A target system for the production of radioisotopes based on an electron accelerator

Abstract

The utility model relates to the target structure technical field of accelerator provides a target system of electron accelerator production radioisotope. The target system includes electron source system, target matrix and remote control area. Among them, electron source system includes electron injection section and electron acceleration section, target matrix includes beam connection pipe, electron - photon conversion area, target irradiation area, first cooling area, second cooling area and shield, and remote control area includes robot. The target system based on electron accelerator production radioisotope that the utility model puts forward can make up the shortcoming such as the target system of existing electron accelerator target complex and complicated, sample target solution target produces loss and the security risk existing in the cooling process, can also overcome the radiation injury that accelerator causes to production personnel when operating, has compact structure, convenient operation, security higher characteristics.

Description

Technical Field

[0001] This utility model relates to the field of target structure technology for accelerators, and specifically to a target system for producing radioactive isotopes based on an electron accelerator. Background Technology

[0002] Radioactive isotopes are isotopes with unstable atomic nuclei that spontaneously emit alpha, beta, and gamma rays, and are one of the origins of nuclear technology applications. With the rapid development of nuclear medicine, medical radioactive isotopes are increasingly widely used in disease diagnosis and clinical treatment. Currently, commonly used medical radioactive isotopes include... 99m Tc, 125 I, 123 I, 14 C 68 Ga、 177 Lu、 18 F, 90 Y、 89 Sr and other isotopes are mainly produced through reactors or accelerators. Accelerators have the technical advantages of being able to accelerate a wide variety of particles, a broad energy range, and high average beam intensity. Compared with reactors, isotopes produced by accelerators have higher specific activity and shorter half-lives, and most decay to emit β-waves. + Or monoenergetic gamma rays, not emitting beta rays - Electrons result in a lower radiation dose to the patient, making them safer. (Liu Ning. Current status and prospect of accelerator preparation of medical radioisotopes[J]. Isotopes, 2022, 35(5): 424-438; Liu Peng. Current status and prospect of medical radioisotope preparation[J]. Isotopes, 2024, 37(1): 77-90; Lu Zhenlong. Application of accelerators in medicine[J]. Nuclear Physics Review, 1989, 6(1): 38-42)

[0003] Accelerators can produce radioactive isotopes through photonuclear reactions. This involves the accelerator generating a high-energy electron beam that bombards a conversion target, producing bremsstrahlung gamma photons. These gamma photons then react with elements in the sample / target element via photonuclear reactions to generate radioactive isotopes. For example, gamma photon irradiation... 100 Mo target generation 99 Mo, irradiation 226 Ra target generation 223 Ra、 224 Ra and 225Ra. The energy of gamma photons has a significant impact on the types of radioactive isotopes. Precise control of gamma photon energy is crucial for forming the desired isotopes, and this energy directly depends on the electron beam energy. Since only a small portion of the electron beam energy is converted into bremsstrahlung, with the remainder being converted into heat, failure to dissipate heat in a timely manner can lead to target melting and radioactive contamination from the volatilization of radionuclides and other products. Therefore, effective cooling of the conversion target and sample target is paramount. Common coolers include helium flow cooling and water cooling, each with its own advantages and disadvantages. Helium cooling systems commonly use expensive equipment such as Gifford-Mcmahon refrigerators and pulse tube refrigerators, requiring specially designed containers and piping to achieve a closed-loop helium flow, minimize helium leakage, and reduce heat leakage from components at room temperature. Water cooling systems are simple to operate and inexpensive, using conventional refrigerators to cool circulating water, making them easier to industrialize. However, water cooling has some drawbacks in the use of sample targets. For example, under high radiation levels, water may undergo radiation cracking, generating strong free radicals and peroxides, which can cause black residues to form on the sample target surface, thus impairing its performance. A mixture of hydrogen and oxygen produced by high radiation, when reaching a certain proportion, can trigger an explosion, potentially damaging the target system and endangering the accelerator's vacuum system. Residual nuclides in the cooling water can cause oxidation and corrosion of the sample target. To mitigate oxidation and corrosion of the target sheet, buffer solutions (such as lithium hydroxide, ammonia, etc.) or sacrificial metals (copper, titanium, stainless steel, etc.) need to be added. Furthermore, irradiated sample targets typically require physical and / or chemical treatment to achieve the separation and purification of target nuclides. During this process, incomplete dissolution or chemical contamination often leads to the loss of target nuclides. (JM. Gitz F. Stichelbo. System for generating radioisotopes by bremsstrahlung, including a bending converter. 202310202229.2 [P]; A. Thiele. Target assembly, associated equipment and method for producing radioisotopes by bremsstrahlung in photonuclear reactions. 202280087167.9 [P]; Zhang Yuhao. Target chamber apparatus for producing radioisotopes by a gas-cooled accelerator. 202010224009.6 [P]; P. Schaefer. Method, system and apparatus for producing technetium-99m by a cyclotron. 201711477557.4 [P]; P.W.H. Dejag. Production of radioisotopes. 201680078016.1 [P])

[0004] Therefore, the existing technology still needs further development and improvement. Utility Model Content

[0005] To address the aforementioned problems, this invention proposes a target system for producing radioactive isotopes based on an electron accelerator. This system overcomes the shortcomings of existing electron accelerator target systems, such as complex and cumbersome target preparation, losses during sample target dissolution, and safety hazards during cooling. It also overcomes the radiation damage to production personnel caused by the accelerator during operation. The system features a compact structure, convenient operation, and high safety.

[0006] The technical solution adopted in this utility model is to provide a target system for producing radioactive isotopes based on an electron accelerator, including an electron source system, a target substrate, and a remote control area. Its special feature is that the electron source system includes an electron injection section and an electron acceleration section. The electron injection section is an electron generating device used to generate electrons; the electron acceleration section is used to transport and accelerate electrons; and the electron acceleration section connects the electron injection section and the target substrate.

[0007] The target substrate includes a beam connection tube, an electron-photon conversion region, a target irradiation region, a first cooling region, a second cooling region, and a shield. The beam connection tube, the electron-photon conversion region, and the first cooling region are symmetrically distributed on both sides of the target irradiation region. The first cooling region is sealed to the electron-photon conversion region. The second cooling region is located at the bottom of the target irradiation region. The remaining part of the target substrate is the shield.

[0008] The beam connection tube is connected to the electron acceleration section at its inlet and to the electron-photon conversion region at its outlet. The electron-photon conversion region includes a target window and a conversion target, with the conversion target close to the target irradiation region. The target irradiation region includes a target bottle and a target bottle trough.

[0009] The remote control area includes a robot equipped with mechanical grippers that, under computer program control, cooperate with the robot to load or remove the target bottle into the target bottle slot.

[0010] Furthermore, the target bottle groove has multiple grooves arranged in a parallel manner, with a diameter ranging from 8 to 14 mm, for fixing the target bottle; there are gaps between the grooves, and the material of the gaps should not easily undergo photonuclear reactions and should not easily block photon propagation, and can be selected from aluminum, beryllium, magnesium, titanium and their alloys.

[0011] Furthermore, the target bottle material can be selected from quartz glass, graphite, alumina ceramic, or magnesium oxide ceramic, and is used to fill the target material.

[0012] Furthermore, both the first cooling zone and the second cooling zone include a cooling cavity, pipes, and open ends. A gap exists between the target window and the conversion target to form a cooling cavity. The upper and lower ends of the cooling cavity are sealed and connected by pipes that extend to the top and bottom of the target base, respectively, forming two open ends. The bottom of the target bottle groove contains a cavity to form a cooling cavity. The lower two sides of the cooling cavity are sealed and connected by pipes that extend to the bottom two sides of the target base, respectively, forming two open ends. The open ends extend out of the target base and are fixed to the target base, and each open end is equipped with a temperature sensor.

[0013] Furthermore, the cooling medium used in the first cooling zone and the second cooling zone is selected from coolant or cooling gas.

[0014] Furthermore, the first cooling zone is a vacuum-sealed gas circulation cooling system used to cool the conversion target, and the gas coolant is selected from helium; the second cooling zone is a vacuum-sealed coolant circulation cooling system used to cool the target bottle, and the liquid coolant is selected from water.

[0015] Furthermore, the target window has a convex-concave lens structure with the convex surface facing the conversion target; wherein the convex surface is an ellipsoid or a spherical surface; the material of the conversion target is tungsten or other high-Z materials, and the high-Z materials are selected from tantalum, lead, platinum, gold, bismuth, and molybdenum.

[0016] Furthermore, the electron beam generated by the electron source system can be emitted from one or both sides of the device; the electron-photon conversion region converts the electrons transmitted in the electron acceleration section into bremsstrahlung photons with an energy range of 10 to 60 MeV.

[0017] Furthermore, the mechanical gripper is a parallel mechanical gripper, and an electronic sensor is installed at the junction of the mechanical gripper and the target bottle.

[0018] The beneficial effects of this utility model are:

[0019] 1. This utility model uses a target bottle containing target material as a sample target. Compared with traditional sample targets (such as disc targets), it eliminates the target preparation process, solves the problem that the traditional target preparation process is relatively cumbersome and has high requirements for the morphology of the target material. At the same time, it avoids the loss of target nuclides due to insufficient dissolution or chemical contamination of the disc target after irradiation. The irradiated target material can be directly used for subsequent separation and purification operations, which improves the yield of radioactive isotopes. The target bottle separates the target material from the cooling medium. At the same time, the second cooling zone is located at the bottom of the target irradiation area, which avoids the corrosion and oxidation reactions between the target material and the cooling medium and the safety hazards caused by the radiation cracking of the cooling water under high radiation levels.

[0020] 2. This utility model uses a gas circulation cooling system to cool the conversion target, which greatly improves the cooling efficiency of the conversion target and can also reduce the uneven heat distribution generated by the target window during electron beam irradiation.

[0021] 3. In this invention, the target bottle tank can accommodate multiple target bottles simultaneously, and the position and number of target bottles can be adjusted according to different nuclear reaction requirements during production. Compared with existing technologies where the target installation position is fixed and only a single type of radioactive isotope can be produced, this invention can simultaneously produce multiple radioactive isotopes and can be used for scaled-up production of radioactive isotopes, thus expanding its application range and improving production efficiency.

[0022] 4. This utility model is designed with mechanical grippers equipped with electronic sensors for gripping target bottles, which greatly reduces the radiation dose that production personnel may receive during operation, making the production and transportation of radioactive isotopes safer, faster and more reliable.

[0023] 5. The electron beam generated by the electron source system of this utility model can be emitted from one or both sides of the device, which is flexible in operation. At the same time, dual-sided target firing can improve the yield and specific activity of radioactive isotopes. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a system structure block diagram of this utility model;

[0026] Figure 2 This is a schematic diagram of the target system device of this utility model;

[0027] Figure 3 shows the results from one side of the target bottle ( Figure 3a ) or both sides ( Figure 3b A schematic diagram of receiving electron beam irradiation;

[0028] Figure 4 This is a top view of the target bottle groove structure;

[0029] Figure 5 This is a cross-sectional view of the first cooling zone structure;

[0030] Figure 6 This is a cross-sectional schematic diagram of the electron-photon conversion region structure;

[0031] Figure 7This is a cross-sectional view of the second cooling zone structure;

[0032] Figure 8 This refers to simultaneous production under both single-sided (top) and double-sided (bottom) firing conditions. 67 Cu and 99 The placement of Mo's target bottles (each with 10 target bottles) in the target bottle slot;

[0033] Figure 9 When firing at a target from one side or both sides, the production... 67 Cu (left) and 99 A trend chart of Mo's (right) total output as a function of the number of target bottles;

[0034] The attached figures are labeled as follows: 1-Beam connection tube, 1a-Beam connection tube inlet, 1b-Beam connection tube outlet, 2-Target window, 3-Conversion target, 4-Helium-cooled inlet, 4a-Inlet main pipe, 4b-Inlet bell mouth, 5-Helium-cooled outlet, 5a-Outlet main pipe, 5b-Outlet bell mouth, 6-Water-cooled inlet, 7-Water-cooled outlet, 8-Target bottle, 9-Target bottle slot, 10-Mechanical gripper, 11-Electronic sensor, 12-Cooling chamber, 12a-Cooling chamber of the first cooling zone, 12b-Cooling chamber of the second cooling zone, 13-Cooling pipe, 13a-Cooling pipe of the first cooling zone, 13b-Cooling pipe of the second cooling zone, 14-Shielding body, 15-Groove. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the detailed description of the embodiments of this utility model provided below is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of this utility model.

[0036] The following is combined Figures 1-9 This invention describes a target system for producing radioactive isotopes based on an electron accelerator.

[0037] like Figure 1 The diagram shown is a structural block diagram of the target system of this utility model, which consists of three parts: an electron source system, a target substrate, and a remote control area. The electron source system includes an electron injection section and an electron acceleration section. The target substrate includes a beam connection tube, an electron-photon conversion area, a target irradiation area, a first cooling area, a second cooling area, and a shield.

[0038] The electron acceleration section connects the electron injection section and the beam connection tube. The electron-photon conversion region connects the beam connection tube, the first cooling region, and the target irradiation region. The target irradiation region connects the second cooling region and the remote control region. The electron injection section, the electron acceleration section, the beam connection tube, the electron-photon conversion region, and the first cooling region are all symmetrically distributed on both sides of the target irradiation region.

[0039] The functions of each section or component are as follows: the electron injection section is used to generate electrons; the electron acceleration section is used to transport and accelerate electrons; the beam connection tube is used to transport electrons; the electron-photon conversion zone is used to generate bremsstrahlung to convert electrons into gamma photons; the target irradiation zone is used to fill target materials to produce target isotopes; the first cooling zone is used to cool the conversion target and target window; the second cooling zone is used to cool the target irradiation zone; and the remote control zone is used to grip the target bottle and monitor it in real time according to the working status.

[0040] like Figure 2 The diagram shows the overall schematic of the target system device of this utility model, including a beam connection tube 1, a beam connection tube inlet 1a, a beam connection tube outlet 1b, a target window 2, a conversion target 3, a helium-cooled inlet 4, a helium-cooled outlet 5, a water-cooled inlet 6, a water-cooled outlet 7, a target bottle 8, a target bottle tank 9, a mechanical gripper 10, an electronic sensor 11, a cooling cavity 12, a cooling pipe 13, and a shield 14. The target window 2 and the conversion target 3 are located in the electron-photon conversion zone, the target bottle 8 and the target bottle tank 9 are located in the target irradiation zone, the helium-cooled inlet 4 and the helium-cooled outlet 5 are located in the first cooling zone, the water-cooled inlet 6 and the water-cooled outlet 7 are located in the second cooling zone, and the mechanical gripper 10 is installed at the robot in the remote control zone.

[0041] The beam connection tube inlet 1a connects to the electron acceleration section, and the outlet 1b is equipped with a target window 2 and a conversion target 3. The target window 2 and the conversion target 3 are connected to the first cooling zone. The conversion target 3 is close to the target bottle 8 and the target bottle slot 9. The lower end of the target bottle slot 9 is connected to the second cooling zone. The mechanical gripper 10 is located outside the target substrate, and the rest of the target substrate is a shield 14. The beam connection tube 1, the target window 2, the conversion target 3, and the first cooling zone are symmetrically distributed on both sides of the target bottle 2, the target bottle slot 9, and the second cooling zone.

[0042] In addition to the above, some components function as follows: target window 2 is used to maintain a vacuum environment, conversion target 3 is used to generate gamma photons, target bottle 8 is used to fill target material, target bottle groove 9 is used to fix the target bottle, mechanical gripper 10 is used to grip the target bottle, and the main material of shielding body 14 is stainless steel, and its inner wall is provided with a lead layer or tungsten layer of a certain thickness for radiation shielding of the target system.

[0043] Figure 3 shows a schematic diagram of electron beam irradiation received from one or both sides of the target bottle 8. Specifically, Figure 3a The electron beam generated by the electron source system passes through the conversion target 3 to generate γ photons that irradiate one side of the target bottle 8; Figure 3bThe diagram shows gamma photons irradiating both sides of the target bottle 8. The conversion target 3 can convert electrons transmitted in the electron acceleration section into bremsstrahlung gamma photons with an energy range of 10–60 MeV. Therefore, the target system of this invention is applicable to various electron accelerators, such as linear electron accelerators or cyclotron electron accelerators. In this embodiment, a petal-shaped electron accelerator is preferred, with an electron beam energy of 40 MeV and a beam power of over 100 kW.

[0044] like Figure 4 The diagram shows a top view of the target bottle tank 9. The target bottle tank 9 contains multiple grooves 15 for accommodating target bottles 8. The grooves 15 are arranged side-by-side, with a diameter ranging from 8 to 14 mm; in this embodiment, a diameter of 12 mm is preferred. There are gaps between the grooves 15, and the material of these gaps must be resistant to photonuclear reactions and not obstruct photon propagation; aluminum, beryllium, magnesium, titanium, and their alloys are suitable choices. The target bottles 8 can be made of quartz glass, graphite, alumina ceramic, or magnesium oxide ceramic. The height of the target material filling does not exceed the height of the target window 2 and the conversion target 3. In this embodiment, the target bottle 8 is preferably 9 to 11 mm in diameter, and the target material filling height does not exceed 30 mm. This target system has relatively low requirements for the form of the target material; it can be a solid powder or solution, eliminating the traditional target preparation process. Therefore, this target system is not limited by the target material and can be used to produce various radioactive isotopes.

[0045] like Figure 5 The diagram shows a cross-sectional view of the first cooling zone. The first cooling zone includes a cooling chamber 12a, a cooling pipe 13a, a helium inlet 4, and a helium outlet 5. The first cooling zone is a vacuum-sealed gas circulation cooling system; in this embodiment, helium is preferred as the gas coolant. Compared to other inert gases, helium has a lighter atomic mass, a reasonable heat capacity, and is not excited by bremsstrahlung photons. Both the helium inlet 4 and the helium outlet 5 extend from the target substrate and are fixed to it. Temperature sensors are installed at both the helium inlet 4 and the helium outlet 5 to detect the inlet and outlet gas temperatures. Both the helium inlet 4 and the helium outlet 5 include open pipes 4a and 5a and bell mouths 4b and 5b. The helium inlet pipe 4a and the helium outlet pipe 5a are connected to an external helium cooling circulation system. The larger ends of the inlet bell mouth 4b and the outlet bell mouth 5b are connected to the helium inlet pipe 4a and the helium outlet pipe 5a, respectively, while their smaller ends are connected to the cooling pipe 13a. Helium gas flows from the helium cooling inlet 4 through the cooling pipe 13a to the cooling chamber 12a, carrying away the heat generated by the target window 2 and the conversion target 3 during irradiation, and then flows from the cooling pipe 13a on the other side to the helium cooling outlet 5.

[0046] like Figure 6 The image shows a cross-sectional schematic diagram of the electron-photon conversion region structure. Combined with... Figure 2 and Figure 5As described, a cooling cavity 12a, forming the first cooling zone, is located between the target window 2 and the conversion target 3. The upper and lower ends of the cooling cavity 12a are sealed and connected by cooling pipes 13a, extending to the top and bottom of the target substrate to form a helium cooling outlet 5 and a helium cooling inlet 4, respectively. The target window 2 has a convex-concave lens structure, with the convex surface being either an ellipsoid or a spherical surface. The convex surface of the target window 2 faces the cooling cavity 12a. This convex structure reduces the attenuation of the electron beam by the target window 2, prevents the target window 2 from releasing a large amount of heat during electron beam irradiation, enhances contact with the cooling medium, thereby reducing the uneven heat distribution generated by the target window 2 and extending its lifespan. The target window 2 and the conversion target 3 have the same diameter, neither exceeding the diameter of the beam connection tube outlet 1b. In this embodiment, the preferred diameter of the target window 2 and the conversion target 3 is 30 mm. The conversion target 3 is made of a metal with high conversion efficiency and high temperature resistance, generally tungsten or other high-Z materials. High-Z materials can be tantalum, lead, platinum, gold, bismuth, or molybdenum. In this embodiment, when the electron beam energy is 40 MeV, a tungsten metal target with a thickness of 3 to 5 mm is preferred.

[0047] like Figure 7 The diagram shows a cross-sectional view of the second cooling zone. The second cooling zone includes a cooling chamber 12b, cooling pipes 13b, a water-cooled inlet 6, and a water-cooled outlet 7. The second cooling zone is a vacuum-sealed coolant circulation cooling system; in this embodiment, water is preferred as the liquid coolant. Figure 2 As described above, the cavity at the bottom of the target bottle tank 9 is the cooling chamber 12b of the second cooling zone. Cooling pipes 13b are sealed and connected downwards on both sides of the lower end of the cooling chamber 12b, extending to the bottom of the target substrate to form a water-cooled inlet 6 and a water-cooled outlet 7, respectively. The water-cooled inlet 6, the water-cooled outlet 7, and part of the cooling pipes 13b are on the outer end face of the target substrate, with part of the cooling pipes 13b extending into the target substrate and connecting to the cooling chamber 12b. When irradiation begins, the cooling inlet 6 connects to the water cooling system, allowing the circulating cooling medium to flow through the cooling pipes 13b to the cooling chamber 12b, carrying away the heat generated by the target bottle irradiation and flowing to the other cooling pipe 13b to the water-cooled outlet 7.

[0048] The robot is equipped with a mechanical gripper 10. In this embodiment, the mechanical gripper 10 is preferably a parallel mechanical gripper. An electronic sensor 11 is installed at the junction of the mechanical gripper 10 and the target bottle 8. The electronic sensor 11 determines the gripping status of the target bottle 8 by measuring the pressure at the junction of the mechanical gripper 10 and the target bottle 8 and feeds back the pressure measurement data to the computer program in real time.

[0049] This invention also provides a method for using a target system for producing radioactive isotopes based on an electron accelerator. Isotope target material is loaded into a target bottle. A computer-controlled robot's mechanical gripper loads the target bottle into a target bottle slot. The valves of the helium cooling inlet and outlet are opened to cool the conversion target. Simultaneously, the valves of the water cooling inlet and outlet are opened to cool the target bottle. An electron beam bombards the conversion target through a beam connection tube, generating bremsstrahlung radiation and producing gamma photons. These gamma photons irradiate the isotope target material in the target bottle, thereby producing the target isotope. After the target firing is completed, the valves of the helium cooling inlet and outlet, as well as the water cooling inlet and outlet, are closed. Finally, the computer-controlled robot's mechanical gripper places the target bottle into a lead container.

[0050] This invention can be used to produce various radioactive isotopes, such as 47 Sc, 64 Cu, 67 Cu, 67 Ga 68 Ge 90 Y, 99 Mo, 103 Pd, 105 Rh, 111 In, 161 Tb, 166 Ho, 186 Re, 188 Re, 212 Pb, 223 Ra, 225 Ac and other medical radioactive isotopes, but not limited to those listed, are used. Some radioactive isotopes and their target materials are shown in Table 1.

[0051] The device described in this invention is used to produce radionuclides. 99 Mohe 67 Taking Cu as an example. If a single target vial contains target material MoO3 or ZnO with a diameter of 10 mm and a height of 30 mm, the following method is used: Figure 8 The method shown will produce 99 Mohe 67 Cu target flasks were placed in adjacent target flask slots, with the number of flasks increasing sequentially from 1 to 10. Single-sided and double-sided irradiation were performed. The accelerator electron energy was 40 MeV, the beam current was 100 μA, the tungsten conversion target thickness was 4 mm, and the single irradiation time was 24 hours. The total yield was simulated and calculated using the FLUKA simulation program. The results are as follows: Figure 9 As shown.

[0052] from Figure 9 It can be seen that when firing at a target from one side, production... 67 Cu and 99 When the number of target bottles for Mo is 5 or more, the total output value is basically stable. 67The total Cu production is approximately 14 MBq / (uA·h). 99 The total Mo production is approximately 701 MBq / (uA·h);

[0053] When shooting from both sides, 67 Cu and 99 Mo's total output was significantly higher than that of single-sided shooting, and production... 67 Cu and 99 When the number of target bottles for Mo is 5 or more, the total output value is basically stable. 67 The total Cu yield is approximately 31 MBq / (uA·h). 99 The total Mo production is approximately 1618 MBq / (uA·h).

[0054] Therefore, it can be seen that if two different medical isotopes are produced simultaneously, such as 99 Mohe 67 Cu can be used as follows Figure 8 As shown, the two types of target bottles are placed in adjacent target bottle slots. Using double-sided shooting helps to achieve higher output. Effective shooting can be achieved when the number of target bottles is controlled to 5 or less.

[0055] The above are merely preferred embodiments of this utility model. It should be noted that the above preferred embodiments should not be considered as limitations on this utility model, and the scope of protection of this utility model should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

[0056] Table 1. Radioisotopes that can be produced by the target system of this invention.

[0057]

Claims

1. A target system for producing radioactive isotopes based on an electron accelerator, comprising an electron source system, a target substrate, and a remote control region, characterized in that, The electron source system includes an electron injection section and an electron acceleration section. The electron injection section is an electron generating device used to generate electrons. The electron acceleration section is used to transport and accelerate electrons. The electron acceleration section connects the electron injection section and the target substrate. The target substrate includes a beam connection tube, an electron-photon conversion region, a target irradiation region, a first cooling region, a second cooling region, and a shield. The beam connection tube, the electron-photon conversion region, and the first cooling region are symmetrically distributed on both sides of the target irradiation region. The first cooling region is sealed to the electron-photon conversion region. The second cooling region is located at the bottom of the target irradiation region. The remaining part of the target substrate is the shield. The beam connection tube is connected to the electron acceleration section at its inlet and to the electron-photon conversion region at its outlet. The electron-photon conversion region includes a target window and a conversion target, with the conversion target close to the target irradiation region. The target irradiation region includes a target bottle and a target bottle trough. The remote control area includes a robot equipped with mechanical grippers that, under computer program control, cooperate with the robot to load or remove the target bottle into the target bottle slot.

2. The target system according to claim 1, characterized in that: The target bottle groove has multiple grooves arranged in a parallel manner, with a diameter ranging from 8 to 14 mm, for fixing the target bottle; there are gaps between the grooves, and the material of the gaps must not easily undergo photonuclear reactions and must not easily block photon propagation, and can be selected from aluminum, beryllium, magnesium, titanium and their alloys.

3. The target system according to claim 2, characterized in that: The target bottle can be made of quartz glass, graphite, alumina ceramic, or magnesium oxide ceramic, and is used to fill the target material.

4. The target system according to claim 1, characterized in that: Both the first cooling zone and the second cooling zone include a cooling cavity, pipes, and open ends. A gap exists between the target window and the conversion target to form a cooling cavity. The upper and lower ends of the cooling cavity are sealed and connected by pipes that extend to the top and bottom of the target base, respectively, forming two open ends. The bottom of the target bottle groove contains a cavity to form a cooling cavity. The lower two sides of the cooling cavity are sealed and connected by pipes that extend to the bottom two sides of the target base, respectively, forming two open ends. The open ends extend out of the target base and are fixed to the target base, and each open end is equipped with a temperature sensor.

5. The target system according to claim 4, characterized in that: The cooling medium used in the first cooling zone and the second cooling zone is selected from coolant or cooling gas.

6. The target system according to claim 5, characterized in that: The first cooling zone is a vacuum-sealed gas circulation cooling system used to cool the conversion target, and the gas coolant is selected from helium; the second cooling zone is a vacuum-sealed coolant circulation cooling system used to cool the target bottle, and the liquid coolant is selected from water.

7. The target system according to claim 1, characterized in that: The target window has a convex-concave lens structure with the convex surface facing the conversion target; the convex surface is an ellipsoid or a spherical surface; the conversion target is made of tungsten or other high-Z materials, and the high-Z materials are selected from tantalum, lead, platinum, gold, bismuth, and molybdenum.

8. The target system according to claim 1, characterized in that: The electron beam generated by the electron source system can be emitted from one or both sides of the device; the electron-photon conversion region converts the electrons transmitted in the electron acceleration section into bremsstrahlung photons with an energy range of 10 to 60 MeV.

9. The target system according to claim 1, characterized in that: The mechanical gripper is a parallel mechanical gripper, and an electronic sensor is installed at the junction of the mechanical gripper and the target bottle.

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