JP2014236913A - Neutron capture therapy system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a neutron capture therapy system which can reduce an influence of radiation on a worker.SOLUTION: A neutron capture therapy system comprises: a cyclotron emitting a charged particle beam; a target 5 generating a neutron beam by being irradiated with the charged particle beam; a first duct linked to the cyclotron; a second duct 12 linked to the first duct and the target 5; a duct arrangement chamber 30 in which the first duct and the second duct 12 are arranged; a radiation shielding body 20 movable between a position covering at least a part of the second duct 12 and a position exposing the second duct 12; a hole part 70 which communicates a chamber different from the duct arrangement chamber 30 with the duct arrangement chamber 30, and allows the target 5 and the second duct 12 to pass therethrough; and transportation means 60 transporting the target 5 and the second duct 12.

Description

  The present invention relates to a neutron capture therapy system for irradiating an irradiated object with a neutron beam.

  Boron neutron capture therapy (BNCT) using a boron compound is known as a neutron capture therapy that kills cancer cells by neutron irradiation. As a neutron capture therapy system used in such boron neutron beam capture therapy, Patent Document 1 discloses a cyclotron that emits a charged particle beam, a target that generates a neutron beam when irradiated with a charged particle beam, and a neutron There is described a neutron beam irradiation apparatus comprising a moderator for decelerating a line.

  In the neutron beam irradiation apparatus of Patent Document 1, the cyclotron and the target are connected by a vacuum duct. Moreover, the radiation chamber of this neutron beam irradiation apparatus is provided with a radiation shield that can be opened and closed like a sliding door. The radiation shield is opened to the left and right of the vacuum duct when irradiated with neutron beams, and is closed after the target is separated from the moderator and pulled out to the cyclotron side during maintenance.

JP 2013-19692 A

  By the way, since the target is always exposed to the charged particle beam at the time of irradiation with the neutron beam, the activation level around the target is in a high state. Even after the irradiation of the charged particle beam to the target is stopped, the activation level around the target remains high unless left for a long time. Here, in the neutron beam irradiation apparatus as described above, since the target and the vacuum duct are arranged in the duct arrangement chamber at the time of maintenance, there is a problem that a large amount of radiation is emitted into the duct arrangement chamber.

  In view of such a problem, an object of the present invention is to provide a neutron capture therapy system that can reduce the amount of radiation radiated into a duct arrangement chamber.

  The neutron capture therapy system of the present invention is a neutron capture therapy system that irradiates an irradiated object with a neutron beam, an accelerator that emits a charged particle beam, and a target that generates a neutron beam by being irradiated with the charged particle beam A first duct connected to the accelerator; a second duct connected to the first duct and the target; a duct arrangement chamber in which the first duct and the second duct are arranged; A radiation shield movable between a position covering at least a part of the two ducts and a position exposing the second duct, a separate chamber different from the duct placement chamber, and a duct placement chamber communicating with each other; It has the hole part which can let a 2nd duct pass, and the moving means to move a target and a 2nd duct, It is characterized by the above-mentioned.

  In the neutron capture therapy system of the present invention, the activation level of the target and the second duct connected to the target is relatively high after irradiation with the neutron beam. Therefore, the neutron capture therapy system of the present invention is provided with a moving means for moving the target and the second duct. During maintenance, the moving means moves the target and the second duct through the hole to another room. It is possible to make it. As described above, since the target having a relatively high activation level and the second duct can be moved to different chambers, the amount of radiation radiated into the duct arrangement chamber can be reduced. If a new target and a second duct are prepared in a separate room in advance, the moving means can move the new target and the second duct to the duct placement chamber through the hole.

  The moving means may include a duct support portion that supports the second duct, and may be movable between the duct placement chamber and the separate chamber in a state where the duct support portion supports the second duct. As described above, the moving means includes the duct support portion that supports the second duct, and the moving means itself can move between the duct arrangement chamber and the separate chamber. Therefore, it is possible to move the second duct in a stable state.

  The moving means may include a rail portion and a table portion that moves along the rail portion, and the table portion may be movable in the longitudinal direction of the second duct. In this case, the table portion can be moved in the direction along the rail portion and in the longitudinal direction of the second duct.

  Moreover, the rail part may be movable between a duct arrangement | positioning room and another room. In this case, when the rail part is required in the duct placement room, the rail part is moved from the separate room to the duct placement room, and when the rail part is not required in the duct placement room, the rail part is moved from the duct placement room to the separate room. Can be moved.

  Further, the second duct may have a protruding portion that protrudes outward, and the radiation shield may have a claw portion for hooking the protruding portion to hold the second duct. In this case, the second duct can be held by the radiation shield only by hooking the protruding portion of the second duct to the claw portion.

  According to the present invention, the amount of radiation radiated into the duct arrangement chamber can be reduced.

It is a figure which shows arrangement | positioning of the neutron capture therapy system which concerns on this embodiment. It is the perspective view which expanded the radiation shield periphery. It is the perspective view which expanded the duct structure in FIG. It is a perspective view which shows the state which removed the piping element in FIG. It is a perspective view which shows the state which removed the piping element in FIG. It is a perspective view which shows the holding structure of the 2nd duct with respect to a radiation shield. It is a perspective view corresponding to FIG. 2 when a radiation shield is made into an open state. It is a perspective view corresponding to FIG. 7 when a duct support part raises. It is a perspective view corresponding to FIG. 8 when removing a target from a shielding material. FIG. 10 is a perspective view corresponding to FIG. 9 when moving the target and the second duct.

  Hereinafter, embodiments of a neutron capture therapy apparatus according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, a neutron capture therapy system 1 for performing the cancer treated with boron neutron capture therapy, a boron patients boron ^{(10 B)} has been administered P (object to be irradiated) is integrated This is a device for treating cancer by irradiating a site with neutron beam N. The neutron capture therapy system 1 has an irradiation chamber 3 that irradiates a patient P fixed to a treatment table 2 with a neutron beam N to treat the patient P with cancer. Further, the neutron capture therapy system 1 includes a cyclotron (accelerator) 4 that generates a charged particle beam L, a target 5 that receives the charged particle beam L to generate a neutron beam N, and a charged particle beam L from the cyclotron 4 to the target 5. A duct structure 10 for guiding, and a radiation shield 20 that accommodates the target 5 and a part of the duct structure 10 are provided.

  The cyclotron 4 is an accelerator that generates charged particle beams L such as proton beams by accelerating charged particles such as hydrogen ions. The cyclotron 4 has a beam radius of 40 mm, for example, and has an ability to generate a charged particle beam L of 60 kW (= 30 MeV × 2 mA). Instead of the cyclotron 4, another accelerator such as a synchrotron, a synchrocyclotron, or a linac may be used.

  The target 5 generates a neutron beam N by being irradiated with the charged particle beam L emitted from the cyclotron 4. The target 5 is made of, for example, beryllium (Be) and has a disk shape with a diameter of 160 mm. The neutron beam N generated by the target 5 is irradiated to the affected area of the patient P in the irradiation chamber 3 with an irradiation field defined by the collimator 6. Instead of the target 5 made of beryllium, a target made of lithium (Li), tantalum (Ta), or tungsten (W) may be used, and the size of the target can be changed as appropriate.

  As shown in FIGS. 1, 2 and 9, the duct structure 10 includes a first duct 11 connected to the cyclotron 4, a second duct 12 connected to the target 5, and a first duct 11. , A third duct 13 connected to the opposite side of the cyclotron 4, and a fourth duct 14 connecting the second duct 12 and the third duct 13. One end of the second duct 12 is connected to the target 5, and the other end of the second duct 12 is connected to the first duct 11 via the fourth duct 14 and the third duct 13. Yes. The 1st-4th ducts 11-14 are arrange | positioned in the room | chamber interior of the duct arrangement | positioning room 30 which comprises substantially rectangular shape by planar view, This duct arrangement | positioning room 30 is the closure covered with the shielding wall W made from concrete. It is space.

  Note that the duct arrangement chamber 30 does not have to be substantially rectangular in a plan view, and may have another shape such as an L shape. Further, the cyclotron 4 may not be arranged in the duct arrangement chamber 30 and may be arranged in a room other than the duct arrangement chamber 30.

  One end of the first duct 11 is connected to the cyclotron 4. The first duct 11 includes a beam adjusting unit (not shown) that adjusts the charged particle beam L. The beam adjusting unit includes a horizontal steering and a horizontal / vertical steering for adjusting the axis of the charged particle beam L, a quadrupole electromagnet for suppressing the divergence of the charged particle beam L, and a four-way slit for shaping the charged particle beam L. Etc. The first duct 11 only needs to have a function of transporting the charged particle beam L, and the beam adjusting unit may not be provided.

  The third duct 13 located on the radiation shield 20 side of the first duct 11 is fixed at the upper end of the column part 32 protruding upward from the upper surface 31 a of the base part 31 arranged in the duct arrangement chamber 30. Yes. The fourth duct 14 is fixed to the radiation shield 20 side of the third duct 13, and the second duct 12 is fixed to the radiation shield 20 side of the fourth duct 14. Moreover, from the upper surface 31a of the base part 31, the 1st cooling pipe 51 for supplying a cooling water to the target cooling plate 50 (refer FIG. 9) which cools the target 5, and cooling discharged | emitted from the target cooling plate 50 A second cooling pipe 52 through which water passes projects upward. The first and second cooling pipes 51 and 52 are connected to a cooler for cooling the cooling water below the upper surface 31 a of the base 31.

  The radiation shield 20 is positioned between a fixed part 21 fixed on the upper surface 31 a of the base part 31, a moving part 22 provided movably with respect to the fixed part 21, and the fixed part 21 and the moving part 22. A substantially cylindrical shielding member 23 and a wall 24 that separates the irradiation chamber 3 and the duct arrangement chamber 30 are provided. The fixed part 21, the moving part 22, and the wall part 24 are made of concrete, for example. At least a part of the wall portion 24 located on the irradiation chamber 3 side of the fixed portion 21 and the moving portion 22 is embedded in a wall W1 (see FIG. 1) that separates the irradiation chamber 3 and the duct arrangement chamber 30. And the collimator 6 used as the output port of the neutron beam N is being fixed to the irradiation chamber 3 side of the wall part 24. FIG.

  The shielding material 23 has a function of shielding radiation such as neutron rays N and gamma rays from being emitted to the outside. A target 5 is provided inside the shielding material 23, and a speed reducing body 28 is provided on the inner side (the irradiation chamber 3 side) of the shielding material 23. The neutron beam N generated by the target 5 is decelerated by the moderator 28 and irradiated to the affected part of the patient P in the irradiation chamber 3. The speed reduction body 28 has, for example, a laminated structure made of a plurality of different materials, and the material of the speed reduction body 28 is appropriately selected according to various conditions such as the energy of the charged particle beam L.

  Specifically, for example, when the output from the cyclotron 4 is a proton beam of 30 MeV and a beryllium target is used as the target 5, the material of the moderator 28 can be lead, iron, aluminum, or calcium fluoride. Further, when the output from the cyclotron 4 is a proton beam of 11 MeV and a beryllium target is used as the target 5, the material of the moderator 28 can be heavy water (D 2 O) or lead fluoride.

  A rail (not shown) extending in the horizontal direction and perpendicular to the longitudinal direction of the second duct 12 is installed at the lower part of the moving unit 22. On the opposite side of the part 21, a piston (not shown) for moving the moving part 22 on the rail is installed. Since the moving part 22 moves on a rail by the drive of a piston, it can move in the direction which approaches the fixing | fixed part 21, and the direction which leaves | separates from the fixing | fixed part 21. FIG. Thus, the radiation shield 20 is closed when the moving unit 22 approaches the fixed unit 21, and the radiation shield 20 is opened when the moving unit 22 moves away from the fixed unit 21, so that the radiation shield 20 can be opened and closed. It has become.

  In addition, you may move the moving part 22 by means other than a rail and a piston. In addition, a mirror may be installed on the side of the moving unit 22 opposite to the fixed unit 21 so that it is possible to confirm whether or not the moving unit 22 can be safely moved without any person or object at the destination of the moving unit 22. .

  Moreover, the fixing | fixed part 21 is provided with the level | step-difference part 21a which protrudes toward the moving part 22 on the upper side, and the moving part 22 is provided with the level | step-difference part 22a which protrudes toward the fixing | fixed part 21 side on the lower side. Below the stepped portion 21a in the fixed portion 21, a duct arrangement space S (FIGS. 2 and 6) in which the second duct 12, the third cooling pipe 53, and the fourth cooling pipe 54 extend in a substantially horizontal direction. Reference) is formed. Therefore, the second duct 12 is exposed when the moving part 22 moves away from the fixed part 21, and at least a part of the second duct 12 is covered when the moving part 22 moves in a direction approaching the fixed part 21. .

  As shown in FIG. 6, a first duct holding portion 25 and a second duct holding portion 26 for holding the second duct 12 are provided on the surface 21 c on the cyclotron 4 side of the fixed portion 21. ing. The 1st and 2nd duct holding | maintenance parts 25 and 26 have the 1st and 2nd protrusion parts 25a and 26a which protrude in the duct arrangement | positioning space S side, respectively. Further, first and second claw portions 25b and 26b for hooking the pair of protrusions 12a and 12b welded to the second duct 12 are provided on the upper surfaces of the protrusions 25a and 26a.

  The first claw portion 25b includes a protruding portion 25c that protrudes upward from the upper surface of the protruding portion 25a, and an extending portion 25d that extends inward from the upper end of the protruding portion 25c. The same protrusion part 26c and the extended part 26d are provided. When the second duct 12 is held by the radiation shield 20, the protruding portion 12a of the second duct 12 is in a space formed between the upper surface of the protruding portion 25a and the lower surface of the extending portion 25d. Get in. And the protrusion part 12b of the 2nd duct 12 enters into the space formed between the upper surface of the protrusion part 26a, and the lower surface of the extension part 26d.

  On the other hand, when the second duct 12 is removed from the radiation shield 20, the protrusions 12a and 12b of the second duct 12 are in the longitudinal direction of the second duct 12 with respect to the claws 25b and 26b. Moving. The first and second duct holding portions 25 and 26 and the protrusions 12a and 12b in the second duct 12 are also arranged in the vicinity of the shielding member 23 on the back side of the second duct 12. (See FIG. 10).

  A third cooling pipe 53 is fixed to the upper part of the second duct 12, and a fourth cooling pipe 54 is fixed to the lower part of the second duct 12. As shown in FIGS. 2 and 9, one end side of the third cooling pipe 53 is connected to the first cooling pipe 51 via the fifth cooling pipe 55. The end side is connected to the target cooling plate 50. One end side of the fourth cooling pipe 54 is connected to the second cooling pipe 52 via the sixth cooling pipe 56, and the other end side of the fourth cooling pipe 54 is connected to the target cooling plate 50. Yes.

  Therefore, the cooling water reaches the target cooling plate 50 from the cooler located below the upper surface 31a of the base portion 31 via the first cooling pipe 51, the fifth cooling pipe 55, and the third cooling pipe 53. The cooling water discharged from the target cooling plate 50 is returned to the cooler through the fourth cooling pipe 54, the sixth cooling pipe 56, and the second cooling pipe 52.

  Further, as shown in FIG. 9, the neutron capture therapy system 1 moves the target 5, the target cooling plate 50, the cooling pipes 53 and 54, and the second duct 12 away from the radiation shield 20. A moving means 60 is provided. A switch unit 90 including various switches for operating each operation of the moving means 60 is provided on the surface 21c of the fixed portion 21 in the radiation shield 20. Below, the moving means 60 is demonstrated. Hereinafter, the target 5, the target cooling plate 50, the cooling pipes 53 and 54, and the second duct 12 that can be attached to and detached from the radiation shield 20 may be collectively referred to as the replacement unit 100.

  The moving means 60 can move up and down in a hole 70 communicating with another room located below the duct arrangement chamber 30 and the duct arrangement chamber 30, and the exchange unit 100 is integrated with the hole 70. It is possible to pass. The moving means 60 includes a vertical rail portion (rail portion) 61 that extends vertically in the hole 70 and is movable in the vertical direction, and a duct support portion 80 that moves up and down along the vertical rail portion 61. ing.

  The duct support portion 80 includes a support portion main body 83 that protrudes from the vertical rail portion 61 toward the fixed portion 21 of the radiation shield 20, and two pieces that extend in the longitudinal direction of the second duct 12 on the upper surface of the support portion main body 83. Horizontal rail portions 81, and a table portion 82 that slides in the longitudinal direction of the second duct 12 with respect to the horizontal rail portions 81 at the top of each horizontal rail portion 81. The table portion 82 includes a bottom plate portion 82a extending in a substantially horizontal direction and two side plate portions 82b extending upward from both sides of the bottom plate portion 82a. Therefore, since the replacement unit 100 is disposed between the side plate portions 82b, the table portion 82 has a shape that can easily support the replacement unit 100.

  Next, a method of removing the replacement unit 100 from the radiation shield 20 and moving the replacement unit 100 to a different chamber from the duct placement chamber 30 by the moving means 60 will be described.

  First, as shown in FIG. 2 and FIG. 3, the worker M who removes the replacement unit 100 stands on the upper surface 31 a of the base portion 31 and removes the first duct 11 from the third duct 13. 3 and 4, the fifth cooling pipe 55 is removed from the first and third cooling pipes 51 and 53, and the sixth cooling pipe 56 is replaced with the second and fourth cooling pipes. Remove from 52,54. Thereafter, as shown in FIGS. 5 and 6, the fourth duct 14 is detached from the second and third ducts 12 and 13. As shown in FIG. 7, when the operator M turns on a switch that moves the moving unit 22, the moving unit 22 moves in the direction of arrow D with respect to the fixed unit 21, and the replacement unit 100 is exposed.

  Next, when the operator M turns on the switch for releasing the engagement of the second duct 12, the second duct 12 moves to the third duct 13 side as shown in FIGS. 6 and 7. . At this time, the projecting portions 12a and 12b of the second duct 12 both move toward the third duct 13 with respect to the claw portions 25b and 26b of the duct holding portions 25 and 26. And the protrusion parts 12a and 12b will be in the state only mounted in the upper surface of the protrusion parts 25a and 26a of the duct holding | maintenance parts 25 and 26. FIG. Thereafter, when the operator M turns on the switch that raises the vertical rail portion 61, the vertical rail portion 61 moves upward from the hole portion 70 and rises to a height slightly lower than the height position of the replacement unit 100.

  As shown in FIG. 8, when the operator M turns on the switch that raises the duct support portion 80, the duct support portion 80 moves upward from the hole portion 70 along the vertical rail portion 61, and the table portion 82. As a result, the replacement unit 100 is raised to a position where it can be supported.

  Then, as shown in FIG. 9, when the operator M turns on the switch that pulls out the target 5, the table unit 82 supports the replacement unit 100, and the table unit 82 holds the replacement unit 100 on the third duct 13 side. Move to. At this time, by moving the table portion 82, the second duct 12 placed on the table portion 82 moves, and the projecting portions 12 a and 12 b of the second duct 12 are connected to the duct holding portions 25 and 26. It moves to the 3rd duct 13 side with respect to each protrusion part 25a, 26a. Therefore, the replacement unit 100 is completely removed from the radiation shield 20 and the replacement unit 100 can be moved by the moving means 60.

  When removing the replacement unit 100 from the radiation shield 20, instead of moving the second duct 12 placed on the table portion 82, the protrusions 12a and 12b are made independent of the second duct 12. The duct holders 25 and 26 may be moved.

  As shown in FIG. 10, when the operator M turns on the switch for moving the replacement unit 100, the position of the replacement unit 100 is such that the replacement unit 100 is positioned immediately above the hole 70 by the sliding movement of the table portion 82. Align. Then, as the duct support portion 80 moves downward along the vertical rail portion 61, the replacement unit 100 and the duct support portion 80 move through the hole portion 70 to another room downstairs. Thereafter, the vertical rail portion 61 moves to the separate room through the hole portion 70, the moving portion 22 approaches the fixed portion 21, and the radiation shield 20 is closed, so that the replacement unit 100 is removed from the radiation shield 20. Is completed.

  As described above, when the operator M turns on each switch of the switch unit 90, the replacement unit 100 can be removed from the radiation shield 20 and moved to another room. In addition, a new replacement unit 100 can be attached to the radiation shield 20 by preparing a new replacement unit 100 in a separate room below the hole 70 in advance and performing the reverse operation. Then, from the state shown in FIGS. 5 and 6, the worker M connects the fourth duct 14 to the second and third ducts 12 and 13, and connects the fifth and sixth cooling pipes 55 and 56. If the first duct 11 is further connected to the third duct 13 by being connected, the neutron beam N can be irradiated as shown in FIG.

  As described above, the neutron capture therapy system 1 includes the moving means 60 that moves the replacement unit 100 to a separate chamber of the duct arrangement chamber 30, and moves the replacement unit 100 to the separate chamber through the hole 70 during maintenance. It is possible. Thus, since the exchange unit 100 having a relatively high activation level can be moved to another room, the amount of radiation emitted into the duct arrangement chamber 30 can be reduced.

  Further, the moving means 60 includes a duct support portion 80 that supports the second duct 12, and is movable between the duct arrangement chamber 30 and another chamber in a state where the duct support portion 80 supports the second duct 12. It has become. Thus, while the moving means 60 is provided with the duct support part 80, the moving means 60 itself can move between the duct placement chamber 30 and the separate chamber. Therefore, the second duct 12 can be moved in a stable state.

  The moving means 60 includes a vertical rail portion 61 and a table portion 82 that moves along the vertical rail portion 61, and the table portion 82 is movable in the longitudinal direction of the second duct 12. Therefore, the table portion 82 can be moved in the vertical direction along the vertical rail portion 61 and in the longitudinal direction of the second duct 12.

  Moreover, the vertical rail part 61 is movable between the duct arrangement | positioning chamber 30 and another chamber. Therefore, when the vertical rail portion 61 is required in the duct placement chamber 30, the vertical rail portion 61 is moved from the separate room to the duct placement chamber 30, and when the vertical rail portion 61 is not required in the duct placement chamber 30, the vertical rail portion 61 is moved. The part 61 can be moved from the duct arrangement chamber 30 to another chamber.

  Further, the second duct 12 has projecting portions 12a and 12b projecting outward, and the radiation shield 20 is a claw for holding the second duct 12 by hooking the projecting portions 12a and 12b. It has parts 25b and 26b. Therefore, the second duct 12 can be held by the radiation shield 20 only by hooking the protrusions 12a and 12b of the second duct 12 to the claw portions 25b and 26b.

  Furthermore, in the radiation shield 20, the fixed portion 21 includes a step portion 21a that protrudes toward the moving portion 22 on the upper side, and the moving portion 22 includes a step portion 22a that protrudes toward the fixed portion 21 on the lower side. The second duct 12 can be held by both the step portion 21 a of the fixed portion 21 and the step portion 22 a of the moving portion 22.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to the said embodiment, You may change in the range which does not change the summary described in each claim.

  In the above-described embodiment, the target cooling plate 50 and the first to sixth cooling pipes 51 to 56 are provided as the cooling structure for cooling the target 5, but the target 5 may be changed by changing the number or shape of the cooling pipes, for example. The structure for cooling can be changed as appropriate.

  In the said embodiment, although the duct structure 10 was equipped with the 1st-4th ducts 11-14, a duct structure can also be changed suitably. For example, the third duct 13 and the fourth duct 14 may be omitted, and the first duct 11 and the second duct 12 may be directly connected.

  Moreover, in the said embodiment, although the radiation shielding body 20 opened and closed when the moving part 22 moved with respect to the fixed part 21 was provided, it replaced with this radiation shielding body 20, and used the radiation shield of a double-aperture spread. Also good. That is, the radiation shield may have a structure that can move between a position that covers at least a part of the second duct 12 and a position that exposes the second duct 12.

  In the above embodiment, the moving means 60 including the vertical rail portion 61 and the duct support portion 80 is used, but the configuration of the moving means can be changed as appropriate.

  Moreover, in the said embodiment, the 2nd duct 12 was hold | maintained at the radiation shield 20 by each protrusion part 12a, 12b of the 2nd duct 12 being hooked on the nail | claw part 25b, 26b of the radiation shield 20. FIG. However, the holding structure of the second duct 12 is not limited to the above. For example, the second duct 12 may be held by suspending it with a wire having a hook.

  In the above embodiment, the replacement unit 100 is moved to a separate room downstairs. However, the destination of the exchange unit 100 may not be a separate room downstairs. For example, the exchange unit 100 may be moved to a room adjacent to the duct arrangement room 30 or a separate room on the upper floor.

  In the above embodiment, the operator M operates the moving unit 60 by turning on the switch unit 90 provided on the surface 21 c of the radiation shield 20. However, the worker M is remotely located at a position farther from the radiation shield 20. You may operate the moving means 60 by operation.

DESCRIPTION OF SYMBOLS 1 ... Neutron capture therapy system, 4 ... Cyclotron (accelerator), 5 ... Target, 11 ... 1st duct, 12 ... 2nd duct, 12a, 12b ... Projection part, 20 ... Radiation shield, 25b, 26b ... Nail Part, 28 ... deceleration body, 30 ... duct arrangement chamber, 60 ... moving means, 61 ... vertical rail part (rail part), 70 ... hole part, 80 ... duct support part, 82 ... table part, L ... charged particle beam, N: Neutron beam, P: Patient (irradiated body).

Claims (5)

A neutron capture therapy system that irradiates an irradiated object with a neutron beam,
An accelerator that emits a charged particle beam;
A target that generates the neutron beam by being irradiated with the charged particle beam;
A first duct connected to the accelerator;
A second duct connected to the first duct and the target;
A duct arrangement chamber in which the first duct and the second duct are arranged;
A radiation shield movable between a position covering at least a part of the second duct and a position exposing the second duct;
A hole that allows the separate chamber different from the duct placement chamber to communicate with the duct placement chamber, and allows the target and the second duct to pass through;
Moving means for moving the target and the second duct;
A neutron capture therapy system comprising:   The moving means includes a duct support portion that supports the second duct, and is movable between the duct placement chamber and the separate chamber in a state where the duct support portion supports the second duct. The neutron capture therapy system according to claim 1, wherein: The moving means includes a rail portion and a table portion that moves along the rail portion,
The neutron capture therapy system according to claim 1 or 2, wherein the table portion is movable in a longitudinal direction of the second duct.   The neutron capture therapy system according to claim 3, wherein the rail portion is movable between the duct arrangement chamber and the separate chamber. The second duct has a protruding portion protruding outward,
The neutron capture therapy according to any one of claims 1 to 4, wherein the radiation shield has a claw for hooking the protrusion and holding the second duct. system.

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