CN116828688A - Self-shielding particle accelerator system - Google Patents

Abstract

The application provides a self-shielding type particle accelerator system, which improves the maintainability of a particle accelerator. The self-shielding particle accelerator system includes: a vacuum box (44) for accelerating the particles; a rear wall (12) that shields radiation; a front wall (14) that surrounds the vacuum box (44) together with the rear wall (12), is capable of shielding radiation from the vacuum box (44), and is capable of moving relative to the rear wall (12); and a guide rail guiding movement of the front wall body which is accessible and separable with respect to the rear wall body.

Description

Self-shielding particle accelerator system

Technical Field

The present application claims priority based on japanese patent application No. 2022-051994 filed on 28 of 3 months of 2022. The entire contents of this japanese application are incorporated by reference into the present specification.

The present application relates to a self-shielding particle accelerator system.

Background

In the production of a medicine for examination labeled with a radioisotope used in positron emission tomography (PET: positron Emission Tomography) and in radiotherapy, a particle accelerator such as a cyclotron is used. A so-called self-shielding type particle accelerator system is known which includes a radiation shielding wall surrounding a particle accelerator in order to shield radiation such as neutron rays and gamma rays generated during operation of the particle accelerator (for example, refer to patent document 1).

Patent document 1: japanese patent laid-open No. 2000-105293

Disclosure of Invention

In such a self-shielded particle accelerator system, maintenance of the particle accelerator in the wall body is performed by opening the radiation shielding wall body, but it is desirable to reduce the burden of maintenance work as much as possible. The present invention provides a self-shielding particle accelerator system for improving maintainability of a particle accelerator.

The self-shielding particle accelerator system of the present invention includes: a vacuum box for accelerating particles; 1 st wall body for shielding radiation; a 2 nd wall body which encloses the vacuum box together with the 1 st wall body, thereby shielding radiation from the vacuum box and being movable relative to the 1 st wall body; and a guide rail for guiding the movement of the 2 nd wall body which can be accessed and separated relative to the 1 st wall body.

The joining of the 1 st wall and the 2 nd wall may be performed at a position where a person can access the vacuum box in a state where the 1 st wall and the 2 nd wall are separated. The joint position of the 1 st wall body and the 2 nd wall body is the side of the vacuum box. The end face on the 2 nd wall side of the 1 st wall is located along a plane intersecting the moving direction of the 2 nd wall, and the end face is located at a position overlapping the vacuum box when viewed from a direction parallel to the plane.

The vacuum box may be provided with an acceleration electrode, a beam detection device, a beam extraction device, and a target device, which are conveniently accessible or removable from the side of the vacuum box.

The 1 st wall may have a 1 st recess in a flat cross section, the 2 nd wall may have a 2 nd recess facing the 1 st recess in a flat cross section, and the 1 st wall and the 2 nd wall may be joined to each other to form a radiation shield in which the vacuum box is accommodated in an internal space formed by the 1 st recess and the 2 nd recess.

The 2 nd wall may be supported by a slider portion that moves along the extending direction of the guide rail on the guide rail, and the slider portion may allow the 2 nd wall to be displaced relative to the guide rail in a direction other than the extending direction of the guide rail. The slider portion allows the 2 nd wall to be displaced relative to the rail in the width direction of the rail.

The guide rail may be provided in a guide rail installation groove provided on the ground, and the guide rail installation groove may extend further in the longitudinal direction from an end portion of the guide rail and may have a guide rail non-existing region where the guide rail does not exist.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a self-shielding type particle accelerator system can be provided that improves the maintainability of the particle accelerator.

Drawings

Fig. 1 is an exploded perspective view showing the structure of a radiation shield included in a cyclotron system according to an embodiment.

Fig. 2 is an exploded perspective view showing the structure of the rear wall body.

Fig. 3 is a diagram showing a connection mechanism for connecting adjacent functional blocks.

Fig. 4 is an exploded perspective view showing the structure of the front wall.

Fig. 5 is an exploded perspective view showing the structure of a cyclotron housed in a radiation shield.

Fig. 6 is a plan view showing a state in which a cyclotron is accommodated in a radiation shield.

Fig. 7 (a) is a perspective view of a frame constituting the FRU function block viewed from above, and fig. 7 (b) is a perspective view of the frame viewed from below.

Fig. 8 (a) is a perspective view of a housing constituting the fli function block viewed from above, and fig. 8 (b) is a perspective view of the housing viewed from below.

Fig. 9 is a perspective view showing a frame constituting the FLS function block.

Fig. 10 is a perspective view showing a frame constituting the FRS function block.

Fig. 11 (a) is a perspective view of a frame constituting the RRU function block viewed from above, and fig. 11 (b) is a perspective view of the frame viewed from below.

Fig. 12 (a) is a perspective view of a housing constituting the RLU function block, viewed from above, and fig. 12 (b) is a perspective view of the housing, viewed from below.

Fig. 13 is a perspective view showing a casing constituting the RLS function block.

Fig. 14 is a perspective view showing a casing constituting the RRS function block.

Fig. 15 is a side view showing a state in which the radiation shield is opened when viewed from the X direction.

Fig. 16 (a) to (c) are side views each showing a state in which another example of the radiation shield is opened when viewed from the X direction.

Fig. 17 is a plan view showing the guide rail.

Fig. 18 (a) is a cross-sectional view of the rail periphery including the slider portion, and fig. 18 (b) is a plan view thereof.

Fig. 19 (a) is a cross-sectional view of the rail periphery including other types of slider parts, and fig. 19 (b) is a cross-sectional view showing a modification of the rail periphery.

Fig. 20 (a) is a cross-sectional view of a rail-absent area, and fig. 20 (b) is a diagram showing a moving mechanism of a wall function block according to a modification.

Description of symbols

1-cyclotron system (self-shielding type particle accelerator system), 10-radiation shield, 12-rear wall (1 st wall), 12 a-recess (1 st recess), 12 h-front end face, 14-front wall (2 nd wall), 14 a-recess (2 nd recess), 44-vacuum box, 253-accelerating electrode, 255-target device, 257-beam extraction device, 259-beam shutter (beam detection device), 303-joint (joint position), 311A, 311B-slider part, 315-rail arrangement groove, 321-plane roller (width direction displacement allowing part), 325-rolling body, 327-rail non-existence region, R-internal space, W, W, W2, W3, W4-rail.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repetitive description thereof will be omitted.

Fig. 1 is an exploded perspective view showing the structure of a radiation shield 10 included in a cyclotron system 1 (self-shielding type particle accelerator system) (fig. 6) according to the present embodiment. As shown in fig. 6, the cyclotron system 1 includes a cyclotron 40 (particle accelerator) and a radiation shield 10 for shielding radiation by surrounding the cyclotron 40. As shown in fig. 1, the radiation shield 10 includes a rear wall 12 and a front wall 14.

As shown in fig. 2, the Rear wall body 12 has a Right Upper wall (RRU: return Right Upper) function block 16, a Left Upper wall (RLU: return Upper) function block 18, a Right Side wall (RRS: return Right Side) function block 20, and a Left Side wall (RLS: return Side) function block 22. The RRS function block 20 and the RLS function block 22 are erected in the vertical direction, and have a substantially L-shaped cross section. The RRU function 16 and the RLU function 18 are disposed to extend in the horizontal direction, and cover the upper portions of the RRS function 20 and the RLS function 22. As shown in fig. 2 and 3, the RRU function block 16, the RLU function block 18, the RRS function block 20, and the RLS function block 22 are connected to each other by fastening the connecting portion C at a plurality of positions by bolts 24 and nuts 26.

As shown in fig. 4, the Front wall 14 has a Right Upper wall (FRU: front Right Upper) functional block 28, a Left Upper wall (fli: front Left Upper) functional block 30, a Right Side wall (FRS: front Right Side) functional block 32, and a Left Side wall (FLS: front Left Side) functional block 34. The FRS function block 32 and the FLS function block 34 are erected in the vertical direction, and have a substantially L-shaped cross section. The FRU function block 28 and the FLU function block 30 are provided extending in the horizontal direction, and cover the upper portions of the FRS function block 32 and the FLS function block 34. Similar to the rear wall 12, the FRU function block 28, the fli function block 30, the FRS function block 32, and the FLS function block 34 are connected to each other by fastening the connecting portions C by bolts 24 and nuts 26 at a plurality of locations.

By joining these rear wall body 12 and front wall body 14, the radiation shield 10 is formed. The cyclotron 40 is housed in an internal space R (refer to fig. 6) formed by the radiation shield 10 and formed by the concave portion 12a of the rear wall body 12 and the concave portion 14a of the front wall body 14 in a flat cross section, so as to constitute the self-shielded cyclotron system 1. As described above, the term "self-shielding" refers to a method of shielding a particle accelerator by a wall body provided for shielding the particle accelerator itself, unlike a wall of a building in which the particle accelerator such as a cyclotron is provided. In this sense, unlike particle accelerator systems in which the walls that shield the particle accelerator form part of a building.

As shown in fig. 5, the cyclotron 40 is a so-called vertical cyclotron, and has a pair of magnetic poles 42, a vacuum box 44, and an annular yoke 46 surrounding the pair of magnetic poles 42 and the vacuum box 44. A part of the pair of magnetic poles 42 is inserted into the vacuum box 44, and the upper surfaces of the pair of magnetic poles are faced to each other with a predetermined gap therebetween in the vacuum box 44. In the gap between the pair of magnetic poles 42, particles such as protons and deuterium are multiply accelerated.

Fig. 6 is a plan view showing a state in which the cyclotron 40 is accommodated in the radiation shield 10. In fig. 6, the RRU function block 16, the RLU function block 18, the FRU function block 28, and the fli function block 30 are shown removed for convenience of explanation.

As shown in fig. 6, the cyclotron 40 is disposed substantially at the center in the radiation shield 10. The wall surfaces that thus divide the space accommodating the cyclotron 40 in a state where the rear wall body 12 is joined to the front wall body 14 are referred to as an inner front surface 48, an inner back surface 50, inner side surfaces 52, 54, and an inner upper surface (56 in fig. 1), respectively. At this time, a lead (Pb) layer 58 and a Polyethylene (PE) layer 60 are laminated in this order except for a portion of the inner front surface 48 facing the yoke 46. A Pb layer 58 and a PE layer 60 are laminated in this order on the inner surfaces 52, 54. Further, only the PE layer 60 is laminated on the inner back surface 50. As shown in fig. 1, 2 and 4, pb layer 58 and PE layer 60 are laminated in this order on inner upper surface 56 except for the portion facing yoke 46.

Next, the FRU function block 28, the FLU function block 30, the FRS function block 32, and the FLS function block 34 constituting the front wall 14 will be further described in detail with reference to fig. 7 to 10, and the RRU function block 16, the RLU function block 18, the RRS function block 20, and the RLS function block 22 constituting the rear wall 12 will be further described in detail with reference to fig. 11 to 14.

Fig. 7 is a perspective view showing a housing 70 constituting the FRU functional block 28. As shown in fig. 7, the housing 70 is configured as a box with an open upper end. The FRU functional block 28 is formed by filling the frame 70 with concrete. A concave step 72 is provided on the joint surface of the housing 70 with the fli function block 30. A concave step 74 is provided on the joint surface of the frame 70 with the RRU function block 16. A recessed step 76 is also provided on the bottom wall surface of the housing 70. The stepped portion 76 is a portion for avoiding interference with the yoke 46. Reinforcing ribs 78 are erected in the frame 70, and reinforcement is achieved.

Holes 80 for inserting bolts 24 are formed in the side walls of the frame body that are joined to the fli function blocks 30. A space for tightening the bolt 24 and the nut 26 is defined in the vicinity of the hole 80. In this way, the hole 80 and the space constitute a connection portion C for connecting with the fli function block 30. A hole 82 for inserting the bolt 24 is formed in the bottom wall of the housing 70, which is joined to the FRS functional block 32. Further, a space for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole 82. In this way, the hole 82 and the space constitute the connection portion C for connecting to the FRS functional block 32.

Next, fig. 8 is a perspective view showing a housing 90 constituting the fli function block 30. As shown in fig. 8, the housing 90 is configured as a box with an open upper end. The fli function block 30 is formed by filling the frame 90 with concrete. A convex step 92 is provided on the joint surface of the frame 90 with the FRU functional block 28. The stepped portion 92 is fitted into the recessed stepped portion 72 of the FRU functional block 28. A concave step 94 is provided on the joint surface of the housing 90 with the RLU function block 18. A recessed step 96 is also provided on the bottom wall surface of the housing 90. The step 96 is a portion for avoiding interference with the yoke 46. Further, reinforcing ribs 98 are erected in the frame 90 to reinforce the structure.

A hole 100 for inserting the bolt 24 is formed in a side wall of the housing 90 that is joined to the FRU functional block 28. A space for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole 100. In this way, the hole 100 and the space constitute a connection portion C for connecting to the FRU functional block 28. A hole 102 for inserting the bolt 24 is formed in the bottom wall of the housing 90, which is joined to the FLS function block 34. A space for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole 102. In this way, the hole 102 and the space constitute a connection portion C for connecting to the FLS function block 34.

Next, fig. 9 is a perspective view showing the housing 110 constituting the FLS function block 34. As shown in fig. 9, the housing 110 is configured as a box with an open upper end. The FLS function block 34 is formed by filling concrete into the frame 110. A convex stepped portion 112 is provided on a joint surface of the housing 110 with the FRS functional block 32. A hole 114 through which the bolt 24 is inserted is formed in a side wall of the housing 110 that is joined to the FRS functional block 32. A space (the same space as that shown in fig. 3) for tightening the bolt 24 and the nut 26 is defined in the vicinity of the hole 114. In this way, the hole 114 and the space constitute a connection portion C for connecting to the FRS functional block 32. A concave step 116 is provided on the joint surface of the housing 110 with the RLS function block 22. A recessed step portion 118 is also provided on the inner surface of the housing 110. The step 118 is a portion for avoiding interference with the yoke 46. Reinforcing ribs 120 are erected in the frame 110 to reinforce the structure.

An auxiliary plate 124 having a hole 122 for inserting the bolt 24 is attached to an upper opening of the housing 110, which is joined to the fli function block 30. A space for performing work of inserting the bolt 24 is partitioned in the vicinity of the hole 122. In this way, the hole 122 and the space constitute a connection portion C for connecting with the fli function block 30.

Next, fig. 10 is a perspective view showing a housing 130 constituting the FRS functional block 32. As shown in fig. 10, the housing 130 is configured as a box with an open upper end. The FRS functional block 32 is formed by filling the frame 130 with concrete. A concave step 132 is provided on the joint surface of the housing 130 with the FLS function block 34. The stepped portion 132 is fitted to the convex stepped portion 112 of the FLS function block 34. Holes (not shown) through which the bolts 24 are inserted are formed in the side walls of the housing 130 that are joined to the FLS function block 34. A space (not shown) for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole. In this way, the hole and the space constitute the connection portion C for connecting to the FLS function block 34. A concave step 136 is provided on the joint surface of the housing 130 with the RRS function block 20. A recessed step portion 138 is also provided on the inner surface of the housing 130. The step 138 is a portion for avoiding interference with the yoke 46. Further, reinforcing ribs 140 are erected in the frame 130 to reinforce the structure.

An auxiliary plate 144 having a hole 142 for inserting the bolt 24 is attached to an upper opening of the housing 130, which is joined to the FRU functional block 28. A space for performing work of inserting the bolt 24 is partitioned in the vicinity of the hole 142. In this way, the hole 142 and the space constitute the connection portion C for connecting to the FRU functional block 28.

The FRS function block 32 and the FLS function block 34 are connected by fastening the connecting portions C with the bolts 24 and nuts 26 in a state where the stepped portions 112 and 132 provided on the joint surfaces are fitted. The FRU functional block 28 and the fli functional block 30 are coupled by fastening the coupling portion C with the bolts 24 and the nuts 26 in a state where the stepped portions 72 and 92 provided on the joint surfaces are fitted. The front wall 14 is formed by fastening the connection portions C to each other with bolts 24 and nuts 26 in a state where the FRU function block 28 and the FLU function block 30 are mounted on the FRS function block 32 and the FLS function block 34.

When the FRU function block 28 and the FLU function block 30 are placed on top of the FRS function block 32 and the FLS function block 34, an adhesive such as mortar is preferably applied to the joint surface in advance. This reduces the risk of gaps between the concrete exposed at the upper openings of the FRS functional blocks 32 and the FLS functional blocks 34 and the lower surfaces of the FRU functional blocks 28 and the FLU functional blocks 30.

Next, fig. 11 is a perspective view showing the structure of the frame 150 forming the RRU function block 16. As shown in fig. 11, the housing 150 is configured as a box with an open upper end. The RRU function block 16 is formed by filling concrete in the frame 150. A concave stepped portion 152 is provided on a joint surface of the housing 150 with the RLU function block 18. A convex stepped portion 154 is provided on a joint surface of the frame 150 with the FRU functional block 28. The stepped portion 154 is fitted into a recessed stepped portion (74 in fig. 7) of the FRU functional block 28. A recessed step 156 is also provided on the bottom wall surface of the housing 150. The step 156 is a portion for avoiding interference with the yoke 46. Further, reinforcing ribs 158 are erected in the frame 150 to reinforce the structure.

A hole 160 for inserting the bolt 24 is formed in a side wall of the housing 150 that is joined to the RLU function block 18. A space for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole 160. In this way, the hole 160 and the space constitute a connection portion C for connecting to the RLU function block 18. A hole 162 for inserting the bolt 24 is formed in the bottom wall of the housing 150, which is joined to the RRS function block 20. A space for tightening the bolt 24 and the nut 26 is defined in the vicinity of the hole 162. In this way, the hole 162 and the space constitute a connection section C for connecting to the RRS function block 20. A through hole 164 is formed in the bottom wall of the housing 150. When the concrete is filled, a pipe is inserted through the through hole 164, and as shown in fig. 1, a channel T is formed to penetrate through the RRU function block 16 in the vertical direction. The channel T is used to release heat generated from the cyclotron 40 or will be used to pass through a cable that supplies power to the cyclotron 40. A plurality of such channels T may be formed as desired. The same channel T may be formed in the RLU functional block 18, the FRU functional block 28, and the fli functional block 30, as needed.

Next, fig. 12 is a perspective view showing a housing 170 constituting the RLU function block 18. As shown in fig. 12, the frame 170 is configured as a box with an open upper end. The RLU function block 18 is formed by filling the frame 170 with concrete. A convex stepped portion 172 is provided on a joint surface of the frame 170 with the RRU function block 16. The stepped portion 172 is fitted into the recessed stepped portion 152 of the RRU function block 16. A convex step 174 is provided on the joint surface of the frame 170 with the fli function block 30. The step 174 is fitted into a recessed step (94 in fig. 8) of the fli function block 30. A recessed step 176 is also provided on the bottom wall surface of the housing 170. The stepped portion 176 is a portion for avoiding interference with the yoke 46. Further, reinforcing ribs 178 are erected in the frame 170 to reinforce the structure.

A hole 180 for inserting the bolt 24 is formed in a side wall of the frame 170 that is joined to the RRU function block 16. Further, a space for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole 180. In this way, the hole 180 and the space constitute a connection section C for connecting to the RRU function block 16. A hole 182 for inserting the bolt 24 is formed in the bottom wall of the housing 170, which is joined to the RLS function block 22. Further, a space for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole 182. In this way, the hole 182 and the space constitute the connection portion C for connecting to the RLS function block 22.

Next, fig. 13 is a perspective view showing a housing 190 constituting the RLS function block 22. As shown in fig. 13, the housing 190 is configured as a box with an open upper end. The RLS function block 22 is formed by filling the frame 190 with concrete. A concave step 192 is provided on the joint surface of the housing 190 with the RRS function block 20. Further, holes 194 through which the bolts 24 are inserted are formed in the side walls of the housing 190 that are joined to the RRS function block 20. Further, a space for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole 194. In this way, the hole 194 and the space constitute a connection section C for connecting to the RRS function block 20. A convex step 196 is provided on the joint surface of the frame 190 with the FLS function block 34. The step 196 is fitted into a recessed step (116 in fig. 9) of the FLS function block 34. Further, reinforcing ribs 198 are erected in the frame 190 to reinforce the structure.

An auxiliary plate 202 having a hole 200 for inserting the bolt 24 formed therethrough is attached to an upper opening of the housing 190, which is joined to the RLU function block 18. A space for performing work of inserting the bolt 24 is partitioned in the vicinity of the hole 200. In this way, the hole 200 and the space constitute a connection portion C for connecting to the RLU function block 18.

Next, fig. 14 is a perspective view showing a housing 210 constituting the RRS function block 20. As shown in fig. 14, the housing 210 is configured as a box with an open upper end. The RRS function block 20 is formed by filling the frame 210 with concrete. A convex stepped portion 212 is provided on a joint surface of the housing 210 with the RLS function block 22. The stepped portion 212 is fitted into the recessed stepped portion 192 of the RLS function block 22. Further, a hole 214 through which the bolt 24 is inserted is formed in a side wall of the housing 210 that is joined to the RLS function block 22. Further, a space for tightening the bolts 24 and nuts 26 is defined in the vicinity of the hole 214. In this way, the hole 214 and the space constitute a connection portion C for connecting to the RLS function block 22. A convex step 216 is provided on the joint surface of the frame 210 with the FRS functional block 32. The stepped portion 216 is fitted into a recessed stepped portion (136 in fig. 10) of the FRS functional block 32. Further, reinforcing ribs 218 are erected in the frame 210 to reinforce the structure.

An auxiliary plate 222 having a hole 220 for inserting the bolt 24 is attached to an upper opening of the housing 210, which is joined to the RRU function block 16. A space for performing work of inserting the bolt 24 is partitioned in the vicinity of the hole 220. In this way, the hole 220 and the space constitute a connection unit C for connecting to the RRU function block 16.

The above-described RRS function block 20 and RLS function block 22 are connected by fastening the connecting portions C to each other by bolts 24 and nuts 26 in a state where the stepped portions 192 and 212 provided on the joint surfaces are fitted. The RRU function block 16 and the RLU function block 18 are connected by fastening the connecting portion C with the bolts 24 and the nuts 26 in a state where the stepped portions 152 and 172 provided on the joint surfaces are fitted. The rear wall 12 is formed by fastening the connecting portions C to each other with bolts 24 and nuts 26 in a state where the RRU function block 16 and the RLU function block 18 are mounted on the RRS function block 20 and the RLS function block 22.

When the RRU function block 16 and the RLU function block 18 are mounted on the RRS function block 20 and the RLS function block 22, an adhesive such as mortar is preferably applied to the joint surface in advance. This reduces the concern of gaps between the concrete exposed in the upper openings of the RRS function blocks 20 and the RLS function blocks 22 and the lower surfaces of the RRU function blocks 16 and the RLU function blocks 18.

As shown in fig. 1, the radiation shield 10 is configured by joining the front wall 14 and the rear wall 12. Further, a coupling mechanism as shown in fig. 3 is not provided between the front wall 14 and the rear wall 12. The purpose is to enable maintenance of the cyclotron 40 accommodated therein by pulling out the front wall body 14 forward while being guided by the guide rail W, with the rear wall body 12 being a fixed side and the front wall body 14 being a movable side. As a guide for guiding the movement of the movable-side functional block in this manner, a guide capable of guiding the movement on a predetermined line may be used in addition to the guide rail W described above. For example, if the movable-side functional block is moved in a split manner, a hinge or the like can be used.

As a material for forming the housings 70, 90, 110, 130, 170, 150, 190, 210 constituting the functional blocks, a metal material such as iron, FRP, or the like can be used. However, iron is preferable from the viewpoint of cost and strength.

In addition, when the housings 70, 90, 110, 130, 170, 150, 190, 210 are formed of iron, the iron has little radiation shielding function, and therefore, it is preferable that the iron is about 1.0mm to 10.0mm from the viewpoint of weight reduction.

As the concrete filled in the frames 70, 90, 110, 130, 170, 150, 190, 210, concrete having a large specific gravity, for example, high-density shielding concrete using aggregate having a large specific gravity such as magnetic steel is preferably used from the viewpoint of radiation shielding function.

When the frame 70, 90, 110, 130, 170, 150, 190, 210 is filled with concrete, it is preferable that the anchor G is suspended by a steel wire or the like in the frame 70, 90, 110, 130, 170, 150, 190, 210, and a part of the anchor G is fixed by the concrete as shown in fig. 2 and 4. Thus, by attaching the detachable hanger J to the anchor G, the functional block can be conveyed.

As described above, in the cyclotron system 1 according to the present embodiment, the radiation shield 10 surrounding the cyclotron 40 is constituted by the concrete filled frame in which the concrete is filled in the frames 70, 90, 110, 130, 170, 150, 190, 210, and therefore, after the concrete is filled in the frames 70, 90, 110, 130, 170, 150, 190, 210 and cured, it can be used as a member constituting the radiation shield as it is. In this way, the work of removing the frame from the concrete is omitted, and therefore, the radiation shield 10 is easy to manufacture, and further, the cyclotron system 1 is easy to manufacture. Further, since defects, cracks, and the like of concrete are hidden by the housings 70, 90, 110, 130, 170, 150, 190, and 210, it is unnecessary to repair these defects, and manufacturing is facilitated. Further, since the mount for mounting the accessory can be freely mounted to the housings 70, 90, 110, 130, 170, 150, 190, 210, the mounting position of the accessory can be changed.

In the cyclotron system 1 according to the present embodiment, the radiation shield 10 is configured by the plurality of functional blocks 16, 18, 20, 22, 28, 30, 32, and 34, and therefore, handling such as transportation and storage is easier than a case where the wall body is configured as a single body.

In the cyclotron system 1 according to the present embodiment, the stepped portions (72 and 92, 112 and 132, 152 and 172, 192 and 212, 74 and 154, 94 and 174, 116 and 196, 136 and 216) are provided on the joint surfaces of the adjacent functional blocks, and the joint is performed in a state in which the stepped portions are fitted to each other, so that the possibility of radiation leakage from between the adjacent functional blocks can be reduced. Further, since an adhesive such as mortar is applied to the joint surface between the upper functional block and the lower functional block where it is difficult to provide such a step, the concern of radiation leakage can be further reduced. Further, when the housings 70, 90, 110, 130, 170, 150, 190, 210 are formed of iron, deformation of the functional blocks can be suppressed to improve the abutting accuracy of the joint surfaces, and the concern of radiation leakage can be further reduced.

Further, since the Pb layer 58 effective for shielding the neutron rays and the PE layer 60 effective for shielding the gamma rays are appropriately laminated on the inner surface of the radiation shield 10, the shielding of these radiation by concrete can be enhanced, and the radiation shielding function can be improved. In addition, the thicknesses of the concrete, pb layer 58, and PE layer 60, etc. are preferably designed in consideration of radiation attenuation characteristics and volume/weight ratio.

The RRU function block 16 is provided with a passage T for connecting the inside and outside of the wall body, and therefore, it is possible to pass through a cable for supplying power to the cyclotron 40 or to release heat generated from the cyclotron.

Further, since the guide rail W for guiding the movement of the movable-side front wall 14 is provided, the movement of the front wall 14 is facilitated, and the maintainability is improved.

In the above embodiment, the radiation shield 10 is constituted by 8 functional blocks 16, 18, 20, 22, 28, 30, 32, 34, but may be formed by other numbers of functional blocks.

The cyclotron 40 is further described with reference again to fig. 5. Fig. 5 is an exploded perspective view of the cyclotron 40 showing the vacuum box 44 in an exploded manner so that the inside can be observed. As described above, the cyclotron 40 is a so-called vertical cyclotron, and the pair of magnetic poles 42, 42 face each other in the Y direction across the acceleration orbit of the particle beam. The vacuum box 44 has a rectangular shape having a long side extending in the X direction as viewed from the Z direction. Particles generated within the vacuum box 44 are accelerated along a helical trajectory in a plane orthogonal to the Y-direction between the poles 42, 42. The target is irradiated with the accelerated particle beam, whereby a particle beam of another nuclide is generated by collision of the particle beam with the target, and the particle beam of the other nuclide is extracted from the exit port 261 of the side surface 45 of the vacuum box 44. The side surface 45 is a surface of the outer surface of the vacuum box 44, which is viewed from the +x direction and the-X direction. The vacuum box 44 is evacuated, and the particle generation space and the acceleration space are evacuated.

As shown in fig. 5, the vacuum box 44 includes an ion source 251 for generating particles, an acceleration electrode 253 for accelerating the particle beam, a target device 255 having a target on which the particle beam is irradiated, a beam extraction device 257 for extracting the particle beam to the target, and a beam shutter 259 (beam detection device) for confirming a beam current of the particle beam or the like. Of these, the ion source 251, the target device 255, the beam extraction device 257, and the beam shutter 259 are devices that are serviced with a high frequency, and thus can be pulled out of the vacuum box 44 from the side 45 of the vacuum box 44. The exit 261 for the particle beam from the vacuum box 44 is also provided on the side surface 45. Therefore, when performing maintenance work of the vacuum box 44, the operator mainly approaches the side 45 of the vacuum box 44.

Next, the opening and closing of the radiation shield 10 will be described. Hereinafter, as shown in fig. 1, the moving direction of the front wall 14 (extending direction of the rail W) when the radiation shield 10 is opened is defined as the Y direction, the width direction of the rail W is defined as the X direction, and the vertically upper direction is defined as the Z direction. When words such as "front face/rear face", "front end/rear end", "front/rear" are used, the +y direction is set to the front and the-Y direction is set to the rear.

Fig. 15 is a side view showing a state in which the radiation shield 10 is opened from the X direction. As described above, the radiation shield 10 is constituted by the rear wall 12 (1 st wall) and the front wall 14 (2 nd wall) which are provided on the floor 301 of the building and are aligned in the front-rear direction and joined to each other at the joint portion 303. In maintenance of the cyclotron 40, as shown in fig. 15, the rear wall 12 and the cyclotron 40 are kept fixed to the floor 301 of the building, and the front wall 14 is moved in parallel forward direction while being guided by the guide rail W (fig. 1) and separated from the rear wall 12. Thereby, the radiation shield 10 is opened and the cyclotron 40 is exposed. From this state, the front wall 14 is moved in parallel rearward while being guided by the guide rail W (fig. 1) and joined to the rear wall 12, whereby the radiation shield 10 is closed.

As shown in fig. 4, the front wall 14 is composed of 2 functional blocks, that is, a right wall functional block 305 and a left wall functional block 307. The right wall block 305 is composed of the FRU block 28 and the FRS block 32, and the left wall block 307 is composed of the FLU block 30 and the FLS block 34. The right wall functional block 305 and the left wall functional block 307 are bolted to each other at the joint C, and move together as an integral front wall 14 when the radiation shield 10 is opened and closed.

The engagement of the rear wall 12 and the front wall 14 in the cyclotron system 1 is performed at a position where a person (for example, a maintenance worker) can approach the vacuum box 44 in a state where the rear wall 12 and the front wall 14 are separated. More specifically, the joint 303 (joint position) between the rear wall 12 and the front wall 14 is located laterally to the vacuum box 44. The joint 303 exists along a plane orthogonal to the Y direction and is located near the side 45 of the vacuum box. More specifically, as shown in fig. 15, the joint 303 is located near the vacuum box 44 when viewed from the X direction.

Considering the front end face 12h of the rear wall body 12 existing in the joint 303, the front end face 12h exists on a plane orthogonal to the Y direction. As shown in fig. 15, when the open radiation shield 10 is viewed from the X direction, the front end surface 12h may be positioned so as to overlap the vacuum box 44. Alternatively, as shown in fig. 16 (a), it is more preferable if the front end surface 12h is located further rearward than the rear end 44b of the vacuum box 44. On the other hand, as shown in fig. 16 (b), it is not preferable that the front end surface 12h is located forward of the front end 44a of the vacuum box 44, but it is preferable that at least the front end surface 12h of the rear wall body 12 is located rearward of the front end 44a of the vacuum box 44. In the present embodiment, the front end 44a and the rear end 44b of the vacuum box 44 are also the front end and the rear end of the side surface 45 of the vacuum box 44.

The operation and effect obtained by the positional relationship between the vacuum box 44 and the joint 303 described above will be described. On the inner wall surfaces of the rear wall 12 and the front wall 14, a Pb layer 58 and a PE layer 60 are provided in the space with the cyclotron 40, and the distance between the side surface 45 of the vacuum box 44 and the PE layer 60 in the X direction is small. Therefore, it is difficult to perform maintenance using the space between the side 45 of the vacuum box 44 and the PE layer 60, assuming the state of fig. 16 (b). In contrast, in the state shown in fig. 15 or fig. 16 (a), at least a part of the side surface 45 of the vacuum box 44 is not hidden by the rear wall 12 but is visible when viewed from the X direction. In this state, the side 45 of the vacuum box 44 is relatively easily accessible to maintenance personnel.

In the maintenance of the cyclotron 40, the equipment included in the vacuum box 44 is most often accessed from the side surface 45 of the vacuum box 44, and the equipment can be easily accessed by the side surface 45 of the vacuum box 44 by moving only the front wall 14 without moving the rear wall 12 and the cyclotron 40 according to the positional relationship. Therefore, the burden of maintaining the cyclotron 40 can be reduced, and the maintainability of the cyclotron 40 can be improved.

As shown in fig. 16 (c), for example, the RRU function block 16 and the RLU function block 18 may be connected to the front wall 14, and the front wall 14, the RRU function block 16, and the RLU function block 18 may be moved in the Y direction as an integral moving side wall when the radiation shield 10 is opened or closed. At this time, the RRS function block 20 and the RLS function block 22 function as the rear wall 12. At this time, the positional relationship between the vacuum box 44 and the front end surface 12h is also set to be satisfied as described above.

The front wall 14 is a heavy member having a large wall thickness for shielding radiation. It is desirable to be able to move the front wall 14 of such a large weight stably and smoothly along the guide rail W. In particular, if a failure occurs in the moving mechanism of the front wall 14 due to an earthquake or the like, it is difficult to move the front wall 14 having a large weight by another mechanism, and therefore there is a problem that the radiation shield 10 cannot be opened or closed, and repair work of the cyclotron 40 cannot be performed. Therefore, the cyclotron system 1 has a structure described below.

As shown in fig. 1, in the cyclotron system 1, 4 guide rails W extending in the Y direction are provided in parallel to move the front wall 14 as described above. When the guide rails W are distinguished from each other, the guide rails W1, W2, W3, W4 are respectively referred to in the arrangement order in the X direction. Fig. 17 is a plan view showing the guide rails W1 to W4 with the radiation shield 10 and the cyclotron 40 removed. In fig. 17, the installation positions of the rear wall 12, the front wall 14, and the cyclotron 40 are shown by broken lines.

The guide rails W1 to W4 are each provided with a slider portion 311 that supports the front wall 14 and is slidable in the Y direction on the guide rail W. By sliding the slider portion 311 on each rail W, the front wall 14 can move in the Y direction as described above. The guide rails W2 and W3 are provided with slider portions 313 that support the cyclotron 40 at four corners and are slidable in the Y direction on the guide rail W. By sliding the slider portion 313 on each rail W, the cyclotron 40 can also be moved in the Y direction. Since the slider portion 313 has the same structure as the slider portion 311, the slider portion 311 will be described below, and a detailed description of the slider portion 313 will be omitted.

The right wall function block 305 of the front wall 14 is supported at 3 points by the total of 3 slider portions 311, which are 2 slider portions 311 provided on the guide rail W1 and 1 slider portion 311 provided on the guide rail W2. The center of gravity of the triangle having the 3 slider portions 311 as vertices is substantially identical to the center of gravity of the right wall functional block 305 in plan view. Similarly, the left wall functional block 307 of the front wall 14 is supported at 3 points by the total of 3 slider portions 311, which are 2 slider portions 311 provided on the guide rail W4 and 1 slider portion 311 provided on the guide rail W3. The center of gravity of the triangle having the 3 slider portions 311 as vertices is substantially identical to the center of gravity of the left wall functional block 307 in plan view. According to this structure, the right wall function block 305 and the left wall function block 307 can be separated by releasing the bolt fastening of the connecting portion C (fig. 14), and thus the right wall function block 305 and the left wall function block 307 can be moved individually in the Y direction.

Hereinafter, the structure of the rail W and the slider portion 311 related to the right wall function block 305 will be mainly described, but the left wall function block 307 is the same structure as the right wall function block 305 in bilateral symmetry, and thus overlapping description will be omitted.

The slider portion provided on one of the guide rails W1 and W2 among the 3 slider portions 311 supporting the right wall function block 305 is further added with a function described below. Hereinafter, the slider portion 311 of the type having the additional function is denoted by the reference numeral "311A", and the other slider portions 311 are denoted by the reference numeral "311B". In the present embodiment, 1 slider portion 311 provided on the guide rail W2 belongs to the slider portion 311A, and 2 slider portions 311 provided on the guide rail W1 belong to the slider portion 311B.

The slider portion 311A has a function of allowing the right wall functional block 305 to be displaced in a direction other than the Y direction with respect to the guide rail W2 in addition to the function of the slider portion 311B. Specifically, the slider portion 311A guides the right wall function block 305 to move in the Y direction with respect to the guide rail W2, and also allows the right wall function block 305 to be displaced in the X direction with respect to the guide rail W2. More specifically, the relative displacement in the X direction between the slider portion 311A and the right wall functional block 305 is allowed.

Like the right wall function block 305, 1 slider part 311 provided on the guide rail W3 out of the 3 slider parts 311 supporting the left wall function block 307 belongs to the slider part 311A, and 2 slider parts 311 provided on the guide rail W4 belong to the slider part 311B.

The structure of the periphery of the guide rail W and the structure of the slider portion 311 will be further described with reference to fig. 17, 18, and 19. Fig. 18 (a) is a cross-sectional view of the periphery of the guide rail W including the slider portion 311A, and fig. 18 (b) is a plan view thereof. Fig. 19 (a) is a cross-sectional view of the periphery of the guide rail W including the slider portion 311B, and fig. 19 (B) is a cross-sectional view showing a modification of the periphery of the guide rail W.

As shown in fig. 18 (a) and (b), a rail installation groove 315, which is formed by excavating the ground 301 and has a rectangular cross section and extends in the Y direction, is formed at a position corresponding to the rail W, and the rail W is laid on the bottom surface of the center of the rail installation groove 315. In fig. 1, the guide rail W and the guide rail installation groove 315 are not shown in detail.

The slider portion 311A has a slider body portion 317, and the slider body portion 317 is fitted into the guide rail W so as to surround the upper surface and the side surfaces of the guide rail W with a コ -shaped guide surface 319. A flat roller 321 (width direction displacement allowing portion) is mounted on the upper surface of the slider body 317, and a right wall function block 305 is mounted on the upper surface of the flat roller 321. The planar roller 321 has a plurality of cylindrical rollers 323 aligned in the X direction and rotated about the Y-direction axis, and the rotation of the rollers 323 allows the relative displacement of the right wall functional block 305 with respect to the slider body 317 in the X direction. That is, the additional function of allowing the displacement of the right wall function block 305 in the X direction with respect to the guide rail W is realized by the flat roller 321.

The slider body 317 includes rolling elements 325 (e.g., spherical balls) interposed between the guide surface 319 and the upper surface and side surfaces of the guide rail W and rolling in the Y direction. Due to the presence of the rolling elements 325, the sliding resistance of the slider body 317 with respect to the rail W is reduced, and the slider body 317 smoothly moves in the Y direction on the rail W, and further, the right wall function block 305 stably and smoothly moves in the Y direction.

As shown in fig. 19 (a), the flat roller 321 of the slider portion 311A is omitted from the slider portion 311B. In the slider portion 311B, the right wall functional block 305 is directly mounted on the upper surface of the slider body portion 317. Therefore, the right wall functional block 305 and the slider body 317 are not relatively displaced, and displacement of the right wall functional block 305 in the X direction with respect to the guide rail W is not allowed. In other respects, the slider portion 311B has the same structure as the slider portion 311A, and therefore the same reference numerals are given in the drawings and overlapping description is omitted.

The operation and effects obtained by the moving mechanism including the guide rail W, the slider portion 311, and the like described above will be described.

The moving mechanism for moving the front wall 14 includes a plurality of guide portions (slider portion 311 and guide rail W) for supporting the wall function block (right wall function block 305 or left wall function block 307) constituting at least a part of the front wall 14 and guiding the wall function block along the moving direction (Y direction) of the front wall 14, and displacement of the wall function block in a direction intersecting the moving direction is permitted in the guide portions other than 1 among the plurality of guide portions. In the specific example of the present embodiment, the slider portion provided on either one of the guide rails W1, W2 (the guide rail W2 in the present embodiment) among the 3 slider portions 311 supporting the right wall function block 305 is set to be the slider portion 311A, and the slider portion 311A allows displacement of the right wall function block 305 in the X direction.

According to this configuration, even when there is some external disturbance in the Y direction movement of the right wall function block 305, such as the linearity and parallelism of the guide rails W1 and W2 are insufficient or the weight balance of the right wall function block 305 supported by the guide rails W1 and W2 is insufficient, the external disturbance is absorbed by the relative displacement of the right wall function block 305 and the guide rail W2 in the guide rail width direction (X direction), and therefore the Y direction movement of the right wall function block 305 can be performed stably and smoothly. Similarly, the Y-direction movement of the left wall function block 307 can be performed stably and smoothly. In addition, on the contrary, the accuracy of the parallelism of the guide rail W can be relaxed, and therefore, the burden of accuracy management at the time of the construction of the guide rail W can be reduced. Even when an external force due to an earthquake or the like acts on the right wall function block 305, the slider portion 311A releases the external force in the rail width direction with respect to the one rail W, and therefore the possibility of damage to the front wall 14, the rail W, and the like is reduced.

The same function as that of the slider portion 311A may be added to 2 slider portions 313 provided on either one of the guide rails W2 and W3 among the 4 slider portions 313 supporting the cyclotron 40. Thus, even when the cyclotron 40 is moved in the Y direction on the basis of the same principle as the right wall function block 305, stable and smooth movement can be performed.

Further, according to the structure in which the rail installation groove 315 is formed in the ground 301 and the rail W is installed in the rail installation groove 315, the linearity of the rail W is easily ensured without being affected by the undulation existing on the ground surface of the ground 301. That is, the smoothness of the bottom surface of the rail installation groove 315 and the straightness of the rail W are easier to manage and easier to secure than the smoothness of the ground 301. Therefore, the Y-direction movement of the right wall function block 305 can be performed stably and smoothly regardless of the fluctuation of the surface of the ground 301. Similarly, the Y-direction movement of the left wall function block 307 can be performed stably and smoothly.

As described above, the right wall function block 305 and the left wall function block 307 can be stably and smoothly moved in the Y direction based on the guide rail W and the slider portion 311. Therefore, for example, even if the ground 301 is fluctuated due to a disaster such as an earthquake or the parallelism of the rails W is deteriorated, the right wall function block 305 and the left wall function block 307 can be moved in the Y direction to open the radiation shield 10, and repair work of the cyclotron 40 can be performed.

Further, according to the structure in which the rail installation groove 315 is formed in the ground 301 and the rail W is installed in the rail installation groove 315, the rail W can be installed at a low position with respect to the ground 301, and the position of the upper surface of the slider portion 311 can be lowered. This makes it easy to reduce the gap S between the bottom surface of the right wall function block 305 and the upper surface of the ground 301 ((a) of fig. 18). Similarly, the gap S between the bottom surface of the left wall function block 307 and the upper surface of the ground 301 is also easily reduced. By reducing the gap S, radiation leakage from the cyclotron 40 to the outside through the gap S can be suppressed, and stable radiation leakage management can be performed. From this viewpoint, it is preferable to make the height of the upper surface of the slider 311 as close as possible to the height of the upper surface of the ground 301, and to reduce the gap S as small as possible.

In addition, when the height of the upper surface of the slider portion 311 is lower than the height of the upper surface of the ground 301, as shown in fig. 19 (b), the portion of the bottom surface of the right wall function block 305 facing the ground 301 may be made higher than the upper surface of the ground 301 by forming a step 326 on the bottom surface of the right wall function block 305. Thus, interference between the right wall function block 305 and the ground 301 can be avoided, thereby ensuring a gap S between the bottom surface of the right wall function block 305 and the ground 301.

Further, since the guide rail W and the slider portion 311 are provided directly below the front wall 14, the floor space of the cyclotron system 1 is reduced as compared with, for example, a system in which wheels and guide rails are provided on the side of the front wall 14. As a result, the installation area required for installing the cyclotron system 1 is suppressed to be small, and the required area of the installed room can be reduced.

In addition, when the rail installation groove 315 is shallow, the floor thickness of the building floor where the rail installation groove 315 is installed can be made thin, and as a result, the weight of concrete used for construction of the floor can be reduced. Further, since a large floor thickness is not required for installing the floor, for example, the building floor can be easily modified to install the cyclotron system 1.

As described above, the rail installation groove 315 is formed in the ground 301, and the rail W is installed in the rail installation groove 315. Further, since the slider portion 311 is engaged with the guide rail W by the rolling elements 325 of the slider body portion 317, the slider portion 311 cannot be lifted from the guide rail W. Therefore, when maintenance and replacement of the slider portion 311 are performed, there is a concern that the slider portion 311 is difficult to be detached from the guide rail W.

As a countermeasure for this, as shown in fig. 17, a rail non-existing region 327 in which the rail W is not provided is provided at the tip end portion of each rail installation groove 315. Fig. 20 (a) is a cross-sectional view of the rail non-existing region 327. That is, the rail installation groove 315 extends longer than the front end surface of the rail W in the +y direction, and the rail W is not present in the extended portion. The Y-direction length of the rail non-existence region 327 is longer than the Y-direction length of the slider portion 311.

According to this structure, the slider portion 311 requiring maintenance and replacement can be easily removed from the rail W by the rail non-existing region 327. That is, after the right wall function block 305 (or the left wall function block 307) is lifted up and the slider portion 311 is separated from the function block bottom surface, the slider portion 311 may be moved along the rail W to the rail non-existing region 327. In this way, the slider portion 311 reaching the front end of the rail W can be further pulled out forward from the front end surface of the rail W toward the rail-absent area 327, and therefore the slider portion 311 can be easily removed from the rail W. In the opposite step, the slider portion 311 can be attached to the guide rail W.

The attachment and detachment of the slider portion 311 using the rail non-existence region 327 to and from the rail W may be performed by the following procedure. First, a temporary guide rail having a slightly shorter length in the Y direction than the guide rail non-existing region 327 is prepared, and is provided on the extension line of the guide rail W in the guide rail non-existing region 327. Then, the slider portion 311 to be removed is moved along the rail W to the rail non-existing region 327, and is transferred to the temporary rail. Then, the slider portion 311 may be taken out of the rail non-existing region 327 together with the temporary rail. In addition, if the slider portion 311 to be mounted is prepared in a state of being placed on the temporary guide rail, the slider portion 311 can be mounted on the guide rail W by the reverse procedure to the above. When the rail non-existing region 327 is not used, the groove filling function block 329 may be inserted to block the rail non-existing region 327 as shown in fig. 20 (a).

The present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art, as represented by the above embodiments. Further, the modified examples can be configured by using the technical matters described in the above embodiments. The structures of the embodiments and the like may be used in combination as appropriate.

Instead of the guide rail W and the slider portion 311 in the above embodiment, a moving mechanism using wheels as shown in fig. 20 (b) may be employed. The mechanism of fig. 20 b includes 2 sets of carriages 331, 332 supporting the wall function block 330 (right wall function block 305 or left wall function block 307) and 2 sets of guide rails W11, W12 guiding the carriages 331, 332 in the Y direction, respectively. The left and right wheels 333 of the carriage 331 travel on 2 rails included in the rail W11, respectively. Similarly, the left and right wheels 334 of the carriage 332 travel on 2 rails included in the rail W12, respectively. The planar roller 321 is interposed between the upper surface of the carriage 331 and the bottom surface of the wall function block 330, and this allows displacement of the wall function block 330 in the X direction relative to the guide rail W11. On the other hand, the bottom surface of the wall function block 330 is in direct contact with the upper surface of the carriage 332.

In the cyclotron system 1, there is no need to have a structure that allows displacement of the right wall function block 305 (or the left wall function block 307) in the X direction with respect to the guide rail W. That is, for example, all of the 3 slider portions 311 (fig. 17) supporting the right wall function block 305 may be slider portions 311B that do not allow displacement of the right wall function block 305 in the X direction. Similarly, all of the 3 slider portions 311 (fig. 17) supporting the left wall functional block 307 may be slider portions 311B.

In the mechanism of fig. 20 (b), the planar roller 321 may be omitted and the bottom surface of the wall function block 330 may be directly brought into contact with the upper surface of the carriage 331. In the mechanism of fig. 20 (b), unlike the slider body 317 ((a) of fig. 19), the wheels 333 and 334 themselves can be slightly displaced in the X direction with respect to the guide rails W11 and W12. Therefore, in the mechanism of fig. 20 (b), the wheels 333, 334 themselves have a function of allowing the displacement of the wall functional block 330 in the X direction. Therefore, even when the bottom surface of the wall function block 330 directly contacts the upper surfaces of the two carriages 331 and 332, the wall function block 330 can be stably and smoothly moved in the Y direction.

In the above embodiment, the front end surface 12h of the rear wall body 12 present in the joint 303 is present along a plane orthogonal to the Y direction, but the present invention is not limited thereto, and the front end surface 12h may be present along a plane intersecting with the Y direction. That is, the joint 303 between the rear wall 12 and the front wall 14 is not limited to being present along a plane orthogonal to the Y direction, and may be present along a plane intersecting the Y direction.

Claims (9)

1. A self-shielded particle accelerator system, comprising:

A vacuum box for accelerating particles;

1 st wall body for shielding radiation;

a 2 nd wall body that is movable relative to the 1 st wall body while shielding radiation from the vacuum box by surrounding the vacuum box together with the 1 st wall body; a kind of electronic device with high-pressure air-conditioning system

And a guide rail for guiding the movement of the 2 nd wall body approaching and separating from the 1 st wall body.

2. The self-shielded particle accelerator system of claim 1, wherein,

the joining of the 1 st wall and the 2 nd wall is performed at a position where a person can access the vacuum box in a state where the 1 st wall and the 2 nd wall are separated.

3. The self-shielded particle accelerator system of claim 2, wherein,

the joint position of the 1 st wall body and the 2 nd wall body is the side of the vacuum box.

4. The self-shielded particle accelerator system of claim 3, wherein,

the end face of the 1 st wall on the 2 nd wall side exists along a plane intersecting with the moving direction of the 2 nd wall,

the end face is located at a position overlapping the vacuum box as viewed in a direction parallel to the plane.

5. The self-shielded particle accelerator system as recited in any one of claims 1-4, wherein,

The vacuum box is provided with an accelerating electrode, a beam detection device, a beam extraction device and a target device which can be accessed or taken out from the side of the vacuum box.

6. The self-shielded particle accelerator system as recited in any one of claims 1-4, wherein,

the 1 st wall has a 1 st recess in a flat section, the 2 nd wall has a 2 nd recess opposite to the 1 st recess in the flat section,

the 1 st wall body and the 2 nd wall body are joined to each other to form a radiation shield in which the vacuum box is housed in an internal space formed by the 1 st concave portion and the 2 nd concave portion.

7. The self-shielded particle accelerator system of claim 1, wherein,

the 2 nd wall is supported by a slider part which moves on the guide rail along the extending direction of the guide rail,

the slider portion allows the 2 nd wall to be relatively displaced with respect to the guide rail in a direction other than the extending direction of the guide rail.

8. The self-shielded particle accelerator system of claim 7, wherein,

the slider portion allows the 2 nd wall to be displaced relative to the rail in the width direction of the rail.

9. A self-shielded particle accelerator system as defined in any one of claims 6 to 8, wherein,

the guide rail is arranged in a guide rail arrangement groove arranged on the ground,

the rail installation groove extends further in the longitudinal direction from the end of the rail and has a rail non-existence region where the rail does not exist.