Isotope production system, radioisotope target assembly, and methods of preparation and recovery

Abstract

The application discloses a nuclide production system, a radioactive target assembly and a preparation method and a recovery method. The radioactive target assembly comprises a base and a cover plate which are sealingly connected, and the base and the cover plate enclose an installation chamber and a buffer chamber. The sealing position of the base and the cover plate is located outside the installation chamber and the buffer chamber to cut off the contact between the installation chamber and the buffer chamber and the outside world. The installation chamber is used for accommodating a target body, the buffer chamber is communicated with the installation chamber, and the buffer chamber is used for accommodating the gas generated during the reaction of the target body. The application is used for providing a radioactive target assembly with good sealing effect and low leakage risk.

Description

Technical Field

[0001] This invention relates to the field of targeted therapy technology, and in particular to a radionuclide production system, a radioactive target assembly, and methods for its preparation and recovery. Background Technology

[0002] Targeted Alpha Therapy (TAT) is an emerging precision oncology treatment method that uses high-energy alpha particles generated from specific radionuclides to treat tumors. In some processes for preparing the radionuclides used in therapy, an accelerator is used to generate a high-energy electron beam that bombards a target within a target assembly. The target, after being bombarded by the high-energy electron beam, produces radionuclides, which can be further processed to obtain the radionuclides required for treatment.

[0003] The target in a target assembly used to prepare radionuclides is typically radioactive and needs to be sealed within a casing. However, after being bombarded by a high-energy electron beam, the target and its decay products continuously emit alpha particles, which capture electrons to form gas. The accumulation of this gas inside the target assembly leads to a gradual increase in internal pressure, potentially causing cracking and radioactive leakage. Summary of the Invention

[0004] The purpose of this invention is to provide a radionuclide production system, a radioactive target assembly, and a preparation and recovery method, for providing a radioactive target assembly with good sealing performance and low leakage risk.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A radiation target assembly includes a sealed base and a cover plate, the base and cover plate forming an installation chamber and a buffer chamber, the sealing position of the base and the cover plate being located outside the installation chamber and the buffer chamber to isolate the installation chamber and the buffer chamber from contact with the outside.

[0007] The mounting chamber is used to accommodate the target, the buffer chamber is connected to the mounting chamber, and the buffer chamber is used to accommodate the gas generated when the target reacts.

[0008] Preferably, the buffer chamber is disposed around the outer periphery of the mounting chamber;

[0009] The buffer chamber is a continuous annular chamber; or the buffer chamber includes multiple sub-chambers, which are arranged sequentially along the outer contour of the mounting chamber at intervals, and each sub-chamber is connected to the mounting chamber.

[0010] Preferably, the depth of the buffer chamber is less than the depth of the mounting chamber;

[0011] And / or, the buffer chamber and the mounting chamber are respectively recessed from the surface of the base facing the cover plate.

[0012] Preferably, the depth D3 of the buffer chamber is 0.2 to 0.5 times the depth D2 of the mounting chamber; and the width D4 of the buffer chamber is 0.1 to 0.25 times the width D5 of the mounting chamber.

[0013] Preferably, the base and the cover plate further form an auxiliary chamber, which is located inside the sealing position of the base and the cover plate, and outside the mounting chamber and the buffer chamber. The position of the radiation target assembly corresponding to the auxiliary chamber serves as the cutting position of the radiation target assembly.

[0014] Preferably, the base and the cover plate further form a connecting channel, one end of which communicates with the buffer chamber and the other end of which communicates with the auxiliary chamber.

[0015] Preferably, the auxiliary chamber is an annular chamber; the base and the cover plate are welded and fixed to the outside of the auxiliary chamber;

[0016] The target is a radium target.

[0017] Preferably, the distance H1 between the auxiliary chamber and the buffer chamber is 1.2 mm to 1.8 mm; the width D6 of the auxiliary chamber is 0.4 mm to 0.6 mm.

[0018] The method for preparing the radiation target assembly includes:

[0019] A base is provided, on which an installation chamber and a buffer chamber are formed, the installation chamber and the buffer chamber being in communication;

[0020] A target is provided, the target being mounted in the mounting chamber and the target being exposed in the buffer chamber;

[0021] A cover plate is provided, which is sealingly connected to the base to seal the target body inside the radiation target assembly.

[0022] Preferably, the target being installed in the mounting chamber specifically includes:

[0023] A stop ring is provided, which is embedded in the buffer chamber and is hollow inside and communicates with the mounting chamber to form a receiving groove;

[0024] The target is placed in the receiving groove and compressed so that it is housed in the mounting cavity;

[0025] Remove the stop ring.

[0026] Methods for recovering radiation target components include:

[0027] A radiation target assembly is provided, wherein the radiation target assembly has an installation chamber, a buffer chamber and an auxiliary chamber formed therein;

[0028] A cutting fixture is provided, wherein the cutting portion of the cutting fixture corresponds to the auxiliary chamber, and the cutting portion cuts the radiation target assembly at the position corresponding to the auxiliary chamber;

[0029] Separate the base and cover plate, and process the target.

[0030] A nuclide production system includes an electron accelerator, a conversion target, and a radiation target assembly of any one of the above; the electron accelerator is used to generate an electron beam that irradiates the conversion target, the radiation target assembly is located on the side of the conversion target away from the electron accelerator, and the radiation target assembly is used to react with photons generated by the electron beam bombardment of the conversion target.

[0031] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0032] By setting up a buffer chamber that communicates with the installation chamber, the buffer chamber can be used to contain the gas generated by the target. The gas diffuses in the buffer chamber and causes a low increase in pressure. Therefore, the space where the target is located will not generate high local pressure due to gas generation, which can effectively reduce the risk of cracking and radioactive leakage of the target assembly and ensure the sealing effect of the radiation target assembly.

[0033] By setting up a buffer chamber connected to the installation chamber and an auxiliary chamber connected to the buffer chamber via a connecting channel, the buffer chamber serves as a primary buffer for the gas, and the auxiliary chamber serves as a secondary buffer for the gas. Through the buffer chamber and the auxiliary chamber, a multi-level gas buffer chamber is formed. Even if the target generates a large amount of gas under long-term irradiation, the gas can be evenly diffused into the two chambers, avoiding excessive local pressure within the radiation target assembly.

[0034] Since both the buffer chamber and the auxiliary chamber are fixed-volume chambers enclosed by rigid bases and cover plates, the shape and volume of the buffer chamber and the auxiliary chamber do not change with the internal pressure, ensuring that the target can always maintain accurate contact with the cover plate or base, and ensuring the cooling system's heat dissipation effect on the target.

[0035] The auxiliary chamber serves not only as a secondary gas buffer space but also as a positioning reference and separation aid for subsequent cutting operations. During recovery, the cutting fixture precisely aligns with the auxiliary chamber for cutting. Because the auxiliary chamber is located outside the installation and buffer chambers, the cutting fixture does not touch the target, avoiding the risk of cross-contamination. Furthermore, the gas pressure accumulated in the auxiliary chamber after irradiation is higher than the external pressure. When cutting into the auxiliary chamber, the gas escapes instantaneously, which helps to push the cover plate and base apart, reducing the difficulty of opening the cover and the risk of mechanical damage to the target. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the radiation target assembly according to an embodiment of the present invention;

[0037] Figure 2 This is an exploded view of the radiation target assembly according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the base structure according to an embodiment of the present invention;

[0039] Figure 4 This is a cross-sectional view of the radiation target assembly according to an embodiment of the present invention;

[0040] Figure 5 This is a cross-sectional view of the radiation target assembly from another perspective of an embodiment of the present invention;

[0041] Figure 6 This is a cross-sectional view of the base according to an embodiment of the present invention;

[0042] Figure 7 This is a structural schematic diagram of the base from another perspective in an embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the structure of the radiation target assembly and the stop ring when the target body is not compressed, according to an embodiment of the present invention;

[0044] Figure 9 This is a schematic diagram of the structure of the radiation target assembly and the stop ring after target compression according to an embodiment of the present invention.

[0045] In the diagram: 100, Radiation target assembly; 1, Base; 2, Cover plate; 11, Installation chamber; 111, First part; 112, Second part; 12, Buffer chamber; 13, Target body; 14, Auxiliary chamber; 15, Connecting channel; 200, Stop ring. Detailed Implementation

[0046] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0047] The terms used to express position and direction in this invention are illustrated with reference to the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this invention.

[0048] like Figures 1 to 7 As shown, the present invention provides a radiation target assembly 100, including a base 1, a cover plate 2, and a target body 13.

[0049] Reference Figures 1 to 4 The base 1 and cover 2 are sealed together to form a sealed whole. When the base 1 and cover 2 are sealed together, they enclose an installation chamber 11 and a buffer chamber 12, which are located within this sealed whole. The base 1 and cover 2 can be made of a shielding material to prevent leakage of radioactive materials from the installation chamber 11 and buffer chamber 12. Furthermore, since the target assembly may be heated by a high-energy electron beam during use, the base 1 and cover 2 are preferably made of a metal material with high thermal conductivity and a high melting point. High thermal conductivity facilitates heat dissipation, and a high melting point ensures effective sealing of the target 13 under high-temperature conditions. Specifically, the base 1 and cover 2 can be made of metal materials such as niobium, stainless steel, or aluminum.

[0050] The mounting chamber 11 can be used to mount the target 13, and the buffer chamber 12 is located outside the mounting chamber 11 and communicates with it. The sealing positions of the base 1 and the cover plate 2 can be located outside the mounting chamber 11 and the buffer chamber 12. For example, the outer edges of the base 1 and the cover plate 2 are sealed by welding, and the mounting chamber 11 and the buffer chamber 12 are located inside the welded positions of the base 1 and the cover plate 2, so that the mounting chamber 11 and the buffer chamber 12 can form a sealed chamber. In some specific embodiments, when the base 1 and the cover plate 2 are made of aluminum, they can be fixed by cold pressure welding; when the base 1 and the cover plate 2 are made of niobium or stainless steel, they can be fixed by electron beam welding or laser welding.

[0051] After the target 13 is installed in the mounting chamber 11, the base 1 and the cover plate 2 are sealed together. The seal between the base 1 and the cover plate 2 then blocks the connection between the mounting chamber 11 and the buffer chamber 12 and the outside world, thus forming a sealed chamber. With the target 13 located within the sealed mounting chamber 11, radiation generated by the target 13 can be effectively prevented from leaking to the outside and causing contamination. Furthermore, the buffer chamber 12 is also sealed inside the radiation target assembly 100 and communicates with the mounting chamber 11, allowing the target 13 installed in the mounting chamber 11 to be exposed to the buffer chamber 12. When gas is generated at the target 13, the gas can diffuse into the buffer chamber 12, creating a gas buffer space.

[0052] When the installation chamber 11 is an independent chamber, that is, the installation chamber 11 is not connected to other chambers such as the buffer chamber 12, the target 13 will occupy all or almost all of the space of the installation chamber 11 after it is installed. At this time, there is basically no space around the target 13 that can contain gas. Therefore, even if the target 13 produces a small amount of gas, the small amount of gas will cause the pressure around the target 13 to increase significantly due to the small space that can contain the gas. This may lead to the risk of cracking and radioactive leakage of the target assembly.

[0053] In this application, by providing a buffer chamber 12 connected to the mounting chamber 11, after the target 13 is installed in the mounting chamber 11, an empty buffer chamber 12 can exist around the target 13. At this time, if the target 13 generates gas, the gas can diffuse into the buffer chamber 12. Since the buffer chamber 12 has a large space and the target 13 generates relatively little gas, the generation of gas will not cause a significant increase in the gas pressure inside the buffer chamber 12, thereby effectively reducing the risk of cracking and radioactive leakage of the target assembly.

[0054] The gas produced by target 13 can be helium. Specifically, target 13 can be a radium target, radium, and its decay products (such as...). 225 Ac、 224 Ra continuously emits alpha particles, which capture electrons to form helium atoms and further form helium gas. The radium target can be any of the following: electroplated deposited metallic radium, radium salt powder, or a mixture thereof.

[0055] When the laser target is electroplated metallic radium, multiple high-purity thin aluminum sheets can be electroplated on both sides to form radium layers. Specifically, the aluminum sheets can be 10 micrometers thick. Furthermore, to facilitate subsequent processing and prevent contamination during the stamping and compression of the target 13, non-reflective shielding discs can be installed on the top and bottom sides of the stack of multiple thin aluminum sheets. When the laser target is radium salt powder, the radium salt powder can be radium carbonate or similar powders. When the laser target is a mixture, it can be formed by mixing radium salt powder and metal powder with good thermal conductivity in a desired proportion.

[0056] Reference Figure 3 In some specific embodiments, the buffer chamber 12 and the mounting chamber 11 can be recessed from the surface of the base 1 facing the cover plate 2, that is, the buffer chamber 12 and the mounting chamber 11 can form openings on the surface of the base 1 facing the cover plate 2. When the cover plate 2 is placed on the base 1 and sealed to the base 1, the cover plate 2 can cover the openings of the buffer chamber 12 and the mounting chamber 11 so that the buffer chamber 12 and the mounting chamber 11 form a sealed chamber.

[0057] The buffer chamber 12 may be disposed around the outer periphery of the mounting chamber 11. For example, the buffer chamber 12 may be a continuous, integral annular chamber, fitted around the outer periphery of the mounting chamber 11 and communicating with the mounting chamber 11. Alternatively, the buffer chamber 12 may include multiple sub-chambers, which are separated by partition walls; the multiple sub-chambers are arranged sequentially along the outer contour of the mounting chamber 11, so that the overall structure formed by the multiple sub-chambers is approximately an annular structure fitted around the outer periphery of the mounting chamber 11; and each sub-chamber may be communicated with the mounting chamber 11, so that each sub-chamber can be a gas buffer chamber for containing the gas generated by the target 13. When multiple sub-chambers are separated by partition walls, the inner wall of the partition wall facing the mounting chamber 11 can be adapted to the outer contour of the mounting chamber 11, for example, the inner wall of the partition wall facing the mounting chamber 11 coincides with the outer contour of the mounting chamber 11. When the target 13 is installed in the mounting chamber 11, the inner wall of the partition wall can abut against the target 13 or have only a small gap. At this time, the partition wall can limit the target 13 to ensure that the target 13 is accurately located in the mounting chamber 11. The cooperation of multiple partition walls achieves effective positioning of the target 13, fixing the target 13 in the center position of the mounting chamber 11 and preventing the target 13 from translating or rotating in the mounting chamber 11. After the position of the target 13 is fixed, the target 13 can always be aligned with the beam center, improving the isotope yield consistency, while avoiding the target 13 from colliding with the inner edge of the buffer chamber 12 to generate debris and contaminate the target 13.

[0058] By using multiple sub-chambers to form the buffer chamber 12, which are formed by removing material from corresponding positions of the base 1, a solid partition wall is formed between adjacent sub-chambers. This partition wall can strengthen the base 1 and effectively resist radial and circumferential stresses, thereby improving the overall rigidity and compressive strength of the base 1. When the air pressure inside the buffer chamber 12 increases, the strengthening effect of the partition wall makes the base 1 stable and less prone to deformation, thus preventing excessive bulging or breakage in the area of ​​the base 1 that forms the buffer chamber 12, improving the sealing reliability of the radiation target assembly and reducing the risk of leakage.

[0059] Furthermore, multiple sub-chambers are arranged in parallel, each connected to the mounting chamber 11 via a corresponding connecting port. When the target 13 in the mounting chamber 11 generates gas, the gas first fills the corresponding sub-chamber through the connecting port. After the sub-chamber is filled with gas, the gas pressure increases, allowing the gas to pass between the mounting chamber 11 and the partition to fill other sub-chambers. The multiple sub-chambers form a multi-stage buffer, slowing down the rate of peak pressure rise in the buffer chamber 12. When one of the multiple sub-chambers leaks, the connection between the target 13 and the partition wall separates the multiple sub-chambers. This allows the other sub-chambers to remain independent and largely unaffected by the leaking sub-chamber, thus keeping the other sub-chambers essentially sealed and reducing the overall radioactive intensity generated when there is a local leak in the radiation target assembly.

[0060] The shape of the buffer chamber 12 can be adapted to the shape of the mounting chamber 11, and the shape of the mounting chamber 11 can be adapted to the shape of the target 13. Specifically, when the target 13 is a cylindrical structure, the mounting chamber 11 can be a cylindrical chamber, and the buffer chamber 12 can be an annular chamber surrounding the mounting chamber 11; when the target 13 is a square structure, the mounting chamber 11 is a square cylindrical chamber, and the buffer chamber 12 can be a square annular chamber surrounding the mounting chamber 11.

[0061] In some specific embodiments, the depth D3 of the buffer chamber 12 can be less than the depth D2 of the mounting chamber 11, that is, the recess depth of the surface of the buffer chamber 12 from the base 1 to the cover plate 2 is less than the recess depth of the surface of the mounting chamber 11 from the base 1 to the cover plate 2; in this case, the buffer chamber 12 and the mounting chamber 11 will form a stepped cavity. The first part 111 of the mounting chamber 11 communicates with the buffer chamber 12 to form a region with a larger diameter in the stepped cavity, and the second part 112 of the mounting chamber 11 is offset from the buffer chamber 12 in the height direction, and the second part 112 of the mounting chamber 11 forms a region with a smaller diameter in the stepped cavity. At this time, the wall surrounding the second part 112 of the mounting chamber 11 can abut against the target 13 or have only a small gap, thereby limiting the target 13 to ensure that the target 13 is accurately located in the mounting chamber 11.

[0062] Reference Figure 6 The thickness D1 of the base 1 can be 1mm to 2.5mm. The depth D2 and width D5 of the mounting chamber 11 are adapted to the volume of the target 13 so that the volume of the mounting chamber 11 is the same as or approximately the same as the volume of the target 13. The volume of the target 13 is the volume of the target 13 when it is encapsulated within the radiation target assembly. Specifically, the depth D2 of the mounting chamber 11 is the same as or approximately the same as the height of the target 13, and the width D5 of the mounting chamber 11 is the same as or approximately the same as the diameter of the target 13. The diameter of the target 13 needs to be less than twice the half-width at half-maximum (WHM) of the beam spot intensity, meaning the width D5 of the mounting chamber 11 is less than twice the WHM of the beam spot intensity. When the width D5 of the mounting chamber 11 decreases, the depth D2 of the mounting chamber 11 needs to be increased to maintain the same volume. However, a larger depth D2 will reduce the strength of the base 1 at the bottom of the mounting chamber 11. To balance the volume of the mounting chamber 11 and the structural strength of the base 1, the depth D2 of the mounting chamber 11 can be 0.3 to 0.85 times the thickness D1 of the base 1, specifically 0.3 mm to 2.1 mm. Preferably, the depth D2 of the mounting chamber 11 is 0.7 mm to 1.6 mm. The width D5 of the mounting chamber 11 can be 7 mm to 12 mm.

[0063] The depth of the buffer chamber 12 needs to be set to ensure that it has sufficient volume to buffer the gas generated by the target 13. However, as the thickness of the buffer chamber 12 increases, the depth of the second part 112 of the mounting chamber 11 decreases, thereby reducing the limiting effect of the second part 112 surrounding the mounting chamber 11 on the target 13. Furthermore, increasing the depth of the buffer chamber 12 also reduces the structural strength of the base 1 and increases processing time. To ensure that the buffer chamber 12 has sufficient space to buffer the gas generated by the target 13, while ensuring the limiting effect of the second part 112 surrounding the mounting chamber 11 on the target 13, maintaining the structural strength of the base 1, and reducing the processing time of the base 1, the depth D3 of the buffer chamber 12 can be 0.2 to 0.5 times the depth D2 of the mounting chamber 11. Specifically, the depth D3 of the buffer chamber 12 can be 0.3 mm to 0.8 mm.

[0064] In addition, refer to Figure 7The width of the buffer chamber 12 also affects its volume. The width D4 of the buffer chamber 12 can be 0.1 to 0.25 times the width D5 of the mounting chamber 11. Preferably, the width D4 of the buffer chamber 12 can be 1 mm to 1.6 mm. The outline of the mounting chamber 11 matches the outline of the target 13. When the target 13 is cylindrical or cubic, the width D5 of the mounting chamber 11 remains consistent throughout, and the width D4 of the buffer chamber 12 remains consistent throughout. When the target 13 is elliptical, rhomboid, or has a varying width, the width of the mounting chamber 11 will also change, and the width of the buffer chamber 12 can also change accordingly. Specifically, corresponding to the width of a certain position in the mounting chamber 11, the buffer chamber 12 expands outward from the edge of that position, and the expansion distance of the buffer chamber 12 is 0.1 to 0.25 times the width of that position in the mounting chamber 11.

[0065] As a specific example, the target 13 and the mounting chamber 11 can both be cylindrical structures, and the buffer chamber 12 can be an annular structure. The thickness of the base 1 is 1.8 mm, the depth of the mounting chamber 11 is 1.3 mm, the width of the mounting chamber 11 (i.e., the diameter of the mounting chamber 11) is 9 mm, the diameter of the target 13 is 9 mm, the depth of the buffer chamber 12 is 0.5 mm, and the width of the buffer chamber 12 is 1.3 mm. In this case, the inner diameter of the buffer chamber 12 can be 9 mm, and the outer diameter of the buffer chamber 12 can be 11.6 mm.

[0066] The width D4 and depth D3 of the buffer chamber 12 can be adjusted according to the required volume of the buffer chamber 12. The minimum volume of the buffer chamber 12 is determined based on the target 13. Specifically, the volume and material of the target 13 are adjusted as needed. The target 13 has a volume V1 and a density ρ, and the mass m of the target 13 is m = V1 × ρ. Based on the beam's radiation power and the radiation time, the gas atoms produced by a fixed-mass target 13 are basically rated. For example, when the target 13 is a radium target, the beam's radiation power is 20 kW, and the radiation time is 10 days, 1 g of radium-22 will produce approximately 1 e 18 One helium atom, 1 mm under standard atmospheric pressure 3 Helium gas has approximately 2.7 electrons. 16 Therefore, the amount of gas produced by target 13 during radiation is V2 = 1e 18 ×m / 2.7e 16 .

[0067] After radiation, it is necessary to ensure that the gas pressure inside the buffer chamber 12 is below a certain pressure value. For example, after the metal base 1 and cover plate 2 form the buffer chamber 12, the base 1 and cover plate 2 can withstand a pressure of 10 atmospheres. To ensure the stability of the base 1 and cover plate 2, the pressure of the buffer chamber 12 can be set to be below 5 atmospheres. Before the target 13 generates gas, the initial pressure of the buffer chamber 12 is one atmosphere. At this time, the maximum change in gas pressure P of the buffer chamber 12 is 4 atmospheres. The volume of the buffer chamber 12, V3 > V2 × a / P, is a redundancy coefficient. That is, to ensure the buffering effect of the buffer chamber 12, the volume of the buffer chamber 12 needs to have a certain redundancy. The design volume of the buffer chamber 12 needs to be a times the limit volume, where a is greater than 1. Preferably, the volume of the buffer chamber 12 has a 30% redundancy, i.e., a is 1.3.

[0068] As a specific example, target 13 is a radium target with a mass of 0.25 g and a density of 5.5 g / cm³. 3 The target 13 has a diameter of 9 mm, and its thickness is 0.7 mm. This means the width D5 of the mounting chamber 11 is 9 mm, and the depth D2 is 0.7 mm. With a beam radiation power of 20 kW and a radiation time of 10 days, the gas volume produced by the target 13 is approximately 9.3 mm³. 3 The volume of buffer chamber 12, V3, is greater than V2 × 1.3 / P, meaning V3 is greater than 3 mm. 3 Adjust the width D4 and depth D3 of the buffer chamber 12 so that the volume of the buffer chamber 12 is greater than 3 mm. 3 This ensures that the buffer chamber 12 can effectively contain the gas generated by the target 13.

[0069] Reference Figure 3 and Figure 4 In some specific embodiments, the base 1 and the cover plate 2 may also form an auxiliary chamber 14. For example, the auxiliary chamber 14 is recessed from the surface of the base 1 facing the cover plate 2, that is, the auxiliary chamber 14 can form an opening on the surface of the base 1 facing the cover plate 2. When the cover plate 2 is placed on the base 1 and sealed to the base 1, the cover plate 2 can cover the opening of the auxiliary chamber 14 so that the auxiliary chamber 14 forms a sealed chamber.

[0070] The auxiliary chamber 14 can be located inside the sealed position of the base 1 and the cover plate 2, that is, the welding position of the base 1 and the cover plate 2 can be located outside the auxiliary chamber 14; and the auxiliary chamber 14 is located outside the mounting chamber 11 and the buffer chamber 12, and the auxiliary chamber 14 is arranged around the outer periphery of the buffer chamber 12. The position of the radiation target assembly 100 corresponding to the auxiliary chamber 14 can be used as the cutting position of the radiation target assembly 100. Specifically, after the radiation target assembly 100 is used, the target body 13 needs to be dissolved, so the target body 13 needs to be removed from the sealed mounting chamber 11; at this time, a cutting jig can be used to cut the radiation target assembly 100 to facilitate the separation of the base 1 and the cover plate 2. After the base 1 and the cover plate 2 are separated, the mounting chamber 11 can be exposed to the outside, and then the target body 13 can be taken out for the dissolution operation.

[0071] To facilitate the cutting of the radiation target assembly 100 and the separation of the base 1 and the cover plate 2, the cutting position of the radiation target assembly 100 needs to correspond to the hollow cavity. When the auxiliary cavity 14 is not provided, the hollow cavity inside the radiation target assembly 100 is the buffer cavity 12. When cutting the radiation target assembly 100 at the position corresponding to the buffer cavity 12, that is, the cutting fixture is located directly above or below the buffer cavity 12 and cutting the radiation target assembly 100 in the vertical direction; at this time, since the buffer cavity 12 is adjacent to the mounting cavity 11, the cutting fixture may come into contact with the target 13 located in the mounting cavity 11 when cutting the buffer cavity 12. If the cutting fixture comes into contact with the target 13, it may damage the target 13 and may cause cross-contamination.

[0072] By providing an auxiliary chamber 14, the cutting position of the cutting fixture on the radiation target assembly 100 can correspond to the auxiliary chamber 14, that is, the cutting fixture is located directly above or below the auxiliary chamber 14 and cuts the radiation target assembly 100 vertically. The auxiliary chamber 14 is located outside the buffer chamber 12 and can be spaced apart from the buffer chamber 12. Therefore, the auxiliary chamber 14 can be far away from the mounting chamber 11. In this case, when the cutting fixture cuts the radiation target assembly, it will not affect the target 13 located in the mounting chamber 11, thereby preventing the risk of cross-contamination and damage to the target 13.

[0073] Reference Figure 7 In some specific embodiments, the distance H1 between the auxiliary chamber 14 and the buffer chamber 12 can be 1.2 mm to 1.8 mm. Specifically, the distance H1 between the auxiliary chamber 14 and the buffer chamber 12 is the distance between the inner edge of the auxiliary chamber 14 and the outer edge of the buffer chamber 12.

[0074] The width D6 of the auxiliary chamber 14 can be 0.4 mm to 0.6 mm. Specifically, the distance H1 between the auxiliary chamber 14 and the buffer chamber 12 is 1.5 mm, and the width D6 of the auxiliary chamber 14 is 0.5 mm.

[0075] By adjusting the distance H1 between the auxiliary chamber 14 and the buffer chamber 12, it is possible to prevent the auxiliary chamber 14 from being too close to the buffer chamber 12, which would reduce the strength of the base 1. It is also possible to prevent the auxiliary chamber 14 from being too close to the edge of the base 1, which would affect the sealing connection between the base 1 and the cover plate 2. By adjusting the width D6 of the auxiliary chamber 14, it is possible to prevent the width D6 from being too small, which would increase the difficulty of aligning the cutting fixture with the auxiliary chamber 14. Furthermore, it is possible to prevent the width D6 of the auxiliary chamber 14 from being too large, which would affect the strength of the base 1.

[0076] The auxiliary chamber 14 can be a closed, complete annular chamber, and the shape of the auxiliary chamber 14 corresponds to the cutting path of the cutting fixture. Specifically, when the cutting fixture needs to cut the radiation target assembly 100 along a circular path, the auxiliary chamber 14 can be an annular chamber; when the cutting fixture needs to cut the radiation target assembly 100 along a square annular path, the auxiliary chamber 14 can be a square annular chamber.

[0077] Reference Figures 5 to 7 In some specific embodiments, the base 1 and the cover plate 2 can also form a connecting channel 15. The connecting channel 15 is located between the buffer chamber 12 and the auxiliary chamber 14, and one end of the connecting channel 15 can communicate with the buffer chamber 12, while the other end of the connecting channel 15 can communicate with the auxiliary chamber 14. The connecting channel 15 can be formed by a recess in the surface of the base 1 facing the cover plate 2. When the cover plate 2 is placed on the base 1 and sealed to it, the cover plate 2 can cover the connecting channel 15, so that the connecting channel 15 has horizontal openings at both ends. These horizontal openings are used to connect the buffer chamber 12 and the auxiliary chamber 14 respectively.

[0078] One or more connecting channels 15 can be provided. When multiple connecting channels 15 are provided, the multiple connecting channels 15 can be evenly distributed around the outer periphery of the buffer chamber 12 so that the gas in the buffer chamber 12 can diffuse evenly toward the auxiliary chamber 14 through the multiple connecting channels 15.

[0079] By connecting the auxiliary chamber 14 and the buffer chamber 12 through the connecting channel 15, the gas in the buffer chamber 12 can flow into the auxiliary chamber 14 through the connecting channel 15. At this time, the buffer chamber 12, the connecting channel 15, and the auxiliary chamber 14 can be connected and form a gas chamber with basically the same gas pressure. Therefore, when the target 13 generates gas, the gas can diffuse towards the gas chamber of the buffer chamber 12, the connecting channel 15, and the auxiliary chamber 14. By using the connecting channel 15 and the auxiliary chamber 14 as the gas buffer chamber 12, the buffer chamber 12 can serve as a primary buffer chamber, and the auxiliary chamber 14 can serve as a secondary buffer chamber. The buffer chamber 12 and the auxiliary chamber 14 form a multi-level gas buffer chamber. Even when the target 13 generates a large amount of gas during long-term radiation, the multi-level gas buffer chamber formed by the buffer chamber 12 and the auxiliary chamber 14 is used to ensure uniform and sufficient diffusion of the gas, avoiding areas with excessively high pressure within the radiation target assembly, and further reducing the pressure impact on the radiation target assembly 100 when the gas is generated.

[0080] Furthermore, by using the auxiliary chamber 14 as a gas buffer chamber, the gas pressure inside the auxiliary chamber 14 will increase as the amount of gas generated by the target 13 increases. When the radiation target assembly 100 is cut using a cutting fixture, the gas inside the auxiliary chamber 14 will escape rapidly due to the internal pressure when the cutting fixture cuts into the auxiliary chamber 14, thereby causing the cover to separate from the base 1, reducing the difficulty of opening the cover and the risk of mechanical damage to the target 13.

[0081] In some specific embodiments, both the base 1 and the cover plate 2 are made of rigid materials. The rigid base 1 and cover plate 2 enclose a buffer chamber 12, an auxiliary chamber 14, and a connecting channel 15. The chambers or channels enclosed by rigid materials can form a fixed volume structure, meaning that the buffer chamber 12, the auxiliary chamber 14, and the connecting channel 15 will not undergo changes in volume or shape due to pressure variations. Since the gas generated by the target 13 during radiation is limited, it will not cause the pressure of the radiation target assembly to reach an ultra-high pressure state. The base 1 and cover plate 2 will not deform due to internal ultra-high pressure, thus fixing the volume and shape of the buffer chamber 12, the auxiliary chamber 14, and the connecting channel 15.

[0082] When the radiation target assembly 100 is irradiated, the target body 13 generates heat. If this heat accumulates, it can cause the target body 13 to overheat and melt. Therefore, the radiation target assembly 100 is equipped with a cooling system to dissipate heat. Existing cooling systems typically place the radiation target assembly 100 in a flowing coolant, which carries away the heat from the radiation target assembly 100. Within the radiation target assembly 100, the heat from the target body 13 needs to be transferred to the external coolant through the base 1 and the cover plate 2, so that the coolant can dissipate heat from the target body 13.

[0083] Therefore, when the base 1 and cover plate 2 deform due to changes in the volume of the chamber or channel, the base 1 and cover plate 2 may not be able to fit accurately against the target 13, which will reduce the contact area between the target 13 and the base 1 or cover plate 2, thereby reducing the heat transfer efficiency between the target 13 and the base 1 or cover plate 2 and affecting the heat dissipation effect of the target 13.

[0084] In this application, by using a cavity or channel surrounded by rigid materials, the volume and shape of the buffer chamber 12, the auxiliary chamber 14 and the connecting channel 15 are fixed, and the base 1 and the cover plate 2 will not be deformed. This allows the target 13 to always remain accurately attached to the base 1 and the cover plate 2, ensuring the cooling effect of the cooling system on the target 13.

[0085] Before sealing the base 1 and cover 2, the auxiliary chamber 14, buffer chamber 12, and connecting channel 15 can all be under normal pressure. After the base 1 and cover 2 are sealed, the auxiliary chamber 14, buffer chamber 12, and connecting channel 15 can maintain a normal pressure. When the target 13 generates gas, the auxiliary chamber 14, buffer chamber 12, and connecting channel 15 can be under high pressure (internal pressure higher than external atmospheric pressure). Alternatively, before sealing the base 1 and cover 2, the auxiliary chamber 14, buffer chamber 12, and connecting channel 15 can each be under negative pressure. After the base 1 and cover 2 are sealed, the auxiliary chamber 14, buffer chamber 12, and connecting channel 15 can maintain a negative pressure. When the target 13 generates gas, the pressure in the auxiliary chamber 14, buffer chamber 12, and connecting channel 15 increases and can reach a normal pressure or a high pressure.

[0086] The present invention also provides a method for preparing a radiation target assembly 100, which is used to prepare the radiation target assembly 100 described above. The preparation method may include steps S01 to S03.

[0087] Step S01: Provide a base 1, and form an installation chamber 11 and a buffer chamber 12 on the base 1. The installation chamber 11 and the buffer chamber 12 are connected to form a stepped cavity.

[0088] Step S02: Provide a target 13, which is installed in the mounting chamber 11 and exposed to the buffer chamber 12.

[0089] Step S03: Provide a cover plate 2, which is sealed to the base 1 to seal the target 13 inside the radiation target assembly 100.

[0090] In step S01, a connecting channel 15 and an auxiliary chamber 14 may also be formed on the base 1. In the base 1, the mounting chamber 11, the buffer chamber 12, the connecting channel 15, and the auxiliary chamber 14 are arranged sequentially from the inside to the outside. The center of the mounting chamber 11 may correspond to the center of the base 1.

[0091] Step S02 may specifically include steps S21 to S23.

[0092] Step S21: Refer to Figure 8 A stop ring 200 is provided, which can be embedded in the buffer chamber 12, the auxiliary chamber 14, and the connecting channel 15 to ensure that the stop ring 200 can be fixed relative to the position of the base 1. The interior of the stop ring 200 is hollow, and the internal space of the stop ring 200 is adapted to the contour of the target 13. After the stop ring 200 is fixed to the base 1, the internal space of the stop ring 200 can communicate with the mounting chamber 11 to form a receiving groove for accommodating the target 13.

[0093] Step S22: Place the target 13 into the receiving slot. At this time, refer to... Figure 8 The target 13 is not compressed using a jig. The target 13 is relatively thick, with a portion of it located inside the mounting chamber 11 and the other portion located inside the stop ring 200. The stop ring 200 is used to limit the portion of the target 13 that protrudes from the mounting chamber 11, thereby ensuring the accurate positioning of the target 13 and facilitating subsequent compression of the target 13.

[0094] After placing the target 13 into the receiving slot, refer to Figure 9 The target 13 can be compressed using a compression jig. After compression, the thickness of the target 13 is reduced, and the thickness of the target 13 after compression can be the same as or approximately the same as the depth of the mounting chamber 11. At this time, the target 13 can be located inside the mounting chamber 11, and the compressed target 13 can not protrude from the mounting chamber 11.

[0095] Step S23: Remove the stop ring 200. At this time, the target 13 is located in the mounting chamber 11, and the outer periphery of the target 13 is exposed to the buffer chamber 12.

[0096] In step S03, the cover plate 2 is welded to the edge of the base 1 so that the mounting chamber 11, the buffer chamber 12, the connecting channel 15 and the auxiliary chamber 14 respectively form sealed chambers that are separated from the outside.

[0097] The present invention also provides a method for recovering a radiation target assembly. After the radiation target assembly 100 has been used for a period of time, this recovery method can be used to process the radiation target assembly 100 to dissolve the target body 13. The recovery method includes steps S11 to S13.

[0098] Step S11: Provide the above-mentioned radiation target assembly 100. The radiation target assembly 100 may be a radiation target assembly 100 that requires dissolution of the target 13 after a period of operation.

[0099] Step S12: Provide a cutting fixture, the cutting part of which corresponds to the auxiliary chamber 14, and the cutting part cuts the radiation target assembly 100 at the position corresponding to the auxiliary chamber 14.

[0100] Step S13: Separate the base 1 and the cover plate 2, and process the target 13.

[0101] In step S11, the radiation target assembly 100 can be fixedly mounted on a dedicated precision bracket. Existing brackets can be used for mounting the radiation target assembly 100.

[0102] In step S12, the cutting part of the cutting fixture is adjusted according to the position of the auxiliary chamber 14 in the radiation target assembly 100 so that the cutting part can be moved directly above or directly below the auxiliary chamber 14. Then the cutting part moves vertically toward the radiation target assembly 100 and cuts the radiation target assembly 100.

[0103] The cutting fixture can be a shearing machine, and the cutting part can be the cutting blade of the shearing machine. After the position of the radiation target assembly 100 is fixed, the cutting blade is adjusted to correspond to the auxiliary chamber 14 by the setting position of the auxiliary chamber 14 within the radiation target assembly 100, and then the cutting blade cuts along the annular contour of the auxiliary chamber 14.

[0104] In step S13, the auxiliary chamber 14 stores some of the gas generated by the target 13, thus the pressure inside the auxiliary chamber 14 is higher than the external pressure. Therefore, after the radiation target assembly 100 is cut by the cutting fixture, the gas in the auxiliary chamber 14 can push open the cover due to the pressure difference, thereby facilitating the separation of the base 1 and the cover plate 2. After the base 1 and the cover plate 2 are separated, the target 13 can be removed and dissolved.

[0105] This invention also provides a nuclide production system, including an electron accelerator, a conversion target, and the aforementioned radiation target assembly 100. The electron accelerator can be a linear electron accelerator used to generate a high-energy electron beam. The conversion target and radiation target assembly 100 are positioned in front of the electron accelerator along the electron beam irradiation direction. The conversion target is located on the side of the radiation target assembly 100 facing the electron accelerator; therefore, the high-energy electron beam generated by the electron accelerator irradiates and bombards the conversion target. The conversion target can be made of a high-Z material (high atomic number material), for example, it can be made of tantalum, tungsten, etc. After being bombarded by the electron beam, the conversion target generates a high-flux of bremsstrahlung gamma photons.

[0106] Along the irradiation direction of the electron beam, the radiation target assembly 100 is located downstream of the conversion target. The gamma photons generated by the conversion target interact with the target 13 in the downstream radiation target assembly 100. Specifically, when the target 13 is a radium target, the gamma photons and the target 13 in the radium target interact. 226Ra interaction and through (γ,n) reaction 226 Ra is converted to 225 Ra. 225 The half-life of Ra is 14.9 days. 225 The target product can be obtained by β-decay of Ra. 225 Ac, 225 Ac can be used for tumor treatment.

[0107] During electron beam target peening, the conversion target and radiation target assembly 100 can be completely immersed in cooling water so that the conversion target and radiation target assembly 100 can be surrounded by rapidly flowing cooling water, ensuring that the heat of the conversion target and radiation target assembly 100 can be removed in time.

[0108] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A radiation target assembly, characterized in that, The device includes a sealed base (1) and a cover plate (2), which together form an installation chamber (11) and a buffer chamber (12). The sealing positions of the base (1) and the cover plate (2) are located outside the installation chamber (11) and the buffer chamber (12) to isolate the installation chamber (11) and the buffer chamber (12) from contact with the outside. The mounting chamber (11) is used to accommodate the target (13), the buffer chamber (12) is connected to the mounting chamber (11), and the buffer chamber (12) is used to accommodate the gas generated when the target (13) reacts; The base (1) and the cover plate (2) also form an auxiliary chamber (14) and a connecting channel (15). The auxiliary chamber (14) is located inside the sealed position of the base (1) and the cover plate (2), and the auxiliary chamber (14) is located outside the mounting chamber (11) and the buffer chamber (12). The position of the radiation target assembly corresponding to the auxiliary chamber (14) is used as the cutting position of the radiation target assembly. One end of the connecting channel (15) is connected to the buffer chamber (12), and the other end of the connecting channel (15) is connected to the auxiliary chamber (14).

2. The radiation target assembly according to claim 1, characterized in that, The buffer chamber (12) is disposed around the outer periphery of the mounting chamber (11); The buffer chamber (12) is a continuous annular chamber; or the buffer chamber (12) includes multiple sub-chambers, which are arranged sequentially along the outer contour of the mounting chamber (11) at intervals from each other, and each sub-chamber is connected to the mounting chamber (11).

3. The radiation target assembly according to claim 1, characterized in that, The depth of the buffer chamber (12) is less than the depth of the mounting chamber (11); And / or, the buffer chamber (12) and the mounting chamber (11) are respectively recessed from the surface of the base (1) facing the cover plate (2).

4. The radiation target assembly according to claim 3, characterized in that, The depth D3 of the buffer chamber (12) is 0.2 to 0.5 times the depth D2 of the mounting chamber (11); the width D4 of the buffer chamber (12) is 0.1 to 0.25 times the width D5 of the mounting chamber (11).

5. The radiation target assembly according to claim 1, characterized in that, The auxiliary chamber (14) is an annular chamber; the base (1) and the cover plate (2) are welded and fixed to the outside of the auxiliary chamber (14); The target (13) is a radium target.

6. The radiation target assembly according to claim 1, characterized in that, The distance H1 between the auxiliary chamber (14) and the buffer chamber (12) is 1.2 mm to 1.8 mm; the width D6 of the auxiliary chamber (14) is 0.4 mm to 0.6 mm.

7. A method for preparing a radiation target assembly, characterized in that, include: A base (1) is provided, on which an installation chamber (11), a buffer chamber (12), an auxiliary chamber (14), and a connecting channel (15) are formed. The installation chamber (11) and the buffer chamber (12) are connected. The auxiliary chamber (14) is located inside the sealing position between the base (1) and the cover plate (2), and the auxiliary chamber (14) is located outside the installation chamber (11) and the buffer chamber (12). The position of the radiation target assembly corresponding to the auxiliary chamber (14) is used as the cutting position of the radiation target assembly. One end of the connecting channel (15) is connected to the buffer chamber (12), and the other end of the connecting channel (15) is connected to the auxiliary chamber (14). A target (13) is provided, which is installed in the mounting chamber (11) and exposed to the buffer chamber (12). A cover plate (2) is provided, which is sealed to the base (1) to seal the target (13) inside the radiation target assembly.

8. The method for preparing the radiation target assembly according to claim 7, characterized in that, The target (13) is installed in the installation chamber (11), specifically including: A stop ring (200) is provided, the stop ring (200) is embedded in the buffer chamber (12), and the interior of the stop ring (200) is hollow and communicates with the mounting chamber (11) to form a receiving groove; The target (13) is placed in the receiving groove and the target (13) is compressed so that the target (13) is housed in the mounting chamber (11); Remove the stop ring (200).

9. A method for recovering a radiation target assembly, characterized in that, include: A radiation target assembly as described in any one of claims 1 to 6 is provided, wherein the radiation target assembly (100) has an installation chamber (11), a buffer chamber (12), and an auxiliary chamber (14) formed therein. A cutting fixture is provided, the cutting part of which corresponds to the auxiliary chamber (14), and the cutting part cuts the radiation target assembly at the position corresponding to the auxiliary chamber (14); Separate the base (1) and the cover plate (2), and process the target (13).

10. A radionuclide production system, characterized in that, The device includes an electron accelerator, a conversion target, and a radiation target assembly as described in any one of claims 1 to 6; the electron accelerator is used to generate an electron beam that irradiates the conversion target, the radiation target assembly is located on the side of the conversion target away from the electron accelerator, and the radiation target assembly is used to react with photons generated by the electron beam bombardment of the conversion target.

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