阅读说明：本技术 靶照射系统及来自固体靶的放射性同位素的回收方法 (Target irradiation system and method for collecting radioisotope from solid target ) 是由 樋口博纪 F·圭拉戈麦斯 越智重治 谷口爱实 村上喜信 小田敬 上野悟史 山口雄贵 于 2020-03-26 设计创作，主要内容包括：本发明涉及靶照射系统及来自固体靶的放射性同位素的回收方法。靶照射系统对具有金属层的固体靶照射从粒子加速器射出的带电粒子束以生成金属层的放射性同位素,具备：靶照射装置,配置在设置于建筑物的室内,将固体靶保持于带电粒子束的照射位置,从而能够对固体靶照射带电粒子束；及溶解装置,配置在室内,使附着于通过靶照射装置完成了带电粒子束的照射的固体靶上的放射性同位素溶解。(The present invention relates to a target irradiation system and a method for collecting radioisotopes from a solid target. The target irradiation system irradiates a solid target having a metal layer with a charged particle beam emitted from a particle accelerator to generate a radioisotope of the metal layer, and includes: a target irradiation device which is disposed in a room provided in a building, and which is capable of irradiating a solid target with a charged particle beam by holding the solid target at an irradiation position of the charged particle beam; and a dissolving device disposed in the chamber for dissolving the radioisotope adhered to the solid target irradiated with the charged particle beam by the target irradiation device.)

1. A target irradiation system for generating a radioisotope of a metal layer by irradiating a solid target having the metal layer with a charged particle beam emitted from a particle accelerator, the target irradiation system comprising:

a target irradiation device which is disposed in a room provided in a building, and which is capable of irradiating the solid target with the charged particle beam by holding the solid target at an irradiation position of the charged particle beam; and

and a dissolving device disposed in the chamber and configured to dissolve the radioisotope adhered to the solid target irradiated with the charged particle beam by the target irradiation device.

2. The target irradiation system according to claim 1, further comprising:

a support unit for supporting the target irradiation device on a floor of the chamber,

the dissolving device is supported on the floor by the support portion.

3. The target irradiation system according to claim 1 or 2, further comprising:

and a transport device that transports the solid target, which is released from the holding by the target irradiation device, to the dissolving device.

4. The target irradiation system according to any one of claims 1 to 3, further comprising:

a shield body provided in the chamber and housing the particle accelerator and the target irradiation device inside to shield the radiation emitted from the particle accelerator and the target irradiation device,

the dissolving device is arranged in the shielding protective body.

5. The target irradiation system according to any one of claims 1 to 4, further comprising:

a transport device that transports the solid target from the target irradiation device to the dissolution device; and

a control part for controlling the operation of the display device,

the control unit controls the transport device to: after the charged particle beam is irradiated to the metal layer, the solid held by the target irradiation device is transported to the dissolution device.

6. The target irradiation system according to any one of claims 1 to 5, further comprising:

a shield and protection body provided in the chamber and accommodating the particle accelerator and the target irradiation device therein to shield the radiation emitted from the particle accelerator and the target irradiation device;

a containment portion within the shielding guard covering the dissolution device; and

and an exhaust unit configured to exhaust the gas in the housing unit to the outside of the shield/protection body.

7. The target irradiation system according to any one of claims 1 to 6, further comprising:

a conveying device for conveying the solid target,

the conveyor is capable of supporting a plurality of the solid targets.

8. The target irradiation system according to any one of claims 1 to 7, further comprising:

a support device supporting the solid target,

the target irradiation device is provided with an irradiation port for emitting the charged particle beam,

the dissolving device is provided with a dissolving opening for supplying and recovering a dissolving liquid,

the support device is connected to the irradiation port and connected to the dissolution port.

9. The target irradiation system according to any one of claims 1 to 8,

the dissolving device is provided with a plurality of dissolving ports for supplying and recovering a dissolving liquid.

10. A target irradiation system for generating a radioisotope of a metal layer by irradiating a solid target having the metal layer with a charged particle beam emitted from a particle accelerator, the target irradiation system comprising:

a target irradiation device configured to hold the solid target at an irradiation position of the charged particle beam so that the solid target can be irradiated with the charged particle beam; and

a dissolving device for dissolving the radioisotope adhered to the solid target irradiated with the charged particle beam by the target irradiation device,

the target irradiation device and the dissolving device are disposed in the same room provided in a building.

11. A method for recovering a radioisotope derived from a solid target, which comprises recovering a radioisotope attached to a metal layer on a solid target having the metal layer,

irradiating the solid target with a charged particle beam by a target irradiation device disposed in a shielded room of a building to cause the solid target to generate the radioisotope,

a dissolving device disposed in the shield chamber and configured to transport the solid target irradiated with the charged particle beam by a transport device capable of transporting the solid target,

dissolving the radioisotope attached to the solid target by the dissolving device.

Technical Field

The present invention relates to a target irradiation system and a method for collecting radioisotopes from a solid target.

Background

As shown in patent document 1, there is known a self-shielded cyclotron system including a self-shield that accommodates a cyclotron inside and suppresses radiation emitted from the cyclotron from being emitted to the outside. In recent years, an apparatus for obtaining a solid Radioisotope (RI) by irradiating a target having a metal layer with a charged particle beam has been developed. Such a radioisotope is used for producing a radiopharmaceutical used for PET examination (positron emission tomography) or the like in a hospital or the like. For example, in patent document 2, the RI is recovered by conveying a target to which a solid radioisotope is attached to a dissolving apparatus and dissolving the radioisotope in the dissolving apparatus.

Documents of the prior art

Patent document

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

Patent document 2: japanese patent laid-open No. 2014-115229

Disclosure of Invention

Technical problem to be solved by the invention

Here, the target is activated after the charged particle beam irradiation. Therefore, it is required to take out the target from the irradiation apparatus and rapidly dissolve the radioisotope in the dissolution apparatus.

The present invention aims to provide a target irradiation system and a method for recovering a radioisotope from a solid target, which can take out a target from an irradiation apparatus and rapidly dissolve the radioisotope in a dissolution apparatus.

Means for solving the technical problem

A target irradiation system according to the present invention is a target irradiation system for irradiating a solid target having a metal layer with a charged particle beam emitted from a particle accelerator to generate a radioisotope of the metal layer, the target irradiation system including: a target irradiation device which is disposed in a room provided in a building, and which is capable of irradiating a solid target with a charged particle beam by holding the solid target at an irradiation position of the charged particle beam; and a dissolving device disposed in the chamber for dissolving the radioisotope adhered to the solid target irradiated with the charged particle beam by the target irradiation device.

In the target irradiation system according to the present invention, the target irradiation device can irradiate the solid target with the charged particle beam by holding the solid target at the irradiation position of the charged particle beam. Thereby, a radioisotope is formed at a portion of the metal layer of the solid target to which the charged particle beam is irradiated. The dissolving device dissolves the radioisotope adhered to the solid target irradiated with the charged particle beam by the target irradiation device. This enables the radioactive isotope to be recovered by recovering the solution. Here, the target irradiation device and the dissolving device are disposed in a room provided in a building. Therefore, both the step of irradiating the solid target with the charged particle beam and the step of recovering the radioisotope by dissolution are performed indoors. Therefore, the solid target can be taken out from the target irradiation apparatus and the radioisotope can be quickly dissolved in the dissolving apparatus.

The target irradiation system further includes a support unit for supporting the target irradiation device on the floor of the room, and the dissolving device may be supported on the floor by the support unit. In this case, the target irradiation device and the dissolving device are supported by a common support unit, and therefore, they can be disposed at positions close to each other.

The target irradiation system may further include a transport device that transports the solid target, which is released from the holding by the target irradiation device, to the dissolving device. In this case, the solid target can be quickly transported from the target irradiation apparatus to the dissolution apparatus.

The target irradiation system may further include a shield and protection body which is provided in the chamber and which accommodates the particle accelerator and the target irradiation device therein to shield the radiation emitted from the particle accelerator and the target irradiation device, and the dissolving device may be provided in the shield and protection body. In this case, the shield can shield the radiation when the solid target is transported from the target irradiation apparatus to the dissolution apparatus.

The target irradiation system further includes a transport device that transports the solid target from the target irradiation device to the dissolving device, and a control unit that controls the transport device to: after the charged particle beam is irradiated to the metal layer, the solid target dissolving device held by the target irradiation device is transported. Thus, the control unit automatically carries out the conveyance of the solid target by the conveyance device. This can further suppress radiation exposure (radiation exposure) to the worker. Further, the control unit automatically carries out the conveyance of the solid target, thereby making it possible to shorten the operation time.

The target irradiation system may further include a shield provided in the chamber and housing the particle accelerator and the target irradiation device therein to shield radiation emitted from the particle accelerator and the target irradiation device, and the target irradiation system may include: a housing part covering the dissolving device in the shielding and protecting body; and an exhaust unit configured to exhaust the gas in the housing unit to the outside of the shield/protection body. At this time, when the solution in the dissolving apparatus is vaporized, the gas is prevented from diffusing into the shield body by the housing. The gas in the housing portion can be discharged to the outside of the shield and protection body through the gas discharge portion. This can suppress corrosion of other devices in the shield protector by the gas.

The target irradiation system further includes a transport device that transports the solid target, and the transport device can support the plurality of solid targets. In this case, the transport device can transport the plurality of solid targets to the irradiation position and the dissolution position without detaching the solid targets during the process. This can reduce the influence of radiation exposure caused by the removal operation.

The target irradiation system further includes a support device for supporting the solid target, the target irradiation device includes an irradiation port for emitting a charged particle beam, the dissolving device includes a dissolving port for supplying and recovering a dissolving liquid, and the support device can be connected to the irradiation port and the dissolving port. In this case, the support device can serve as a part of the target irradiation device and a part of the dissolving device.

The dissolving device may include a plurality of dissolving ports for supplying and recovering the dissolving solution. In this case, the process of dissolving the radioisotopes of the plurality of nuclides can be performed without replacing the dissolving opening.

A target irradiation system for irradiating a solid target having a metal layer with a charged particle beam emitted from a particle accelerator to generate a radioisotope of the metal layer, the target irradiation system comprising: a target irradiation device that can irradiate a charged particle beam onto a solid target by holding the solid target at an irradiation position of the charged particle beam; and a dissolving device for dissolving the radioisotope adhered to the solid target irradiated with the charged particle beam by the target irradiation device, wherein the target irradiation device and the dissolving device are disposed in the same room provided in the building. According to this target irradiation system, the same operational effects as those of the above-described target irradiation system can be obtained.

A method for recovering a radioisotope derived from a solid target, which comprises recovering a radioisotope of a metal layer attached to a solid target having the metal layer, wherein the radioisotope is generated in the solid target by irradiating the solid target with a charged particle beam by a target irradiation device disposed in a shield room provided in a building, the solid target irradiated with the charged particle beam is transported by a dissolution device disposed in the shield room by a transport device capable of transporting the solid target, and the radioisotope attached to the solid target is dissolved by the dissolution device. According to this recovery method, the step of irradiating the solid target with the charged particle beam, the step of transporting the solid target, and the step of recovering the radioisotope by dissolution are all performed in a shielded room. Therefore, the solid target can be taken out from the target irradiation apparatus and the radioisotope can be quickly dissolved in the dissolving apparatus. In each step, radiation can be shielded.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a target irradiation system and a method for collecting radioisotopes from a solid target, which can take a target out of an irradiation apparatus and quickly dissolve the radioisotopes in a dissolution apparatus.

Drawings

Fig. 1 is a schematic configuration diagram showing a self-shielded cyclotron system including a target irradiation system according to an embodiment of the present invention.

Fig. 2 is a perspective view of a solid target.

Fig. 3 is an enlarged view of the target irradiation system.

Fig. 4 is a flowchart showing the processing content of the control unit.

Fig. 5 is an enlarged view showing the operation of the target irradiation system.

Fig. 6 is an enlarged view showing the operation of the target irradiation system.

Fig. 7 is an enlarged view showing the operation of the target irradiation system.

Fig. 8 is an enlarged view showing the operation of the target irradiation system.

Fig. 9 is an enlarged view showing the operation of the target irradiation system.

Fig. 10 is an enlarged view showing a self-shielded cyclotron including a target irradiation system according to a modification.

Fig. 11 is a conceptual configuration diagram illustrating a target irradiation system according to a modification example.

Fig. 12 is a schematic configuration diagram showing a target irradiation system according to a modification example.

Fig. 13 is a schematic diagram showing a main part of the target irradiation system shown in fig. 12.

FIG. 14 is a perspective view showing an example of a specific structure of the target exchanger.

Fig. 15 is a sectional view showing a state where the support device is pressed against the irradiation port.

Fig. 16 is a sectional view showing a state where the supporting device is pressed against the dissolution port.

FIG. 17 is a front view of the dissolution port.

Fig. 18 is a schematic diagram showing an operation of the target irradiation system.

Fig. 19 is a schematic diagram showing an operation of the target irradiation system.

Fig. 20 is a schematic diagram showing an operation of the target irradiation system.

Fig. 21 is a schematic diagram showing an operation of the target irradiation system.

Fig. 22 is a schematic diagram showing an operation of the target irradiation system.

Fig. 23 is a schematic diagram showing an operation of the target irradiation system.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and redundant description thereof is omitted.

As shown in fig. 1, the self-shielded cyclotron system 100 is a system installed inside a building 150. The self-shielded cyclotron system 100 according to the present embodiment is a system for producing a radioisotope (hereinafter, may be referred to as RI) using a charged particle beam. The self-shielded cyclotron system 100 can be used as, for example, a cyclotron for PET, and RI produced in this system is used for, for example, production of radiopharmaceuticals (including radiopharmaceuticals) that are radioisotope-labeled compounds (RI compounds). Examples of the radioisotope-labeled compound used in PET examination (positron emission tomography examination) in hospitals and the like include¹⁸F-FLT (fluorothymidine),¹⁸F-FMISO (fluoronitroimidazole) and¹¹C-Raclepride (raclopride) and the like.

The self-shielded cyclotron system 100 includes a cyclotron 2 (particle accelerator), a target irradiation system 3, and a shield/shield 4. The self-shielded cyclotron system 100 is installed on a floor 151 of a building 150 in a cyclotron room 152 inside the building. The cyclotron room 152 is a house covered with concrete (shielding wall). Thus, a user can acquire radioisotopes on-site within a building using the self-shielded cyclotron system 100.

The cyclotron 2 is an accelerator that emits a charged particle beam. The cyclotron 2 is a circular accelerator that supplies charged particles from an ion source into an acceleration space, accelerates the charged particles in the acceleration space, and outputs a charged particle beam. The cyclotron 2 has a pair of magnetic poles, a vacuum box, and an annular yoke surrounding the pair of magnetic poles and the vacuum box. A pair of magnetic poles are partially opposed to each other with a predetermined gap between their main surfaces in the vacuum chamber. In the gap between the pair of magnetic poles, the charged particles are multiply accelerated. Examples of the charged particles include protons and heavy particles (heavy ions). In the present embodiment, the cyclotron 2 includes a plurality of ports 2a that emit charged particle beams. A target irradiation device 20 described later is formed in one of the plurality of ports 2 a. The cyclotron 2 adjusts the trajectory of the charged particle beam in the acceleration space, and takes out the charged particle beam from a desired port 2 a.

The shield/shield 4 is provided in a chamber (inside the cyclotron chamber 152), and houses the cyclotron 2 and the target irradiation device 20 described later therein so as to shield the radiation emitted from the cyclotron 2 and the target irradiation device 20 described later. The shield and protection body 4 is disposed in the building and accommodates the cyclotron 2 inside to suppress the radiation released from the cyclotron 2 from being released into the cyclotron room 152. The shield 4 can shield the radiation in all directions by covering the cyclotron 2 in all directions. In the present embodiment, the shield protector 4 has a hexahedral box-shaped structure, but the shape is not particularly limited. The shield 4 separates the interior space (cyclotron room 152) of the building 150 from the interior space 120 of the self-shielded cyclotron system 100. The interior space of the building 150 may be a space through which other equipment, workers, and the like can pass. Therefore, unlike the self-shielded cyclotron system 100 of the present embodiment, a system in which only the cyclotron 2 is disposed in a room of a building is not suitable for the shield 4. The wall of the shield body 4 is made of, for example, polyethylene, iron, lead, heavy concrete, or the like. In addition to the cyclotron 2, a vacuum pump, wiring, and the like for operating the cyclotron 2 are disposed in the shield and shield body 4. Further, the shield 4 is also provided with the components of the target irradiation system 3. Therefore, the shield 4 functions as a support portion for supporting the target irradiation device 20 described later on the floor 151 of the cyclotron room 152. The dissolving device 21 described later is supported on the floor 151 by the shield and protector 4 functioning as a support portion. With the above-described configuration, the target irradiation device 20 and the dissolving device 21 described below are disposed in the same room (inside the cyclotron room 152) installed in the building 150.

The target irradiation system 3 is a part that irradiates the solid target 10 with a charged particle beam and dissolves and collects the radioisotope generated by the irradiation. The target irradiation system 3 is formed in the vicinity of the outer periphery of the cyclotron 2 and is disposed in the shield 4. The solution containing the radioisotope obtained by the target irradiation system 3 is transported to an apparatus 160 such as a purification apparatus for purifying the radioisotope in the solution or a synthesis apparatus for synthesizing a chemical through a transport pipe 161.

Referring to fig. 2, a solid target 10 is illustrated. The solid target 10 includes a target substrate 13 and a metal layer 11. Specifically, as shown in fig. 2, the solid target 10 has a metal layer 11 as a target material formed on a target substrate 13 made of a metal plate. The metal layer 11 is not limited to a high-purity metal layer, and may be a metal oxide layer. The target substrate 13 is set in the apparatus, and the charged particle beam B is irradiated to the metal layer 11, whereby a trace amount of the radioisotope 12 is generated in the irradiated portion. Thus, the metal layer 11 contains the electronA radioactive isotope 12. As the material of the target substrate 13, a material insoluble in the dissolving solution, for example, Au, Pt, or the like is used. The target substrate 13 shown in fig. 2 is formed into a disk shape, but the shape and thickness are not particularly limited. Examples of the material of the target material, i.e., the metal layer 11, include⁶⁴Ni、⁸⁹Y、¹⁰⁰Mo、⁶⁸Zn, and the like. The radioisotope 12 generated in correspondence with the metal layer 11 is exemplified by⁶⁴Cu、⁸⁹Zr、^99mTc、⁶⁸Ga and the like. The metal layer 11 is formed by applying a plating process to the surface 10a of the target substrate 13. Further, the plate-like metal layer may be attached to the target substrate 13 without being limited to the plating treatment. The metal layer 11 shown in fig. 2 is formed in a circular shape at the center of the target substrate 13, but the shape and position are not particularly limited. When the charged particle beam B is irradiated to the metal layer 11, cooling water or the like may be supplied to the rear surface 10B of the target substrate 13. This allows the cooling water or the like to absorb heat generated in the metal layer 11 (and the target substrate 13) by the irradiation of the charged particle beam B.

Next, the structure of the target irradiation system 3 will be described in detail with reference to fig. 3. The target irradiation system 3 irradiates a solid target 10 having a metal layer 11 with a charged particle beam emitted from the cyclotron 2 to generate a radioisotope of the metal layer 11. The target irradiation system 3 includes: a target irradiation device 20, a dissolving device 21, a conveying device 22, and a control unit 50.

The target irradiation device 20 is a device including: the solid target 10 is disposed in a room (inside the cyclotron room 152) provided in the building 150, and can be irradiated with the charged particle beam B by holding the solid target 10 at the irradiation position of the charged particle beam B. The target irradiation device 20 holds the solid target 10 having the metal layer 11 at the irradiation position of the charged particle beam B. After the irradiation of the solid target 10 with the charged particle beam B is completed, the target irradiation device 20 releases the holding of the solid target 10. Specifically, the target irradiation device 20 includes a fixed unit 23 and a movable unit 24. The target irradiation device 20 holds the solid target 10 at the irradiation position RP by sandwiching the solid target 10 between the fixed unit 23 and the movable unit 24. The fixed unit 23 and the movable unit 24 are both housed in the shield 4.

The fixing means 23 is a cylindrical member fixed to the outer peripheral portion of the cyclotron 2. The fixing means 23 is provided in a state of extending along the irradiation axis BL of the charged particle beam B emitted from the cyclotron 2 and protruding from the outer periphery of the cyclotron 2. The fixing unit 23 includes an internal space 26 for passing the charged particle beam B therethrough at a position corresponding to the irradiation axis BL of the charged particle beam B. The internal space 26 is formed to extend along the irradiation axis BL with the irradiation axis BL as a center line. The fixing unit 23 and the internal space 26 are disposed to be inclined downward with respect to the horizontal direction.

The fixed unit 23 has a horizontally extending surface on the lower end side as an opposed surface 23a opposed to the upper surface of the movable unit 24. The fixing unit 23 holds the solid target 10 at the position of the facing surface 23 a. A sealing member such as an O-ring is provided on the facing surface 23 a. The facing surface 23a also functions as a sealing surface for sealing the solid target 10 by contacting the solid target 10 via a sealing member. In the present embodiment, a portion of the facing surface 23a where the internal space 26 is opened (further, a position of the irradiation axis BL therein) corresponds to the irradiation position RP. Therefore, when the target irradiation device 20 holds the solid target 10, the metal layer 11 in the solid target 10 is disposed in the opening of the internal space 26.

The fixing unit 23 includes a vacuum foil 25 at a middle position of the internal space 26. The vacuum foil 25 keeps a region on the upstream side of the vacuum foil 25 in the internal space 26 in vacuum.

The fixing unit 23 has a charged particle beam B disposed at an irradiation position and a flow path 27 for blowing a gas such as helium to the vacuum foil 25. The flow path 27 includes a main flow path 27a and branch flow paths 27b and 27c branched from the main flow path 27 a. The branch flow path 27b extends toward the vacuum foil 25, and blows gas toward the vacuum foil 25. The branch flow path 27c extends to the irradiation position RP of the solid target 10 and blows a gas to the held solid target 10.

The movable unit 24 advances and retreats in the vertical direction with respect to the fixed unit 23. When the solid target 10 is set on the conveyance tray 60, the movable unit 24 is disposed at a position spaced downward from the fixed unit 23. When the solid target 10 is held at the irradiation position RP, the movable unit 24 is disposed at a position where the solid target 10 is sandwiched between the fixed unit 23 and the movable unit 24 (see fig. 5).

The movable unit 24 has a columnar shape extending in the vertical direction. The movable unit 24 is connected to a drive mechanism 28 that moves in the vertical direction at a part of the outer peripheral surface. A small diameter portion 29 protruding upward is formed at the upper end of the movable unit 24. The diameter of the small diameter portion 29 is smaller than at least the diameter of the inner peripheral portion of the transport tray 60 described later. Thereby, the small diameter portion 29 passes through the through hole on the inner peripheral side of the transport tray 60, abuts against the solid target 10, and presses the solid target 10 against the upper fixing unit 23.

The movable unit 24 has a horizontally extending surface on the upper end side of the small diameter portion 29 as an opposing surface 24a opposing the opposing surface 23a of the fixed unit 23. A sealing member such as an O-ring is provided on the facing surface 24 a. The facing surface 24a also functions as a sealing surface for sealing the solid target 10 by contacting the solid target 10 via a sealing member. When the target irradiation device 20 holds the solid target 10, the opposing surface 23a and the opposing surface 24a sandwich the solid target 10 (see fig. 5).

The movable unit 24 has an internal space 31 opened in the facing surface 24 a. The internal space 31 is a space for storing a cooling medium for cooling the solid target 10. In the internal space 31, a supply pipe 32 for supplying the cooling medium and a discharge pipe 33 for discharging the cooling medium are connected.

The dissolving device 21 is a device which is disposed in a room (inside the cyclotron room 152) and dissolves the radioisotope adhered to the solid target 10 which has been irradiated with the charged particle beam B by the target irradiation device 20. The dissolving device 21 dissolves the metal layer 11 containing the radioisotope in the solid target 10. The dissolving device 21 includes a fixed unit 40 and a movable unit 41. The dissolving device 21 holds the solid target 10 by being sandwiched between the fixed unit 40 and the movable unit 41. In a state where the solid target 10 is held, the dissolving apparatus 21 supplies a dissolving solution to at least the metal layer 11, dissolves the metal of the metal layer 11 containing the radioisotope in the dissolving solution, and recovers the dissolving solution together with the radioisotope. As the solution, hydrochloric acid, nitric acid, or the like can be used. The fixed unit 40 and the movable unit 41 are housed in the shield body 4.

The fixing means 40 is disposed at a position away from the fixing means 23 of the target irradiation device 20 toward the side opposite to the cyclotron 2. The fixing unit 40 includes: a cylindrical body portion 48 extending in the vertical direction, and a support portion 49 supporting the body portion 48 on the outer peripheral side. The body 48 has a horizontally extending surface on the lower end side as the facing surface 40a facing the movable unit 41. The solid target 10 is held at the position of the opposed surface 40 a. A sealing member such as an O-ring is provided on the facing surface 40 a. The facing surface 40a also functions as a sealing surface for sealing the solid target 10 by coming into contact with the solid target 10 via a sealing member. The solid target 10 is held at the position of the opposed surface 40 a.

The body portion 48 has an internal space 42 opened in the facing surface 40 a. The internal space 42 is a dissolution tank for storing a dissolution solution for dissolving the metal layer 11 of the solid target 10. A supply suction pipe 43 for supplying the solution and a suction pipe 44 for sucking the solution and the gas sucked into the internal space 42 are connected to the internal space 42. The diameter of the internal space 42 opened on the opposed surface 40a is smaller than at least the diameter of the solid target 10 and larger than the diameter of the metal layer 11. The diameter of the facing surface 40a itself is not particularly limited, but is smaller than the diameter of the solid target 10 in the present embodiment.

The support portion 49 is a cylindrical member having an end wall spreading radially outward from the outer peripheral surface of the body portion 48. The support portion 49 has a through hole 49a at the center for inserting the main body portion 48. A flange portion is formed near the upper end of the body portion 48. The flange portion engages with an upper edge portion of the through hole 49a of the main body portion 48.

The movable unit 41 advances and retracts in the vertical direction with respect to the fixed unit 40. When the solid target 10 is attached to the fixed unit 40, the movable unit 41 is disposed at a position spaced downward from the fixed unit 40. When the metal layer 11 of the solid target 10 is dissolved in the dissolving device 21, the movable unit 41 is disposed at a position where the solid target 10 is sandwiched between the fixed unit 40 and the movable unit 41 (see fig. 9).

The movable unit 41 includes a main body 46 and a catch 47 provided on the upper end side of the main body 46. The main body 46 has a columnar shape extending in the vertical direction. The main body 46 is connected to a driving mechanism (not shown) that moves in the vertical direction at a part of the outer peripheral surface. A groove structure for supporting the disc portion 47 is formed at the upper end of the body portion 46.

The tray 47 includes: a bottom wall 47a extending horizontally at the upper end of the body 46, and a side wall 47b rising upward from the outer peripheral edge of the bottom wall 47 a. The bottom wall 47a has a horizontally extending surface as the facing surface 41a facing the facing surface 40a of the fixing unit 40. The facing surface 41a is in contact with the solid target 10. When the dissolving device 21 holds the solid target 10, the opposing surface 40a and the opposing surface 41a sandwich the solid target 10 (see fig. 9). The inside diameter of the side wall portion 47b is larger than the diameter of the solid target 10. When the solid target 10 is held, the upper end portion of the side wall portion 47b is disposed at a position higher than the solid target 10. Therefore, when the dissolving liquid leaks from the internal space 42 when the metal layer 11 of the solid target 10 is dissolved, the receiving portion 47 receives the dissolving liquid. The bottom wall 47a has an uneven structure on its lower surface side for fitting into the groove structure of the body 46.

In the dissolving apparatus 21, the main body portion 48 and the tray portion 47 which are in contact with the dissolving liquid are configured as replaceable disposable devices. That is, the main body 48 is detachably attached to the support portion 49. The tray 47 is detachably attached to the main body 46. Here, "detachable" means an attachment method in which a worker can easily detach the attachment tool by a normal maintenance work even after the attachment is completed. For example, the detachable attachment structure may be a structure that is attached by bolting, or a structure that is attached by fitting or engaging with a strength of a degree that does not come off during dissolution. For example, a fixing structure such as welding or welding is not a detachable type. As the material of the replaceable body portion 48 and the replaceable pad portion 47, for example, a material having high acid resistance such as Teflon (registered trademark) can be used.

The transport device 22 transports the solid target 10, which is released from the holding by the target irradiation device 20, to the dissolving device 21. The transport device 22 transports the solid target 10 from the target irradiation device 20 to the dissolution device 21. The transport device 22 is arranged within the shielding and shielding body 4. The conveyance device 22 includes: a conveyance tray 60 for conveying the solid target 10 in a state of being placed thereon, and a conveyance driving unit 61 for driving the conveyance tray 60. The transfer tray 60 is an annular member having a support portion for supporting the solid target 10 on the upper surface side. The transport tray 60 has a groove portion formed over the entire circumference at the inner peripheral edge portion of the upper surface, and the outer peripheral edge portion of the lower surface side of the solid target 10 is mounted on the groove portion. The conveyance drive section 61 is configured by a combination of a drive source and a drive force transmission mechanism, not shown. The transport driving unit 61 moves the transport tray 60 from the position of the target irradiation device 20 to the horizontal direction to transport the solid target 10 irradiated with the charged particle beam to the position of the dissolving device 21 at least when transporting the solid target to the dissolving device 21. The conveyance driving section 61 conveys the conveyance tray 60 from the area between the fixed unit 23 and the movable unit 24 of the target irradiation device 20 to the area between the fixed unit 40 and the movable unit 41 of the dissolving device 21. The conveyance driving unit 61 may be configured by using a known driving source such as a rotary motor and a linear motor, and a driving force transmission mechanism such as a gear and a lever. The conveyance driving unit 61 may have any configuration as long as it can avoid interference with other members and can perform a desired operation. The position of the transport tray 60 in each stage will be described in detail when the operation to be described later is described.

The control unit 50 controls the self-shielded cyclotron system 100. The control unit 50 includes a CPU, a RAM, a ROM, an input/output interface, and the like. The control unit 50 determines the control content based on the detection signals from the sensors in the device and the program stored in the ROM, and controls the components in the self-shielded cyclotron system 100. The control unit 50 may not be constituted by one processing device, but may be constituted by a plurality of processing devices. The control unit 50 may be disposed inside the shield and protection body 4 or outside the shield and protection body 4.

The control unit 50 includes: an irradiation control unit 51, a holding control unit 52, a dissolution control unit 53, and a transport control unit 54. The irradiation control unit 51 mainly controls the cyclotron 2 and controls the operation related to the irradiation of the charged particle beam B by the cyclotron 2. The holding control unit 52 mainly controls the target irradiation device 20, and controls operations related to holding of the solid target 10 by the target irradiation device 20. The dissolution controller 53 mainly controls the dissolution device 21 and controls the operation related to dissolution of the metal layer 11 of the solid target 10. The conveyance controller 54 mainly controls the conveyance device 22 and controls operations related to conveyance of the solid target 10. The conveyance control unit 54 controls the conveyance device 22 to: after the charged particle beam B is irradiated to the metal layer 11, the solid target 10 held by the target irradiation device 20 is transported to the dissolving device 21.

Next, the operation of the target irradiation system 3 will be described together with the contents of the control processing performed by the control unit 50, with reference to fig. 3 to 9. Fig. 4 is a flowchart showing the control processing content of the control unit 50. Fig. 4 to 9 are diagrams showing states of the target irradiation system 3 at respective stages during operation. For convenience of explanation, the control unit 50 and the conveyance driving unit 61 are not shown in fig. 4 to 9. Note that symbols not used in the description may be appropriately omitted.

As shown in fig. 4, the control unit 50 performs a process for setting the solid target 10 in the target irradiation system 3 (step S10). In the process of S10, the control unit 50 places the target irradiation device 20, the dissolution device 21, and the transport device 22 at the initial positions. The control unit 50 drives the driving units of the respective constituent elements to set the target irradiation system 3 in the state shown in fig. 3. In this state, the movable unit 24 is disposed at a position spaced downward from the fixed unit 23. The movable unit 41 is disposed at a position spaced downward from the fixed unit 40. The conveyance tray 60 is disposed at a position spaced downward from the fixing unit 23 and at a reference height. Here, the "reference height" means: a predetermined height position between the fixed unit 23 and the movable unit 24 and between the fixed unit 40 and the movable unit 41 in the height direction. At this height position, the conveyance tray 60 does not interfere with the units 23, 24, 40, and 41 even if it moves in the horizontal direction. The controller 50 may notify the operator of the fact that the solid target 10 can be installed, for example, by using a monitor. When it is detected that the worker places the solid target 10 on the conveyance tray 60, the control unit 50 recognizes that the installation of the solid target 10 is completed. The control unit 50 can detect that the installation of the solid target 10 is completed by the detection of the sensor or the input of the operator.

Subsequently, the control unit 50 performs a process of holding the solid target 10 at the irradiation position RP of the charged particle beam B (step S20: FIG. 4). In S20, the holding control unit 52 of the control unit 50 controls the drive mechanism 28 of the movable unit 24 to move the movable unit 24 upward. Thereby, as shown in fig. 5, the solid target 10 is sandwiched between the fixed unit 23 and the movable unit 24 at the irradiation position RP. In addition, during the upward movement of the movable unit 24, the solid target 10 placed on the transport tray 60 is supported by the movable unit 24 passing through the through hole of the transport tray 60 from below. At this time, the conveyance tray 60 can be raised in a state of being supported by the movable unit 24. Alternatively, the conveyance tray 60 may be driven to ascend together with the movable unit 24.

Subsequently, the control unit 50 performs a process of irradiating the solid target 10 with the charged particle beam B (step S30: FIG. 4). In S30, the irradiation control unit 51 of the control unit 50 controls the cyclotron 2 to irradiate the solid target 10 with the charged particle beam B. At this time, the holding control unit 52 controls the flow path system to: helium gas or the like is blown from the flow path 27 of the fixing unit 23 to the solid target 10 and the vacuum foil 25. The holding controller 52 controls the piping system of the supply pipe 32 and the discharge pipe 33 so that the cooling medium flows into the internal space 31 to cool the solid target 10.

When the process at S30 ends, the holding control unit 52 of the control unit 50 controls the drive mechanism 28 of the movable unit 24 to move the movable unit 24 downward. Thereby, as shown in fig. 6, the movable unit 24 returns to the position of the initial state. The transport tray 60 is also returned to the reference height position in a state where the solid target 10 is placed.

Next, in S40 of the control unit 50 (step S40: fig. 4) that the control unit 50 performs the process of conveying the solid target 10 from the target irradiation device 20 to the dissolution device 21, the conveyance control unit 54 of the control unit 50 controls the conveyance drive unit 61 (see fig. 3) of the conveyance device 22 so that the conveyance tray 60 is horizontally moved from the target irradiation device 20 to the position of the dissolution device 21. As a result, as shown in fig. 7, the conveyance tray 60 is disposed between the fixed unit 40 and the movable unit 41 while maintaining the position of the reference height in the height direction. Thereby, the solid target 10 is disposed at a position facing the facing surface 40a, which is opened in the internal space 42, on the lower side.

Subsequently, the control unit 50 performs a process of setting the solid target 10 in the dissolution device 21 (step S50: FIG. 4). In S50, as shown in fig. 8, the dissolution controller 53 of the controller 50 controls the piping system of the suction pipe 44 to adsorb the solid target 10 to the facing surface 40a via the internal space 42. Before the solid target 10 is adsorbed, the solid target 10 is pressed against the facing surface 40a of the main body 48 by the raising of the conveyance tray 60. Thereby, the internal space is sealed in a state where an O-ring (not shown) provided between the solid target 10 and the body portion 48 is compressed. Thereafter, the conveyance controller 54 controls the conveyance driver 61 (see fig. 3) to move the conveyance tray 60 to the position of the target irradiation device 20. This prevents the conveyance tray 60 from interfering with the movable unit 41.

In S50, the dissolution controller 53 controls the driving unit of the movable unit 41 to move the movable unit 41 upward. As a result, as shown in fig. 9, the solid target 10 is sandwiched between the facing surface 40a of the fixed unit 40 and the facing surface 41a of the movable unit 41. At this time, the solid target 10 is pressed against the body 48 from above while being accommodated in the tray 47.

Next, the control unit 50 performs a process of dissolving the metal layer 11 of the solid target 10 in the dissolving device 21 to recover the radioisotope contained in the metal layer 11 (step S60: fig. 4). In S60, the dissolution controller 53 of the controller 50 controls the piping system of the supply/suction pipe 43 to supply the dissolution liquid SL from the supply/suction pipe 43 to the internal space 42. The dissolution controller 53 controls the line system of the intake pipe 44 to suck and collect the solution SL in which the radioisotope is dissolved from the supply and intake pipe 43. As described above, the control process shown in fig. 4 ends. After the recovery of the radioisotope is completed, the worker removes the solid target 10 together with the main body portion 48 and the receiving portion 47 and removes the solid target to the outside of the shield/protection body 4.

As shown in fig. 1, the solution SL in which the radioisotope is dissolved is discharged to the outside of the shield 4, and is transported to an apparatus 160 such as a purification apparatus for purifying the radioisotope in the solution SL or a synthesis apparatus for synthesizing a chemical. The purification apparatus or the synthesis apparatus may be disposed in the same building 150 or may be disposed in different buildings (facilities). In the case where the solution SL is supplied to a synthesizing apparatus or the like in the same building 150, the solution SL is supplied to the synthesizing apparatus or the like through a supply pipe 161 connected to the supply suction pipe 43. Since radiation is released from the solution SL, the duct 161 is covered with a shield and a shield or passes through a shield wall (floor or wall) of the building 150. In the case of transporting the solution SL to a different building, the recovered solution SL is stored in a shield box (a box that suppresses radiation from being released to the outside, such as a lead box), and is transported together with the shield box by an automobile or the like.

Next, the operational effects of the target irradiation system 3 according to the present embodiment will be described.

A target irradiation system 3 according to the present embodiment irradiates a solid target 10 having a metal layer 11 with a charged particle beam B emitted from a cyclotron 2 to generate a radioisotope of the metal layer 11, the target irradiation system 3 including: a target irradiation device 20 which is disposed in a cyclotron room 152 provided in the building 150 and which is capable of irradiating the solid target 10 with the charged particle beam B by holding the solid target 10 at an irradiation position of the charged particle beam B; and a dissolving device 21 disposed in the cyclotron room 152, and dissolving the radioisotope adhered to the solid target 10 that has been irradiated with the charged particle beam B by the target irradiation device 20.

In the target irradiation system 3, the target irradiation device 20 is configured to hold the solid target 10 at the irradiation position of the charged particle beam B, and to irradiate the solid target 10 with the charged particle beam B. As a result, radioisotopes are formed at the portions of the metal layer 11 of the solid target 10 to which the charged particle beam B is irradiated. The dissolving device 21 dissolves the radioisotope adhered to the solid target 10 irradiated with the charged particle beam B by the target irradiation device 20. This enables the radioactive isotope to be recovered by recovering the solution. Here, the target irradiation device 20 and the dissolving device 21 are disposed in a cyclotron room 152 provided in the building 150. Therefore, the step of irradiating the solid target 10 with the charged particle beam and the step of recovering the radioisotope by dissolution are both performed in the cyclotron chamber 152. Therefore, the solid target 10 can be taken out from the target irradiation apparatus 20 and the radioisotope can be quickly dissolved in the dissolving apparatus 21.

The target irradiation system 3 further includes: the shield/shield 4 serves as a support portion for supporting the target irradiation device 20 on the floor 151 of the cyclotron room 152, and the dissolving device 21 is supported on the floor 151 by the support portion. At this time, since the target irradiation device 20 and the dissolving device 21 are supported by a common support portion, both devices can be disposed at close positions.

The target irradiation system 3 further includes: and a transport device 22 that transports the solid target 10, whose holding by the target irradiation device 20 is released, to the dissolving device 21. At this time, the solid target 10 can be quickly transported from the target irradiation device 20 to the dissolution device 21.

The target irradiation system 3 further includes: a shield/shield 4 disposed in the cyclotron room 152 and housing the cyclotron 2 and the target irradiation device 20 therein to shield the radiation emitted from the cyclotron 2 and the target irradiation device 20, and a dissolving device 21 disposed in the shield/shield 4. At this time, the shield 4 can shield the radiation when the solid target 10 is transported from the target irradiation apparatus 20 to the dissolution apparatus 21.

The target irradiation system 3 further includes a transport device 22 and a control unit 50, the transport device 22 transports the solid target 10 from the target irradiation device 20 to the dissolving device 21, and the control unit 50 controls the transport device 22 to: after the charged particle beam B is irradiated to the metal layer 11, the solid target 10 held by the target irradiation device 20 is transported to the dissolving device 21. Thereby, the conveying of the solid target 10 by the conveying device 22 is automatically performed by the control section 50. This can further suppress radiation exposure to the worker. Further, the control unit 50 automatically carries out the conveyance of the solid target 10, thereby making it possible to shorten the operation time.

The target irradiation system 3 irradiates a solid target 10 having a metal layer 11 with a charged particle beam B emitted from a cyclotron 2 to generate a radioisotope of the metal layer 11, the target irradiation system 3 including: a target irradiation device 20 that can irradiate the solid target 10 with the charged particle beam B by holding the solid target 10 at an irradiation position of the charged particle beam B; and a dissolving device 21 for dissolving the radioisotope adhered to the solid target 10 irradiated with the charged particle beam B by the target irradiation device 20, wherein the target irradiation device 20 and the dissolving device 21 are disposed in the same cyclotron room 152 installed in the building 150. According to the target irradiation system 3, the same operational effects as described above can be obtained.

A method for collecting a radioisotope derived from a solid target 10, which comprises collecting a radioisotope of a metal layer 11 attached to a solid target 10 having the metal layer 11, wherein the radioisotope is generated on the solid target 10 by irradiating the solid target 10 with a charged particle beam B by a target irradiation device 20 disposed in a shield room of a building 150, the solid target 10 on which irradiation of the charged particle beam B is completed is transported to a dissolving device 21 disposed in the shield room by a transport device 22 capable of transporting the solid target 10, and the radioisotope attached to the solid target 10 is dissolved by the dissolving device 21. According to this recovery method, the step of irradiating the solid target 10 with the charged particle beam B, the step of transporting the solid target 10, and the step of recovering the radioisotope by dissolution are all performed in a shielded room. Therefore, the solid target can be taken out from the target irradiation apparatus 20 and the radioisotope can be quickly dissolved in the dissolving apparatus 21. In each step, radiation can be shielded.

In the self-shielded cyclotron system 100 according to the present embodiment, the target irradiation device 20 holds the target having the metal layer 11 at the irradiation position RP of the charged particle beam B. Therefore, the charged particle beam B is irradiated to the solid target 10 held by the target irradiation device 20. As a result, the radioisotope 12 is formed in the metal layer 11 of the solid target 10 at the portion irradiated with the charged particle beam B. The dissolving device 21 is provided with a dissolving device for dissolving the metal layer 11 containing the radioisotope in the solid target 10. This enables the radioactive isotope to be recovered by recovering the solution. The transportation device 22 transports the solid target 10 from the target irradiation device 20 that irradiates the solid target 10 with the charged particle beam B to the dissolving device 21 that collects the radioisotope. Here, the target irradiation device 20, the dissolving device 21, and the transport device 22 are disposed in the shield and shield body 4. Therefore, the step of irradiating the solid target 10 with the charged particle beam B, the step of collecting the radioisotope by dissolution, and the step of transporting the target between the two steps are all performed in the shield and shield body 4. Therefore, in each step, the radiation emitted from the solid target 10 after the irradiation of the charged particle beam is blocked by the self-shielding body. As described above, the safety against radiation exposure when obtaining a radioisotope can be further improved.

The self-shielded cyclotron system 100 further includes a control unit 50, and the control unit 50 can control the transport device 22 to: after the charged particle beam B is irradiated to the metal layer 11, the solid target 10 held by the target irradiation device 20 is transported to the dissolving device 21. Thereby, the conveying of the solid target 10 by the conveying device 22 is automatically performed by the control section 50. This can further improve the safety against radiation exposure. Further, the control unit 50 automatically carries out the conveyance of the solid target 10, thereby making it possible to shorten the operation time.

The present invention is not limited to the above-described embodiments, and various modifications can be made as described below without departing from the scope of the present invention.

For example, a structure as in fig. 10 may be employed. The self-shielded cyclotron system shown in fig. 10 may include: a housing part 70 that covers the dissolving device 21 in the shield and protection body 4; and an exhaust unit 71 for exhausting the gas in the housing unit 70 to the outside of the shield body 4. The containing section 70 covers only the dissolving device 21 and does not cover the target irradiation device 20. In addition, an opening 70a may be formed in the accommodating portion 70 at a portion through which the tray is conveyed. The opening 70a may be closed when the transport tray does not pass through. The exhaust portion 71 may include an exhaust pipe that passes through the shield and protection body 4 from the housing portion 70 and communicates with the outside of the shield and protection body 4. The exhaust unit 71 may include a pump or the like provided in the exhaust pipe.

Thus, when the solution in the dissolving device 21 is vaporized, the gas can be prevented from diffusing into the shield and protection body 4 by the housing portion 70. The gas in the housing portion 70 can be discharged to the outside of the shield and protection body 4 through the gas discharge portion 71. This can suppress corrosion of other devices in the shield and shield body 4 by the gas.

The configuration of the target irradiation system shown in each of the figures of the above embodiments is merely an example, and the shape and arrangement may be appropriately changed within the scope of the present invention. For example, the transport device may employ an arm-shaped gripping portion that grips the target instead of the transport tray.

In addition, the control unit automatically carries out the transport of the target by the transport device. Instead, the driving itself of the conveyor can be performed by manual operation of a worker. In this case, since the target is accommodated in the self-shielding body, the safety against radiation exposure can be further improved.

The target irradiation system 3 shown in fig. 11 (a) may be used. In the example shown in fig. 11 (a), the target irradiation device 20 and the dissolution device 21 may be disposed in an irradiation chamber 153 different from the cyclotron chamber 152 of the building 150. At this time, the charged particle beam emitted from the cyclotron 2 is transported from the cyclotron room 152 to the target irradiation device 20 of the irradiation room 153 via the transport line 155. At this time, the target irradiation device 20 and the dissolving device 21 are supported by the floor 151 of the irradiation chamber 153 via the support unit 156.

Further, the target irradiation system 3 shown in fig. 11 (b) may be used. In the example shown in fig. 11 (b), the cyclotron 2, the target irradiation apparatus 20, and the dissolution apparatus 21 are disposed in the same cyclotron chamber 152. In this case, the shield 4 may be omitted, unlike the structure shown in fig. 1.

In the above-described embodiment, the cyclotron is given as an example of the particle accelerator, but the present invention is not limited to the cyclotron. For example, as the particle accelerator, a linear accelerator may be employed.

The target illumination system 200 shown in fig. 12 may be employed. The target irradiation system 200 includes: a fixing unit 211 of the target irradiation device 210, a fixing unit 221 of the dissolving device 220, a supporting device 230, a target exchanger 240, and a control unit 260.

In addition, an XYZ coordinate system is set for the purpose of describing the target irradiation system 200. The X-axis direction is a direction parallel to the horizontal direction. One side in the X-axis direction (the sheet near side in fig. 12) is set as the positive side in the X-axis direction. The Y-axis direction is a direction orthogonal to the X-axis direction and parallel to the horizontal direction. One side in the Y-axis direction (left side of the paper in fig. 12) is set as the positive side in the Y-axis direction. The vertical direction is defined as the Z-axis direction. The upper side is set as the positive side in the Z-axis direction.

As shown in fig. 13, the fixing unit 211 of the target irradiation device 210 includes an internal space 213 through which the charged particle beam B passes, at a position corresponding to the irradiation axis BL of the charged particle beam B. The internal space 213 is formed to extend along the irradiation axis BL with the irradiation axis BL as a center line. In the present embodiment, the irradiation axis BL of the charged particle beam B extends parallel to the Y-axis direction. The charged particle beam B is irradiated from the positive side to the negative side in the Y-axis direction. Therefore, the internal space 213 extends parallel to the Y-axis direction.

The fixing unit 211 includes an irradiation port 212 for emitting the charged particle beam B. The irradiation port 212 has a surface extending parallel to the XZ plane as an opposing surface opposing the sealing surface 230a of the support device 230. The irradiation port 212 has an opening portion in which the internal space 213 is opened. The charged particle beam B is emitted from the opening.

The fixing unit 221 of the dissolving apparatus 220 is disposed at a position apart from the fixing unit 211 of the target irradiation apparatus 210 toward the X-axis direction. The fixing unit 221 includes a plurality of dissolving ports 222A and 222B for supplying and recovering the dissolving liquid SL. The dissolving ports 222A and 222B can recover radioisotopes of different species from each other. Therefore, the dissolving ports 222A and 222B can supply and collect different dissolving liquids SL. However, the dissolving ports 222A, 222B can recover radioisotopes of the same nuclide. The dissolving ports 222A and 222B are provided adjacent to each other in the X-axis direction. The dissolving ports 222A and 222B have surfaces extending parallel to the XZ plane as opposed surfaces facing the sealing surface 230a of the support device 230. The center lines SCL, SCL of the opposed surfaces of the dissolution ports 222A, 222B extend parallel to the Y-axis direction while being spaced apart from each other in the X-axis direction. The centerlines SCL, SCL of the dissolution ports 222A, 222B are set at the same height as the irradiation axis BL. The dissolving ports 222A and 222B are detachable from the dissolving apparatus 220. That is, the dissolving ports 222A and 222B may be detachably attached to the mounting table 223. This allows the dissolution port 222 to be replaced with a radioisotope.

The structure of the dissolution port 222A will be described in detail with reference to fig. 16 and 17. The dissolving port 222B has the same configuration as the dissolving port 222A, and therefore, the description thereof is omitted. The dissolution port 222A has an opposing surface 222A to which a sealing surface 230a of the support device 230 is pressed. The dissolution port 222A includes a flow path 224 and an adsorption structure 226.

The flow path 224 allows the solution SL to flow therethrough. The flow path 224 is formed inside the dissolution port 222A member and opens to the facing surface 222A. The flow path 224 causes the solution SL to flow out from the opening, and sucks the solution SL from the opening. Further, a flow passage forming member 227 protruding to the negative side in the Y axis direction protrudes from the position of the center line SCL of the facing surface 222 a. The flow path forming member 227 is inserted into the internal space 233 of the support device 230, and forms a flow path of the solution SL in the internal space 233. The flow paths 224 open at positions adjacent to each other in the circumferential direction of the flow path forming member 227. The dissolving port 222A has two flow paths 224, but the number is not particularly limited.

The suction structure 226 is a mechanism that sucks the seal surface 230a in contact with the facing surface 222 a. Suction structure 226 has annular groove 226a centered on center line SCL. The adsorption structure 226 further includes a vacuum exhaust passage 226b formed in the dissolution port 222A. The vacuum exhaust passage 226b opens at the position of the groove portion 226 a.

As shown in fig. 12 and 13, the support device 230 is a device for supporting the solid target 10. The support device 230 is connected to the irradiation port 212 and to the dissolution ports 222A and 222B. Therefore, the support device 230 functions as a movable unit of the target irradiation device 210. The support device 230 functions as a movable unit of the dissolving device 220. In the present embodiment, as described later, a plurality of support devices 230 can be attached to the target exchanger 240. Therefore, the target irradiation system 200 can include a plurality of support devices 230 according to the application. In the present embodiment, the target irradiation system 200 includes two support devices 230A and 230B.

Referring to fig. 15, the structure of the supporting device 230 will be described in detail. As shown in fig. 15, the support device 230 is a member having a substantially cylindrical shape. The center line CL of the support device 230 extends parallel to the Y-axis direction. The support device 230 includes a 1 st member 231 and a 2 nd member 232. The support device 230 is divided into a 1 st member 231 and a 2 nd member 232 at a position halfway in the longitudinal direction, i.e., the Y-axis direction. The 1 st member 231 is disposed on the positive side in the Y axis direction, i.e., on the upstream side in the irradiation direction of the charged particle beam B. The 2 nd member 232 is disposed on the negative side in the Y axis direction, i.e., on the downstream side in the irradiation direction of the charged particle beam B.

The supporting device 230 supports the solid target 10 by sandwiching the solid target 10 between the 1 st member 231 and the 2 nd member 232. The support device 230 supports the solid target 10 and makes it inclined with respect to the center line CL. The direction of inclination of the solid target 10 is not particularly limited. Here, the solid target 10 is inclined so as to be directed upward (positive side in the Z-axis direction) from the positive side in the Y-axis direction toward the negative side. The 1 st member 231 has a support surface 231a at the negative side end in the Y axis direction. The 2 nd member 232 has a bearing surface 232a at the positive side end in the Y axis direction. The support surface 231a of the 1 st member 231 and the support surface 232a of the 2 nd member 232 face each other in parallel. The support surfaces 231a and 232a are inclined in the same manner as the inclination direction of the solid target 10. Sealing portions each having an O-ring are provided near the outer peripheral end of the solid target 10 on the support surfaces 231a and 232 a.

The 1 st member 231 has the above-described seal surface 230a at the positive side end in the Y axis direction. Therefore, the 1 st member 231 functions as a member connected to the irradiation port 212 and connected to the dissolution ports 222A and 222B. A seal portion having an O-ring is provided on the seal surface 230 a. The 1 st member 231 has an internal space 233 extending parallel to the Y-axis direction at the position of the center line CL. The inner space 233 extends from the seal surface 230a to the support surface 231 a. Thereby, the solid target 10 is exposed to the internal space 233. The internal space 233 functions as a transport path of the target irradiation device 210 for guiding the charged particle beam B to the solid target 10. The internal space 233 functions as a dissolving tank of the dissolving device 220 through which the dissolving liquid SL flows. Since the 1 st member 231 is a member through which the charged particle beam B passes and through which the solution SL flows, a material having chemical resistance, radiation resistance, and heat resistance, such as Nb or ceramic, is preferably used as the material of the 1 st member 231.

When the support device 230 is coupled to the irradiation port 212, the sealing surface 230a of the 1 st member 231 is pressed against the irradiation port 212. The internal space 233 is in communication with the internal space 213. The support device 230 is arranged such that the center line CL coincides with the irradiation axis BL. In this state, the position where the irradiation axis BL intersects the surface 10a of the solid target 10 becomes the irradiation position RP.

The 2 nd member 232 functions as a cooling structure for cooling the solid target 10. The 2 nd member 232 has a groove 234 at the position of the support surface 232 a. The rear surface 10b of the solid target 10 is exposed in the inner space of the groove 234. Therefore, the cooling medium W supplied to the groove portion 234 comes into contact with the solid target 10. The 2 nd member 232 has cooling channels 236, 237 extending in the Y-axis direction. The cooling channels 236, 237 communicate with the groove 234. The cooling channel 236 supplies the cooling medium W to the groove 234. The cooling flow passage 237 collects the cooling medium W from the groove 234. Since the 2 nd member 232 is a member from which the solid target 10 is exposed, a rust-proof material such as SUS is preferably used as a material of the 2 nd member 232.

Next, as shown in fig. 16, when the support device 230 is coupled to the dissolution port 222A, the sealing surface 230a of the 1 st member 231 is pressed against the facing surface 222A of the dissolution port 222A. The support device 230 is configured such that the centerline CL coincides with the centerline SCL of the dissolving port 222A. A part of the sealing surface 230a faces the groove 226a of the suction structure 226. Thereby, the sealing surface 230a is adsorbed to the groove portion 226a that is evacuated. The flow passage forming member 227 is inserted into the internal space 233. Thereby, a flow path of the solution SL is formed in the internal space 233. The internal space 233 is in communication with the opening of the flow path 224. The solution SL supplied from the flow path 224 contacts the surface 10a of the solid target 10. The solution SL in which the radioisotope is dissolved is recovered from the flow path 224.

Next, the target exchanger 240 will be explained. As shown in fig. 12 and 13, the target exchanger 240 functions as a transport device for transporting the solid target 10. The target exchanger 240 supports the solid target 10 via the supporting device 230. The target exchanger 240 includes a holder 241 to which a plurality of support devices 230 can be attached. Thus, the target exchanger 240 can support a plurality of solid targets 10. The holder 241 is slidable in the X-axis direction with the plurality of support devices 230 attached. Therefore, the holder 241 together with the plurality of supporting devices 230 can convey the solid target 10 in the X-axis direction.

An example of a specific structure of the target exchanger 240 will be described with reference to fig. 14. As shown in fig. 14, the target exchanger 240 includes: a base plate 242, a 1 st sliding plate 243, a 2 nd sliding plate 244, a 1 st cylinder 246, a 2 nd cylinder 247, and a 3 rd cylinder 248.

The base plate 242 is a member on which the 1 st sliding plate 243 and the 2 nd sliding plate 244 are mounted. On the upper surface of the base plate 242, a guide rail 242a (refer to fig. 12) extending in the Y-axis direction is provided. The substrate 242 is orthogonally connected to a fixing plate 249, and the fixing plate 249 is used to fix the target exchanger 240 to the cyclotron.

The 1 st sliding plate 243 is a plate-like member having a rectangular outer shape in a plan view. A guide rail 251 extending in the X-axis direction is provided on the edge portion of the 1 st sliding plate 243 on the Y-axis direction positive side. A 1 st cylinder 246 is attached to the side surface of the 1 st sliding plate 243 on the negative side in the Y axis direction. The 1 st cylinder 246 moves the drive shaft forward and backward in the Y axis direction, and thereby the holder 241 reciprocates in the Y axis direction together with the 1 st sliding plate 243. A 2 nd cylinder 247 is mounted on the upper surface of the 1 st sliding plate 243. The drive shaft of the 2 nd cylinder 247 can advance and retreat in the X-axis direction.

A 3 rd cylinder 248 is mounted on the upper surface of the 1 st sliding plate 243. The drive shaft of the 3 rd cylinder 248 is capable of advancing and retreating in the Y-axis direction. The 3 rd cylinder 248 is connected to a drive shaft of the 2 nd cylinder 247. Therefore, the 2 nd cylinder 247 advances and retreats the drive shaft in the X axis direction, and thereby the 3 rd cylinder 248 reciprocates in the X axis direction together with the holder 241 with the drive shaft (details will be described later) engaged therewith.

A mounting plate 252 extending in the Y-axis direction is mounted on the upper surface of the 3 rd cylinder 248. A striking element 253 is attached to the Y-axis direction positive end of the attachment plate 252. The striker 253 abuts on a microswitch 259 provided on a 2 nd sliding plate 244 described later, thereby detecting the position of the 2 nd sliding plate 244 in the X axis direction.

The 2 nd sliding plate 244 has a rectangular parallelepiped base portion 256 and a holder 241 erected on the base portion 256. A bush 255 having a U-shaped cross section extending in the X-axis direction is attached to the lower surface of the base 256. The holder 241 has a rectangular shape when viewed from the front. The holder 241 has four holding holes 257 for holding the support device 230, and the substantially cylindrical support device 230 is fitted into and held in each of the holding holes 257. The four holding holes 257 are arranged side by side in the X-axis direction. Thereby, the holder 241 can hold four support devices 230 at maximum. In the present embodiment, the holder 241 holds two support devices 230A and 230B, but can hold two more support devices 230 by addition.

On the front surface of the base 256 of the 2 nd sliding plate 244, four micro switches 259 are mounted at the same pitch as that of the holding holes 257. When the striker 253 abuts on the microswitch 259, the position of the 2 nd sliding plate 244 in the X-axis direction is detected. Further, engagement holes 261 are provided below the micro switches 259, respectively. The engagement hole 261 is configured such that: the diameter thereof is substantially the same as the diameter of the drive shaft of the 3 rd cylinder 248, and the drive shaft can be engaged with the engagement hole 261. Thereby, the holder 241 reciprocates in the X-axis direction by driving the 2 nd cylinder 247.

As described above, the target exchanger 240 can convey the supported solid target 10 in the X-axis direction together with the supporting device 230. The target exchanger 240 conveys the support device 230 to a position facing the irradiation port 212 or the dissolution ports 222A and 222B. In this case, the target exchanger 240 includes a mechanism for pressing the support device 230 against the irradiation port 212 or the dissolution ports 222A and 222B. Specifically, as shown in fig. 12 and 13, the target exchanger 240 includes pushing mechanisms 270A and 270B. The pushing mechanisms 270A and 270B include: a support member 271 coupled to the 1 st sliding plate 243; a cylinder 272 for moving the drive shaft in the Y-axis direction; and a pushing member 273 for pushing out the supporting device 230. The pushing member 273 is provided on the drive shaft of the cylinder 272. Thereby, the pushing member 273 is moved to the Y-axis direction positive side by the cylinder 272, and the supporting device 230 is pressed toward the dissolving device 220. As shown in fig. 13, the pushing mechanism 270A is provided at a position facing the supporting device 230A. The pushing mechanism 270B is provided at a position facing the support device 230B. For example, when the holder 241 disposes the support device 230A at a position facing the dissolution port 222B (see fig. 20), the pushing mechanism 270A presses the support device 230A against the dissolution port 222B.

The control unit 260 controls the operation of the target exchanger 240 by sending control signals to the respective driving units (cylinders) of the target exchanger 240. An example of the control content by the control unit 260 will be described with reference to fig. 13 and 18 to 23. However, the operation of the target irradiation system 200 is not limited to the following example, and the number of solid targets 10 and the number of nuclear species may be appropriately changed.

Fig. 13 and 18 to 23 show an example of the operation when two solid targets 10 are used to recover a single nuclear radioisotope. First, as shown in fig. 13, the two support devices 230A, 230B are held by a holder 241. The supporting device 230A is held in the first holding hole 257 as viewed from the front side in the X-axis direction. The supporting device 230B is held in the second holding hole 257 as viewed from the front side in the X-axis direction. The controller 260 controls the 2 nd cylinder 247 (see fig. 14) of the target exchanger 240 to dispose the holder 241 at a position facing the fixing unit 211. At this time, the supporting device 230A, which is the holding hole 257 on the most positive side in the X-axis direction of the holder 241, is disposed at a position facing the irradiation port 212. This position is referred to as the "initial position". In the following description, the control content is expressed as "the control unit 260 positions the support device 230A at a position facing the irradiation port 212". The same expression is used for the control content having the same purpose as the control content.

Next, as shown in fig. 18, the controller 260 controls the 1 st cylinder 246 of the target exchanger 240 to move the 1 st sliding plate 243 (see fig. 12) to the positive side in the Y-axis direction, thereby pressing the supporting device 230A against the irradiation port 212. At this time, although the support device 230B also moves to the positive side in the Y-axis direction, the support device 230B does not particularly press against other members. In the following description, the control content is expressed as "the control unit 260 presses the support device 230A against the irradiation port 212". The same expression is used for the control content having the same purpose as the control content. The controller 260 controls the target irradiation device 210 to irradiate the charged particle beam B on the solid target of the support device 230A. When the irradiation is completed, the control unit 260 releases the pressing of the support device 230A to the irradiation port 212.

Next, as shown in fig. 19, the controller 260 disposes the support device 230A at a position facing the dissolution port 222B. As shown in fig. 20, the controller 260 controls the 1 st cylinder 246 of the target exchanger 240 to move the 1 st sliding plate 243 (see fig. 12) to the positive side in the Y-axis direction, thereby disposing the support device 230A in front of the dissolution port 222B. The controller 260 also extends the cylinder 272 of the pushing mechanism 270A to press the supporting device 230A against the dissolution port 222B. At this time, although the support device 230B is also moved to the positive side in the Y-axis direction, the support device 230B is not particularly pressed against other members. In the following description, the control content is expressed as "the control unit 260 presses the support device 230A against the dissolution port 222B". The same expression is used for the control content having the same purpose as the control content. The controller 260 controls the dissolving device 220 to supply the dissolving solution SL to the supporting device 230A, and to recover the dissolving solution SL in which the radioisotope of the solid target 10 is dissolved. When the collection is completed, the controller 260 releases the pressing of the dissolution port 222B by the supporting device 230A. Then, the controller 260 returns the positions of the supporting devices 230A and 230B to the initial positions.

Next, as shown in fig. 21, control unit 260 positions support device 230B at a position facing irradiation port 212, and presses support device 230B against irradiation port 212. The controller 260 controls the target irradiation device 210 to irradiate the charged particle beam B onto the solid target of the support device 230B. When the irradiation is completed, the control unit 260 releases the pressing of the support device 230B to the irradiation port 212.

Next, as shown in fig. 22, the control unit 260 positions the support device 230B at a position facing the dissolution port 222B, and presses the support device 230B against the dissolution port 222B. The controller 260 controls the dissolving device 220 to supply the dissolving solution SL to the supporting device 230B, and to recover the dissolving solution SL in which the radioisotope of the solid target 10 is dissolved. When the collection is completed, the control unit 260 releases the pressing of the dissolution port 222B by the supporting device 230B. Then, the controller 260 returns the positions of the supporting devices 230A and 230B to the initial positions. Recovery of radioisotopes using two solid targets 10 is accomplished as described above.

Next, an example of an operation when two radioisotopes of two nuclear species are collected using two solid targets 10 will be described. The operation common to the above-described operation will be described with reference to the common drawings.

The control unit 260 irradiates the charged particle beam B onto the solid target 10 of the support device 230A by performing the operation shown in fig. 18. Next, as shown in fig. 23, the controller 260 positions the support device 230A at a position facing the dissolution port 222A, and presses the support device 230A against the dissolution port 222A. The controller 260 controls the dissolving device 220 to supply the dissolving solution SL to the supporting device 230A, and to recover the dissolving solution SL in which the radioisotope of the solid target 10 is dissolved. When the collection is completed, the controller 260 releases the pressing of the dissolution port 222A by the supporting device 230A. Then, the controller 260 returns the positions of the supporting devices 230A and 230B to the initial positions.

Next, the control unit 260 irradiates the charged particle beam B onto the solid target 10 of the support device 230B by performing the operation shown in fig. 21. Next, the radioisotope of the solid target 10 of the supporting apparatus 230B is collected by performing the operation shown in fig. 22. In this case, a solution SL different from the solution used in the dissolution port 222A is used in the dissolution port 222B. Thus, the radioisotope of the solid target 10 of the support device 230B is recovered by the solution SL different from the solution for the support device 230A. Then, the controller 260 returns the positions of the supporting devices 230A and 230B to the initial positions. Recovery of radioisotopes using two solid targets 10 is accomplished as described above.

Alternatively, a solid target 10 can be used to recover a radionuclide radioisotope. In this case, the support device 230B is omitted from fig. 18 to 20, and the operations shown in fig. 18 to 20 are performed using only the support device 230A.

As described above, the target irradiation system 200 further includes the target exchanger 240 that transports the solid target 10, and the target exchanger 240 can support a plurality of solid targets 10. In this case, the target exchanger 240 can transport the plurality of solid targets 10 to the irradiation position and the dissolution position without detaching the solid targets 10 in the middle. This can reduce the influence of radiation exposure caused by the removal operation.

For example, after the radioisotope of the solid target 10 of the supporting device 230A shown in fig. 18 and 23 is collected, the solid target 10 of the supporting device 230B shown in fig. 21 and 22 is processed without performing a replacement work (detaching work) of the solid target 10 in particular. In this manner, in the target irradiation system 200, once the solid targets 10 are provided to the plurality of supporting devices 230, the target irradiation system 200 can automatically perform the processes of switching, irradiating, dissolving, and recovering the solid targets 10a plurality of times. This can greatly reduce the radiation exposure associated with the replacement work of the solid target 10.

The target irradiation system 200 further includes a support device 230 for supporting the solid target 10, the target irradiation device 210 includes an irradiation port 212 for emitting the charged particle beam B, the dissolving device 220 includes dissolving ports 222A and 222B for supplying and recovering the dissolving liquid SL, and the support device 230 can be connected to the irradiation port 212 and to the dissolving ports 222A and 222B. In this case, the support device 230 can serve as a part of the target irradiation device 210 and a part of the dissolving device 220.

The dissolving device 220 may include a plurality of dissolving ports 222A and 222B for supplying and recovering the dissolving liquid SL. In this case, the process of dissolving the radioisotopes of the plurality of nuclides can be performed without replacing the dissolving ports 222A and 222B.

Description of the symbols

2-cyclotron, 3, 200-target irradiation system, 4-shield (support), 10-solid target, 11-metal layer, 20, 210-target irradiation device, 21, 220-dissolution device, 22-transport device, 50-control section, 70-containment, 71-exhaust, 100-self-shielded cyclotron system, 212-irradiation port, 222A, 222B-dissolution port, 230A, 230B-support device (target irradiation device, dissolution device), 240-target exchanger (transport device).