Target container, radionuclide producing apparatus, and radionuclide producing method

Abstract

To reduce the necessity of sealing a target substance in a capsule or the like.SOLUTION: A target container (20) for producing a radionuclide by irradiating a target material (TA) with a particle beam (B) includes a container body (MB) having a holding portion (211) for holding the target material, at least one roller (23) having an adhesion surface (231) to which a part of the target material held by the holding portion is adhered, and a moving mechanism (24) for rotating the roller to move the target material adhered to the adhesion surface into an irradiation range (RA) in which the particle beam is irradiated.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a target vessel, a radionuclide production apparatus, and a radionuclide production method. [Background technology]

[0002] A particle beam is irradiated onto a target material with a relatively low melting point, 68 Ga and 211 Techniques for producing radioactive nuclides such as At are known (see Non-Patent Documents 1 and 2). In this case, the target material is encapsulated in a capsule or the like to prevent leakage of the target material liquefied by the heat during irradiation. In Non-Patent Document 1, the target material is held in a crucible-shaped container. In Non-Patent Document 2, the target material is sealed in a capsule made of Nb by electron beam welding. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Nagatsu K., Minegishi K. et al. Production of 211At by a vertical beam irradiation method. Appl. Radiat. Isot. 94, 363-371 (2014) [Non-patent document 2] Steyn, GF et al. The 12th International workshop on targetry and target chemistry Abstract book. July 21-24 (2008) Seattle Washington Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional techniques, a particle beam is irradiated onto a target material enclosed in a capsule or the like, and therefore the capsule or the like is easily deteriorated by the particle beam and the liquefied target material. Furthermore, for example, in the technique of Non-Patent Document 2, the target material must be precisely sealed in a new capsule every time a particle beam is irradiated. In other words, sealing the target material in a capsule requires advanced technology and costs, making it difficult to implement in general practice.

[0005] An object of one aspect of the present invention is to provide a target container, a radionuclide production apparatus, and a radionuclide production method that reduce the need to encapsulate a target material in a capsule or the like. [Means for solving the problem]

[0006] In order to solve the above problems, a target container according to one embodiment of the present invention is a target container for producing radioactive nuclides by irradiating a target material with a particle beam, and includes: a container body having a holding portion for holding the target material; at least one roller having an attachment surface to which a portion of the target material held in the holding portion is attached; and a moving mechanism that rotates the at least one roller to move the target material attached to the attachment surface into an irradiation range where the particle beam is irradiated.

[0007] In order to solve the above problems, a radionuclide manufacturing apparatus according to one aspect of the present invention includes the target vessel described above and an accelerator that generates a particle beam.

[0008] In order to solve the above problems, a radionuclide production method according to one aspect of the present invention is a radionuclide production method for producing a radionuclide by irradiating a target material with a particle beam, and includes the steps of bringing the target material held in a holder into contact with the surface of a roller to adhere it, rotating the roller to move the target material adhered to the surface into an irradiation range where the particle beam is irradiated, and irradiating the particle beam onto the target material moved into the irradiation range. [Effects of the Invention]

[0009] According to one aspect of the present invention, it is possible to realize a target container, a radionuclide production apparatus, and a radionuclide production method in which the need for encapsulating a target material in a capsule or the like is reduced. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a partial cross-sectional view showing a radionuclide manufacturing apparatus according to an embodiment of the present invention as viewed from the side. [Figure 2] FIG. 2 is a rear view of the radionuclide manufacturing apparatus according to the embodiment of the present invention. [Figure 3] 1 is a partial cross-sectional view showing a state in which a radionuclide manufacturing apparatus according to an embodiment of the present invention is seen from the rear. [Figure 4] 1 is a side view showing a state in which a radionuclide manufacturing apparatus according to an embodiment of the present invention is viewed from the side. [Figure 5] 1 is a flow diagram illustrating a method for producing radionuclides according to an embodiment of the present invention. [Figure 6] 1 is a diagram showing a state of a radionuclide manufacturing apparatus in a radionuclide manufacturing method according to an embodiment of the present invention. FIG. [Figure 7] FIG. 10 is a diagram illustrating the recovery of target material from a target container. [Figure 8] 1A-1C are diagrams showing various embodiments of rollers. [Figure 9] 1A-1C are diagrams showing various embodiments of rollers. [Figure 10] 1A to 1C are diagrams showing various aspects of heating mechanisms. [Figure 11] 1A to 1C are diagrams showing various aspects of supply ports and recovery ports. [Figure 12] 10A and 10B are diagrams illustrating examples of a state in which a target material is attached to a roller. [Figure 13] 10A and 10B are diagrams illustrating examples of a state in which a target material is attached to a roller. [Figure 14] 10A and 10B are diagrams illustrating examples of a state in which a target material is attached to a roller. [Figure 15]10A and 10B are diagrams illustrating examples of a state in which a target material is attached to a roller. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Embodiment] The configuration of a radionuclide manufacturing apparatus 1 according to one embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a partial cross-sectional view of the radionuclide manufacturing apparatus 1 according to an embodiment of the present invention as seen from the side (negative Y-axis direction). FIG. 2 is a view of the radionuclide manufacturing apparatus 1 according to an embodiment of the present invention as seen from the rear (negative X-axis direction). FIG. 3 is a partial cross-sectional view of the radionuclide manufacturing apparatus 1 according to an embodiment of the present invention as seen from the rear (negative X-axis direction). FIG. 4 is a side view of the radionuclide manufacturing apparatus 1 according to an embodiment of the present invention as seen from the side (negative Y-axis direction). In FIGS. 1 to 4, an XYZ coordinate system is shown, with the up-down direction being the Z direction.

[0012] The radionuclide production apparatus 1 will be described below mainly based on Fig. 1. The radionuclide production apparatus 1 is an apparatus for producing a radionuclide RN by irradiating a target material TA with a particle beam B, and includes an accelerator 10, a target container 20, a tilting mechanism 30, and a pressing mechanism 40.

[0013] The accelerator 10 is, for example, a cyclotron, and irradiates a particle beam B onto a target material TA in a target vessel 20. The particle beam B can be, for example, an ion beam such as a proton, alpha particle, or electron beam, or a neutron beam.

[0014] A beam duct 11 is disposed between the accelerator 10 and the target vessel 20. The beam duct 11 has a passage through which the particle beam B passes, and its end is connected to (the flange FR of) the target vessel 20. The beam duct 11 has a supply port 111a and a discharge port 111b for cooled He gas.

[0015] The flange FR is fixed to the target vessel 20 with screws or the like, and can be sealed with an O-ring or the like to maintain airtightness. The flange FR can be connected to the beam duct 11 by being pressed by a pressing mechanism 40.

[0016] A foil-shaped vacuum foil F0 and a container foil F1 are arranged on the path of the particle beam B. The vacuum foil F0 is fixed inside the beam duct 11 and maintains a vacuum on the accelerator 10 side. The container foil F1 is fixed between the flange FR and the target container 20 and seals the target container 20. The particle beam B emitted from the accelerator 10 passes through the vacuum foil F0 and the container foil F1 and enters the target container 20.

[0017] The target container 20 is a container for producing radionuclides RN by irradiating a target material TA with a particle beam B. The target material TA is, for example, a material (e.g., a metal) having a melting point of 330°C or less, such as Ga, Bi, Cd, or Tl (see IAEA Radioisotopes and Radiopharmaceuticals Reports, No. 4, (2021)). Note that the target material TA may be a eutectic, such as LBE (Lead-bismuth eutectic; melting point 123°C), which is a mixture of materials with a lower melting point (see Bigourdan, T. et al. EPJ Web of Conferences 285, 09002 (2023)).

[0018] The radioactive nuclides RN to be produced include, for example, those shown in Table 1 below. 68 Ga(← 68 Ge), 71 As, 72 As, 73 As, 74 As, 211 At, 111 In, 117m Sn, 201 Table 1 shows the correspondence between the target material TA, particle beam B, and the radioactive nuclide RN produced.

[0019] [Table 1] 1) Steyn, GF et al. The 12th International Workshop on Targetry and Target Chemistry Abstract Book. July 21-24 (2008) Seattle Washington; same as Non-Patent Document 2 2)Nabanita Naskar and Susanta Lahiri, Applied Radiation and Isotopes 176 (2021) 109876;In the original paper 71 As and 72 Although only As is listed, considering the physical properties of nuclear reactions, 73 As and 74 It is also possible to generate As. 3) Nagatsu K., Minegishi K. et al. Production of 211At by a vertical beam irradiation method. Appl. Radiat. Isot. 94, 363-371 (2014); same as Non-Patent Document 1 4)Kanchan Kushwaha et al., Journal of Radioanalytical and Nuclear Chemistry 328 (2021) 835-846 5)Duchemin, C. et al., Applied Radiation and Isotopes 115 (2016) 113-124 6)Sankha Chattopadhyay et al., Applied Radiation and Isotopes 204 (2024) 111128

[0020] The target container 20 has a lower container part 21 and an upper container part 22. The lower container part 21 and the upper container part 22 together constitute the container body MB. The container body MB has a lid 221, a supply port 222, and a recovery port 223. The lid 221 is an openable and closable lid for introducing the target material TA into the container body MB. The supply port 222 is a supply port for supplying a dissolving liquid for dissolving the target material TA. The recovery port 223 is a recovery port for recovering the target material TA dissolved by the dissolving liquid from the container body MB.

[0021] The container body MB is fixed to a base BS1 by a clamper KP (see FIGS. 2 and 4) and placed on a deflection table (stage) ST. The deflection table ST is tiltably fixed to a base BS2 by a tilting mechanism 30. The base BS2 is placed on a base BS3 via rails R1 and R2 so as to be movable in the X-axis and Y-axis directions. The bases BS2 and BS3 are loosely connected by a spring SL.

[0022] The container body MB has a holding portion 211 that holds the target material TA. The holding portion 211 is a recess formed in the container body MB, and has a recessed shape that corresponds to the roller 23. The target material TA is heated by the heater HT and liquefied and placed between the holding portion 211 and the roller 23. The liquefied target material TA adheres to the peripheral surface (adhesion surface 231) of the roller 23.

[0023] That is, the target vessel 20 includes a heater HT as a heating mechanism that heats and liquefies the target material TA held in the holder 211. The target material TA liquefied by heating with this heating mechanism adheres to the attachment surface 231. That is, the vessel body MB includes the heater HT as a heating mechanism, and is capable of liquefying the target material TA (solid metal, etc.) by heating.

[0024] This heating temperature is, for example, equal to or higher than the melting point of the target material TA. For example, the melting point of Ga is 30°C, that of Bi is 271°C, that of Tl is 304°C, and that of Cd is 321°C. The heating temperature is selected depending on the target material TA. A preferable heating temperature is a temperature about 10% higher than the melting point (Celsius). For example, from Bi to Cd, 211 When At is produced, the preferred upper limit of the heating temperature is about 300°C (≈271°C x 110%).

[0025] The heating temperature may be, for example, about 50% higher than the melting point (Celsius) of the target material TA. By doing so, even if the heating temperature drops to a certain extent due to external factors, the heating temperature can be maintained at or above the melting point of the target material TA, thereby maintaining the liquefied state of the target material TA. As a result, it becomes easier to continue stable irradiation of the target material TA that has liquefied, adhered to the roller 23, and then solidified. Note that the upper limit of the heating temperature can be appropriately determined by one skilled in the art, taking into consideration the volatility of the target material TA and the melting point and volatility of the radionuclide RN that is generated.

[0026] The roller 23 is held in the internal space S of the container body MB. This internal space S is filled with an inert gas to prevent oxidation of the target material TA. Furthermore, when the target material TA adhering to the roller 23 is peeled off, the internal space S allows the peeled target material TA to be returned to the holder 211, making it reusable.

[0027] The roller 23 has an attachment surface 231 to which a portion of the target material held in the holder 211 is attached. Details of this will be described later. Here, as an example, the roller 23 has a cylindrical outer shape, and its circumferential surface functions as the attachment surface 231. The attachment surface 231 of the roller 23 comes into contact with the liquefied target material TA in the holder 211, and the liquefied target material TA is attached to the rotating attachment surface 231 (roller surface). By rotating the roller 23, the irradiation of the particle beam B onto the roller 23 is made uniform, and embrittlement of the roller 23, and therefore of the target container 20, is suppressed.

[0028] The roller 23 has an internal space SP and a cylindrical shape. A refrigerant (e.g., cooling water) flows into this internal space SP, allowing the liquefied target material TA attached to the roller 23 to solidify. That is, the target container 20 is equipped with a cooling mechanism that cools and solidifies the liquefied target material TA attached to the attachment surface 231. Here, as shown in FIG. 3 , a flow path 242 is formed inside the rotation shaft 241 of the roller 23, and functions as the cooling mechanism. By flowing cooling water from the flow path 242 into the internal space SP of the roller 23, the roller 23 and, in turn, the target material TA can be cooled. This causes the molten target material TA attached to the roller 23 to solidify and be stably held on the roller 23. As a result, stable irradiation of the target material TA is achieved, which in turn facilitates shortening the production time of the radionuclide RN and increasing the production amount.

[0029] A joint connectable to a cooling water pipe is attached to the end of the rotating shaft 241 in order to flow cooling water in the flow path 242. The flow path 242 preferably has a cross-sectional area that allows the flow of a quantity of water sufficient to remove the heat generated during irradiation with the particle beam B.

[0030] The target container 20 has a moving mechanism 24. The moving mechanism 24 rotates a roller 23 about an axis A to move the target material TA adhered to the adhesion surface 231 into an irradiation range RA where the particle beam B is irradiated.

[0031] Here, the axial direction of the rotation shaft 241 of the roller 23 is substantially perpendicular to the direction of the incident particle beam B. Note that the axial direction of the rotation shaft 241 of the roller 23 may be parallel or oblique to the direction of the incident particle beam B.

[0032] As shown in Fig. 3, this movement mechanism 24 is composed of a gear 243 provided on a rotation shaft 241 of the roller 23, and a motor 244 that rotates the gear 243. It is preferable to have a mechanism for adjusting the rotation speed of the roller 23. That is, it is preferable that this rotation speed is slow enough to prevent the attached target material TA from scattering from the roller 23, and fast enough to prevent the attached target material TA from dripping. However, the type of power that rotates the roller 23 and the rotation direction are not important. The contact portion between the rotation shaft 241 and the container body MB is sealed with an O-ring or the like.

[0033] It is preferable that the rollers 23 be able to withstand the thermal shocks of the target material TA, the dissolving solution, and irradiation, and not be damaged even when subjected to the rotational force of the rotation shaft 241. Furthermore, it is preferable that the rollers 23 have a thickness of approximately 1 to 5 mm so that heat from the target material TA can be transferred to the cooling water in the internal space SP and removed from the target material TA. Examples of materials that can be used to form the rollers 23 include titanium, niobium, and ceramics.

[0034] The container body MB has a second holding part 214 and a recovery port 223. The second holding part 214 holds the target material TA after being irradiated with the particle beam B when the container body MB is tilted. The recovery port 223 recovers the target material TA inside the second holding part 214. As will be described later, the target material TA can be dissolved in a dissolving liquid and removed as a liquid from the recovery port 223.

[0035] The tilting mechanism 30 tilts the container body MB, making it possible to switch which of the holding part 211, the second holding part 214, and the recovery port 223 faces downward. As shown in FIG. 2, the tilting mechanism 30 has an actuator 31 and bearings 32 to 35. As a result, as shown in FIG. 6 described below, the tilt of the deflection table ST can be changed to tilt the container body MB on the deflection table ST so that either the holding part 211, the second holding part 214, or the recovery port 223 faces downward. When the angle θ is 0, θ1, or θ2, it becomes the irradiation angle, the dissolution angle, and the recovery angle (see FIG. 6).

[0036] 1, the pressing mechanism 40 presses the vessel body MB against the beam duct 11 by means of a cylinder 41. At this time, the deflection table ST placed on rails R1 and R2 is also moved together with the vessel body MB.

[0037] Hereinafter, a method for producing a radionuclide by irradiating a target material with a particle beam to produce a radionuclide will be described in detail. Fig. 5 is a flow diagram showing a method for producing a radionuclide according to an embodiment of the present invention. Fig. 6 is a diagram showing the state of a radionuclide production apparatus in the method for producing a radionuclide according to an embodiment of the present invention. Fig. 7 is a diagram showing the recovery of a target material TA from a target container 20. Hereinafter, the method for producing a radionuclide will be described with reference to Figs. 5 to 7.

[0038] (1) Loading the target material TA into the target vessel 20 (step S11) The lid 221 of the upper part 22 of the container is opened, and after the solid target material TA is introduced into the container body MB, the lid 221 is closed.

[0039] After that, confirm that the angle of the deflection table ST is the irradiation angle (θ=0) (see state M1 in Figure 6), place the container body MB on the deflection table ST, connect the power supplies for the dissolving liquid / recovery liquid tube and heater HT, and connect the cooling water tube to the roller 23. Press the container body MB against the beam duct 11 using the cylinder 41.

[0040] (2) Adhesion of target material TA to roller 23 (step S12) While the inside of the target vessel 20 is replaced with an inert gas such as He, the heater HT in the vessel lower part 21 is heated to liquefy the target TA in the target vessel 20. As a result, the target material TA held by the holder 211 is liquefied and comes into contact with and adheres to the surface (adhesion surface 231) of the roller 23 (see state M1 in FIG. 6 ).

[0041] (3) Movement of the target material TA by rotation of the roller 23 (step S13) The roller 23 is rotated by the movement mechanism 24 to move the target material TA adhered to the adhesion surface 231 into the irradiation range RA where the particle beam B is irradiated. At this time, the roller 23 is rotated at, for example, about 60 to 120 rpm, so that the target material TA can be widely adhered to the adhesion surface 231 of the roller 23. Meanwhile, cooling water is flowed into the internal space SP of the roller 23 to cool the target material TA adhered to the roller 23.

[0042] (4) Irradiation of particle beam B (step S14) The particle beam B is irradiated onto the target material TA that has been moved into the irradiation range RA. That is, the particle beam B is irradiated onto the roller 23 to which the target material TA is attached. During irradiation, the roller 23 is cooled by cooling water flowing into the internal space SP, and the container foil F1 is cooled by He gas. Meanwhile, the target material TA in the holder 211 is heated by the heater HT to prevent it from solidifying. Heat radiation from the heater HT is controlled based on the temperature measured by the thermocouple TC.

[0043] (5) Movement of the target material TA due to tilting of the target vessel 20 (step S15, state M3 in FIG. 6) After irradiation with the particle beam B, cooling of the roller 23 is stopped, and the container body MB is released from pressing against the beam duct 11. Heating of the target material TA by the heater HT continues, and the target material TA is maintained in a molten state. Thereafter, the target container 20 is tilted to the melting angle (θ=θ1), and the molten target material TA in the holder 211 is moved into the second holder 214.

[0044] (6) Recovering the target material TA from the target vessel 20 (step S16, state M4 in FIG. 6) A dissolving liquid is injected from the supply port 222 to chemically dissolve the target material TA in the target container 20. As shown in Fig. 7, by applying compressed gas to the container CT1, the dissolving liquid in the container CT1 can be injected from the supply port 222. At this time, the dissolution of the target material TA is promoted by using both heating by the heater HT and rotation of the roller 23.

[0045] Thereafter, the angle of the target container 20 may be returned to the irradiation angle (θ=0), and the target material TA adhering to the roller 23 may be dissolved while being rotated. In this way, the angle of the target container 20 may be repeatedly changed to agitate the dissolving solution in the target container 20, thereby facilitating the dissolution of the target material TA.

[0046] Furthermore, the angle of the target vessel 20 is set to a recovery angle (θ=θ2), and the dissolved target material TA (target solution) is recovered from the recovery port 223. As shown in Fig. 7, compressed gas or negative pressure is applied to the buffer vessel CT2 to transport the target solution in the target vessel 20, for example, to a temporary recovery vessel (or directly into a vessel CT3 of the purification device). When the target solution has been recovered in the temporary recovery vessel, it is transferred from the temporary recovery vessel to the hot cell, and the recovery is completed.

[0047] In addition, the angle of the target container 20 may be returned to the irradiation angle (θ=0), a dissolving solution may be added, and the roller 23 may be rotated to clean the inside of the target container 20. At this time, the angle of the target container 20 may be changed repeatedly. The solution may be stirred to clean the entire inside of the target container 20, and the target material TA that has spread inside the target container 20 due to evaporation, scattering, etc. may be dissolved. Thereafter, the angle of the target container 20 is set to the recovery angle (θ=θ2), and the solution inside the target container 20 is allowed to flow into the recovery port 223.

[0048] A target container 20 according to one embodiment of the present invention is a target container 20 for producing a radioactive nuclide RN by irradiating a target material TA with a particle beam B, and comprises: a container body MB having a holding portion 211 for holding the target material TA; at least one roller 23 having an attachment surface 231 to which a portion of the target material TA held by the holding portion 211 is attached; and a moving mechanism that rotates the at least one roller 23 to move the target material TA attached to the attachment surface 231 within an irradiation range where the particle beam B is irradiated.

[0049] This reduces the need to encapsulate the target material TA in a capsule, etc. Also, by deflecting the target container 20 and transferring the solution, the target material TA in the target container 20 can be recovered, making it unnecessary to physically recover the solid target material TA using a robot, etc.

[0050] [Modification] Modifications of the present invention will be described below. For the sake of convenience, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0051] A. Roller 23 Various embodiments of rollers 23 will be described below. Figures 8 and 9 are perspective views showing various embodiments of rollers 23. Figure 8 shows rollers 23 and 23a to 23c, and Figure 9 shows rollers 23d to 23f.

[0052] Rollers 23 are cylindrical and have recesses 232 (grooves). Roller 23a is a smooth cylindrical shape and has no recesses. Roller 23b is cylindrical and has embossed recesses 232b. Roller 23c is spherical and has no recesses.

[0053] Roller 23d is frustoconical and has no grooves, roller 23e is a double frustoconical roller and has no grooves, and roller 23f is table-shaped and has no grooves.

[0054] Roller 23 may have at least one of a circumferential surface and an end surface. The circumferential surface or the end surface of roller 23 functions as an adhesion surface 231. Rollers 23, 23a to 23e have adhesion surfaces 231, 231a to 231d, 231e (231e1, 231e2) as their circumferential surfaces. Roller 23f has adhesion surface 231f as their end surface. Here, the circumferential surface of roller 23 is a surface that is disposed around rotation axis 241 of roller 23, and the end surface of roller 23 is a surface that intersects with rotation axis 241 of roller 23.

[0055] The peripheral surfaces may be spherical. Rollers 23, 23a, 23b, 23d, and 23e have curved peripheral surfaces 231, 231a, 231b, 231d, and 231e. Roller 23c has a spherical peripheral surface, which is an attachment surface 231c. Roller 23f has a flat end surface, which is an attachment surface 231f.

[0056] The peripheral surfaces may be tapered. The rollers 23d and 23e have adhesive surfaces 231d and 231e (231e1 and 231e2) as tapered peripheral surfaces.

[0057] The adhering surface 231 may have a plurality of recesses. The adhering surface 231 of the roller 23 has groove-shaped recesses 232, and the adhering surface 231b of the roller 23b has embossed recesses 232b.

[0058] Roller 23 may have a first roller having a first rotation axis and a second roller having a second rotation axis. Roller 23e has a first roller and a second roller. The first roller and the second roller have attachment surfaces 231e1 and 231e2, respectively. In this case, the axial directions of first rotation axis A1 and second rotation axis A2 may be different from each other.

[0059] B. Heating mechanism Various embodiments of the heating mechanism will be described below. Figure 10 is a cross-sectional view showing various embodiments of the heating mechanism. Figure 10 shows target vessels 20, 20a to 20c.

[0060] In the target container 20, the target material TA is heated by a heater HT installed in the container body MB. In the target container 20a, the target material TA is heated by a blower HTa that supplies heated gas. In the target container 20b, the target material TA is heated by an induction heater HTb. In the target container 20c, the target material TA is heated by a heater HTc that heats the roller 23 from the inside.

[0061] C. Arrangement of supply port 222 and recovery port 223 The following describes various aspects of the supply port 222 and the recovery port 223. Figure 11 is a cross-sectional view showing various aspects of the supply port 222 and the recovery port 223. Figure 11 shows target vessels 20, 20d, and 20e.

[0062] In the target vessel 20, the supply port 222 is arranged on the upper side of the target vessel 20, and the recovery port 223 is arranged on the side of the target vessel 20. In the target vessel 20d, the supply port 222d and the recovery port 223d are arranged on the upper side of the target vessel 20d. In the target vessel 20e, the supply port 224 and the recovery port 223 are arranged on the side of the target vessel 20e. Specifically, the supply port 224 is arranged on the rear side surface, and the recovery port 223e is arranged on the right side surface.

[0063] D. Thickness limiting member The container body MB may have a thickness limiting member 215 that limits the thickness of the target material TA attached to the attachment surface 231.

[0064] The thickness limiting member 215 will be described below. Figures 12 to 15 are diagrams showing examples of the state of adhesion of the target material TA to the roller 23. In the target container 20 of Figure 12, the surface 212 extending from the holder 211 to the irradiation area RA has a shape corresponding to the adhesion surface 231. On the other hand, the surfaces 212f to 212h of the target containers 20f to 20h of Figures 13 to 15 do not have a shape corresponding to the adhesion surface 231. States M01 to M03, M01f to M03f, ..., M01h to M03h represent the states of the roller 23 before, during, and at the end of rotation, respectively.

[0065] Because the distance between the roller 23 and the surface 212 of the target container 20 is relatively narrow and uniform, the thickness of the target material TA attached to the attachment surface 231 tends to be relatively uniform. In this case, it can be considered that the inner wall of the container body MB having the surface 212 functions as a thickness limiting member. By making the thickness of the target material TA attached to the attachment surface 231 uniform, it can be expected that the target material TA will spread over the entire irradiation surface of the roller 23. This makes the thermal load applied to the irradiation surface constant, suppressing damage, embrittlement, and unwanted reactions of the roller 23, and facilitating the stable production of radioactive nuclides RN.

[0066] However, the spread and thickness of the adhesion to the roller 23 depend on the temperature, the shape of the roller 23, the rotation speed, the properties of the target material TA, etc. The target material TA that peels off from the roller 23 during rotation accumulates in the space between the container foil F1 and the roller 23.

[0067] Because the surfaces 212f-212h of the target containers 20f-20h are spaced relatively far from the rollers 23, it is difficult to uniformize the thickness of the target material TA adhered to the adhesion surface 231. For this reason, thickness limiting members 215f-215g are used to uniformize the thickness of the target material TA on the rollers 23.

[0068] The thickness limiting member 215f is a plate-like member that protrudes toward the roller 23, and shapes the target material TA attached to the roller 23 to a uniform thickness and spreads it over the entire surface of the roller 23. The target material TA that cannot pass through the thickness limiting member 215f falls into the holder 211f, liquefies, and re-adheres to the roller 23. Note that the target material TA that peels off from the roller 23 during rotation accumulates in the space between the container foil F1 and the roller 23.

[0069] The thickness limiting member 215g is a rod-shaped member having an axis aligned with the axis of the roller 23, and shapes the target material TA adhered to the roller 23 to a uniform thickness and spreads it over the entire surface of the roller 23. The target material TA that cannot pass through the thickness limiting member 215g falls into the holder 211g, liquefies, and re-adheres to the roller 23. The target material TA that peels off from the roller 23 after passing through the thickness limiting member 215g falls into the holder 211g and re-adheres to the roller 23.

[0070] The thickness limiting member 215h is a brush-like member (plurality of fibrous members) that is arranged along the roller 23 and protrudes toward the roller 23, and spreads the target material TA that has adhered to the roller 23 over the entire surface of the roller 23. The target material TA that has not been able to pass through the thickness limiting member 215h and the target material TA that has peeled off from the roller 23 after passing through the thickness limiting member 215h drop into the holder 211h, liquefy, and adhere to the roller 23 again.

[0071] From the above, the following can be said. The thickness limiting member 215 has a portion that faces the attachment surface 231 with a predetermined gap therebetween. The inner wall of the container body MB having the surface 212 and the thickness limiting members 215f to 215h all have a portion that faces the attachment surface 231 with a predetermined gap therebetween. The thickness of the target material TA is limited within this predetermined gap. Note that, in this case, this portion extends along the rotation axis 241 of the roller 23.

[0072] The thickness limiting member 215 may be any one of the following (1) to (4). (1) The inner wall of the container body having a surface facing the attachment surface 231 (for example, the surface 212 of the target container 20) (2) A protruding member protruding toward the attachment surface 231 (for example, the thickness limiting member 215f of the target container 20f) (3) A rod-shaped member arranged along the attachment surface 231 (for example, the thickness limiting member 215g of the target container 20g) (4) A fibrous member arranged along the attachment surface 231 (for example, the thickness limiting member 215h of the target vessel 20h)

[0073] 〔summary〕 A target container according to a first aspect of the present invention is a target container for producing radioactive nuclides by irradiating a target material with a particle beam, and comprises: a container body having a holding portion for holding the target material; at least one roller having an attachment surface to which a portion of the target material held in the holding portion is attached; and a moving mechanism that rotates the at least one roller to move the target material attached to the attachment surface into an irradiation range where the particle beam is irradiated.

[0074] A target container according to a second aspect of the present invention is the same as that of the first aspect, and is provided with a heating mechanism that heats and liquefies the target material held in the holding portion, and the target material liquefied by heating by the heating mechanism adheres to the adhesion surface.

[0075] A target container according to a third aspect of the present invention is the target container of the second aspect, wherein the target material has a melting point of 330° C. or less.

[0076] A target container according to a fourth aspect of the present invention is the target container of the third aspect, wherein the target material is any one of Ga, Bi, Cd, and Tl.

[0077] A target container according to a fifth aspect of the present invention is the target container of any one of the first to fourth aspects, further comprising a cooling mechanism that cools and solidifies the liquefied target material adhered to the adhesion surface.

[0078] A target container according to a sixth aspect of the present invention is the target container of any of the first to fifth aspects, wherein a peripheral surface or an end surface of the roller functions as the attachment surface.

[0079] A target container according to a seventh aspect of the present invention is the sixth aspect, wherein the peripheral surface has a spherical shape.

[0080] A target container according to an eighth aspect of the present invention is the target container of the sixth aspect, wherein the peripheral surface has a taper.

[0081] A target container according to a ninth aspect of the present invention is the sixth aspect, wherein the attachment surface has a plurality of recesses.

[0082] A target container according to a 10th aspect of the present invention is any of the 6th to 9th aspects, wherein the at least one roller has a first roller having a first rotation axis and a second roller having a second rotation axis.

[0083] According to an eleventh aspect of the present invention, in the target container of the tenth aspect, the first rotation axis and the second rotation axis have axial directions different from each other.

[0084] A target container according to a twelfth aspect of the present invention is a target container according to claim 6, wherein in any of the sixth to eleventh aspects, the container body has a thickness limiting member that limits the thickness of the target material adhered to the adhesion surface.

[0085] A target container according to a thirteenth aspect of the present invention is the target container of the twelfth aspect, which has a portion facing the attachment surface with a predetermined gap therebetween.

[0086] A target container according to a 14th aspect of the present invention is a target container according to the 13th aspect, wherein the thickness limiting member is an inner wall of the container body having a surface facing the adhesion surface, a protruding member protruding toward the adhesion surface, a rod-shaped member arranged along the adhesion surface, or a fibrous member arranged along the adhesion surface.

[0087] A target container according to a 15th aspect of the present invention is any of the first to fourteenth aspects, wherein the container body has a second holding portion that holds the target material after particle beam irradiation when the container body is tilted, and a recovery port that recovers the target material in the second holding portion.

[0088] A target container according to a 16th aspect of the present invention is the 15th aspect, and is provided with a tilting mechanism that tilts the container body to switch whether the holding portion, the second holding portion, or the recovery port is facing downward.

[0089] A radionuclide manufacturing apparatus according to a seventeenth aspect of the present invention comprises the target vessel according to any one of the first to sixteenth aspects, and an accelerator that generates a particle beam.

[0090] A radionuclide production method according to an 18th aspect of the present invention is a radionuclide production method for irradiating a target material with a particle beam to produce a radionuclide, and includes the steps of bringing the target material held in a holder into contact with the surface of a roller to adhere it, rotating the roller to move the target material adhered to the surface into an irradiation range where the particle beam is irradiated, and irradiating the particle beam onto the target material moved into the irradiation range.

[0091] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0092] 1. Radionuclide production equipment 10 Accelerator 11 Beam Duct 111a Supply port 111b Outlet 20 target container MB container body 21 Lower part of the container 22 Top of the container 211 Holding part 214 Second holding part 215 Thickness limiting member 222 Supply port 223 Collection port 23 Roller 231 Adhesion Surface 24 Moving mechanism 241 Rotational Axis 242 Channel 243 Gears 244 Motor 30 Tilt mechanism 31 Actuator 32 Bearings 40 Pressing mechanism 41 cylinders ST deflection table (stage) R1, R2 rails

Claims

1. A target vessel for producing radionuclides by irradiating a target material with a particle beam, comprising: a container body having a holding portion for holding a target material; at least one roller having an attachment surface to which a portion of the target material held in the holder is attached; a moving mechanism that rotates the at least one roller to move the target material adhered to the adhesion surface into an irradiation range where the particle beam is irradiated; A target vessel comprising:

2. a heating mechanism for heating and liquefying the target material held by the holding unit; The target container according to claim 1 , wherein the target material liquefied by heating by the heating mechanism adheres to the attachment surface.

3. The target vessel of claim 2 , wherein the target material has a melting point of 330° C. or less.

4. 4. The target container according to claim 3, wherein the target material is any one of Ga, Bi, Cd, and Tl.

5. 5. The target container according to claim 2, further comprising a cooling mechanism that cools and solidifies the liquefied target material adhered to the adhesion surface.

6. The target container according to claim 1 , wherein a peripheral surface or an end surface of the roller functions as the attachment surface.

7. The target vessel of claim 6 , wherein the peripheral surface has a spherical shape.

8. The target vessel of claim 6 , wherein the peripheral surface is tapered.

9. The target container of claim 6 , wherein the attachment surface has a plurality of recesses.

10. The at least one roller a first roller having a first axis of rotation; a second roller having a second axis of rotation; The target container of claim 6 .

11. The first rotation shaft and the second rotation shaft have different axial directions. The target container of claim 10.

12. The target container according to claim 6 , wherein the container body has a thickness limiting member that limits a thickness of the target material adhered to the attachment surface.

13. The target container according to claim 12 , wherein the thickness limiting member has a portion facing the attachment surface with a predetermined gap therebetween.

14. The thickness limiting member is an inner wall of the container body having a surface facing the attachment surface; a protruding member protruding toward the attachment surface; a rod-shaped member disposed along the attachment surface; or The target vessel of claim 13 , wherein the target vessel is a fibrous member disposed along the attachment surface.

15. The container body is a second holder that holds the target material after particle beam irradiation when the container body is tilted; 5. The target container according to claim 1, further comprising: a recovery port for recovering the target material in the second holding portion.

16. The target container according to claim 15 , further comprising a tilting mechanism that tilts the container body to switch which of the holding portion, the second holding portion, and the recovery port faces downward.

17. A target container according to claim 1; an accelerator that generates a particle beam; A radionuclide manufacturing apparatus comprising:

18. A method for producing a radionuclide by irradiating a target material with a particle beam, comprising: a step of bringing the target material held by the holder into contact with a surface of a roller to adhere the target material; a step of rotating the roller to move the target material adhering to the surface into an irradiation range where the particle beam is irradiated; irradiating a particle beam onto a target material moved within the irradiation range; A method for producing a radionuclide, comprising:

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