Self-shielding cyclotron system

Abstract

The present invention provides a self-shielding cyclotron system capable of further improving safety against radiation when obtaining radioactive isotopes. A transport unit (22) transports a target (10) from a target holding unit (20) for irradiating the target (10) with a charged particle beam (B) to a dissolution unit (21) for collecting radioisotopes. The target holding unit (20), the dissolving unit (21), and the conveying unit (22) are disposed within the self-shielding body (4). Thus, a step for irradiating the target (10) with the charged particle beam (B), a step for recovering the radioisotope by dissolving the radioisotope, and a step for transporting the target between the two steps are performed within the self-shielding body (4). Thereby, in each step, radiation emitted from the target (10) irradiated with the charged particle beam is blocked by the self-shielding body.

Description

[0001] This application is a divisional application of application number 201910057247.X, filed on January 22, 2019, entitled "Self-Shielded Cyclotron Accelerator System". Technical Field

[0002] This invention relates to a self-shielded cyclotron accelerator system. Background Technology

[0003] As shown in Patent Document 1, a self-shielded cyclotron accelerator system with a self-shielding body is known, which internally houses the cyclotron accelerator and suppresses the release of radiation from the cyclotron accelerator to the outside. In recent years, a device has been developed to obtain solid radioisotopes (RI) by irradiating a target with a metal layer with a beam of charged particles. These radioisotopes are used to manufacture radiopharmaceuticals used in PET scans (positron emission tomography) in hospitals and other facilities. For example, in Patent Document 2, a target with a solid radioisotope attached is transported to a dissolution device, where the radioisotope is dissolved, thereby recovering the RI.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2000-105293 Patent Document 2: Japanese Patent Application Publication No. 2014-115229 Here, the target is activated after being irradiated by a beam of charged particles. Therefore, there is a need to further improve radiation safety when removing the target from the irradiation device and installing it in the dissolution device. Summary of the Invention

[0005] The purpose of this invention is to provide a self-shielded cyclotron accelerator system that can further improve the safety against radiation when obtaining radioactive isotopes.

[0006] The self-shielded cyclotron accelerator system of the present invention comprises: a cyclotron accelerator that emits a beam of charged particles; and a self-shielding body disposed within a building, which houses the cyclotron accelerator and suppresses the release of radiation emitted from the cyclotron accelerator to the outside. The self-shielded cyclotron accelerator system comprises: a target holding section that holds a target having a metal layer at the irradiation position of the charged particle beam; a dissolution section that dissolves the metal layer containing a radioactive isotope in the target; and a transport section that transports the target from the target holding section to the dissolution section. The target holding section, the dissolution section, and the transport section are disposed within the self-shielding body.

[0007] In the self-shielded cyclotron accelerator system of the present invention, a target holding section holds a target with a metal layer at the irradiation position of a charged particle beam. The charged particle beam is then irradiated onto the target held by the target holding section. As a result, a radioactive isotope is formed in the metal layer of the target at the irradiated portion of the charged particle beam. Furthermore, a dissolution section dissolves the metal layer containing the radioactive isotope in the target. Thus, the radioactive isotope can be recovered by recovering the dissolving liquid. A transport section transports the target from the target holding section, which irradiates the target with a charged particle beam, to the dissolution section, which recovers the radioactive isotope. Here, the target holding section, the dissolution section, and the transport section are disposed within a self-shielding body. Therefore, the processes of irradiating the target with a charged particle beam, recovering the radioactive isotope by dissolution, and transporting the target between the two processes are all performed within the self-shielding body. Thus, in each process, radiation emitted from the target after irradiation by the charged particle beam is blocked by the self-shielding body. As described above, radiation safety when obtaining radioactive isotopes can be further improved.

[0008] The self-shielded cyclotron accelerator system also includes a control unit that can control the delivery unit to transport the target held in the target holding section to the dissolution section after the metal layer has been irradiated with a charged particle beam. Thus, the target delivery based on the delivery unit is automatically performed by the control unit. This further suppresses radiation to operators. Furthermore, the automatic target delivery by the control unit shortens the operation time.

[0009] The effects of the invention According to the present invention, a self-shielded cyclotron accelerator system is provided that can further improve the safety against radiation when obtaining radioactive isotopes. Attached Figure Description

[0010] Figure 1 This is a schematic structural diagram of a self-shielded cyclotron accelerator system according to an embodiment of the present invention.

[0011] Figure 2 This is a 3D view of the target.

[0012] Figure 3 This is an enlarged view of the radioactive isotope manufacturing department.

[0013] Figure 4 This is a flowchart representing the processing content of the control unit.

[0014] Figure 5 This is an enlarged diagram showing the operation of the radioactive isotope manufacturing unit.

[0015] Figure 6 This is an enlarged diagram showing the operation of the radioactive isotope manufacturing unit.

[0016] Figure 7This is an enlarged diagram showing the operation of the radioactive isotope manufacturing unit.

[0017] Figure 8 This is an enlarged diagram showing the operation of the radioactive isotope manufacturing unit.

[0018] Figure 9 This is an enlarged diagram showing the operation of the radioactive isotope manufacturing unit.

[0019] Figure 10 This is an enlarged view of the self-shielded cyclotron system involved in the modified example.

[0020] Explanation of symbols 2-Cyclotron, 4-Self-shielding body, 10-Target, 11-Metal layer, 20-Target holding part, 21-Dissolving part, 22-Transporting part, 50-Control part, 70-Containing part, 71-Exhausting part, 100-Self-shielding cyclotron system. Detailed Implementation

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, identical or equivalent parts are labeled with the same symbols in the drawings, and repeated descriptions are omitted.

[0022] like Figure 1 As shown, the self-shielded cyclotron system 100 is a system installed inside the building 150. The self-shielded cyclotron system 100 according to this embodiment is a system for producing radioactive isotopes (hereinafter, sometimes referred to as RI) using charged particle beams. The self-shielded cyclotron system 100 can, for example, be used as a cyclotron for PET scans, and the RI produced in this system can be used, for example, to produce radiopharmaceuticals (including radiopharmaceuticals) as radioisotope-labeled compounds (RI compounds). As a radioisotope-labeled compound used in PET scans (positron emission tomography) in hospitals, etc., there are... 18 F-FLT (Fluorothymidine) 18 F-FMISO (fluorothiazole) and 11 C-Racopride, etc.

[0023] The self-shielded cyclotron system 100 includes a cyclotron 2, a radioactive isotope manufacturing unit 3, and a self-shielding body 4. The self-shielded cyclotron system 100 is installed on the floor 151 of a building 150 within a cyclotron chamber 152. The cyclotron chamber 152 is a room covered with concrete (shielding wall). Thus, users can obtain radioactive isotopes on-site within the building by using the self-shielded cyclotron system 100.

[0024] The cyclotron accelerator 2 is an accelerator that emits a beam of charged particles. The cyclotron accelerator 2 is a longitudinally positioned circular accelerator that supplies charged particles from an ion source into an acceleration space, accelerates the charged particles within the acceleration space, and outputs a beam of charged particles. The cyclotron accelerator 2 has a pair of magnetic poles, a vacuum chamber, and an annular yoke surrounding the pair of magnetic poles and the vacuum chamber. Within the vacuum chamber, a portion of the main surfaces of the pair of magnetic poles face each other at a predetermined interval. Within the gap between the pair of magnetic poles, the charged particles are accelerated multiple times. Examples of charged particles include protons and heavy particles (heavy ions). In this embodiment, the cyclotron accelerator 2 has multiple ports 2a for emitting the beam of charged particles. A target holding portion 20, described later, is formed on one of the multiple ports 2a. The cyclotron accelerator 2 adjusts the trajectory of the charged particle beam within the acceleration space and extracts the charged particle beam from the desired port 2a.

[0025] The self-shielding body 4 is disposed within the building, housing the cyclotron accelerator 2 and suppressing the release of radiation from the cyclotron accelerator 2 into the cyclotron chamber 152. The self-shielding body 4 provides omnidirectional radiation shielding by completely covering the cyclotron accelerator 2. In this embodiment, the self-shielding body 4 has a hexahedral box-shaped structure, but its shape is not particularly limited. The self-shielding body 4 isolates the interior space of the building 150 (cyclotron chamber 152) from the interior space 120 of the self-shielded cyclotron system 100. The interior space of the building 150 can be configured as a space for installing other equipment or for personnel to pass through. Therefore, a system where only the cyclotron accelerator 2 is disposed within the building's interior differs from the self-shielded cyclotron system 100 of this embodiment, where the walls surrounding the building's rooms do not function as the self-shielding body 4. The walls of the self-shielding body 4 are constructed of materials such as polyethylene, iron, lead, or heavy concrete. Inside the self-shielding body 4, in addition to the cyclotron accelerator 2, a vacuum pump or wiring for operating the cyclotron accelerator 2 is also disposed. Furthermore, the self-shielding body 4 is also equipped with the components of the radioactive isotope manufacturing unit 3.

[0026] The radioactive isotope manufacturing unit 3 is a part that irradiates the target 10 with a charged particle beam and dissolves and recovers the radioactive isotopes generated by the irradiation. The radioactive isotope manufacturing unit 3 is formed near the outer periphery of the cyclotron 2 and is disposed within the self-shielding body 4. The solution containing the radioactive isotope obtained by the radioactive isotope manufacturing unit 3 is transported via a delivery pipe 161 to a purification device for purifying the radioactive isotope in the solution or a synthesis device for synthesizing a reagent, or other similar apparatus 160.

[0027] refer to Figure 2 The target 10 will be described below. The target 10 includes a target substrate 13 and a metal layer 11. Specifically, as follows... Figure 2As shown, the target 10 has a metal layer 11 formed on a target substrate 13 made of a metal plate, which serves as the target material. Furthermore, the metal layer 11 is not limited to a high-purity metal layer; it can also be a metal oxide layer. When this target substrate 13 is placed in a device, a charged particle beam B is irradiated onto the metal layer 11, thereby generating trace amounts of radioactive isotope 12 in the irradiated portion. Thus, the metal layer 11 contains radioactive isotope 12. The target substrate 13 is made of a material that is insoluble in a solution, such as Au or Pt. Figure 2 The target substrate 13 shown is formed in a circular plate shape, but its shape and thickness are not particularly limited. Examples of materials that can be used as the target material, i.e., the metal layer 11, include... 64 Ni、 89 Y、 100 Mo、 68 Zn, etc. Examples of radioactive isotopes 12 generated corresponding to this metal layer 11 include... 64 Cu、 89 Zr、 99m Tc, 68 Ga, etc. The metal layer 11 is formed by plating the surface 10a of the target substrate 13. Furthermore, it is not limited to plating; a plate-shaped metal layer may also be attached to the target substrate 13. Figure 2 The metal layer 11 shown is formed in a circular shape at the center of the target substrate 13, but its shape and position are not particularly limited. In addition, when the charged particle beam B irradiates the metal layer 11, cooling water or the like is supplied to the back surface 10b of the target substrate 13. As a result, the heat generated by the irradiation of the charged particle beam B on the metal layer 11 (and the target substrate 13) can be absorbed by the cooling water or the like.

[0028] Next, refer to Figure 3 The structure of the radioactive isotope manufacturing unit 3 will be described in detail. The radioactive isotope manufacturing unit 3 includes a target holding unit 20, a dissolution unit 21, a delivery unit 22, and a control unit 50.

[0029] The target holding unit 20 holds the target 10, which has a metal layer 11, at the irradiation position of the charged particle beam B. After the irradiation of the target 10 by the charged particle beam B ends, the target holding unit 20 releases the target 10. Specifically, the target holding unit 20 includes a fixing unit 23 and a movable unit 24. The target holding unit 20 holds the target 10 at the irradiation position RP by clamping the target 10 with the fixing unit 23 and the movable unit 24. Both the fixing unit 23 and the movable unit 24 are housed within the self-shielding body 4.

[0030] The fixing unit 23 is a cylindrical member fixed to the outer periphery of the cyclotron 2. The fixing unit 23 is arranged to extend along the irradiation axis BL of the charged particle beam B emitted from the cyclotron 2 and to protrude from the outer periphery of the cyclotron 2. At a position corresponding to the irradiation axis BL of the charged particle beam B, the fixing unit 23 has an internal space 26 for the charged particle beam B to pass through. The internal space 26 is formed extending along the irradiation axis BL, with the irradiation axis BL as its centerline. The fixing unit 23 and the internal space 26 are arranged to be inclined downwards relative to the horizontal direction.

[0031] The fixing unit 23 has a surface on its lower end side that extends horizontally as a counter surface 23a opposite to the upper surface of the movable unit 24. The fixing unit 23 holds the target 10 at the position of the counter surface 23a. A sealing member such as an O-ring is provided on the counter surface 23a. The counter surface 23a abuts against the target 10 via the sealing member, thereby also functioning as a sealing surface for the target 10. In this embodiment, the portion of the opening of the internal space 26 on the counter surface 23a (and the position of the irradiation axis BL therein) corresponds to the irradiation position RP. Thus, when the target holding part 20 holds the target 10, the metal layer 11 in the target 10 is held in place at the opening of the internal space 26.

[0032] The fixing unit 23 has a vacuum foil 25 located at the midpoint of the internal space 26. The vacuum foil 25 maintains a vacuum in the area of ​​the internal space 26 that is upstream of the vacuum foil 25.

[0033] The fixing unit 23 has a charged particle beam B disposed at the irradiation position and a flow path 27 for blowing a gas such as helium onto the vacuum foil 25. The flow path 27 has a main flow path 27a and branch flow paths 27b and 27c branching from the main flow path 27a. Branch flow path 27b extends toward the vacuum foil 25 and blows gas onto the vacuum foil 25. Branch flow path 27c extends toward the irradiation position RP of the target 10 and blows gas onto the held target 10.

[0034] The movable unit 24 moves forward and backward relative to the fixed unit 23 in the vertical direction. When the target 10 is placed on the transport tray 60, the movable unit 24 is positioned downwardly from the fixed unit 23. When the target 10 is held in the irradiation position RP, the movable unit 24 is positioned to clamp the target 10 between itself and the fixed unit 23 (see reference). Figure 5 ).

[0035] The movable unit 24 has a cylindrical shape extending in the vertical direction. A portion of the outer peripheral surface of the movable unit 24 is connected to a drive mechanism 28 that moves in the vertical direction. 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 at least smaller than the diameter of the inner peripheral portion of the conveyor tray 60, which will be described later. Thus, the small-diameter portion 29 passes through a through hole on the inner peripheral side of the conveyor tray 60 and abuts against the target 10, pressing the target 10 against the upper fixed unit 23.

[0036] The movable unit 24 has a surface on the upper end side of the small-diameter portion 29 that extends horizontally as a counter-surface 24a opposite to the counter-surface 23a of the fixed unit 23. A sealing member such as an O-ring is provided on the counter-surface 24a. The counter-surface 24a abuts against the target 10 via the sealing member, thereby also functioning as a sealing surface for the target 10. When the target holding portion 20 holds the target 10, the counter-surface 23a and the counter-surface 24a clamp the target 10 (see reference). Figure 5 ).

[0037] Additionally, the movable unit 24 has an internal space 31 with an opening on the opposing surface 24a. The internal space 31 is a space for storing cooling medium for cooling the target 10. A supply pipe 32 for supplying cooling medium and a discharge pipe 33 for discharging cooling medium are connected in the internal space 31.

[0038] The dissolving unit 21 dissolves the metal layer 11 containing the radioactive isotope in the target 10. The dissolving unit 21 includes a fixing unit 40 and a movable unit 41. The dissolving unit 21 holds the target 10 by clamping it with the fixing unit 40 and the movable unit 41. While holding the target 10, the dissolving unit 21 supplies a dissolving solution to at least the metal layer 11, dissolving the metal containing the radioactive isotope in the solution, and recovering the solution along with the radioactive isotope. Hydrochloric acid, nitric acid, etc., can be used as the dissolving solution. The fixing unit 40 and the movable unit 41 are housed within the self-shielding body 4.

[0039] The fixing unit 40 is positioned at a distance from the fixing unit 23 of the target holding part 20, opposite to the cyclotron 2. The fixing unit 40 includes a cylindrical main body 48 extending vertically and a support part 49 supporting the main body 48 on its outer periphery. The main body 48 has a surface at its lower end that extends horizontally as a counter surface 40a opposite to the movable unit 41. The target 10 is held in position on the counter surface 40a. An O-ring or similar sealing member is provided on the counter surface 40a. The counter surface 40a abuts against the target 10 via the sealing member, thereby also functioning as a sealing surface for the target 10. The target 10 is held in position on the counter surface 40a.

[0040] The main body 48 has an internal space 42 that opens onto the opposing surface 40a. The internal space 42 is a dissolution tank for storing a dissolving solution used to dissolve the metal layer 11 of the target 10. A supply pipe 43 for supplying the dissolving solution and a suction pipe 44 for drawing in the dissolving solution and gas from the internal space 42 are connected to the internal space 42. The diameter of the internal space 42, which opens onto the opposing surface 40a, is at least smaller than the diameter of the target 10 and larger than the diameter of the metal layer 11. Furthermore, the diameter of the opposing surface 40a itself is not particularly limited, but in this embodiment, it is smaller than the diameter of the target 10.

[0041] The support portion 49 is a cylindrical member having an end face wall that extends radially outward from the outer periphery of the main body portion 48. The support portion 49 has a through hole 49a at its central position for insertion into the main body portion 48. A flange is formed near the upper end of the main body portion 48. This flange engages with the upper edge of the through hole 49a in the main body portion 48.

[0042] The movable unit 41 moves forward and backward relative to the fixed unit 40 in the vertical direction. When the target 10 is mounted on the fixed unit 40, the movable unit 41 is positioned at a position spaced downward from the fixed unit 40. When the metal layer 11 of the target 10 is dissolved in the dissolution section 21, the movable unit 41 is positioned to clamp the target 10 between itself and the fixed unit 40 (see reference). Figure 9 ).

[0043] The movable unit 41 includes a main body 46 and a receiving plate 47 disposed on the upper end side of the main body 46. The main body 46 has a cylindrical shape extending in the vertical direction. A portion of the outer peripheral surface of the main body 46 is connected to a drive mechanism (not shown) that moves in the vertical direction. A groove structure for supporting the receiving plate 47 is formed at the upper end of the main body 46.

[0044] The receiving portion 47 includes a bottom wall portion 47a extending horizontally from the upper end of the main body portion 46 and a side wall portion 47b rising upward from the outer periphery of the bottom wall portion 47a. The bottom wall portion 47a has a surface extending horizontally as a counter surface 41a opposite to the counter surface 40a of the fixing unit 40. The counter surface 41a abuts against the target 10. When the dissolving portion 21 holds the target 10, the counter surface 40a and the counter surface 41a clamp the target 10 (see reference). Figure 9 The inner diameter of the sidewall portion 47b is larger than the diameter of the target 10. Furthermore, when the target 10 is held, the upper end of the sidewall portion 47b is positioned higher than the target 10. Therefore, if the solution leaks from the internal space 42 when the metal layer 11 of the target 10 is dissolved, the receiving portion 47 receives the solution. Additionally, the lower surface of the bottom wall portion 47a has a concave-convex structure for engaging with the groove structure of the main body portion 46.

[0045] In the dissolving section 21, the main body 48 and the receiving plate 47, which come into contact with the dissolving liquid, are configured as replaceable disposable parts. That is, the main body 48 is installed in a detachable manner relative to the support 49. The receiving plate 47 is installed in a detachable manner relative to the main body 46. Here, "detachable" means an installation method in which the operator can easily disassemble the part through normal maintenance work even after one installation. For example, detachable installation structures include those that are installed by bolt connection, those that are installed by fitting or locking with a strength that does not detach during dissolution, etc. For example, fixing structures such as welding or fusion are not suitable for detachable installation methods. The materials of the replaceable main body 48 and the receiving plate 47 can be, for example, highly acid-resistant materials such as Teflon (registered trademark).

[0046] The transport section 22 transports the target 10 from the target holding section 20 to the dissolution section 21. The transport section 22 is disposed within the self-shielding body 4. The transport section 22 includes a transport tray 60 for transporting the target 10 and a transport drive section 61 for driving the transport tray 60. The transport tray 60 is an annular member having a support portion for supporting the target 10 on its upper surface side. The transport tray 60 has a groove formed throughout the entire circumference of the inner circumference side edge of the upper surface, and the outer circumference of the target 10 on the lower surface side is placed in this groove. The transport drive section 61 is constructed by a combination of a drive source (not shown) and a drive force transmission mechanism. At least when transporting the target 10 after it has been irradiated by a charged particle beam to the dissolution section 21, the transport drive section 61 transports the target 10 to the position of the dissolution section 21 by moving the transport tray 60 horizontally from the position of the target holding section 20. The transport drive unit 61 transports the transport tray 60 from the area between the fixed unit 23 and the movable unit 24 of the target holding unit 20 to the area between the fixed unit 40 and the movable unit 41 of the melting unit 21. Furthermore, the transport drive unit 61 can be constructed using any known drive source such as a rotary motor or a linear motor, and a drive force transmission mechanism such as gears and rods. The transport drive unit 61 can be of any structure as long as it is configured to avoid interference with other components and to perform the desired action. The positions of the transport tray 60 in each stage will be explained in detail when describing the operation later.

[0047] The control unit 50 controls the self-shielded cyclotron system 100. The control unit 50 comprises a CPU, RAM, ROM, and input / output interfaces. The control unit 50 determines the control content based on detection signals from various sensors within the device and the program stored in the ROM, and controls the various components within the self-shielded cyclotron system 100. Furthermore, the control unit 50 may consist of multiple processing devices instead of a single processing device. The control unit 50 may be located inside or outside the self-shielding enclosure 4.

[0048] 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 primarily controls the cyclotron 2, controlling actions related to the irradiation of the charged particle beam B through the cyclotron 2. The holding control unit 52 primarily controls the target holding unit 20, controlling actions related to holding the target 10 through the target holding unit 20. The dissolution control unit 53 primarily controls the dissolution unit 21, controlling actions related to dissolving the metal layer 11 of the target 10. The transport control unit 54 primarily controls the transport unit 22, controlling actions related to transporting the target 10. The transport control unit 54 controls the transport unit 22 to transport the target 10 held in the target holding unit 20 to the dissolution unit 21 after the metal layer 11 has been irradiated with the charged particle beam B.

[0049] Next, refer to Figures 3-9 The operation of the self-shielded cyclotron system 100 will be explained together with the control processing based on the control unit 50. Figure 4 This is a flowchart showing the control processing content of the control unit 50. Figures 4-9 This is a diagram showing the state of the radioactive isotope manufacturing unit 3 at each stage of the operation. Additionally, for ease of explanation, in Figures 4-9 In the text, the control unit 50 and the conveying drive unit 61 are omitted. Furthermore, symbols not used in the description are sometimes appropriately omitted as well.

[0050] like Figure 4 As shown, the control unit 50 performs a process (step S10) for setting the target 10 in the radioactive isotope manufacturing unit 3. In step S10, the control unit 50 positions the target holding unit 20, the dissolving unit 21, and the transport unit 22 in their initial positions. The control unit 50 sets the radioactive isotope manufacturing unit 3 in position by driving the drive units of each component. Figure 3 The state shown is as follows. In this state, the movable unit 24 is positioned downwards from the fixed unit 23. The movable unit 41 is positioned downwards from the fixed unit 40. The conveyor tray 60 is positioned downwards from the fixed unit 23 at a reference height. Here, "reference height" refers to a predetermined height position in the height direction between the fixed unit 23 and the movable unit 24, and between the fixed unit 40 and the movable unit 41. At this height position, even if the conveyor tray 60 moves horizontally, it will not interfere with the units 23, 24, 40, and 41. The control unit 50 can notify the operator that the target 10 can be set through a monitor or the like. If it is detected that the operator has placed the target 10 on the conveyor tray 60, the control unit 50 knows that the target 10 has been set. The control unit 50 can detect the completion of the target 10 setting through sensor detection or operator input.

[0051] Next, the control unit 50 performs the process of holding the target 10 at the irradiation position RP of the charged particle beam B (step S20: Figure 4 In S20, the holding control unit 52 of the control unit 50 controls the drive mechanism 28 of the movable unit 24, thereby causing the movable unit 24 to move upward. Thus, as... Figure 5 As shown, the target 10 is held between the fixed unit 23 and the movable unit 24 at the irradiation position RP. Furthermore, as the movable unit 24 moves upward, the target 10, placed on the transport tray 60, is supported by the movable unit 24, which passes through a through-hole in the transport tray 60 from below. At this time, the transport tray 60 can rise while supported by the movable unit 24. Alternatively, the transport tray 60 can be driven to rise together with the movable unit 24.

[0052] Next, the control unit 50 performs the process of irradiating the target 10 with the charged particle beam B (step S30: Figure 4 In S30, the irradiation control unit 51 of the control unit 50 irradiates the target 10 with a charged particle beam B by controlling the cyclotron accelerator 2. At this time, the holding control unit 52 controls the flow path system to spray helium gas, etc., from the flow path 27 of the stationary unit 23 to the target 10 and the vacuum foil 25. Furthermore, the holding control unit 52 controls the piping system of the supply pipe 32 and the discharge pipe 33 to allow the cooling medium to flow into the internal space 31 to cool the target 10.

[0053] If the processing of S30 is completed, the holding control unit 52 of the control unit 50 moves the movable unit 24 downward by controlling the drive mechanism 28 of the movable unit 24. Thus, as... Figure 6 As shown, the movable unit 24 returns to its initial position. Furthermore, the transport tray 60 also returns to its reference height position with the target 10 mounted on it.

[0054] Next, the control unit 50 performs the process of conveying the target 10 from the target holding unit 20 to the dissolving unit 21 (step S40: Figure 4 In S40, the conveying control unit 54 of the control unit 50 controls the conveying drive unit 61 of the conveying unit 22 (see reference). Figure 3 This causes the transport tray 60 to move horizontally from the target holding section 20 to the melting section 21. Thus, as... Figure 7 As shown, the conveyor tray 60 maintains a reference height position in the height direction and is positioned between the fixed unit 40 and the movable unit 41. Consequently, the target 10 is positioned opposite the opposing surface 40a of the opening in the internal space 42 on its lower side.

[0055] Next, the control unit 50 performs the process of placing the target 10 on the dissolution unit 21 (step S50: Figure 4 In S50, such as Figure 8As shown, the dissolution control unit 53 of the control unit 50 controls the piping system of the suction pipe 44 and causes the target 10 to be adsorbed onto the opposing surface 40a via the internal space 42. Furthermore, before adsorbing the target 10, the target 10 is pressed against the opposing surface 40a of the main body 48 by the rising of the transport tray 60. This seals the internal space by crushing the O-ring (not shown) provided between the target 10 and the main body 48. Afterwards, the transport control unit 54 controls the transport drive unit 61 (see reference 54). Figure 3 This moves the transport tray 60 toward the target holding part 20. This prevents the transport tray 60 from interfering with the movable unit 41.

[0056] In S50, the dissolution control unit 53 controls the drive unit of the movable unit 41, causing the movable unit 41 to move upward. Thus, as... Figure 9 As shown, the target 10 is held between the opposing surface 40a of the fixed unit 40 and the opposing surface 41a of the movable unit 41. At this time, the target 10 is accommodated in the receiving plate portion 47 and pressed against the main body portion 48 from above.

[0057] Next, the control unit 50 performs a process to recover the radioactive isotopes contained in the metal layer 11 of the target 10 by dissolving the metal layer 11 in the dissolution unit 21 (step S60: Figure 4 In S60, the dissolution control unit 53 of the control unit 50 controls the piping system of the supply pipe 43 to supply the dissolving liquid SL from the supply pipe 43 to the internal space 42. Furthermore, the dissolution control unit 53 controls the piping system of the suction pipe 44 to draw in and recover the dissolving liquid SL from the radioactive isotope dissolution. As described above, Figure 4 The control process shown is now complete. Additionally, after the recovery of the radioactive isotope is finished, the operators disassemble the target 10 along with the main body 48 and the receiving plate 47, and remove it from the outside of the self-shielding body 4.

[0058] like Figure 1As shown, the solution SL from the dissolution of the radioactive isotope is discharged from the outside of the shield 4 and transported to a purification device for purifying the radioactive isotope in the solution SL, or a synthesis device for synthesizing a reagent, etc., in device 160. The purification device or the synthesis device can be located in the same building 150 or in another building (facility). When the solution SL is transported to the synthesis device, etc., in the same building 150, the solution SL is transported to the synthesis device, etc., through a delivery pipe 161 connected to the suction pipe 44. Since radiation is released from the solution SL, the delivery pipe 161 is covered by a shield or passes through the shielding wall (floor or wall) of the building 150. When the solution SL is transported to another building, the recovered solution SL is stored in a shielded box (a box that suppresses the release of radiation to the outside, such as a lead box), and transported together with the shielded box by a vehicle, etc.

[0059] Next, the function and effects of the self-shielded cyclotron accelerator system 100 involved in this embodiment will be explained.

[0060] In the self-shielded cyclotron accelerator system 100 according to this embodiment, the target holding section 20 holds a target having a metal layer 11 at the irradiation position RP of the charged particle beam B. Thus, the charged particle beam B irradiates the target 10 held by the target holding section 20. As a result, a radioactive isotope 12 is formed in the metal layer 11 of the target 10 at the irradiated portion by the charged particle beam B. Furthermore, the dissolution section 21 dissolves the metal layer 11 containing the radioactive isotope in the target 10. Thus, the radioactive isotope can be recovered by recovering the dissolving liquid. The transport section 22 transports the target 10 from the target holding section 20, which irradiates the target 10 with the charged particle beam B, to the dissolution section 21, which recovers the radioactive isotope. Here, the target holding section 20, the dissolution section 21, and the transport section 22 are disposed within the self-shielding body 4. Therefore, the process of irradiating the target 10 with the charged particle beam B, the process of recovering the radioactive isotope by dissolving it, and the process of transporting the target between the two processes are all performed within the self-shielding body 4. Thus, in each process, radiation emitted from the target 10 after irradiation by the charged particle beam is blocked by the self-shielding body. As described above, radiation safety when obtaining radioactive isotopes can be further improved.

[0061] The self-shielded cyclotron accelerator system 100 also includes a control unit 50, which controls the delivery unit 22 to deliver the target 10 held in the target holding unit 20 to the dissolution unit 21 after the metal layer 11 is irradiated with the charged particle beam B. Thus, the delivery of the target 10 based on the delivery unit 22 is automatically performed by the control unit 50. This further improves radiation safety. Furthermore, the automatic delivery of the target 10 by the control unit 50 shortens the operation time.

[0062] This invention is not limited to the embodiments described herein, and various modifications can be made without departing from the spirit of this invention.

[0063] For example, it can be adopted Figure 10 That kind of structure. Figure 10 The self-shielded cyclotron accelerator system shown may include: a receiving portion 70 that covers the dissolution portion 21 within the self-shielding body 4; and an exhaust portion 71 that discharges gas from the receiving portion 70 to the outside of the self-shielding body 4. The receiving portion 70 does not cover the target holding portion 20, but only the dissolution portion 21. Furthermore, an opening 70a may be formed in the receiving portion 70 at the point through which the transport tray passes. This opening 70a can be closed when the transport tray is not passing through. The exhaust portion 71 may have an exhaust pipe that passes through the receiving portion 70 through the self-shielding body 4 and communicates with the outside of the self-shielding body 4. The exhaust portion 71 may include a pump or the like installed in the exhaust pipe.

[0064] Therefore, when the solution in the dissolution section 21 vaporizes, the gas diffusion into the self-shielding body 4 can be suppressed by the containment section 70. Furthermore, the gas in the containment section 70 is discharged to the outside of the self-shielding body 4 through the exhaust section 71. As a result, corrosion of other equipment inside the self-shielding body 4 due to gas can be suppressed.

[0065] Furthermore, the structure of the radioactive isotope manufacturing unit shown in the figures of the above embodiments is only one example, and the shape or configuration can be appropriately changed as long as it is within the scope of the present invention. For example, the conveying unit may be replaced by an arm-shaped holding part for holding the target instead of a conveying tray.

[0066] Furthermore, the target transport based on the conveyor unit is automated via the control unit. Alternatively, the drive of the conveyor unit itself can be manually operated by the operator. In this case, since the target is housed within a self-shielding body, radiation safety can be further improved.

Claims

1. A self-shielded cyclotron accelerator system, comprising: A cyclotron emits a beam of charged particles; and A self-shielding enclosure, located inside a building, houses the cyclotron and suppresses radiation emitted from the cyclotron from escaping to the outside. The self-shielded cyclotron accelerator system has the following features: The target holding section holds a target with a solid metal layer at the irradiation position of the charged particle beam; A dissolution section, which dissolves the radioactive isotope-containing metal layer in the target having a solid metal layer; and The delivery unit transports the target having the solid metal layer from the target holding unit to the dissolving unit. The target holding section, the dissolution section, and the transport section are all disposed within the self-shielding body. The process of irradiating the target with a charged particle beam, the process of recovering the radioactive isotope through dissolution, and the process of transporting the target between the two processes are all performed within the self-shielding body.

2. The self-shielded cyclotron accelerator system according to claim 1, further comprising a control unit, The control unit controls the delivery unit to deliver the target held in the target holding unit to the dissolution unit after irradiating the metal layer with the charged particle beam.

3. The self-shielded cyclotron accelerator system according to claim 1 or 2, comprising: The receiving portion covers the dissolving portion within the self-shielding body; and The exhaust section discharges the gas inside the containment section to the outside of the self-shielding body.

4. The self-shielded cyclotron accelerator system according to claim 1 or 2, wherein, The self-shielding body completely covers the cyclotron.

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