RI manufacturing device and target storage device

Abstract

The present invention relates to an RI manufacturing device and a target storage device, and can provide a target storage device capable of improving cooling efficiency and an RI manufacturing device capable of improving the efficiency of nuclear reactions. The RI manufacturing device (1) is provided with a cooling flow path (46, 48), wherein the cooling flow path (46, 48) can allow a cooling medium to flow, so that the storage portion (3) is cooled from the outer peripheral side of the heat transfer wall portion (41, 42) provided relative to the storage portion (3) around the irradiation axis (RL). At this time, by allowing the cooling medium to flow through the cooling flow path (46, 48), the target in the storage portion (3) can be cooled from a position further outward than the storage portion with the irradiation axis as a reference via the heat transfer wall portion (41, 42) around the irradiation axis (RL). In this way, the target can be cooled from different directions through the internal space (31A, 31B) and the cooling flow path (46, 48).

Description

Technical Field

[0001] This application claims priority based on Japanese Patent Application No. 2021-055409, filed on March 29, 2021. The entire contents of this Japanese application are incorporated herein by reference.

[0002] The present invention relates to a target containing device. Background Art

[0003] The radioactive isotopes used in the examination drugs for PET examinations using positron emission tomography (PET) are produced using a radiation source such as a cyclotron installed near the examination room in the hospital. Specifically, a particle beam (e.g., a proton beam, a deuteron beam, etc.) from the radiation source is guided to a target storage device and then interacts with a target (e.g., target water ( 18 Radioactive isotopes are produced by nuclear reactions involving oxygen (O) and water. Furthermore, the produced radioactive isotopes are added to a predetermined compound (e.g., fluorodeoxyglucose (FDG)) or substituted for a portion thereof to produce a test drug.

[0004] As an RI production apparatus for producing such radioactive isotopes, there is known an apparatus including a container for accommodating a liquid target and a flow path for cooling the container from one side of the irradiation axis of the particle beam (for example, see Patent Document 1).

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-246131

[0006] Here, the target reaches a high temperature due to irradiation with the particle beam. Improving the cooling efficiency of the target can improve the efficiency of the nuclear reaction. Therefore, there is a need for a target storage device that can improve cooling efficiency and an RI production device that can improve the efficiency of the nuclear reaction. Summary of the Invention

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a target storage device capable of improving cooling efficiency and an RI manufacturing device capable of improving nuclear reaction efficiency.

[0008] To achieve the above-mentioned purpose, one embodiment of the present invention involves an RI manufacturing device that manufactures radioactive isotopes through nuclear reactions of a target irradiated by a particle beam. The above-mentioned RI manufacturing device comprises: a container that accommodates the target at the irradiation position of the particle beam; a first flow path that can allow a cooling medium to flow so as to cool the container from a side relative to the irradiation axis of the particle beam; and a second flow path that can allow a cooling medium to flow so as to cool the container from a position further outside the container with respect to the irradiation axis through at least a portion of a wall portion provided around the irradiation axis relative to the container.

[0009] The RI manufacturing device includes a first flow path through which a cooling medium can flow so as to cool the container from the side relative to the irradiation axis of the particle beam. Thus, by allowing the cooling medium to flow through the first flow path, the target in the container can be cooled from the side relative to the irradiation axis. Furthermore, the RI manufacturing device includes a second flow path through which a cooling medium can flow so as to cool the container from a position further outward from the container with respect to the irradiation axis, via at least a portion of a wall portion provided relative to the container and surrounding the irradiation axis. At this time, by allowing the cooling medium to flow through the second flow path, heat is removed from the container from the inside to the outside with respect to the irradiation axis, via the wall portion surrounding the irradiation axis, thereby cooling the target in the container. In this way, the target can be cooled from different directions via the first and second flow paths. Therefore, the cooling efficiency of the target can be improved, thereby improving the efficiency of the nuclear reaction of the target.

[0010] The second flow path can cool the portion of the container that accommodates the liquid target. In this case, the second flow path cools the liquid target, which has reached a high temperature due to irradiation with the particle beam, thereby suppressing evaporation of the liquid target. This improves the efficiency of the nuclear reaction in the liquid target.

[0011] The second flow path can be configured to cool the portion of the container that accommodates the gas target. In this case, the second flow path cools the gas target, thereby liquefying it. Therefore, increasing the amount of liquid target can improve the efficiency of the nuclear reaction.

[0012] The container may include a first container capable of accommodating a liquid target and a second container connected to the first container for accommodating a gas target, wherein the second flow path cools the container from the opposite side of the first flow path relative to the irradiation axis, across the second container. In this case, the liquid target in the first container evaporates due to irradiation with the particle beam and is stored as a gas target in the second container. The first and second flow paths cool the gas target from both sides relative to the irradiation axis. This allows the gas target to be liquefied by cooling and returned to the first container as a liquid target. Therefore, increasing the amount of liquid target can improve the efficiency of the nuclear reaction.

[0013] A component that blocks the flow of the cooling medium may be provided in the second flow path. In this case, by blocking the flow of the cooling medium in the second flow path with the component, laminar flow can be replaced with turbulent flow, thereby improving cooling efficiency.

[0014] A target storage device according to one embodiment of the present invention is a device for storing a target that can produce radioactive isotopes through nuclear reactions by being irradiated with a particle beam. The target storage device comprises: a storage portion for storing the target; a first flow path for allowing a cooling medium to flow so that when the target is irradiated with a particle beam, the storage portion is cooled from a side relative to the irradiation axis of the particle beam; and a second flow path for allowing a cooling medium to flow so that the storage portion is cooled from the outer peripheral side of the wall portion through at least a portion of the wall portion arranged around the irradiation axis relative to the storage portion.

[0015] The target storage device includes a first flow path through which a cooling medium can flow so as to cool the storage portion from the side relative to the irradiation axis of the particle beam. Thus, by allowing the cooling medium to flow through the first flow path, the target of the storage portion can be cooled from the side relative to the irradiation axis. Furthermore, the target storage device includes a second flow path through which a cooling medium can flow so as to cool the storage portion from a position further outward than the storage portion with the irradiation axis as a reference via at least a portion of a wall portion provided around the irradiation axis relative to the storage portion. At this time, by allowing the cooling medium to flow through the second flow path, the target of the storage portion can be cooled from the outer peripheral side via the wall portion surrounding the irradiation axis. In this way, the target can be cooled from different directions via the first flow path and the second flow path. Therefore, the cooling efficiency of the target can be improved.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to provide a target storage device capable of improving cooling efficiency and an RI manufacturing device capable of improving nuclear reaction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view of an RI production apparatus according to an embodiment of the present invention.

[0019] Figure 2 It is a top view of the RI production apparatus.

[0020] Figure 3 It is a cross-sectional view of the target storage device according to this embodiment.

[0021] Figure 4 It is a perspective view of the target holding device.

[0022] Figure 5 It is a diagram illustrating the flow of the cooling medium in the target storage device.

[0023] Figure 6 This is an enlarged view of the cooling flow path.

[0024] Explanation of symbols

[0025] 1-RL manufacturing device, 3-accommodation portion, 10-target accommodation device, 31A, 31B-interior space (first flow path), 41, 42-heat transfer wall portion, 46, 48-cooling flow path (second flow path). DETAILED DESCRIPTION

[0026] Hereinafter, the mode for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0027] Figure 1 : is a cross-sectional view of the RI manufacturing apparatus 1. The RI manufacturing apparatus 1 is provided with a target holding device 10 as an embodiment of the RI manufacturing apparatus of the present invention. The RI manufacturing apparatus 1 manufactures radioactive isotopes (RI). The RI manufacturing apparatus 1 can be used as a cyclotron for PET, for example. The RI manufactured by the RI manufacturing apparatus 1 is used, for example, to manufacture radiopharmaceuticals (including radiopharmaceutical products) as radioisotope-labeled compounds (RI compounds). As radioisotope-labeled compounds used in PET examinations (positron emission tomography examinations) in hospitals, etc., there are 18 F-FLT (fluorothymidine), 18 F-FMISO (flumisonidazole), 11 C-raclopride, etc.

[0028] The RI production apparatus 1 is a so-called self-shielded particle accelerator system, comprising an accelerator (cyclotron) 2 for accelerating charged particles and a self-shielded structure 6, a radiation shield (wall) surrounding the accelerator 2 to shield it from radiation. Within the internal space S formed by the self-shielded structure 6, in addition to the accelerator 2, are located a target storage device 10 for producing RI, a vacuum pump 4 for evacuating the interior of the accelerator 2, and other components. Furthermore, the internal space is equipped with accessories necessary for operating the accelerator 2 and auxiliary equipment used for cooling the target storage device 10.

[0029] The accelerator 2 is a so-called vertical cyclotron accelerator and includes a pair of magnetic poles, a vacuum chamber, and an annular magnetic yoke surrounding the pair of magnetic poles and the vacuum chamber. Portions of the pair of magnetic poles face each other at a predetermined distance from each other on the upper surface of the vacuum chamber. Charged particles such as hydrogen ions are multiply accelerated within the gap between the pair of magnetic poles. A vacuum pump 4 is used to maintain the vacuum environment within the accelerator 2 and is, for example, fixed to the side of the accelerator 2. The accelerator 2 emits a charged particle beam in the irradiation direction indicated by arrow B in the figure.

[0030] The target container 10 receives the charged particle beam irradiated from the accelerator 2 to manufacture RI, and contains a material (eg, target water; 18 O water) containing part. Figure 1 and Figure 2 As shown, the target storage device 10 is usually fixed to the side of the accelerator 2. The RI manufacturing apparatus 1 of this embodiment includes two target storage devices 10 arranged on both sides of the accelerator 2. For example, the target storage device 10 arranged on the left side of the figure is arranged on the upper side, and the target storage device 10 arranged on the right side of the figure is arranged on the lower side (refer to Figure 2 The target storage device 10 is covered by a target shield 7 provided in the accelerator 2. The self-shielding body 6 is composed of a plurality of parts and is formed so as to cover the accelerator 2 and the target storage device 10.

[0031] Next, refer to Figure 3 and Figure 4 , the target storage device 10 included in the RI production apparatus 1 of the present invention will be described in further detail. Figure 3 It is a cross-sectional view of the target storage device 10 according to this embodiment. Figure 3 This is a cross-sectional view obtained by cutting the target storage device 10 at the position of the irradiation axis RL. Figure 4 This is a cross-sectional perspective view of a portion of the target storage device 10. Figure 3 , appropriate reference Figure 4 .

[0032] like Figure 3 As shown, the target storage device 10 involved in this embodiment includes a foil, a storage portion 3, and cooling mechanisms 4A and 4B. The radioactive isotope production device includes the above-mentioned target storage device 10 and an accelerator (not shown). As the accelerator, a cyclotron accelerator is used, for example, which generates a charged particle beam (hereinafter referred to as a "particle beam"). The generated particle beam B is irradiated to the target storage device 10 along the irradiation axis RL. Examples of the particle beam B irradiated to the target storage device 10 include proton beams, deuteron beams, and the like. The target storage device 10 is attached to the outlet of the particle beam B from the accelerator via a manifold (not shown) arranged between the target storage device 10 and the accelerator. In the following description, the direction in which the irradiation axis RL extends is sometimes referred to as the longitudinal direction D1 of the target storage device 10. In addition, the side on which the particle beam B is irradiated in the longitudinal direction D1 (the upstream side in the direction of travel of the particle beam) is sometimes referred to as the front side of the target storage device 10, and the side opposite thereto is sometimes referred to as the rear side of the target storage device 10. Furthermore, a direction perpendicular to the longitudinal direction D1 and the up-down direction of the target storage device 10 may be referred to as a width direction D2.

[0033] Furthermore, when describing positional relationships, terms such as "outer side" and "inner side" relative to the irradiation axis RL are sometimes used. The outer side relative to the irradiation axis RL refers to the side farther from the irradiation axis RL in a direction perpendicular to the irradiation axis RL. The outer side relative to the irradiation axis RL is sometimes simply referred to as the "outer peripheral side." The inner side relative to the irradiation axis RL refers to the side closer to the irradiation axis RL in a direction perpendicular to the irradiation axis RL. The inner side relative to the irradiation axis RL is sometimes simply referred to as the "inner peripheral side."

[0034] The target container 10 has, for example, a cylindrical outer shape. It includes a target container 12, which primarily forms the container 3; a cooling mechanism component 13, which primarily forms the cooling mechanism 4A; and an inner ring 14 and an outer ring 15, which primarily form the cooling mechanism 4B. The front flange 11, target container 12, and cooling mechanism component 13 are constructed from metal blocks. Furthermore, the front flange 11, target container 12, and cooling mechanism component 13 overlap in this order from the front to the rear in the longitudinal direction D1.

[0035] The foil is a component that partitions the container 3 at the front. The foil is placed in the target container 12. The foil allows the particle beam B to pass through, while blocking the liquid target 101 and fluids such as He gas from passing through. Therefore, after the particle beam B is irradiated by the foil, it passes through the foil and irradiates the liquid target 101. For example, He gas is sprayed onto the front surface of the foil to cool the foil. The foil is a relatively thin foil made of a metal or alloy such as Ti, with a thickness of approximately 10 to 50 μm. The foil is placed so as to cover at least the entire area of ​​the container 3.

[0036] The container 3 is a portion for storing the liquid target 101. The container 3 is composed of a recess 22 formed in the target container 12, a cavity 25 formed in the target container 12 and communicating with the recess 22, and a space surrounded by the foil. The target container 12 can be formed of Nb, for example. 18 O (target water) is used as the liquid target 101. The recess 22 is recessed from the front surface of the target container 12, for example, the fixing surface 12a of the fixing foil, toward the rear side in the longitudinal direction D1. The recess 22 has a bottom surface 22a and a peripheral surface 22b extending from the outer peripheral edge of the bottom surface 22a toward the front side in the longitudinal direction D1. When viewed from the longitudinal direction D1, the container 3 has a circular shape (see FIG. Figure 4 The cavity 25 is a space extending obliquely upward from the upper end of the recess 22. The cavity 25 is inclined so as to extend upward toward the rear side in the longitudinal direction D1. The cavity 25 is connected to the upper end of the recess 22. When viewed from the longitudinal direction D1, the cavity 25 has a fan-shaped shape (refer to FIG. Figure 5 ).

[0037] The target container 12 is provided with a gas introduction hole (not shown) for introducing an inert gas (for example, He gas) into the container 3. The target container 12 is provided with a flow hole 26 (see FIG. Figure 4 ), the flow hole 26 is used when the container 3 is filled with the liquid target 101, and is used when the liquid target 101 in the container 3 is discharged.

[0038] The chamber 3 includes a first chamber E1, which holds the liquid target 101, and a second chamber E2, located above the first chamber E1 and receiving the gas target formed by evaporation of the boiling liquid target 101. The second chamber E2 is formed continuously above the first chamber E1. Here, the space formed by the recess 22 corresponds to the first chamber E1, and the space formed by the cavity 25 corresponds to the second chamber E2.

[0039] The cooling mechanism 4A cools the container 3 using a cooling medium on the side opposite to the irradiation direction of the particle beam B irradiating the liquid target 101 (i.e., the rear side). The cooling mechanism 4A includes a first cooling unit 30A for cooling the first container E1 and a second cooling unit 30B for cooling the second container E2. The first cooling unit 30A includes a first nozzle 32A disposed in the first internal space 31A (first flow path). The second cooling unit 30B includes a second nozzle 32B disposed in the second internal space 31B (first flow path).

[0040] The first internal space 31A and the second internal space 31B are spaces for the cooling medium to flow through. The first internal space 31A and the second internal space 31B are formed by installing the cooling mechanism forming member 13 in the recess 30 on the rear side of the target container 12, thereby forming the space between the target container 12 and the cooling mechanism forming member 13. The first internal space 31A is formed on the rear side of the first accommodating portion E1 of the accommodating portion 3 in the longitudinal direction D1. The second internal space 31B is formed on the rear side of the second accommodating portion E2 of the accommodating portion 3 in the longitudinal direction D1. In other words, the second internal space 31B is located above the first internal space 31A. A heat transfer wall 34A is provided between the first internal space 31A and the first accommodating portion E1. A heat transfer wall 34B is provided between the second internal space 31B and the second accommodating portion E2. Furthermore, the first internal space 31A and the second internal space 31B are separated by a partition 36.

[0041] The first nozzle 32A sprays the cooling medium onto the heat transfer wall 34A between the first nozzle 32A and the first accommodating section E1. The first nozzle 32A sprays the cooling medium perpendicularly to the heat transfer wall 34. The first nozzle 32A is separate from the heat transfer wall 34. The second nozzle 32B sprays the cooling medium onto the heat transfer wall 34B between the second nozzle 32A and the second accommodating section E2. The second nozzle 32B sprays the cooling medium perpendicularly to the heat transfer wall 34B. The second nozzle 32B is separate from the heat transfer wall 34B.

[0042] Next, the cooling mechanism 4B will be described. First, the inner ring 14 is mounted in the target container 12 so as to surround the housing 3 around the irradiation axis RL. Therefore, the target container 12 is provided with an annular recess 40 (especially referring to FIG. 1 ) so that the inner ring 14 can be mounted from the outer circumference. Figure 4 ). In addition, the inner ring 14 has a split structure in which the inner ring 14 is divided into semicircular parts 14A and 14B, and is mounted on the recess 40 from the outer peripheral side (refer to Figure 5 ). The inner ring 14 is in the shape of a circular ring with a substantially quadrilateral cross section. However, the inner diameter of the inner ring 14 is partially reduced at the portion corresponding to the cavity 25 (refer to Figure 5 ), an inclined surface 14b is formed on the inner circumference (reference Figure 4 A support surface 40a facing the inner ring 14 on the rear side is formed in the target container 12. The outer ring 15 is attached to the support surface 40a so as to support the inner ring 14 attached to the recess 40 from the outer peripheral side.

[0043] The target container 12 has a wall portion opposite to the inner circumferential surface 14a of the inner ring 14 at the position of the recessed portion 22 of the container 3. The wall portion is configured as a heat transfer wall portion 41 formed around the irradiation axis RL of the first container E1. The heat transfer wall portion 41 is formed as a cylindrical thin-walled portion. Furthermore, the target container 12 has a wall portion opposite to the inclined surface 14b of the inner ring 14 at the position of the cavity portion 25. The wall portion is configured as a heat transfer wall portion 42 formed around the irradiation axis RL of the second container E2. The heat transfer wall portion 41 is formed as a thin-walled portion at a position opposite to the heat transfer wall portion 34B on the outer peripheral side. The heat transfer wall portion 42 is formed in a fan shape when viewed from the longitudinal direction, and the heat transfer wall portion 41 is formed on the entire circumference of the portion other than the heat transfer wall portion 42 (refer to Figure 5 ). In addition, a step wall portion 44 is formed between the heat transfer wall portion 41 and the heat transfer wall portion 42, rising from the support surface 40a toward the heat transfer wall portion 42 (refer to Figure 5 ).

[0044] A cooling channel 46 (second channel) for flowing a cooling medium is formed between the heat transfer wall 41 surrounding the first housing portion E1 and the inner circumferential surface 14a of the inner ring 14. The first housing portion E1 of the housing portion 3 is located further inward than the heat transfer wall 41 with respect to the irradiation axis RL. Furthermore, the cooling channel 46 is located further outward than the heat transfer wall 41 with respect to the irradiation axis RL. Therefore, the cooling channel 46 allows the cooling medium to flow through the heat transfer wall 41, which is located relative to the housing portion 3 around the irradiation axis RL, to cool the first housing portion E1 of the housing portion 3 from a position further outward than the first housing portion E1 of the housing portion 3 with respect to the irradiation axis RL. The cooling channel 46 allows the cooling medium to flow through the heat transfer wall 41, which is located relative to the housing portion 3 around the irradiation axis RL, to cool the first housing portion E1 of the housing portion 3 from the outer circumference of the heat transfer wall 41. The cooling flow path 46 can cool the first accommodation portion E1 in the accommodation unit 3 that can accommodate the liquid target 101. With this configuration, the cooling flow path 46 allows a cooling medium to flow through the cooling flow path 46 so as to dissipate heat from the first accommodation portion E1 of the accommodation unit 3 from the inside to the outside with respect to the irradiation axis RL via the heat transfer wall portion 41.

[0045] A cooling channel 48 (second channel) for flowing a cooling medium is formed between the heat transfer wall 42 surrounding the second housing portion E2 and the inclined surface 14b of the inner ring 14. The second housing portion E2 of the housing portion 3 is located further inward than the heat transfer wall 42 with respect to the irradiation axis RL. Furthermore, the cooling channel 48 is located further outward than the heat transfer wall 42 with respect to the irradiation axis RL. Therefore, the cooling channel 48 allows the cooling medium to flow through the heat transfer wall 42, which is disposed relative to the housing portion 3 around the irradiation axis RL, to cool the second housing portion E2 of the housing portion 3 from a position further outward than the second housing portion E2 of the housing portion 3 with respect to the irradiation axis RL. The cooling channel 48 allows the cooling medium to flow through the heat transfer wall 42, which is disposed relative to the housing portion 3 around the irradiation axis RL, to cool the second housing portion E2 of the housing portion 3 from the outer circumference of the heat transfer wall 42. The cooling channel 48 cools the second accommodation portion E2 of the accommodation portion 3, which accommodates the gas target 102. The cooling channel 48 cools the second accommodation portion E2 of the accommodation portion 3 from the side opposite the second internal space 31B with respect to the irradiation axis RL, across the second accommodation portion E2. With this configuration, the cooling channel 48 allows a coolant to flow through the heat transfer wall 42, dissipating heat from the second accommodation portion E2 of the accommodation portion 3 from the inside to the outside, based on the irradiation axis RL. Furthermore, the second internal space 31B allows a coolant to flow through the heat transfer wall 34B, which is disposed around the irradiation axis RL relative to the accommodation portion 3, to cool the second accommodation portion E2 of the accommodation portion 3 from a position further inward of the second accommodation portion E2 of the accommodation portion 3 with respect to the irradiation axis RL. The second internal space 31B allows a coolant to flow through the heat transfer wall 34B, dissipating heat from the second accommodation portion E2 of the accommodation portion 3 from the outside to the inside, based on the irradiation axis RL.

[0046] A flow path 47 communicating with the cooling flow path 46 is formed between the support surface 40a and the inner ring 14. This flow path 47 communicates with a coolant supply pipe 51 and a coolant discharge pipe 52. Thus, the flow path 47 supplies and recovers the coolant to and from the cooling flow paths 46 and 48.

[0047] Next, refer to Figure 3 and Figure 5, the flow of the cooling medium relative to the cooling channels 46 and 48 will be described. In addition, the supply pipe 51 and the discharge pipe 52 are provided in an area near the lower end of the support surface 40a. In addition, a partition 54 for blocking the flow of the cooling medium is provided between the supply pipe 51 and the discharge pipe 52. First, the cooling medium supplied from the supply pipe 51 is supplied to the cooling channel 46 by flowing through the channel 47 (F1). As a result, a portion of the cooling medium flows through the cooling channel 46 (F2). In the step wall portion 44, the cooling medium flows over the step wall portion 44 (F3) and is supplied to the cooling channel 48. As a result, the cooling medium flows through the cooling channel 48 (F4). In the next step wall portion 44, the cooling medium flows downward along the step wall portion 44 (F5) and is supplied to the cooling channels 46 and 47. As a result, the cooling medium flows through the cooling flow path 46 ( F6 ) and flows through the cooling flow path 47 ( F7 ).

[0048] Next, the effects of the RI manufacturing apparatus 1 and the target storage apparatus 10 according to the present embodiment will be described.

[0049] The RI production apparatus 1 includes a first internal space 31A and a second internal space 31B through which a cooling medium can flow to cool the housing 3 from one side (rear side) relative to the irradiation axis RL of the particle beam B. Thus, by allowing the cooling medium to flow through the first internal space 31A and the second internal space 31B, the target in the housing 3 can be cooled from the side relative to the irradiation axis RL. Furthermore, the RI production apparatus 1 includes cooling flow paths 46 and 48 through which the cooling medium can flow to cool the housing 3 from a position further outward of the housing 3 relative to the irradiation axis RL via heat transfer walls 41 and 42 disposed around the irradiation axis RL relative to the housing 3. At this time, by allowing the coolant to flow through the cooling channels 46 and 48, heat is removed from the housing 3 from the inside to the outside with respect to the irradiation axis RL via the heat transfer walls 41 and 42 surrounding the irradiation axis RL, thereby cooling the target in the housing 3. In this way, the target can be cooled from different directions via the first internal space 31A, the second internal space 31B, and the cooling channels 46 and 48. This improves the cooling efficiency of the target, thereby improving the efficiency of the nuclear reaction in the target.

[0050] The cooling channel 46 can cool the first housing portion E1 in the housing 3 that can accommodate the liquid target 101. In this case, the cooling channel 46 cools the liquid target 101, which has reached a high temperature due to irradiation with the particle beam B, thereby suppressing evaporation of the liquid target 101. Consequently, the efficiency of the nuclear reaction of the liquid target 101 can be improved.

[0051] The cooling channel 48 can cool the second accommodation portion E2 of the accommodation unit 3 that accommodates the gas target 102. In this case, the cooling channel 48 cools the gas target 102, thereby liquefying it. Therefore, by increasing the amount of liquid target 101, the efficiency of the nuclear reaction can be improved.

[0052] The chamber 3 may include a first chamber E1 capable of accommodating a liquid target 101 and a second chamber E2 communicating with the first chamber E1 and capable of accommodating a gas target 102. The cooling channel 48 cools the chamber 3 from the side opposite the second internal space 31B relative to the irradiation axis RL, across the second chamber E2. In this case, the liquid target 101 in the first chamber E1 evaporates upon exposure to the particle beam B and is stored as the gas target 102 in the second chamber E2. The second internal space 31B and the cooling channel 48 cool the gas target 102 from both sides relative to the irradiation axis RL. This allows the gas target 102 to be cooled and liquefied, returning to the first chamber E1 as the liquid target 101. Consequently, the efficiency of the nuclear reaction can be improved by increasing the amount of liquid target 101.

[0053] The target storage device 10 further includes a first internal space 31A and a second internal space 31B through which a cooling medium can flow to cool the storage portion 3 from one side (rear side) relative to the irradiation axis RL of the particle beam B. Thus, by allowing the cooling medium to flow through the first internal space 31A and the second internal space 31B, the target in the storage portion 3 can be cooled from one side relative to the irradiation axis RL. Furthermore, the target storage device 10 includes cooling flow paths 46 and 48 through which the cooling medium can flow to cool the storage portion 3 from a position further outward of the storage portion 3 relative to the irradiation axis RL via heat transfer walls 41 and 42 provided around the irradiation axis RL relative to the storage portion 3. At this time, by flowing the coolant through the cooling channels 46 and 48, heat can be removed from the housing 3 from the inside to the outside with respect to the irradiation axis RL via the heat transfer walls 41 and 42 surrounding the irradiation axis RL, thereby cooling the target in the housing 3. In this way, the target can be cooled from different directions via the first internal space 31A, the second internal space 31B, and the cooling channels 46 and 48. This improves the cooling efficiency of the target, thereby increasing the efficiency of the nuclear reaction in the target. Therefore, the cooling efficiency of the target can be improved.

[0054] The present invention is not limited to the above-described embodiment.

[0055] For example, a component that blocks the flow of the cooling medium may be provided in the cooling channels 46 and 48. In this case, the laminar flow is replaced with a turbulent flow by the component that blocks the flow of the cooling medium in the cooling channels 46 and 48, thereby improving the cooling efficiency. Figure 6 As shown, a component 60 that obstructs the flow of the cooling medium is provided on at least one of the inner circumferential surface 14a of the inner ring 14 and the heat transfer wall portion 41. In this case, the component 60 forms a slit in the cooling flow path 46. This slit structure obstructs the flow, thereby causing the cooling medium to flow turbulently.

[0056] The specific structures of the RI manufacturing device and the target storage device of the present invention are not limited to the above-mentioned embodiments.

[0057] Way.

[0058] It is sufficient to provide at least one of the cooling flow paths 46 and 48 , and the other one may be omitted.

Claims

1. An RI production apparatus for producing radioactive isotopes by a nuclear reaction of a target irradiated with a particle beam, the RI production apparatus comprising: a housing portion for housing the target at an irradiation position of the particle beam; a first flow path capable of allowing a cooling medium to flow therethrough so as to cool the housing portion from a side relative to an irradiation axis of the particle beam; and The second flow path is configured to allow a cooling medium to flow therethrough so as to cool the side surface of the container from a position outside the container with respect to the irradiation axis through at least a portion of a wall portion provided around the irradiation axis relative to the container. The second flow path can cool a portion of the container that can accommodate the gas target.

2. An RI production apparatus for producing radioactive isotopes by a nuclear reaction of a target irradiated with a particle beam, the RI production apparatus comprising: a housing portion for housing the target at an irradiation position of the particle beam; a first flow path capable of allowing a cooling medium to flow therethrough so as to cool the housing portion from a side relative to an irradiation axis of the particle beam; and The second flow path is configured to allow a cooling medium to flow therethrough so as to cool the side surface of the container from a position outside the container with respect to the irradiation axis through at least a portion of a wall portion provided around the irradiation axis relative to the container. The accommodation portion includes a portion capable of accommodating a liquid target and a portion capable of accommodating a gas target.

3. The RI production apparatus according to claim 1 or 2, wherein: The second flow path can cool a portion of the container that can accommodate the liquid target.

4. The RI production apparatus according to claim 1 or 2, wherein: A member that obstructs the flow of the cooling medium is provided in the second flow path.

5. A target storage device for storing a target capable of producing a radioactive isotope by a nuclear reaction by being irradiated with a particle beam, the target storage device comprising: a receiving portion for receiving the target; a first flow path capable of flowing a cooling medium so as to cool the housing portion from a side relative to an irradiation axis of the particle beam when the target is irradiated with the particle beam; and The second flow path is configured to allow a cooling medium to flow therethrough so as to cool the side surface of the container from a position outside the container with respect to the irradiation axis through at least a portion of a wall portion provided around the irradiation axis relative to the container. The second flow path can cool a portion of the container that can accommodate the gas target.

6. A target storage device for storing a target capable of producing a radioactive isotope by a nuclear reaction by being irradiated with a particle beam, the target storage device comprising: a receiving portion for receiving the target; a first flow path capable of flowing a cooling medium so as to cool the housing portion from a side relative to an irradiation axis of the particle beam when the target is irradiated with the particle beam; and The second flow path is configured to allow a cooling medium to flow therethrough so as to cool the side surface of the container from a position outside the container with respect to the irradiation axis through at least a portion of a wall portion provided around the irradiation axis relative to the container. The accommodation portion includes a portion capable of accommodating a liquid target and a portion capable of accommodating a gas target.

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