installed on the outer peripheral side of the side poles 21A, 22A, 21B, 22B is different. In FIG. 5, the winding center axis of the coils 41A and 41B and the winding center axis of the coils 51A and 51B are arranged so as to coincide with each other. On the other hand, in the present embodiment shown in FIG. 8, the winding central axes of the coils 61A, 61B, 62A, 62B are not parallel to the winding central axes of the coils 41A, 41B installed on the main pole. For example, in this embodiment, the two central axes are installed so as to form an angle of approximately 90 degrees. In other words, the coils 61A, 61B, 62A, and 62B have coil surfaces along the side surfaces of the side poles on which the coils are installed. In addition, a coil surface refers to the coil surface contained in the plane orthogonal to the winding axis of a coil. Further, the coil 61A and the coil 61B are disposed on the outer side surfaces of the side pole 21A and the side pole 21B in the longitudinal direction of the beam duct 7. Similarly, the coil 62 </ b> A and the coil 62 </ b> B are disposed on the outer side surfaces of the side pole 22 </ b> A and the side pole 22 </ b> B in the longitudinal direction of the beam duct 7.

  However, since this is an example, it may be installed such that the direction of the central axis has an angle with respect to the ring track 3. From the viewpoint of magnetic field symmetry, it is desirable that the coil 61A is symmetrical with respect to the coil 61B and the coil 62A is symmetrical with respect to the deflection surface 10 with respect to the coil 62B. Further, it is desirable that the coil 61A is symmetrical with respect to the coil 62A and the coil 61B is symmetrical with respect to the coil 62B with respect to a plane perpendicular to the deflection surface 10 and passing through the center of the deflection electromagnet apparatus 100.

  The coils 61 </ b> A, 61 </ b> B, 62 </ b> A, 62 </ b> B desirably have a shape having a major axis in a direction perpendicular to the ring track 3 and parallel to the deflection surface 10. Specifically, a racetrack shape, an oval shape, a rectangular shape, or the like can be adopted. Further, it is desirable that the direction of these long axes and the direction of the long axes of the coils 41A and 41B coincide. With such an arrangement, the distribution of the magnetic field across the beam duct 7 in the direction orthogonal to the ring trajectory 3 becomes uniform in the same manner as in the first embodiment, and the charged particle beam can be deflected with high accuracy. Become.

  Further, it is desirable that the yoke 5A and the yoke 5B have end portions at positions sufficiently protruding from the installation positions of the coils 61A, 61B, 62A, and 62B in the direction along the ring raceway 3. The magnetic field generated when a current is passed through these coils has magnetic lines of force along the direction of the ring orbit 3 before and after passing through the inside of the coils, so that a magnetic path that circulates inside the yoke 5A and the yoke 5B is formed. This is because a certain distance is required.

  Further, the yokes 5A and 5B preferably have the same length as the major axis direction of each coil in the direction perpendicular to the ring track 3 and parallel to the deflection surface 10. This is because if the width in this direction is too wide, a magnetic path that circulates in a plane parallel to the deflection surface 10 inside the yoke 5A is likely to be formed.

  The yoke 5A and the yoke 5B are preferably members formed by combining a plurality of magnetic bodies. In particular, in order to install the coils 61A, 61B, 62A, 62B, it is desirable that the yokes 5A, 5B have a structure that can be divided.

  In the present embodiment, the direction of current applied to each coil and the formed magnetic field will be described. The coils 41 </ b> A and 41 </ b> B are supplied with a counterclockwise current when the bending electromagnet device 100 is viewed from above in the vertical direction. The direction of the magnetic field formed by this energization and the magnetic path formed are the same as in the first embodiment.

The current supplied to the coils 61A and 61B flows in the opposite direction on the side facing the deflection surface 10 on the side adjacent to the coils 41A and 41B. The same applies to the coils 62A and 62B. In other words, the current supplied to the coils 41A and 41B is supplied in a direction different from the current flowing through the coils 61A, 61B, 62A, and 62B at the outer peripheral side and the position closest to the beam duct 7. In FIG. 8, the current flowing through the coils 61A and 61B is + on the side facing the deflection surface 10, and the current flowing through the coils 61A and 61B of the coils 41A and 41B is-. Note that the direction of the current is an example, but this relationship is the same even if the direction of the current is opposite.

  When the current shown in FIG. 8 is applied to the coils 61A, 61B, 62A, 62B, a magnetic path in the direction of the magnetic force lines 6 is formed. Since the magnetic field from the coil 61A toward the main pole 1A is opposite to the magnetic field formed by the coil 62A, the magnetic field lines are bent toward the side pole 21A. The reason for moving toward the side pole 21A is that a magnetic path having a smaller magnetic resistance is adopted as described in the first embodiment.

  The magnetic field formed by the coil 62A is also directed to the side pole 22A for the same reason. In addition, since the same relationship holds for the coil 61B and the coil 62B, the magnetic field formed by these coils is also concentrated on the side poles 21B and 22B. Since the magnetic field lines need to be closed loops, the magnetic field lines that enter or exit from each side pole form a magnetic path from the main pole 1B to the main pole 1B, thereby forming a magnetic path for the magnetic field lines 6.

  Also in the coil system in the present embodiment, the distance between the main pole 1 and the side poles 21 and 22 can be made narrower than in the conventional coil system of FIG. 2, so the magnetic field distribution shown in FIG. It can be formed, and the amount of beam displacement can also be suppressed small.

  A deflecting electromagnet apparatus 100, which is a preferred third embodiment of the present invention, will be described with reference to FIG.

  As shown in FIG. 9, the deflection electromagnet apparatus 100 of the present embodiment is a side that is a first magnetic pole in order from the upstream side in the traveling direction of the charged particle beam along the beam duct 7 through which the charged particle beam passes. The poles 21A and 21B, the main poles 1A and 1B that are the second magnetic poles, and the side poles 22A and 22B that are the third magnetic poles are arranged. The difference from the first embodiment is that, for each of the yokes 5A and 5B arranged above and below, side poles 23A and 23B, which are fourth magnetic poles, are further installed on the upstream side, and further on the downstream side. The side poles 24A and 24B, which are five magnetic poles, are installed.

  More specifically, the main poles 1A and 1B, the coils 41A and 41B, the side poles 21A, 21B, 22A and 22B, and the coils 51A and 51B are configured in the same manner as in the first embodiment. In addition to the above configuration, the bending electromagnet device 100 of the present embodiment includes side poles 23A, 23B, 24A, and 24B. A coil 71A is installed on the side pole 23A, a coil 72A is installed on the side pole 24A, a coil 71B is installed on the side pole 23B, and a coil 72B is installed on the side pole 24B.

  These coils 71A, 71B, 72A, 72B are racetrack-shaped coils, and each coil is wound around a side pole on which each coil is installed. In this way, the deflection electromagnet apparatus 100 includes a new side pole and coil, so that five pole portions are installed symmetrically with respect to the deflection surface 10, and the magnetic field distribution formed in the system of the first embodiment is Furthermore, a new magnetic field distribution can be formed by adding a magnetic field in the same direction as the magnetic field formed between the main poles 1A and 1B to the upstream side and the downstream side of the ring track 3. By forming such a magnetic field distribution, the charged particle beam is displaced in both directions around the ring orbit 3 within the deflection surface 10. By making such a displacement possible, the amplitude of one side with respect to the ring track 3, that is, the absolute value of the displacement when the ring track 3 is used as a reference can be further reduced.

  The yokes 5A and 5B shown in each embodiment can be formed by stacking, for example, iron plates. When such a forming method is adopted, generally, voids are likely to be generated in the stacking direction, and the magnetic resistance in the stacking direction is likely to be high. The magnetic field lines 6 of the magnetic field formed by the bending electromagnet apparatus 100 of the present embodiment have a closed loop shape in a plane including the ring orbit 3 as shown in FIG. 5, for example, and are parallel to the cross section shown in FIG. It is preferable to stack the iron plates in the direction, in other words, in parallel with the plane.

Although the present invention has been described with reference to the embodiment, each example is an example, and the scope of the present invention is not limited thereto. The shape, material, joining method of each member, and fixing direction may be appropriately changed without departing from the gist of the present invention. Moreover, the coil mentioned in each Example may be either a normal conducting coil or a superconducting coil.

1 Bending electromagnet 1A Main pole (upper side)
1B Main pole (lower side)
2A Bending electromagnet 2B Bending electromagnet 21A, 22A, 23A, 24A Side pole (upper side)
21B, 22B, 23B, 24B Side pole (lower side)
3 Ring track 41A, 41B, 42A, 42B, 43A, 43B, 51A, 51B, 61A, 61B, 62A, 62B, 71A, 71B, 72A, 72B Coil 5A Yoke (upper)
5B York (lower side)
6 Magnetic field lines (magnetic path)
7 Beam duct 8 Support member 9 Deflection track 10 Deflection surface 11 Deflection electromagnet apparatus 100 Deflection electromagnet apparatus

Claims (9)

A pair of yokes arranged vertically opposite to each other;
A beam duct installed between the pair of yokes;
A nonmagnetic support member for supporting the pair of yokes;
In a deflection electromagnet apparatus comprising:
The yoke protrudes at least toward the beam duct and is disposed along the longitudinal direction of the beam duct; a first magnetic pole, a second magnetic pole, and a third magnetic pole;
A first coil wound around the second magnetic pole;
A second coil including both the first magnetic pole and the third magnetic pole on the inner diameter side;
A deflecting electromagnet device characterized in that is provided. A pair of yokes arranged vertically opposite to each other;
A beam duct installed between the pair of yokes;
A nonmagnetic support member for supporting the pair of yokes;
In a deflection electromagnet apparatus comprising:
The yoke protrudes at least toward the beam duct and is disposed along the longitudinal direction of the beam duct; a first magnetic pole, a second magnetic pole, and a third magnetic pole;
A first coil wound around the second magnetic pole;
A second coil having a coil surface along a side surface of the first magnetic pole;
A third coil having a coil surface along a side surface of the third magnetic pole;
Is provided,
The deflection electromagnet apparatus according to claim 1, wherein the second coil and the third coil are provided outside the first magnetic pole and the third magnetic pole in a longitudinal direction of the beam duct. The bending electromagnet device according to claim 1 or 2,
The pair of yokes are formed by laminating plate-like magnetic bodies,
The deflection electromagnet apparatus according to claim 1, wherein a direction of the stacking is a direction intersecting with a longitudinal direction of the beam duct. The deflection electromagnet device according to claim 1, wherein a current is supplied to the first coil in a direction different from that of the second coil. The superconducting magnet device according to claim 2,
The second coil is energized in a different direction from the third coil,
The first coil is energized so that it is in a direction different from the current flowing through the second coil and the third coil at a position on the outer peripheral side of the first coil and closest to the beam duct. A deflection electromagnet apparatus characterized by the above. The superconducting magnet device according to any one of claims 1 to 5,
The first coil is a racetrack-shaped coil,
The cross section of the second magnetic pole with respect to a plane parallel to the coil surface of the first coil is elliptical or solid racetrack,
The deflection electromagnet device, wherein a major axis of the first coil and a major axis of a cross section of the second magnetic pole are parallel to each other. The deflection electromagnet device according to any one of claims 1 to 6.
The deflecting electromagnet apparatus according to claim 1, wherein the first magnetic pole and the second magnetic pole constitute a linear portion of a racetrack-shaped magnetic body. A pair of yokes arranged vertically opposite each other with a gap between them;
A beam duct installed to include the center of the gap and to include a deflection trajectory of the charged particle beam;
A first coil fixed to the yoke and having a winding center axis perpendicular to a plane parallel to the deflection trajectory;
A second coil fixed to the yoke and having a winding central axis parallel to the first coil central axis;
The deflection electromagnet device, wherein the first coil and the second coil are disposed adjacent to each other. A pair of yokes arranged vertically opposite each other with a gap between them;
A beam duct installed to include the center of the gap and to include a deflection trajectory of the charged particle beam;
A first coil fixed to the yoke and having a winding center axis perpendicular to a plane parallel to the deflection trajectory;
A second coil and a third coil fixed to the yoke and having a winding center axis inclined with respect to the center axis of the first coil;
The deflection electromagnet apparatus, wherein the second coil and the third coil are disposed adjacent to the first coil.

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