Acceleration cavity

Abstract

To provide an acceleration cavity whose interior can be efficiently evacuated.SOLUTION: An acceleration cavity includes: an electrically conductive cylindrical-shaped casing in which a plurality of divided members obtained by dividing planar dividing surfaces along a central axis are provided, and the dividing surfaces face each other with a gap between them; a plurality of cell parts that are arranged inside the casing in a line in the axial direction of the central axis of the casing and are communicated with each other by a communication part through which charged particles can pass; and a vacuum manifold connected to the plurality of cell parts through the gaps.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to accelerating cavities. [Background technology]

[0002] When a high frequency wave is input to the accelerating cavity, an accelerating electric field is generated inside the accelerating cavity, and the accelerating electric field accelerates charged particles such as electrons. For example, a configuration in which a plurality of cells are arranged in the axial direction of a central axis and the cells are connected to each other by communication parts is known as an accelerating cavity of this type (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 1-107499 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, a method has been proposed for manufacturing such an accelerating cavity, in which divided members are formed in advance at dividing surfaces on a plane along the central axis, and the divided members are joined together at the dividing surfaces. In an accelerating cavity manufactured by such a method, a configuration is required for efficiently evacuating the inside of the accelerating cavity.

[0005] The present disclosure has been made in consideration of the above, and has an object to provide an acceleration cavity capable of efficiently evacuating the inside to a vacuum. [Means for solving the problem]

[0006] The acceleration cavity of the present disclosure comprises a conductive cylindrical housing in which a divided member is divided into multiple pieces by planar dividing surfaces along a central axis, with the dividing surfaces facing each other with a gap between them, a plurality of cell sections arranged inside the housing in a line along the axial direction of the central axis of the housing and connected to each other by connecting parts that allow charged particles to pass through, and a vacuum manifold connected to the plurality of cell sections via the gaps. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide an acceleration cavity capable of efficiently evacuating the inside to a vacuum. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view illustrating an example of an acceleration cavity according to the first embodiment. [Diagram 2] FIG. 2 is a diagram showing a configuration along the cross section AA in FIG. [Diagram 3] FIG. 3 is a diagram showing a configuration along the cross section BB in FIG. [Figure 4] FIG. 4 is a cross-sectional view illustrating an example of an accelerating cavity according to the second embodiment. [Diagram 5] FIG. 5 is a diagram showing a configuration along the CC cross section in FIG. [Figure 6] FIG. 6 is a cross-sectional view illustrating an example of an acceleration cavity according to the third embodiment. [Figure 7] FIG. 7 is a diagram showing a configuration along the cross section DD in FIG. [Figure 8] FIG. 8 is a cross-sectional view showing another example of the accelerating cavity according to the third embodiment. [Figure 9] FIG. 9 is a diagram showing a configuration along the E-E cross section in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of an acceleration cavity according to the present disclosure will be described with reference to the drawings. Note that the present invention is not limited to these embodiments. In addition, the components in the following embodiments include those that are replaceable and easy for a person skilled in the art, or those that are substantially the same.

[0010] Fig. 1 is a plan view showing an example of an acceleration cavity 100 according to the first embodiment. Fig. 2 is a diagram showing a configuration along the AA cross section in Fig. 1. Note that Fig. 2 shows a state in which the dividing surface 12 is hatched, although it is not a cross section. Fig. 3 is a diagram showing a configuration along the BB cross section in Fig. 2.

[0011] The acceleration cavity 100 shown in Figs. 1 to 3 generates an acceleration electric field therein by inputting high frequency waves, and accelerates charged particles M, such as electrons, emitted from a radiation source BS. The acceleration cavity 100 and the radiation source BS are used to configure an accelerator AC. The accelerator AC is used in various fields, such as academic fields such as high energy physics experiments and synchrotron radiation facilities, medical fields such as radiation therapy or inspection, and industrial fields such as non-destructive inspection. In the following description, when describing the axial direction of the central axis AX among the directions in the acceleration cavity 100, the radiation source BS side (the side where the charged particles M are incident) is referred to as the incident side, and the opposite side to the incident side (the side where the charged particles are emitted) is referred to as the exit side.

[0012] As shown in FIGS. 1 to 3, an acceleration cavity 100 according to this embodiment includes a housing 10, a cell unit 20, a coupling cavity 30, and a vacuum manifold 40.

[0013] The housing 10 has a cylindrical shape having electrical conductivity. The housing 10 is formed by joining a plurality of divided members 11. The divided members 11 have planar divided surfaces 12 along the central axis AX. The divided members 11 are joined in a state where the divided surfaces 12 face each other. The divided members 11 are provided in a state where a gap 13 is provided between the opposing divided surfaces 12. In this embodiment, a configuration in which the housing 10 is divided in a lateral direction of the central axis AX along a plane perpendicular to the horizontal plane and passing through the central axis AX will be described as an example. The number of divisions of the housing 10 is not limited to two, and may be three or more. The divided members 11 have a shape in which the parts facing each other are generally rounded. This suppresses local application of voltage.

[0014] The cell units 20 are formed inside the housing 10. The cell units 20 are arranged side by side in the axial direction of the central axis AX of the housing 10. The cell units 20 are connected to each other by communication units 22 that allow charged particles to pass through. The communication units 22 are formed along the central axis AX. The cell units 20 accelerate the charged particles by high frequency waves.

[0015] The coupling cavities 30 connect the adjacent cell portions 20. The coupling cavities 30 propagate high frequency waves between the adjacent cell portions 20. The coupling cavities 30 are arranged in locations that do not contribute to the acceleration of charged particles. The coupling cavities 30 are arranged outside the cell portions 20 in the same direction among directions perpendicular to the central axis AX. In the first embodiment, all the coupling cavities 30 are arranged above the cell portions 20 with respect to the central axis AX.

[0016] The vacuum manifold 40 is a part that forms a negative pressure when evacuating the multiple cell parts 20. The vacuum manifold 40 is connected to a vacuum forming part 42 such as a vacuum pump via a pipe 43. In this embodiment, the vacuum manifold 40 is provided, for example, inside the housing 10. The vacuum manifold 40 is formed as one space and is disposed above each of the coupling cavities 30. The vacuum manifold 40 is connected to the multiple cell parts 20 via the gaps 13 between the divided members 11. Each of the cell parts 20 is connected to one vacuum manifold 40. In this embodiment, the vacuum manifold 40 is also connected to the coupling cavity 30 via a communication part 45. Therefore, the vacuum manifold 40 is connected to the multiple cell parts 20 via each of the coupling cavities 30. This configuration ensures that the vacuum manifold 40 and the multiple cell parts 20 are connected to each other.

[0017] As shown in Figure 2, in the housing 10, the dividing surface 12 of each divided member 11 is formed with a unit cell portion 21 and a unit communicating portion 23 which constitute part of the cell portion 20 and the communicating portion 22, a unit connecting cavity 31 which constitutes part of the connecting cavity 30, and a unit manifold 41 which constitutes part of the vacuum manifold 40.

[0018] The cell section 20 is formed by combining unit cell sections 21 provided in each divided member 11. The communication section 22 is formed by combining unit communication sections 24 provided in each divided member 11. The coupling cavity 30 is formed by combining unit coupling cavities 31 provided in each divided member 11. The vacuum manifold 40 is formed by combining unit manifolds 41 formed in each divided member 11.

[0019] The acceleration cavity 100 of this embodiment has a conductive cylindrical shape and includes a housing 10 in which a divided member 11 is divided into multiple parts on a plane along a central axis AX, with divided surfaces 12 along the plane facing each other with a gap 13 between them, a plurality of cell sections 20 arranged inside the housing 10 in a line along the axial direction of the central axis AX of the housing 10 and connected to each other by communication sections 22 that allow charged particles to pass through, and a vacuum manifold 40 connected to the plurality of cell sections 20 via the gap 13.

[0020] According to this configuration, in a configuration in which the housing 10 is arranged with the divided surfaces 12 of the divided members 11 divided into multiple parts facing each other with gaps 13 between them, the vacuum manifold 40 is connected to the multiple cell sections 20 via the gaps 13, making it possible to efficiently evacuate the inside.

[0021] In the acceleration cavity 100 according to this embodiment, the vacuum manifold 40 is connected to the gap 13 of the housing 10 in a direction perpendicular to the central axis AX. With this configuration, the vacuum manifold 40 can be disposed relative to the housing 10 in a direction perpendicular to the central axis AX.

[0022] In the acceleration cavity 100 according to this embodiment, all of the coupling cavities 30 are disposed on the same side of the cell unit 20 in the direction perpendicular to the central axis AX. In this configuration, by moving the coupling cavities 30 to the same side of the cell unit 20 in the direction perpendicular to the central axis AX, the directions of the electric fields in the direction perpendicular to the central axis AX (vertical direction) are reversed for two coupling cavities 30 connected to one cell unit 20. As a result, the electric fields in the vertical direction are cancelled, so that it is possible to prevent the center of the electric field distribution in the cell unit 20 from shifting to the vertical direction. As a result, it is possible to prevent the bias of the charged particle beam.

[0023] The acceleration cavity 100 according to this embodiment further includes a coupling cavity 30 that is provided inside the housing 10 and connects adjacent cell units 20, and the coupling cavity 30 is connected to a vacuum manifold 40. According to this configuration, since the vacuum manifold 40 is connected to the cell unit 20 via the coupling cavity 30, the cell unit 20 can be evacuated to a vacuum by the vacuum manifold 40 more reliably.

[0024] In the acceleration cavity 100 according to this embodiment, the vacuum manifold 40 is provided inside the housing 10. In this configuration, by providing the vacuum manifold 40 inside the housing 10, it is possible to reduce the number of parts.

[0025] Next, a second embodiment will be described. Fig. 4 is a cross-sectional view showing an example of an acceleration cavity 200 according to the second embodiment. Fig. 4 shows a state in which the dividing surface 112 is hatched, although it is not a cross-section. Fig. 5 is a view showing a configuration along the CC cross section in Fig. 4.

[0026] 4 and 5, an acceleration cavity 200 according to the second embodiment includes a housing 110, a cell unit 120, a coupled cavity 130, and a vacuum manifold 140. The housing 110 is formed by joining a plurality of divided members 111. The divided members 111 are joined with their divided surfaces 112 facing each other, and are provided with a gap 113 between the opposing divided surfaces 112. A plurality of cell units 120 are formed inside the housing 110 lined up in the axial direction of the central axis AX, and are communicated with each other by communication units 122. In addition, in the acceleration cavity 200 of the second embodiment, the notation by symbols is omitted, but as in the first embodiment, in the housing 110, on the dividing surface 112 of each divided member 111, there are formed unit cell portions and unit communicating portions which constitute part of the cell portion 120 and the communicating portion 122, unit combined cavities which constitute part of the combined cavity 130, and unit manifolds which constitute part of the vacuum manifold 140.

[0027] In the acceleration cavity 200 according to this embodiment, the coupling cavity 130 and the vacuum manifold 140 are disposed on opposite sides of the cell unit 120 in a direction perpendicular to the central axis AX. That is, in the direction perpendicular to the central axis AX, the coupling cavity 130 is disposed on one side of the cell unit 120, and the vacuum manifold 140 is disposed on the other side of the cell unit 120 opposite to the one side. In the example shown in FIG. 4, the coupling cavity 130 is disposed on the upper side of the cell unit 120, and the vacuum manifold 140 is disposed on the lower side of the cell unit 120.

[0028] In this configuration, the vacuum manifold 140 and the cell unit 120 are connected via the gap 113. Therefore, the vacuum manifold 140 can evacuate the cell unit 120 via the gap 113. This allows the cell unit 120 to be evacuated efficiently.

[0029] Next, a third embodiment will be described. Fig. 6 is a cross-sectional view showing an example of an acceleration cavity 300 according to the third embodiment. In Fig. 6, the dividing surface 212 is hatched, although it is not a cross-section. Fig. 7 is a view showing the configuration along the cross section DD in Fig. 6.

[0030] As shown in Figs. 6 and 7, the acceleration cavity 300 according to the third embodiment includes a housing 210, a cell unit 220, a coupled cavity 230, and a vacuum manifold 240. The housing 210 is formed by joining a plurality of divided members 211. The divided members 211 are joined with their divided surfaces 212 facing each other, and are provided with a gap 213 between the opposing divided surfaces 212. The gap 213 is sealed by welding, adhesion, a sealing material, or the like, except for the vacuum manifold 240 and the communication part 222 provided outside the housing 210. A plurality of cell units 220 are formed inside the housing 210 lined up in the axial direction of the central axis AX, and are communicated with each other by the communication part 222. In addition, in the acceleration cavity 300 of the third embodiment, the notation by symbols is omitted, but as in the above embodiments, in the housing 210, on the dividing surface 212 of each divided member 211, there are formed unit cell portions and unit communicating portions which constitute part of the cell portion 220 and the communicating portion 222, unit combined cavities which constitute part of the combined cavity 230, and unit manifolds which constitute part of the vacuum manifold 240.

[0031] 6 and 7, in the acceleration cavity 300 according to the third embodiment, the vacuum manifold 240 is provided outside the housing 210. That is, the vacuum manifold 240 and the housing 210 are provided as separate components. This configuration increases the degree of freedom in arranging the vacuum manifold 240.

[0032] 6 and 7, the vacuum manifold 240 is provided inside a manifold forming member 242 that is disposed to the side in the axial direction of the central axis AX with respect to the housing 210. The manifold forming member 242 has an arc-shaped cross section as shown in Fig. 7, for example, but is not limited to this configuration and may have other shapes, such as a rectangular shape or a triangular shape.

[0033] 6 and 7, the housing 210 has an exhaust hole 214. The exhaust hole 214 is disposed at a position of the housing 210 that is away from each cell portion 220. The exhaust hole 214 is formed in a direction intersecting the dividing surface 212. The exhaust hole 214 communicates between the gap 213 and the vacuum manifold 240.

[0034] Fig. 8 is a cross-sectional view showing another example of the acceleration cavity according to the third embodiment. Fig. 8 shows a state in which the dividing surface 212 is hatched, although it is not a cross-section. Fig. 9 is a diagram showing a configuration along the E-E cross-section in Fig. 8. The acceleration cavity 300A shown in Figs. 8 and 9 is different in configuration from the acceleration cavity 300A in that the vacuum manifold 240A (manifold forming member 242A) is disposed below the housing 210. In this configuration, the vacuum manifold 240A is connected to the cell unit 220 via the gap 213.

[0035] In the acceleration cavities 300 and 300A according to this embodiment, the vacuum manifold 240 is provided outside the housing 210. This configuration increases the degree of freedom in arranging the vacuum manifold 240.

[0036] In the acceleration cavity 300, the housing 210 has exhaust holes 214 at a position away from the multiple cell sections 220, the exhaust holes 214 being formed in a direction intersecting the dividing surface 212 and communicating between the gaps 213 and a vacuum manifold 240 provided outside the housing 210. In this configuration, the cell sections 220 can be efficiently evacuated through the exhaust holes 214 by the vacuum manifold 240.

[0037] As described above, the acceleration cavity according to the first aspect of the present disclosure comprises a conductive cylindrical housing 10 in which a divided member 11 divided into multiple parts on a plane along a central axis AX is arranged with divided surfaces 12 along the plane facing each other with a gap 13 therebetween, a plurality of cell sections 20 arranged inside the housing 10 in a line along the axial direction of the central axis AX of the housing 10 and connected to each other by communication sections 22 that allow charged particles to pass through, and a vacuum manifold 40 connected to the plurality of cell sections 20 via the gap 13.

[0038] According to this configuration, in a configuration in which the housing 10 is arranged with the divided surfaces 12 of the divided members 11 divided into multiple parts facing each other with gaps 13 between them, the vacuum manifold 40 is connected to the multiple cell sections 20 via the gaps 13, making it possible to efficiently evacuate the inside.

[0039] The acceleration cavity according to the second embodiment of the present disclosure is similar to the acceleration cavity according to the first embodiment in that vacuum manifold 40 is connected to gap 13 of housing 10 in a direction perpendicular to central axis AX.

[0040] According to this configuration, the vacuum manifold 40 can be disposed relative to the housing 10 in a direction perpendicular to the central axis AX.

[0041] The acceleration cavity according to the third aspect of the present disclosure is an acceleration cavity according to the first or second aspect, further comprising coupling cavities 30 provided inside the housing 10 and connecting adjacent cell units 20, all of the coupling cavities 30 being arranged on the same side of the cell units 20 in a direction perpendicular to the central axis AX.

[0042] In this configuration, by moving the coupling cavities 30 to the same side of the cell unit 20 in the direction perpendicular to the central axis AX, the center of the electric field distribution in the direction perpendicular to the central axis AX can be aligned with the central axis AX. This makes it possible to suppress the bias of the charged particle beam.

[0043] The acceleration cavity according to the fourth aspect of the present disclosure is the same as the acceleration cavity according to the third aspect, except that the coupling cavity 30 is connected to a vacuum manifold 40 .

[0044] According to this configuration, since the vacuum manifold 40 is connected to the cell portion 20 via the coupling cavity 30, the cell portion 20 can be evacuated to a vacuum by the vacuum manifold 40 more reliably.

[0045] The acceleration cavity according to the fifth embodiment of the present disclosure is similar to the acceleration cavity according to the third embodiment in that the coupling cavity 130 and the vacuum manifold 140 are disposed on opposite sides of the cell unit 120 in the direction perpendicular to the central axis AX.

[0046] In this configuration, the vacuum manifold 140 and the cell unit 120 are connected via the gap 113. Therefore, the vacuum manifold 140 can evacuate the cell unit 120 via the gap 113. This allows the cell unit 120 to be evacuated efficiently.

[0047] The acceleration cavity according to the sixth aspect of the present disclosure is the acceleration cavity according to any one of the first to fifth aspects, in which a vacuum manifold 40 is provided inside the housing 10.

[0048] In this configuration, by providing the vacuum manifold 40 inside the housing 10, it is possible to reduce the number of parts.

[0049] The acceleration cavity according to the seventh aspect of the present disclosure is the acceleration cavity according to any one of the first to fifth aspects, in which a vacuum manifold 240 is provided outside the housing 210.

[0050] This configuration allows greater freedom in placement of the vacuum manifold 240.

[0051] The acceleration cavity according to the eighth aspect of the present disclosure is the acceleration cavity according to the seventh aspect, in which the housing 210 has an exhaust hole 214 formed in a position away from the multiple cell sections 220, in a direction intersecting the dividing surface 212, and communicating between the gap 213 and a vacuum manifold 240 provided outside the housing 210.

[0052] In this configuration, the vacuum manifold 240 allows the cell portion 220 to be efficiently evacuated via the exhaust holes 214 . [Explanation of symbols]

[0053] 10,110,210 Case 11,111 Partition 12,112,212 split plane 13,113,213 Gap 20,120,220 Cell section 21 Unit cell section 22,45,122 Communication part 23,24 Unit communication part 30,130 combined cavity 31 Unit Coupled Cavity 40,140,240 Vacuum manifold 41 unit manifold 42 Vacuum forming section 43 Piping 100,200,300,300A acceleration cavity 214 Exhaust Vent 242 Manifold forming member AC accelerator AX center axis BS source M charged particles

Claims

1. a conductive cylindrical housing, in which divided members are divided into a plurality of sections along a plane extending along a central axis, with some of the divided surfaces along the plane facing each other with a gap therebetween, and other portions of the divided surfaces being joined together; a plurality of cell units arranged inside the housing in a lined-up state in an axial direction of a central axis of the housing and connected to each other by communication units through which charged particles can pass; a vacuum manifold connected to the plurality of cell portions via the gap; An accelerating cavity comprising:

2. The vacuum manifold is connected to the gap of the housing in a direction perpendicular to the central axis. The acceleration cavity of claim 1 .

3. a coupling cavity provided inside the housing and connecting the adjacent cells, All of the coupling cavities are arranged on the same side of the cell portion in a direction perpendicular to the central axis. The acceleration cavity of claim 1 .

4. The coupling cavity is connected to the vacuum manifold. The acceleration cavity of claim 3 .

5. The coupling cavity and the vacuum manifold are disposed on opposite sides of the cell portion in a direction perpendicular to the central axis. The acceleration cavity of claim 3 .

6. The vacuum manifold is provided inside the housing. The acceleration cavity of claim 1 .

7. The vacuum manifold is provided outside the housing. The acceleration cavity of claim 1 .

8. The housing has an exhaust hole formed in a position away from the plurality of cells in a direction intersecting the dividing surface, the exhaust hole communicating the gap with the vacuum manifold provided outside the housing. The acceleration cavity of claim 7 .

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