Targets used in particle beam generators, and neutron capture therapy systems

Abstract

The present invention provides a target for use in a neutron capture therapy system and a particle beam generator that can improve the heat dissipation performance of the target, reduce foaming, and extend the service life of the target. [Solution] The neutron capture therapy system includes a neutron generator and a beam shaping body. The neutron generator includes an accelerator and a target. A charged particle beam accelerated and generated by the accelerator interacts with the target to generate a neutron beam. The target includes an action layer that interacts with the charged particle beam to generate a neutron beam, a foam suppression layer that suppresses foaming caused by the charged particle beam, a first heat dissipation layer, and a second heat dissipation layer. The first heat dissipation layer directly and rapidly conducts the heat accumulated in the action layer to the second heat dissipation layer, and the second heat dissipation layer dissipates the heat using a cooling medium.

Description

Technical Field

[0001] The present invention relates to a target used in a radiation irradiation system, and more particularly to a target used in a particle beam generation device.

Background Art

[0002] With the development of atomic science, for example, radiation therapy using cobalt 60, linear accelerators, electron beams, etc. has already become one of the main means of cancer treatment. However, conventional photon or electron therapy kills tumor cells due to the physical conditions of the radiation itself, and at the same time damages many normal tissues in the beam path, and because the degree of sensitivity of tumor cells to radiation is different, conventional radiation therapy has a low therapeutic effect on malignant tumors with high radiation resistance (for example, glioblastoma multiforme (g lioblastoma multiforme), melanoma).

[0003] In order to reduce radiation damage to normal tissues around tumors, the concept of targeted therapy in chemotherapy (chemoth erapy) has been applied to radiation therapy, and for tumor cells with high radiation resistance, at present, proton beam therapy, heavy particle therapy, neutron capture therapy, etc. radiation sources with high relative biological effectiveness (R BE) are actively being developed. Among these, neutron capture therapy combines the above two concepts. For example, in boron neutron capture therapy, boron-containing drugs specifically accumulate in tumor cells, and by combining with high-precision control of neutron beams, it provides a better cancer treatment option than conventional radiation.

[0004] In boron neutron capture therapy using accelerators, The accelerator delivers a proton beam with enough energy to overcome the Coulomb repulsion between the target nuclei. To accelerate it to energy and cause a nuclear reaction with the target to generate neutrons, neutrons In the process of generating it, the target is an accelerated proton beam at a very high energy level. When irradiated, the temperature rises significantly, and the metal parts are prone to foaming, This will affect the lifespan of the device.

[0005] Therefore, it is necessary to provide new technical means to solve the above technical problems. . [Overview of the Initiative]

[0006] To solve the above problems, the present invention relates to a first aspect of a neutron beam generator used in a neutron beam generator. The target comprises a working layer that interacts with a charged particle beam to generate a neutron beam, and the Located behind the working layer along the incident direction of the charged particle beam, and in relation to the charged particle beam A foam suppression layer that can suppress foaming, and a heat dissipation layer that conducts the heat accumulated in the target to the outside. It includes a heat layer and a heat conduction layer that conducts the amount of heat in the working layer to the heat dissipation layer.

[0007] Preferably, the heat conductive layer is installed between the working layer and the foam suppression layer, and the foam The heat layer is connected to the heat layer, and the heat dissipation performance of the foam suppression layer is low, so the heat accumulated in the working layer is effectively transferred to the heat dissipation layer. Since heat cannot be directly conducted, a heat conduction layer is installed to dissipate the heat accumulated in the working layer. By conducting heat directly and rapidly to the layer, and dissipating heat through the cooling medium in the heat dissipation layer, By lowering the target temperature, deformation caused by excessively high target temperatures is prevented. - The service life of the target is extended, and since the heat quantity is basically not conducted by the foaming suppression layer, for the foaming suppression layer, it is not necessary to consider its thermal conductivity, and only the anti-foaming property needs to be considered. That's it.

[0008] Furthermore, the heat conduction layer and the heat dissipation layer surround the foaming suppression layer, and a housing space for housing the foaming suppression layer is formed in the heat dissipation layer or the heat conduction layer.

[0009] Furthermore, the housing space includes a bottom surface and side walls connected to the bottom surface, and the foaming suppression layer has a top surface in contact with the bottom surface and an outer wall in contact with the side walls.

[0010] Preferably, the material of the action layer is Li, its compound or its alloy, the materials of the heat dissipation layer and the heat conduction layer are Cu, its compound or its alloy, and the material of the foaming suppression layer is , Ta, its compound or its alloy.

[0011] Preferably, the target is flat and has a central axis perpendicular to the plate surface. In the same radial direction perpendicular to the central axis, the maximum distance from the action layer to the central axis is smaller than the maximum distance from the foaming suppression layer to the central axis, and the maximum distance from the foaming suppression layer to the said central axis is smaller than the maximum distance from the heat dissipation layer to the central axis and the maximum distance from the heat conduction layer to the central axis.

[0012] Preferably, the target further includes an anti-oxidation layer that prevents oxidation of the action layer and isolates the action layer from air. The anti-oxidation layer, the action layer, the heat conduction layer, the foaming suppression layer and the heat dissipation layer are arranged in sequence along the incident direction of the charged particle beam.

[0013] Furthermore, the working layer, the heat conduction layer, and the foaming suppression layer are successively processed on the heat dissipation layer in a film-forming manner, and the antioxidant layer is processed on the working layer in a film-forming manner or is a polymer film and is processed on the working layer by a film coating process.

[0014] Furthermore, the antioxidant layer is made of Al, Al2O3, or polyimide. With the antioxidant layer, there is no need to specifically store the target, and it can be exposed to air, which is very convenient especially when installing and replacing the target. The antioxidant layer can further prevent the by-products in the working layer from overflowing from the target. Regarding the material of the antioxidant layer, it is not easily corroded by the working layer, and at the same time, it is considered that the loss of the incident proton beam and the heat generation caused by the proton beam can be reduced.

[0015] Furthermore, the polyimide has the following molecular structural formula.

Chemical Formula

[0016] The target used in the particle beam generator according to the second aspect of the present invention includes a working layer for generating the particle beam, a foaming suppression layer capable of suppressing the foaming of the working layer in the process of generating the particle beam, and a first heat dissipation layer and a second heat dissipation layer for conducting the heat quantity accumulated in the target to the outside. The foaming suppression layer is installed between the first heat dissipation layer and the second heat dissipation layer, and the first heat dissipation layer conducts the heat quantity in the working layer to the second heat dissipation layer. The heat dissipation performance of the foaming suppression layer is low, and it can effectively conduct the heat ​Because this is not possible, a first heat dissipation layer is installed to directly transfer the heat accumulated in the working layer to the second heat dissipation layer. By rapidly conducting heat and dissipating it through the cooling medium in the second heat dissipation layer, the target By lowering the temperature of the target, deformation caused by excessively high temperature of the target is prevented, and the target The lifespan of the foam-suppressing layer is extended, and since heat is not basically conducted by the foam-suppressing layer, Therefore, there is no need to consider its thermal conductivity; only its foam-preventing properties need to be considered.

[0017] Preferably, the first heat dissipation layer is installed between the working layer and the foam suppression layer, and By connecting to the second heat dissipation layer, the contact area with the working layer is large, and the amount of heat is transferred to the second layer. It can quickly conduct heat to the heat dissipation layer.

[0018] Furthermore, the first heat dissipation layer and the second heat dissipation layer surround the foam suppression layer, and the first heat dissipation A housing space for housing the foam suppression layer is formed in the layer or the second heat dissipation layer. Since thermal conductivity is not inherently prevented by the foam-suppressing layer, the thermal conductivity of the foam-suppressing layer should be taken into consideration. There is no need to consider anything else; only the foam-preventing properties need to be taken into account.

[0019] Furthermore, the containment space includes a bottom surface and side walls connected to the bottom surface, and the foam suppression The layer has a top surface that contacts the bottom surface and an outer wall that contacts the side wall.

[0020] Preferably, the target further includes an antioxidant layer that prevents oxidation of the working layer. The oxidation prevention layer, the working layer, the first heat dissipation layer, the foam suppression layer, and the second heat dissipation layer are installed in that order. The antioxidant layer eliminates the need for special storage of the target, allowing it to be exposed to air. It is especially convenient when installing and replacing targets, and the oxidation prevention layer is Furthermore, it is possible to prevent by-products in the working layer from overflowing from the target, and acid Regarding the material for the corrosion prevention layer, it must be resistant to corrosion by the working layer and also reduce the loss of the incident proton beam. It is also considered that the loss and the heat generated by the proton beam can be reduced.

[0021] Furthermore, the working layer, the first heat dissipation layer, and the foam suppression layer are formed in a manner that creates a film. The two heat dissipation layers are processed in sequence, and the oxidation prevention layer is applied to the working layer in a manner that forms a film. It is processed or is a polymer film, and the working layer is added by a film coating process. It will be constructed.

[0022] Furthermore, the target is flat and has a central axis perpendicular to the surface of the plate, In the same radial direction perpendicular to the central axis, the maximum distance from the working layer to the central axis is: The maximum distance from the foam suppression layer to the central axis and the distance from the oxidation prevention layer to the central axis The maximum distance from the foam suppression layer to the central axis is smaller than the maximum distance at the first The maximum distance from the heat dissipation layer to the central axis and the maximum distance from the second heat dissipation layer to the central axis It's smaller than the distance.

[0023] Furthermore, the material of the working layer is Li, its compounds, or its alloys, and the first heat dissipation layer The material of the second heat dissipation layer is Cu, a compound thereof, or an alloy thereof, and the material of the foam suppression layer The material of the antioxidant layer is Ta, its compounds, or its alloys, and the material of the antioxidant layer is Al, Al2O3 Alternatively, it is polyimide.

[0024] Furthermore, the polyimide has the following molecular structural formula. [ka]

[0025] A target used in a particle beam generator according to a third aspect of the present invention is the particle beam A working layer that generates a beam, and foaming of the working layer during the process of generating the particle beam. A foam suppression layer that can suppress foaming, and a first heat dissipation layer that conducts the heat accumulated in the target to the outside. The first heat dissipation layer and the second heat dissipation layer are connected to each other, and the first The heat dissipation layer is installed between the working layer and the foam suppression layer. Furthermore, the amount of heat accumulated in the working layer cannot be effectively transferred to the heat dissipation layer, therefore, the first heat dissipation By installing a layer, the amount of heat accumulated in the working layer is directly and rapidly transferred to the second heat dissipation layer, and the second By dissipating heat using a cooling medium in the heat dissipation layer, the target temperature is lowered. This prevents deformation caused by excessively high temperatures in the target, extends the service life of the target, and The first heat dissipation layer has a large contact area with the working layer and rapidly conducts heat to the second heat dissipation layer. It is possible.

[0026] Preferably, the first heat dissipation layer and the second heat dissipation layer surround the foam suppression layer, and the first A accommodating space for housing the foam suppression layer is formed in the heat dissipation layer or the second heat dissipation layer. Since thermal conductivity is basically not conducted by the foam-suppressing layer, the thermal conductivity of the foam-suppressing layer should be considered. There is no need to consider other factors; only the foam-preventing properties need to be taken into account.

[0027] Preferably, the target further includes an antioxidant layer that prevents oxidation of the working layer. The oxidation prevention layer, the working layer, the first heat dissipation layer, the foam suppression layer, and the second heat dissipation layer are installed in that order. The antioxidant layer eliminates the need for special storage of the target, allowing it to be exposed to air. It is especially convenient when installing and replacing targets, and the oxidation prevention layer is Furthermore, it is possible to prevent by-products in the working layer from overflowing from the target, and acid Regarding the material for the corrosion prevention layer, it must be resistant to corrosion by the working layer and also reduce the loss of the incident proton beam. It is also considered that the loss and the heat generated by the proton beam can be reduced.

[0028] Furthermore, the working layer, the first heat dissipation layer, and the foam suppression layer are formed in a manner that creates a film. The two heat dissipation layers are processed in sequence, and the oxidation prevention layer is applied to the working layer in a manner that forms a film. It is processed or is a polymer film, and the working layer is added by a film coating process. It will be constructed.

[0029] Furthermore, the target is flat and has a central axis perpendicular to the surface of the plate, In the same radial direction perpendicular to the central axis, the maximum distance from the working layer to the central axis is: The maximum distance from the foam suppression layer to the central axis and the distance from the oxidation prevention layer to the central axis The maximum distance from the foam suppression layer to the central axis is smaller than the maximum distance at the first The maximum distance from the heat dissipation layer to the central axis and the maximum distance from the second heat dissipation layer to the central axis It's smaller than the distance.

[0030] Furthermore, the material of the working layer is Li, its compounds, or its alloys, and the first heat dissipation layer The material of the second heat dissipation layer is Cu, a compound thereof, or an alloy thereof, and the material of the foam suppression layer The material of the antioxidant layer is Ta, its compounds, or its alloys, and the material of the antioxidant layer is Al, Al2O3 Alternatively, it is polyimide.

[0031] Furthermore, the polyimide has the following molecular structural formula. [ka]

[0032] A target used in a particle beam generator according to a fourth aspect of the present invention is a polymer fiber. The antioxidant layer, which is made of aluminum, interacts with the incident charged particle beam to generate a neutron beam. A working layer, and a generating layer that can suppress foaming of the working layer during the process of generating the particle beam. The system includes a foam suppression layer and a heat dissipation layer, and the oxidation prevention layer isolates the working layer from the air. The target does not need to be stored in any special way and can be exposed to the air, especially the target It is very convenient when installing and replacing, and the oxidation prevention layer is further in the working layer This prevents by-products from overflowing from the target.

[0033] Preferably, the material of the polymer film is a polyimide having the following molecular structural formula. ru. [ka]

[0034] Preferably, the antioxidant layer is processed into the working layer by a film coating process. Furthermore, the thickness of the antioxidant layer is greater than 5 nm.

[0035] Preferably, the target further includes a heat conductive layer and has low heat dissipation performance of the foam suppression layer. Therefore, the amount of heat accumulated in the working layer cannot be effectively transferred to the heat dissipation layer, so the heat conduction layer The system is installed to directly and rapidly transfer the heat accumulated in the working layer to the heat dissipation layer, and to cool the heat dissipation layer. By releasing heat through the medium, the target temperature is lowered, thus reducing the target temperature. To prevent deformation caused by excessively high pressure, extend the service life of the target, and the foam-suppressing layer It is installed between the heat dissipation layer and the heat conduction layer, and the heat conduction layer is connected to the heat dissipation layer. Furthermore, a housing space for accommodating the foam suppression layer is formed in the heat dissipation layer or the heat conduction layer. Since heat is not conducted through the foam-suppressing layer, the heat conduction of the foam-suppressing layer is... There is no need to consider the properties of the material; only the foam-preventing properties need to be considered.

[0036] Furthermore, the containment space includes a bottom surface and side walls connected to the bottom surface, and the foam suppression The layer has a top surface that contacts the bottom surface and an outer wall that contacts the side wall. Furthermore, the heat The thickness of the conductive layer is 5 μm to 50 μm.

[0037] Furthermore, the target is flat and has a central perpendicular line perpendicular to the surface of the plate, and the center In the same radial direction perpendicular to the perpendicular, the maximum distance from the working layer to the central axis is the The distance from the foam suppression layer to the central axis is smaller than the maximum distance from the foam suppression layer to the central axis The maximum distance to the line is the maximum distance from the heat conduction layer to the central axis and from the heat dissipation layer. It is smaller than the maximum distance to the aforementioned central axis.

[0038] Furthermore, the working layer, the heat conductive layer, and the foam suppression layer are formed in a manner that creates a film. The heat dissipation layer is processed in sequence.

[0039] Furthermore, the material of the working layer is Li, its compounds, or its alloys, and the thermal conductive layer and The material of the heat dissipation layer is Cu, a compound thereof, or an alloy thereof, and the material of the foam suppression layer is , Ta, its compounds or alloys. Furthermore, the working layer has a thickness of 49 μm to 18 It is 9 μm in size and reacts well with proton beams with energies of 2.2 MeV to 3 MeV, and gamma rays It reduces pollution caused by excessive thickness and prevents energy buildup, thus reducing the emission of the target. Without affecting thermal performance, the foam suppression layer prevents foaming caused by the charged particle beam. The incident charged particle beam is suppressed and configured to have a thickness of 5 μm to 50 μm. This rapidly diffuses the hydrogen generated within the target, thereby reducing the concentration of hydrogen, or By releasing hydrogen to the outside, the foaming caused by the incident charged particle beam is effectively suppressed. This avoids or reduces deformation caused by foaming of the target, extending the target's service life. It can be extended.

[0040] The substrate of the target used in the particle beam generator according to the fifth aspect of the present invention is the A foam suppression layer that can suppress foaming of the target during the process of generating a particle beam, The first heat dissipation layer and the second heat dissipation layer are included to conduct the heat accumulated in the target to the outside, The foam suppression layer is installed between the first heat dissipation layer and the second heat dissipation layer, and the first heat dissipation layer is It is connected to the second heat dissipation layer.

[0041] Preferably, the first heat dissipation layer and the second heat dissipation layer surround the foam suppression layer, and the first A housing space for accommodating the foam suppression layer is formed in the heat dissipation layer or the second heat dissipation layer. The containment space includes a bottom surface and side walls connected to the bottom surface, and the foam suppression layer is It has a top surface that contacts the bottom surface and an outer wall that contacts the side wall.

[0042] Preferably, the first heat dissipation layer and the foam suppression layer are formed in a way that creates a film, and the second heat dissipation layer The heat layers are processed sequentially.

[0043] Preferably, the base material is flat and has a central axis perpendicular to the surface of the plate, and the middle In the same radial direction perpendicular to the central axis, the maximum distance from the foam suppression layer to the central axis is , the maximum distance from the first heat dissipation layer to the central axis and the distance from the second heat dissipation layer to the central axis It is smaller than the maximum distance to [the specified location].

[0044] Preferably, the material of the first heat dissipation layer and the second heat dissipation layer is Cu, a compound thereof, or an alloy thereof. The material of the foam-suppressing layer is Ta, a compound thereof, or an alloy thereof.

[0045] A neutron capture therapy system according to a sixth aspect of the present invention comprises a neutron generator and a beam shaping device. The neutron generator includes an accelerator and a target, and the neutrons are accelerated by the accelerator. The charged particle beam generated interacts with the target to generate a neutron beam, The beam shaping apparatus includes a reflector, a speed reducer, a thermal neutron absorber, a radiation shield, and a beam outlet. The speed reducer reduces the neutrons generated by the target to the epithermal neutron energy region. The reflector surrounds the decelerator and guides the escaping neutrons to the decelerator, thus preventing heat loss. The neutron beam intensity is improved, and the thermal neutron absorber prevents excess neutrons from entering superficial normal tissue during treatment. To avoid administering a dose, the radiation shield absorbs thermal neutrons, and the beam It is installed around the exit and is designed to reduce the dose to normal tissue in the non-irradiated area. The target shields neutrons and photons, and interacts with the charged particle beam to block the neutron beam. A working layer that generates particles, and a position located behind the working layer along the incident direction of the charged particle beam. Furthermore, a foam suppression layer that can suppress foaming by the charged particle beam, and the charged particle beam The heat amount located behind the foam suppression layer along the direction of incidence and accumulated in the target It includes a heat dissipation layer that conducts heat to the outside, and a heat conduction layer that conducts the heat from the working layer to the heat dissipation layer. The foam suppression layer has low heat dissipation performance, and the heat accumulated in the working layer is not effectively transferred to the heat dissipation layer. Because this is not possible, a heat conduction layer is installed to directly and quickly transfer the heat accumulated in the working layer to the heat dissipation layer. By conducting heat and dissipating it through the cooling medium in the heat dissipation layer, the target temperature is reduced. By lowering the temperature, deformation caused by excessively high target temperatures is prevented, and the target's service life is extended. Extend the number.

[0046] Preferably, the heat conductive layer is installed between the working layer and the foam suppression layer, and before By connecting to the heat dissipation layer, the contact area with the working layer is large, and the amount of heat transferred to the heat dissipation layer is rapid. It can conduct electricity quickly.

[0047] Preferably, the heat dissipation layer and the heat conduction layer surround the foam suppression layer and the heat conduction The layer is connected to the heat dissipation layer. Since the amount of heat is not basically conducted by the foam suppression layer, Regarding the foam suppression layer, there is no need to consider its thermal conductivity; only the foam prevention properties need to be considered. Good. Furthermore, the heat dissipation layer or the heat conduction layer has a housing space for housing the foam suppression layer. It is formed. Furthermore, the containment space includes a bottom surface and side walls connected to the bottom surface, The foam-suppressing layer has a top surface that contacts the bottom surface and an outer wall that contacts the side wall.

[0048] Preferably, the foam-suppressing layer is made of a material that suppresses foaming, for example, a hydrogen diffusion agent at 200°C. Number 10E-6cm 2 It is manufactured using materials of / s or higher, and furthermore, the material of the foam suppression layer is N b, Ta, Pd, V, and at least one of their alloys and compounds, and the heat dissipation The layers and the heat conduction layer are manufactured from a heat conduction material, and furthermore, the materials of the heat dissipation layer and the heat conduction layer are It contains at least one of Cu, Fe, Al, their alloys, and compounds.

[0049] Preferably, the target further includes an antioxidant layer that prevents oxidation of the working layer. The oxidation prevention layer is positioned in front of the working layer along the incident direction of the charged particle beam, The antioxidant layer eliminates the need to store the target and allows it to be exposed to air. This is especially convenient when installing and replacing targets, and the oxidation prevention layer is Furthermore, it is possible to prevent by-products in the working layer from overflowing from the target, and oxidation Regarding the material of the protective layer, it must be resistant to corrosion by the working layer and also reduce the loss of the incident proton beam. And it was also considered that the heat generated by the proton beam could be reduced, and furthermore, The material of the anti-oxidation layer is Al, Ti, their alloys and compounds, or stainless steel. Includes at least one type.

[0050] Furthermore, the oxidation prevention layer, the working layer, the heat conduction layer, the foam suppression layer and the heat dissipation layer These are installed sequentially along the direction of incidence of the charged particle beam.

[0051] Furthermore, the working layer, heat conduction layer, and foam suppression layer are formed in a film manner to dissipate heat. The layers are processed sequentially, and the antioxidant layer is processed into the working layer in a manner that forms a film. It is either a polymer film and is processed into the working layer by a film coating process. Furthermore, the materials of the oxidation prevention layer, working layer, heat conduction layer, and foam suppression layer are sequentially subjected to a vacuum environment. By evaporating the gas and depositing it on the heat dissipation layer, the thickness of each layer of the target can be precisely controlled. It can be controlled.

[0052] Furthermore, the target is flat and has a central axis perpendicular to the surface of the plate, In the same radial direction perpendicular to the central axis, the maximum distance from the working layer to the central axis is: The maximum distance from the foam suppression layer to the central axis and the distance from the oxidation prevention layer to the central axis The maximum distance is smaller than the maximum distance at the center axis, and the maximum distance from the foam suppression layer to the central axis is the heat dissipation The maximum distance from the layer to the central axis and the maximum distance from the heat conductive layer to the central axis It's small.

[0053] Furthermore, the material of the working layer is Li, its compounds, or its alloys, and the charged particles are The beam is a proton beam, and the materials of the heat dissipation layer and the heat conduction layer are Cu, its compounds, or The alloy is, and the material of the foam suppression layer is Ta, a compound thereof or an alloy thereof, and the acid The material for the anti-corrosion layer is Al, Al2O3, or polyimide.

[0054] Furthermore, the polyimide has the following molecular structural formula. [ka]

[0055] Furthermore, the aforementioned proton beam has an energy of 2.2 MeV to 3 MeV, and lithium It can generate a high action surface area and avoid producing too many fast neutrons. Without doing so, to obtain a higher quality beam, the working layer has a thickness of 49 μm to 189 μm. It can react sufficiently with protons, reduces gamma ray contamination, and reduces energy consumption due to excessive thickness. Without causing energy accumulation and affecting the target's heat dissipation performance, the foam suppression The layer has a thickness of 5 μm to 50 μm, and the incident charged particle beam penetrates the target. The hydrogen generated is rapidly diffused to reduce the concentration of hydrogen or to release the hydrogen to the outside. By effectively suppressing foaming caused by the incident charged particle beam, the target emission This can avoid or reduce deformation caused by foam, and extend the service life of the target. The thickness of the oxidation-preventive layer is greater than 5 nm, and the thickness of the thermal conductive layer is 5 μm to 50 μm. Therefore, the service life of the target is 200mA-h or more.

[0056] Preferably, the neutron capture therapy system further includes a treatment table and a collimator, and the The neutron beam generated by the neutron generator passes through the beam shaping body onto the treatment table. The beam is irradiated onto the patient, and between the patient and the beam outlet, the beam emitted from the beam outlet is present. A radiation shielding device is installed to shield the normal tissue of the person from radiation, and the collimator is the beam Installed after the exit, it collects the neutron beam and contains a first cooling tube and a second cooling tube within the beam shaping body. Cooling pipes are installed, and the heat dissipation layer of the target has a cooling inlet, a cooling outlet, and the cooling inlet There is a zigzag-shaped cooling passage installed between the cooling outlet and the first cooling pipe and the second The cooling pipe has one end connected to the cooling inlet and cooling outlet of the target, respectively, and the other end is connected to the outside The cooling source is connected to the zigzag cooling passage, and the curvature geometry of the zigzag cooling passage is continuously curved. Smooth curves or sequentially end-to-end connected curve segments or straight segments The continuous, smooth curve is a sine wave function. The zigzag path is By extending the flow path and increasing the contact area between the heat conduction wall and the cooling medium, the heat dissipation surface is increased. This also creates a secondary flow, improving the mixing effect and enhancing heat conduction and heat dissipation capabilities. This can be done, helping to extend the service life of the target. The cooling passage is continuous. Using a smoothly curved shape, such as a sine wave function, further reduces the flow resistance due to the flow path. It can be reduced.

[0057] Furthermore, the target is located within the beam shaping body, and the accelerator is a charged particle beam It has an accelerating tube that accelerates the charged particle beam, and the accelerating tube shapes the beam along the direction of the charged particle beam. It extends to the body and sequentially penetrates the reflector and the decelerator, and the target is located inside the decelerator. The first cooling tube and the second cooling tube are located at the end of the acceleration tube, and the acceleration tube It is installed between the reflector and the deceleration body.

[0058] A neutron capture therapy system according to a seventh aspect of the present invention comprises a neutron generator and a beam shaping device. The neutron generator includes an accelerator and a target, and the neutrons are accelerated by the accelerator. The charged particle beam generated interacts with the target to generate a neutron beam, The beam shaping apparatus includes a reflector, a speed reducer, a thermal neutron absorber, a radiation shield, and a beam outlet. The speed reducer reduces the neutrons generated by the target to the epithermal neutron energy region. The reflector surrounds the decelerator and guides the escaping neutrons to the decelerator, thus preventing heat loss. The neutron beam intensity is improved, and the thermal neutron absorber prevents excess neutrons from entering superficial normal tissue during treatment. To avoid administering a dose, the radiation shield absorbs thermal neutrons, and the beam It is installed around the exit and is designed to reduce the dose to normal tissue in the non-irradiated area. The target shields neutrons and photons, and interacts with the charged particle beam to block the neutron beam. A working layer that generates foam, and a suppression of foaming in the working layer during the process of generating a neutron beam. It includes a foam suppression layer and a heat dissipation layer, and the working layer has a thickness of 49 μm to 189 μm. Yes, it can react sufficiently with the proton beam, reduces gamma ray contamination, and is not too thick. This does not cause energy accumulation and affect the target's heat dissipation performance.

[0059] Preferably, the thickness of the working layer is 97 μm.

[0060] Preferably, the target is placed between the working layer and the foam suppression layer, and It further includes a heat conduction layer connected to the heat dissipation layer, which conducts the heat from the working layer to the heat dissipation layer. The foam suppression layer has low heat dissipation performance, and the heat accumulated in the working layer is not effectively transferred to the heat dissipation layer. Because this is not possible, a heat conduction layer is installed to directly and quickly transfer the heat accumulated in the working layer to the heat dissipation layer. By conducting heat rapidly and dissipating heat through a cooling medium in the heat dissipation layer, the target temperature is reached. By reducing the temperature, deformation caused by excessively high target temperatures is prevented, and the target's durability is extended. The lifespan is extended. Furthermore, the thickness of the thermal conductive layer is 5 μm to 50 μm, and the foam suppression The thickness of the suppression layer is 5 μm to 50 μm, and the foam suppression layer is affected by the incident charged particle beam. The hydrogen generated in the target is rapidly diffused to reduce the concentration of hydrogen, or the hydrogen By releasing the particles to the outside and effectively suppressing foaming caused by the incident charged particle beam, To avoid or reduce deformation caused by foaming of the target, and to extend the service life of the target. It is possible.

[0061] Preferably, the material of the working layer is Li, a compound thereof, or an alloy thereof, and the charged particles The particle beam has an energy of 2.2 MeV to 3 MeV, and has high compatibility with lithium targets. It can generate usable cross-sections without generating excessive high-speed neutrons, resulting in higher quality Obtain the beam.

[0062] Furthermore, the material of the heat dissipation layer and the heat conduction layer is Cu, a compound thereof, or an alloy thereof. The material of the foam-suppressing layer is Ta, its compounds, or its alloys.

[0063] Furthermore, the working layer, heat conduction layer, and foam suppression layer are formed in a film manner to dissipate heat. The layers are processed sequentially.

[0064] Furthermore, the target is flat and has a central axis perpendicular to the surface of the plate, In the same radial direction perpendicular to the central axis, the maximum distance from the working layer to the central axis is: The distance from the foam suppression layer to the central axis is smaller than the maximum distance from the foam suppression layer to the central axis, and The maximum distance to the central axis is the maximum distance from the heat dissipation layer to the central axis and the heat conduction layer It is smaller than the maximum distance from the central axis.

[0065] Preferably, the target isolates the working layer from air and has a thickness greater than 5 nm. It also contains a large antioxidant layer, and the antioxidant layer eliminates the need to store the target in a special way. Furthermore, it can be exposed to the air, which is especially useful when attaching and replacing targets. It is convenient for this purpose, and the antioxidant layer further prevents byproducts in the working layer from overflowing from the target. This can prevent this, and the material of the oxidation-preventive layer is less susceptible to corrosion by the working layer. Furthermore, it is possible to reduce the loss of the incident proton beam and the heat generated by the proton beam. The following factors are considered simultaneously, and the antioxidant layer is made of Al2O3 or polyimide, The working layer is processed in a manner that forms a film, or it is a polymer film, and is a film The working layer is processed by a coating process.

[0066] The target used in the particle beam generator according to the eighth aspect of the present invention is a charged particle beam The system includes, in order along the incident direction of the element, an oxidation prevention layer, a working layer, a foam suppression layer, and a heat dissipation layer. The working layer interacts with a charged particle beam to generate a neutron beam, and has a thickness of 49 μm to 18 It is 9 μm thick, allowing it to react sufficiently with protons, reducing gamma ray contamination, and is not too thick. This does not cause energy accumulation and affect the target's heat dissipation performance. The oxidation-preventive layer isolates the working layer from air and has a thickness greater than 5 nm, preventing oxidation. The protective layer eliminates the need to store the target in a special way, allowing it to be exposed to air. It is very convenient when attaching and replacing targets, and the oxidation prevention layer further This prevents by-products in the working layer from overflowing from the target, thus preventing oxidation. Regarding the layer material, it must be resistant to corrosion by the working layer and also reduce the loss of the incident proton beam. It was also considered that the heat generated by the proton beam could be reduced, and the foam suppression layer This suppresses foaming caused by the charged particle beam and has a thickness of 5 μm to 50 μm. The hydrogen generated in the target by the configured and incident charged particle beam is rapidly diffused. This reduces the concentration of hydrogen or releases hydrogen to the outside, and then the incident charged particle beam... By effectively suppressing foaming, deformation of the target due to foaming can be avoided or This can reduce the target's lifespan and extend its useful life.

[0067] Preferably, the charged particle beam has an energy of 2.2 MeV to 3 MeV, It can generate a high action surface with a thium target, and also generates excess fast neutrons To obtain a higher quality beam without generating any unwanted particles.

[0068] Preferably, the target conducts the heat from the working layer to the heat dissipation layer and has a thickness of 5 μm. It further includes a heat-conducting layer with a thickness of m~50μm. The foam suppression layer has low heat dissipation performance and heat accumulates in the working layer. Because the heat generated cannot be effectively transferred to the heat dissipation layer, a heat conduction layer is installed to facilitate the process. The heat accumulated in the layer is directly and rapidly transferred to the heat dissipation layer, and the heat is then cooled by the cooling medium in the heat dissipation layer. By releasing the gas, the target temperature is lowered, preventing the target temperature from becoming too high. This prevents deformation caused by [unspecified factor] and extends the service life of the target.

[0069] Furthermore, the foam suppression layer is installed between the heat dissipation layer and the heat conduction layer, and the heat conduction The layer is connected to the heat dissipation layer, and the heat dissipation layer or the heat conduction layer contains the foam suppression layer. A containment space is formed. Since heat is not conducted by the foam suppression layer, foam suppression is achieved. Regarding the coating, there is no need to consider its thermal conductivity; only its foam-preventing properties need to be considered. .

[0070] Furthermore, the material of the working layer is Li, its compounds, or its alloys, and the heat dissipation layer and The material of the thermal conductive layer is Cu, its compounds, or its alloys, and the material of the foam suppression layer is T a, the compound or alloy thereof, wherein the antioxidant layer is made of Al2O3 or polyimide. To be created.

[0071] Furthermore, the working layer, heat conduction layer, and foam suppression layer are formed in a film manner to dissipate heat. The layers are processed sequentially, and the antioxidant layer is processed into the working layer in a manner that forms a film. It is either a polymer film and is processed into the working layer by a film coating process. ru.

[0072] Furthermore, the target is flat and has a central axis perpendicular to the surface of the plate, In the same radial direction perpendicular to the central axis, the maximum distance from the working layer to the central axis is: The maximum distance from the foam suppression layer to the central axis and the distance from the oxidation prevention layer to the central axis The maximum distance is smaller than the maximum distance at the center axis, and the maximum distance from the foam suppression layer to the central axis is the heat dissipation The maximum distance from the layer to the central axis and the maximum distance from the heat conductive layer to the central axis It's small.

[0073] A ninth aspect of the present invention provides a target processing apparatus for use in a particle beam generator. The target comprises a working layer that generates the particle beam, and a layer that generates the particle beam. A foam suppression layer that can suppress foaming of the working layer during the process, and a foam suppression layer that accumulates on the target The processing apparatus includes a heat dissipation layer that conducts the heat to the outside, and the processing apparatus includes a vacuum chamber, an exhaust device, and an evaporation The exhaust system includes a power source, a support frame, and a heating device, and the exhaust device exhausts air from the vacuum chamber. A vacuum environment is formed, and the evaporation source uses the materials of the foam suppression layer and the working layer in the vacuum channel. The gas is evaporated sequentially by the vacuum, and the support frame is used to place the heat dissipation layer, The heating device is configured to sequentially deposit the gas material onto the surface of the heat dissipation layer facing the evaporation source. Next, the heat dissipation layer is heated. Using this processing device, the thickness of each layer of the target can be precisely controlled. It can be controlled

[0074] Preferably, the target further includes an antioxidant layer that prevents oxidation of the working layer. The evaporation source evaporates the working layer into a gas, and then evaporates the antioxidant layer into a gas. .

[0075] Preferably, the target has a heat conductive layer that conducts the heat of the working layer to the heat dissipation layer. Furthermore, the evaporation source evaporates the foaming suppression layer into gas and then the heat conductive layer into gas The foam suppression layer has low heat dissipation performance, and the working layer Because the heat accumulated in the heat cannot be effectively transferred to the heat dissipation layer, a heat conduction layer is installed. The heat accumulated in the working layer is directly and rapidly transferred to the heat dissipation layer, and the heat dissipation layer is cooled by the cooling medium. By releasing heat, the target temperature is lowered, and the target temperature rises. This prevents deformation caused by excessive force and extends the service life of the target.

[0076] Furthermore, the processing apparatus detects the thickness of the working layer and the foam suppression layer, and the gas deposition rate The system further includes a film thickness detection device that controls the degree of thickness.

[0077] A tenth aspect of the present invention provides a method for processing a target used in a particle beam generator. The target comprises a working layer that generates the particle beam, and a layer that generates the particle beam. A foaming suppression layer that can suppress foaming of the working layer during the foaming process, and a foaming suppression layer that accumulates on the target A heat dissipation layer that conducts the amount of heat absorbed to the outside, and a heat conduction layer that conducts the amount of heat from the working layer to the heat dissipation layer. The processing method includes a method of forming a film on the heat dissipation layer, in which the foam suppression layer is formed in order. This includes processing the heat conduction layer and the working layer. The foam suppression layer has low heat dissipation performance and heat accumulates in the working layer. Because the heat generated cannot be effectively transferred to the heat dissipation layer, a heat conduction layer is installed to facilitate the process. The heat accumulated in the layer is directly and rapidly transferred to the heat dissipation layer, and the heat is then cooled by the cooling medium in the heat dissipation layer. By releasing the gas, the target temperature is lowered, preventing the target temperature from becoming too high. This prevents deformation caused by and extends the service life of the target, and when this processing method is used, the target The thickness of each layer of the net can be precisely controlled.

[0078] Preferably, the target further includes an antioxidant layer that prevents oxidation of the working layer. The processing method involves coating the working layer with a film-like antioxidant layer or the antioxidant layer This includes processing the working layer in a manner that forms a film.

[0079] Preferably, the method for forming the film is physical vapor deposition, sputtering, or thermal welding. Alternatively, it is atomic layer deposition.

[0080] An eleventh aspect of the present invention provides a method for processing targets used in neutron beam generators. The target is provided with a working layer that interacts with a charged particle beam to generate a neutron beam. , located in front of the working layer along the incident direction of the charged particle beam, and the acid of the working layer An oxidation-preventing layer to prevent oxidation, and a position located behind the working layer along the incident direction of the charged particle beam. A foam suppression layer is placed and can suppress foaming by the charged particle beam, and the charged particle beam Located behind the foam suppression layer along the direction of incidence of the foam, and the heat accumulated in the target It includes a heat dissipation layer that conducts heat to the outside, and the oxidation prevention layer and the working layer are processed by different methods. .

[0081] Preferably, the target has a heat conductive layer that conducts the heat of the working layer to the heat dissipation layer. Furthermore, the foam suppression layer, heat conduction layer and working layer are formed in a manner that creates a film. The materials are processed sequentially into a heat layer. Furthermore, the materials of the foam suppression layer, heat conduction layer and working layer are subjected to a vacuum environment. By sequentially evaporating the gas and depositing it on the heat dissipation layer, the thickness of each layer of the target is precisely controlled. It can be controlled precisely.

[0082] Preferably, the antioxidant layer is a polymer film, and is formed by a film coating process. The aforementioned working layer is processed. Furthermore, using a polymer film makes assembly easier and reduces costs. stomach.

[0083] Target used in the neutron capture therapy system and particle beam generator of the present invention In this system, a first heat dissipation layer is installed to directly and quickly transfer the heat accumulated in the working layer to the second heat dissipation layer. By conducting heat to the target and dissipating heat through the cooling medium in the second heat dissipation layer, the target temperature By lowering the temperature, deformation caused by excessively high target temperatures is prevented, and the target's resistance is reduced. Extend the service life. [Brief explanation of the drawing]

[0084] [Figure 1] This is a schematic diagram of a neutron capture therapy system in an embodiment of the present invention. [Figure 2] This is a schematic diagram of a target in an embodiment of the present invention. [Figure 3] Figure 2 is an exploded view of the target. [Figure 4] Figure 2 is a schematic diagram of the first embodiment of the heat dissipation layer of the target. [Figure 5] This is a schematic diagram of the first heat dissipation layer in Figure 4. [Figure 6] Figure 2 is a schematic diagram of the second embodiment of the heat dissipation layer of the target. [Figure 7]This is a schematic diagram of the first heat dissipation layer in Figure 6. [Figure 8] This is a schematic diagram of a target processing apparatus in an embodiment of the present invention. [Figure 9] This is a flowchart of the target processing method in an embodiment of the present invention. [Figure 10] This is the neutron yield obtained by impacting lithium targets of different thicknesses with 2.2 MeV protons, as calculated by simulation, in an embodiment of the present invention. [Figure 11] This is the neutron yield obtained by impacting lithium targets of different thicknesses with 2.5 MeV protons, as calculated by simulation, in an embodiment of the present invention. [Figure 12] This is the neutron yield obtained by impacting lithium targets of different thicknesses with 3 MeV protons, as calculated by simulation, in an embodiment of the present invention. [Modes for carrying out the invention]

[0085] The embodiments of the present invention will be described in more detail below with reference to the drawings, so that those skilled in the art may understand. If available, this can be done by referring to the text in the specification.

[0086] As shown in Figure 1, the neutron capture therapy system in this embodiment is preferably boron-based The neutron capture therapy system 100 includes a neutron generator 10, a beam shaping device 20, and a collimator. The neutron generator 10 includes the accelerator 11 and the target T. The accelerator 11 accelerates charged particles (such as protons and deuterium nuclei) to produce protons. A charged particle beam C is generated, and the charged particle beam C is irradiated onto the target T. And, in interaction with target T, generates a neutron beam N, and target T is preferably The target is a metal. The required neutron yield and energy, and the available accelerated charged particles Depending on the magnitude of the energy and current, the physical and chemical properties of the metal target, etc., Selecting a nuclear reaction, the nuclear reactions that are generally considered are: 7 Li(p,n) 7 Be and 9 B e(p,n) 9 B is the case, and both of these reactions are endothermic reactions. The two types of nuclear reactions have energy thresholds of 1.881 MeV and 2.055 MeV, respectively. Therefore, the ideal neutron source for boron neutron capture therapy is epithermal neutrons at the keV energy level. Therefore, theoretically, protons with energy slightly above the threshold can be targeted to metallic lithium. By striking it, relatively low-energy neutrons can be generated, and It can be used clinically without requiring much deceleration, but lithium (Li) and The interaction surface between the two types of beryllium (Be) targets and protons at the threshold energy is high. In order to generate a sufficient neutron flux, protons with relatively high energy are generally used. This triggers a nuclear reaction. An ideal target is one with a high neutron yield, and the generated neutrons The energy distribution is close to the epithermal neutron energy region (explained in detail below), resulting in strong penetration. It does not emit much radiation of a certain nature, is safe, inexpensive, easy to operate, and heat resistant. While they may possess certain characteristics, it is practically impossible to find a nuclear reaction that satisfies all the requirements. As is well known to those skilled in the art, the target T is made of an alloy, compound or other material of Li, Be. It may be manufactured, for example, by forming Ta or W and their alloys or compounds. Accelerator 1 1 is a linear accelerator, cyclotron, synchrotron, synchrocyclotron. That's good too.

[0087] The neutron beam N generated by the neutron generator 10 is then directed to the beam shaping body 20 and collimated. The beam is irradiated onto the patient 200 on the treatment table 40 through the beam 30. The beam shaping body 20 is neutral The beam quality of the neutron beam N generated by the neutron generator 10 can be adjusted, Meter 30 collects the neutron beam N, and the neutron beam N is used in the treatment process. It has high targetability. The beam shaping body 20 consists of a reflector 21, a decelerator 22, and a thermal neutron absorber. 23. Further comprising a radiation shield 24 and a beam outlet 25, the neutron generator 10 generates Because the energy spectrum of the generated neutrons is broad, in addition to the epithermal neutrons that meet therapeutic needs, To minimize the content of other types of neutrons and photons, and to avoid causing harm to the operator or patient. To avoid causing this, the neutrons emitted from the neutron generator 10 are directed to the decelerator. Through 22, the energy of fast neutrons (>40 keV) enters the epithermal neutron energy region (0 It needs to be adjusted to 0.5eV~40keV, and the decelerator 22 intermittently interacts with fast neutrons. It is manufactured from a material with a large surface area and a small cross-section for interaction with epithermal neutrons, and in this embodiment, the deceleration Body 22 is D2O, AlF3, Fluental™, CaF2, Li2CO3, MgF Made from at least one of 2 and Al2O3, the reflector 21 surrounds the deceleration body 22. Furthermore, the neutrons that have passed through the decelerator 22 and diffused into the surroundings are reflected back to the neutron beam N. The utilization rate is improved, and the material is manufactured with high neutron reflectivity. In this embodiment, the reflector 2 1 is made of at least one of Pb or Ni, and the moderator 22 has thermal neutrons at its rear (<0.5eV) absorber 23 is present and manufactured from a material with a large surface area for interaction with thermal neutrons. In the example, the thermal neutron absorber 23 is made of Li-6 and absorbs the heat that has passed through the moderator 22. By absorbing neutrons, the thermal neutron content in neutron beam N is reduced, and shallow orthogonal pulses are detected during treatment. To avoid giving unnecessary doses to normal tissue and to make it understandable, thermal neutron absorbers slow down radiation. It may be integrated with the body, the material of the speed reducer contains Li-6, and the radiation shield 24 is a bee It is installed surrounding the beam outlet 25 and blocks neutrons and photons that leak out from parts other than the beam outlet 25. The material of the radiation shielding body 24 is at least one of the photon shielding material and the neutron shielding material. It includes one type, and in this embodiment, the material of the radiation shield 24 is lead (Pb) as a photon shielding material. and includes polyethylene (PE) as a neutron shielding material. To make it easier to understand, beam shaping body 20 This could be any other structure, as long as it provides the epithermal neutron beam necessary for treatment. The meter 30 is installed behind the beam outlet 25, and the epithermal neutron beam emitted from the collimator 30 The beam is irradiated onto patient 200, passes through superficial normal tissue, and is then slowed down by thermal neutrons to tumor cells. Upon reaching cell M, as can be understood, collimator 30 may be removed or replaced by other structures. However, the neutron beam exits from beam exit 25 and directly irradiates the patient 200. In this embodiment, between the patient 200 and the beam outlet 25, there is further a beam outlet 25 A radiation shielding device 50 is installed to shield the beam emitted from the device from radiation into the patient's normal tissue, and understanding Therefore, it is not necessary to install the radiation shielding device 50.

[0088] Patient 200 took or was injected with a boron (B-10)-containing drug, and subsequently... The drug is selectively accumulated in tumor cells M, and then the boron (B-10)-containing drug is targeted by thermal neutrons. In contrast, by utilizing the characteristic of having a high capture cross-section, 10B(n,α)7Li neutron capture is performed. Furthermore, nuclear fission reactions produce two types of heavy charged particles: 4He and 7Li. The charged particles have an average energy of approximately 2.33 MeV and offer high linear energy transfer (Li It has the characteristics of near energy transfer (LET) and short range. The linear energy transfer and range of the alpha particle are 150 keV / μm and 8 μm, respectively, and 7L The linear energy transfer and range of the heavily charged particles are 175 keV / μm and 5 μm, and there are two types. The total range of these particles is equivalent to the size of a single cell, thus reducing radiation damage to living organisms. Under the premise that the tumor cells are contained by the bell and do not cause too much damage to normal tissue, the tumor cells are locally controlled. This allows you to achieve your objective of killing.

[0089] The structure of target T will be described in detail below with reference to Figures 2 and 3.

[0090] Target T is placed between accelerator 11 and beam shaping body 20, and accelerator 11 is load The accelerating tube 111 accelerates the electron particle beam C, and in this embodiment, the accelerating tube 111 is a load The electric particle beam C extends into the beam shaping body 20 along its direction and is subsequently decelerated by the reflector 21. The target T penetrates the body 22 and is located within the deceleration body 22 and at the end of the acceleration pipe 111. By positioning it this way, a high-quality neutron beam is obtained.

[0091] Target T consists of a working layer 12, a foam suppression layer 13, a (first) heat dissipation layer 14, and a (second heat dissipation layer 13. The thermal layer includes a thermal conductive layer 15. The working layer 12 interacts with the charged particle beam C to form a neutron beam. In the process of generating neutrons, the target reaches a very high energy level. Because it is irradiated by the accelerated charged particle beam C, it causes foaming and temperature rise of the target. This causes foaming, reducing the lifespan of the target. The foam suppression layer 13 is a charged particle beam C Located behind the working layer 12 along the direction of incidence, and affected by the incident charged particle beam C Rapidly diffuse the hydrogen generated during Get T to reduce the concentration of hydrogen or remove the hydrogen By releasing it into the area and effectively suppressing foaming caused by the incident charged particle beam C, To avoid or reduce deformation caused by foaming of the target, and to extend the service life of the target. The foam suppression layer 13 is made of a material that suppresses foaming, for example, a hydrogen diffusion agent at 200°C. The material is manufactured with a number of 10E-6 cm2 / s or more, and in one example, the foam suppression layer 13 The material includes at least one of Nb, Ta, Pd, V, their alloys, and compounds. The heat dissipation layer 14 is located behind the foam suppression layer 13 along the incident direction of the charged particle beam C, By conducting the heat accumulated in the target and dissipating it through the cooling medium, the target By lowering the temperature of the target, deformation caused by excessively high temperature of the target is prevented, To extend the service life. Because the foam suppression layer 13 has low heat dissipation performance, the heat accumulated in the working layer 12 Since heat cannot be effectively transferred to the heat dissipation layer 14, a heat conduction layer 15 is installed to perform The heat accumulated in the heat dissipation layer 12 is directly and rapidly transferred to the heat dissipation layer 14. The conductive layer 15 is made of a thermal conductive material, and in one embodiment, the heat dissipation layer 14 and the thermal conductive layer 15 The material includes at least one of Cu, Fe, Al, their alloys, and compounds. The conductive layer 15 is installed between the working layer 12 and the foam suppression layer 13 and is connected to the heat dissipation layer 14. In other words, the foam suppression layer 13 is located between the heat dissipation layer 14 and the heat conduction layer 15 that are connected to each other. With this installation, the heat conductive layer 15 has a large contact area with the working layer 12. Furthermore, the heat can be quickly transferred to the heat dissipation layer 14, and the heat is basically transferred to the foam suppression layer 13. Since it does not conduct heat, there is no need to consider the thermal conductivity of the foam suppression layer 13. Only the foam prevention characteristics need to be considered. As shown in Figure 3, in this embodiment, the heat dissipation layer 14 and The thermal conductive layer 15 surrounds the foam suppression layer 13, and the thermal conductive layer 15 contains the foam suppression layer 13. A storage space 151 is formed, and the storage space 151 is connected to the bottom surface 1511. The foam suppression layer 13 includes a side wall 1512 and a top surface 131 that is in contact with the bottom surface 1511. The outer wall 132 is in contact with the side wall 1512, and as can be understood, the containment space is in the heat dissipation layer It may be formed, or it may be formed together in the heat conduction layer and the heat dissipation layer. Target T is the action The material may further include an antioxidant layer 16 that prevents oxidation of layer 12, and the antioxidant layer 16 is charged Located in front of the working layer 12 along the incident direction of the particle beam C, the antioxidant layer 16 and the thermal conductive layer 1 5 seals the working layer 12, that is, isolates the working layer 12 from the air, Get T doesn't need to be stored in any special way and can be exposed to air, especially when targeting It is extremely convenient when installing and replacing, and significantly reduces costs, and has an oxidation-resistant layer 1 6. Furthermore, byproducts (e.g., 8Be) in the working layer 12 overflow from the target T. This can prevent corrosion, and the material of the oxidation-preventive layer 16 is less susceptible to corrosion by the working layer. Furthermore, it is possible to reduce the loss of the incident proton beam and the heat generated by the proton beam. This is also taken into consideration, for example, Al, Ti, their alloys and compounds or stainless steel. It contains at least one of the following, and in one example, Al2O3 is used, and after its pre-oxidation Furthermore, it has a higher antioxidant effect, and the radiation after Al is activated by neutrons The product has a shorter half-life, reduces secondary emission, and in other examples, the antioxidant layer 16 is a polymer film, for example, a polyimide (PI) film. Polyimide has the following molecular structure. [ka]

[0092] Polyimide is resistant to high temperatures, has high insulation properties, excellent mechanical properties, and high radiation resistance. It has a thermal decomposition temperature that reaches over 400 degrees Celsius, and effectively shields high-energy neutrons. This allows for reducing radiation damage to normal tissue in the case of deep tumors, and also enables high-frequency radiation. The subfilm is added to the working layer 12 in a film coating process (e.g., hot pressing, bonding, etc.). It is easy to manufacture, assemble, and low cost. To make it easier to understand, it does not require an anti-oxidation layer. That's good too.

[0093] In one embodiment, a proton beam is struck against a lithium target to generate neutrons, The proton beam passes through an oxidation prevention layer 16, a working layer 12, a heat conduction layer 15, and foaming layer in the direction of incidence. After passing through the suppression layer 13 and the heat dissipation layer 14, the proton beam has an energy of 2.2 MeV to 3 MeV. It is V, and can generate a lithium target and a high working surface, as well as excess To obtain a higher quality beam without generating fast neutrons, the working layer 12 has a thickness of 49 μm. It is approximately 189 μm thick, can react sufficiently with protons, reduces gamma ray contamination, and thickens This can cause energy buildup due to excessive heat, affecting the target's heat dissipation performance. It's not there.

[0094] Using simulation software, the energies of 2.2 MeV, 2.5 MeV, and The process involves striking lithium targets of different thicknesses with 3 MeV proton beams. The simulation was performed to obtain neutron yields at different lithium target thicknesses, as shown in Figure 10. As shown in ~12, the energy of the proton beam is 2.2 MeV, and the corresponding target When the working layer thickness is 49 μm, the neutron yield is highest, and the proton beam energy If the voltage is 2.5 MeV and the working layer thickness of the corresponding target is 97 μm, then The stron yield is the highest, the proton beam energy is 3 MeV, and the corresponding target is The neutron yield is highest when the working layer thickness is 189 μm.

[0095] In this embodiment, the energy of the proton beam is 2.5 MeV, and the target working layer If the thickness of 12 is 97 μm, the neutron beam required for irradiation can be obtained, and also The sperm yield is never too low.

[0096] Ta generates radioactive products after being activated by neutrons, and the foam suppression layer 13 remains Assuming that all of the proton beam is absorbed, the thickness should be as thin as possible, and the foam suppression layer The thickness of 13 may be 5 μm to 50 μm, reducing energy loss of the proton beam. Therefore, the antioxidant layer 16 should be as thin as possible, and its thickness should not be greater than 5 nm. It is also possible that the heat conduction layer 15 satisfies the requirement of rapidly conducting heat to the heat dissipation layer 14, Using high-purity copper, the thickness is 5μm to 50μm, and the service life of the target is 200 It is greater than or equal to mA-h.

[0097] The entire target T is flat and has a central axis A perpendicular to the surface of the plate, and can be understood. As described above, the thickness is the thickness of each layer of target T along the central axis A of target T. Yes, the edges of each layer of target T may have different thicknesses depending on structural requirements.

[0098] The heat dissipation layer 14 may have multiple types of structures, and the thickness of the heat dissipation layer 14 depends on the cooling structure. It is sufficient to satisfy the requirements, and in the first embodiment of the heat dissipation layer shown in Figures 4 and 5, the heat dissipation layer 14 is a plate It is in the shape of a first plate 141 and a second plate 142, the first plate 141 facing the working layer 12 It has a first side 1411 and a second side 1412 facing the first side 1411, and the second side 1412 A cooling passage P is formed therein for the cooling medium to flow, and the second plate 142 is the same as the first plate 141. The cooling passage P is in close contact with the second side 1412, and as can be understood, the first plate 14 of the second plate 142 It may be installed on the side opposite to 1. The cooling passage P is zigzag-shaped, and the zigzag-shaped cooling The exit passage P includes a plurality of parallel zigzag sub-passages P1, that is, a plurality of zigzag The walls W are arranged in parallel, and there are zigzag grooves S between adjacent walls W (i.e., parallel zigzag grooves) A zigzag-shaped sub-passage P1 is formed. The curvature geometry of the parallel zigzag sub-passage P1 is as follows: The following is the sine wave function.

number

[0099] To make it easier to understand, the cooling passage P may also be in other zigzag shapes, for example, Continuously curved smooth curves or sequential end-to-end curved segments or straight segments is a zigzag passage that extends the flow path, increases the contact area between the heat conduction wall surface and the cooling medium to increase the heat dissipation surface while increasing the contact area, forms a secondary flow, and improves the stirring effect , can improve the heat conduction ability and heat dissipation effect, and helps to extend the target service life . The cooling passage P is a continuously curved smooth curve, for example, using a sine wave function , can further reduce the flow resistance due to the flow path. The zigzag cooling passage P may be arranged in other arrangement methods

[0100] The heat dissipation layer 14 further has a cooling inlet IN and a cooling outlet OUT. The cooling passage P communicates with the cooling inlet IN and the cooling outlet OUT. The cooling medium enters from the cooling inlet IN, passes through the cooling passage P , and then exits from the cooling outlet OUT. The target T is irradiated by a high-energy level accelerated proton beam, causing the temperature to rise and generate heat. The heat conduction layer and the heat dissipation layer conduct the heat outward , and discharge the heat by the cooling medium flowing through the cooling passage, thereby cooling the target T . There are three cooling inlets IN and three cooling outlets OUT respectively. They are symmetrically installed at both ends of the cooling passage P on the first plate 141 , and extend and penetrate in the direction from the first side 1411 to the second side 1412. An inlet groove S1 and an outlet groove S2 are further formed on the second side 1412 . The inlet groove S1 and the outlet groove S2 communicate with the cooling inlet IN, the cooling outlet OUT, and each parallel zigzag sub-passage P1 respectively . Thus, the cooling medium entering from the cooling inlet IN enters each parallel zigzag sub-passage P1 from the inlet groove S1 , and then exits from the cooling outlet OUT through the outlet groove S2. As can be understood, the cooling inlets IN and the cooling outlets OUT may have other numbers or arrangement forms It may be in other forms, and may be installed together on the second board, and on the first board and on the second board respectively It may be installed in this manner. A circumferential wall W1 is further provided on the outer circumference of the cooling inlet IN and cooling outlet OUT. The second plate 142 is placed in close contact with the surface of the circumferential wall W1 that faces the second plate 142, and the first plate 1 A housing cavity is formed between 41 and the second plate 142, allowing cooling from the IN inlet. The cooling medium that enters can only exit through the cooling outlet OUT, and the second plate 142 and the first plate The contact surface with 141 is flat, and the height of the zigzag wall W and the height of the circumferential wall W1 are, It is the same and can be understood as a staircase or other structure, in which case zigzag The height of the zigzag wall W and the height of the circumferential wall W1 may be different, and each parallel zigzag shape The sub-passages P1 should be independent of each other. The flow direction D of the cooling medium in passage P1 (the overall flow direction of the cooling medium in the cooling passage) They may be different, further improving heat dissipation efficiency. The inlet groove S1 and outlet groove S2 are installed in different locations. It may be installed in a manner such as, for example, the cooling medium sequentially passes through each parallel zigzag sub-passage P1. It flows. In this embodiment, the material of both the first and second plates is Cu, and has high heat dissipation. It has performance and low cost. The number and size of the grooves S that form the cooling passage P are actual Determined according to the size of the target, the cross-section of the groove can take on various shapes, such as rectangular, circular, The cross-section may be polygonal, elliptical, or otherwise, and different cross-sections may have different shapes.

[0101] Both the first plate 141 and the second plate 142 are connected by bolts or screws or welded or similar means. Other fixing structures are used to fix the deceleration body 22 or the end of the acceleration pipe 111, or the first Plate 141 and the second plate 142 are connected in advance, and one of them is inside the reduction gear 22 or the acceleration tube It is fixed to the end of 111. As you can see, the heat dissipation layer is further removed from other removable connections. It may be fixed or attached in a manner that makes it easy to replace the target, and the heat dissipation layer 14 is The first plate 141 and / or the second plate 142 may further have support members (not shown), and the first plate 141 and / or the second plate 142 are The cooling inlet IN and cooling outlet OUT are fixed by a support member, and the cooling inlet IN and cooling outlet OUT are installed on the support member. Alternatively, in this embodiment, a first cooling is performed between the accelerating tube 111 and the reflector 21 and decelerator 22. A first cooling pipe D1 and a second cooling pipe D2 are installed, and one end of the first cooling pipe D1 and the second cooling pipe D2 is Each is connected to the cooling inlet IN and cooling outlet OUT of target T, and the other end is connected to an external cooling source. The cooling medium may be deionized water, and may have extremely low conductivity and high voltage. It prevents interference with the generation of leakage current in the environment and the generation of neutron beams, and is understandable. Furthermore, the first and second cooling tubes may be installed within the beam shaping body in other ways. Furthermore, if the target is located outside the beam-shaped body, it may be further removed.

[0102] As shown in Figures 6 and 7, this is a second embodiment of the heat dissipation layer, and the following parts differ from the first embodiment. Only the minutes will be explained. In the second embodiment of the heat dissipation layer, the zigzag cooling passage P′ is a multiple It includes a spiral, zigzag sub-passage P1′, i.e., one or more zigzag walls W′ The structure unfolds spirally around the same center, with each wall W' forming multiple layers in the radial direction, and each wall W' forms a shape The resulting layers are arranged alternately in the radial direction, with grooves S′ (i.e., spiral grooves) between adjacent layers. A zigzag sub-passage P1' is formed. The trajectory of the spiral, zigzag sub-passage P1'. The function is as follows:

Number

[0103] The cooling inlet IN′ is installed at the center of the second plate 142′ and penetrates through the center of each spiral zigzag-shaped sub-passage P1′. There are four cooling outlets OUT′, which are installed circumferentially and evenly on the outer periphery of the cooling passage P′ on the first plate 141′, extend and penetrate in the direction from the first side 1411′ to the second side 1412′. As can be understood, they may be installed in other installation methods. The center of the cooling passage P′, that is, the center of each spiral zigzag-shaped sub-passage P1′, serves as the inlet groove S1 ′, and an outlet groove S2′ is further formed on the second side 1412′ of the first plate 141′. The outlet groove S2′ communicates with the cooling outlet OUT′ and each spiral zigzag-shaped sub-passage P1′. Thus, the cooling medium entering from the cooling inlet IN′ enters each spiral zigzag-shaped sub-passage P1′ from the center of the cooling passage P′, and further exits through the outlet groove S2′ to the cooling outlet OUT′. A circumferential wall W1′ is installed on the outer periphery of the cooling outlet OUT′, and the second plate 142′ adheres to the surface of the circumferential wall W1′ facing the second plate 142′. By forming a housing cavity between the first plate 141′ and the second plate 142′, the cooling medium entering from the cooling inlet IN′ can only exit through the cooling outlet OUT′. The contact surface between the second plate 142′ and the first plate 141′ is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall enters each spiral zigzag-shaped sub-passage P1′ from the center of the cooling passage P′ respectively, and further exits through the outlet groove S2′ to the cooling outlet OUT′. A circumferential wall W1′ is installed on the outer periphery of the cooling outlet OUT′, and the second plate 142′ adheres to the surface of the circumferential wall W1′ facing the second plate 142′. By forming a housing cavity between the first plate 141′ and the second plate 142′, the cooling medium entering from the cooling inlet IN′ can only exit through the cooling outlet OUT′. The contact surface between the second plate 142′ and the first plate 141′ is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall enters each spiral zigzag-shaped sub-passage P1′ from the center of the cooling passage P′ respectively, and further exits through the outlet groove S2′ to the cooling outlet OUT′. A circumferential wall W1′ is installed on the outer periphery of the cooling outlet OUT′, and the second plate 142′ adheres to the surface of the circumferential wall W1′ facing the second plate 142′. By forming a housing cavity between the first plate 141′ and the second plate 142′, the cooling medium entering from the cooling inlet IN′ can only exit through the cooling outlet OUT′. The contact surface between the second plate 142′ and the first plate 141′ is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall is installed on the outer periphery of the cooling outlet OUT′, and the second plate 142′ adheres to the surface of the circumferential wall W1′ facing the second plate 142′. By forming a housing cavity between the first plate 141′ and the second plate 142′, the cooling medium entering from the cooling inlet IN′ can only exit through the cooling outlet OUT′. The contact surface between the second plate 142′ and the first plate 141′ is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall adheres to the surface of the circumferential wall W1′ facing the second plate 142′, and a housing cavity is formed between the first plate 141′ and the second plate 142′, so that the cooling medium entering from the cooling inlet IN′ can only exit through the cooling outlet OUT′. The contact surface between the second plate 142′ and the first plate 141′ is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall entering from the cooling inlet IN′ can only exit through the cooling outlet OUT′. The contact surface between the second plate 142′ and the first plate 141′ is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall entering from the cooling inlet IN′ can only exit through the cooling outlet OUT′. The contact surface between the second plate 142′ and the first plate 141′ is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall ]is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall is a flat surface, and the height of the zigzag-shaped wall W′ and the height of the circumferential wall W1′ are the same. As can be understood, it may be a stepped surface or other structures. In this case, the zigzag-shaped wall The height of W′ and the height of the circumferential wall W1′ may be different, and each spiral zigzag The sub-passages P1′ should be independent of each other. The flow direction of the cooling medium in passage P1' may be different, and the heat dissipation efficiency may be further improved. A projection 1413' may be further installed in the center of the first plate 141', and the projection 141 3′ rectifies the flow and increases the heat conduction area, lowering the temperature of the central hot spot. Section 1413' has a height greater than the height of wall W' and circumferential wall W1', and is cooled by the second plate. It may extend into the entrance IN′, and the shape of the protruding part 1413′ may be a solid cone, a hollow cone, It can be in sheet form or other similar formats.

[0104] To achieve the above target structure, for target T, each of the other layers (antioxidant) A method of forming a film with layer 16, working layer 12, heat conduction layer 15, and foam suppression layer 13, for example. For example, PVD (Physical Vapor Deposition), The heat dissipation layer 14 can be processed by sputtering, thermal welding, atomic layer deposition, etc. (See Figure 8) As shown, the manufacturing process for target T includes the following steps S10 to S50.

[0105] In S10, a heat dissipation layer 14 (made of copper plate) is placed, and the target is exposed from the heat dissipation layer 14. The maximum distance to the central axis A of T is R1. In S20, a method is used to form a film on the surface of the heat dissipation layer 14, such as sputtering. The foam suppression layer 13(Ta) is processed, and the maximum distance from the foam suppression layer 13 to the central axis A is R2 Therefore, R2 is made smaller than R1, and the film (foaming suppression layer 13) in the heat dissipation layer 14 is Areas that do not need to be formed need to be shielded, for example, by using a metal plate on the surface of the heat dissipation layer 14. The distance from the surface to the central axis A occludes the section from R2 to R1. In S30, a film such as sputtering is formed on the surface of the foam suppression layer 13. The heat conductive layer 15 (Cu) is processed according to the formula, and the maximum distance from the heat conductive layer 15 to the central axis A is R3 Therefore, make R3 larger than R2, that is, before performing step S32, step S31 In this case, remove the metal plate used for shielding, In S40, a heat welding or PVD film is formed on the surface of the heat conductive layer 15. The working layer 12(Li) is processed according to the formula, and the maximum distance from the working layer 12 to the central axis A is R4. By making R4 smaller than R3, the surface of the workpiece obtained in step S32 is filled It is necessary to shield the region where it is not necessary to form a film (working layer 12), for example, a metal plate Using the distance obtained in step S32 from the surface of the workpiece to the central axis A is R4-R3. By shielding the section, and in this embodiment making R4 smaller than R2, the foam suppression layer It was possible to completely absorb the remaining protons, In S50, oxidation is performed by forming a film such as an atomic layer deposition on the surface of the working layer 12. The oxidation prevention layer 16 (Al2O3) is processed, and the maximum distance from the oxidation prevention layer 16 to the central axis A is R It is 5, and R5 is made greater than R4, that is, step S3 before step S34. In step 3, remove the metal plate used for shielding.

[0106] In this embodiment, R5 and R3 are equal to R1, and as can be understood, in other settings That's fine.

[0107] If the antioxidant layer 16 is a polymer film (e.g., PI film), then step S50 This involves hot pressing, bonding, and other processes to create an oxidation-preventive layer 16 on polymer film products. The working layer 12 may be processed by a coating process, and the silicone does not contain water. Pressure adhesive can be used, it does not react with the metal layer, it is easy to assemble, and the cost is low. The liquid polymer film material may be applied to the working layer 12 and then cured. This may be considered a method of processing that forms a film, for example, by rotary coating, It is uniform.

[0108] In one embodiment, with respect to target T, each layer (antioxidant layer 16, working layer 12, heat transfer layer) The conductive layer 15 and foam suppression layer 13) materials are sequentially formed into gas in a vacuum environment and deposited on the heat dissipation layer 14. As shown in Figure 9, in this embodiment, the processing apparatus 300 for target T is true Empty chamber 310, exhaust device 320, evaporation source 330, support frame 340 and heating device 3 Includes 50. The exhaust device 320 exhausts air from the vacuum chamber 310 to form a vacuum environment. The evaporation source 330 sequentially evaporates the material of each layer into gas in the vacuum chamber 310, and in this embodiment... In this configuration, the evaporation source 330 uses electron beam or ion beam evaporation, and the bottom of the vacuum chamber It is installed in the section. The support frame 340 is used to place the heat dissipation layer 14, and in this embodiment In this configuration, the support frame 340 is installed at the top of the vacuum chamber 310, and the heating device 350 After heating the heat dissipation layer 14, the gas material is deposited on the surface of the heat dissipation layer 14 facing the evaporation source 330. The processing device 300 detects the thickness of the material in each layer and controls the gas deposition rate. The device further includes a film thickness detection device 360.

[0109] Using the above processing apparatus and process, it is possible to precisely control the thickness of each target layer. The support frame 340 has multiple heat dissipation layers fixed to it, and the film formation process is carried out sequentially. It may also be a rotating structure, improving machining efficiency and allowing for simultaneous machining of multiple targets. To enable and understand that the processing device 300 can also be constructed in other ways good.

[0110] The target in this embodiment, due to its structure and processing, exhibits high foam prevention and heat dissipation properties. It has the capability and a service life of 400mA-h or more. To make it easier to understand, the processing equipment of this embodiment The placement and processing methods may be used for targets that do not have an oxidation prevention layer or a heat conduction layer. Target T may be manufactured by other manufacturing methods.

[0111] In this embodiment, the target T is disc-shaped, and as can be understood, target T The target T may be a rectangular or other flat plate shape, and the target T may be a different solid shape. It may also be possible to have target T, which further facilitates target replacement or particle beams. To ensure the beam acts uniformly on the target, a movable component is used relative to the accelerator or beam shaping body. It may be present. The foam suppression layer 13, the heat dissipation layer 14, and the heat conduction layer 15 further target T A base material T1 can be constructed, and different working layers 12 can be processed onto it to create different types - Forms a target T. The target T further supports or attaches to the target. It may include a support (not shown) for the first cooling tube D1 and the second cooling tube. Used to attach at least a portion of the drainage tube D2, and manufactured from aluminum alloy material. Even if Al is activated by neutrons, the radioactive products have a short half-life and are secondary. Reduce radiation.

[0112] To make it clear, the target of this invention is neutron emission in other medical and non-medical fields. It can be applied to a bio-device, and its neutron generation is used in nuclear reactions between the particle beam and the target. If based on this, the target material will also be distinguished according to different nuclear reactions, and furthermore, other particles It can be applied to sub-beam generators.

[0113] The above description of exemplary specific embodiments of the present invention will help those skilled in the art to understand the present invention. While this facilitates the process, it is clear that the present invention is not limited to the scope of specific embodiments and is not limited to those skilled in the art. The spirit and scope of the invention are limited and determined in the attached claims, with various variations being the extent of the invention. If these changes are present within the context, they are evident and all fall within the scope of the claims of this invention.

Claims

1. A working layer that interacts with the incident charged particle beam to generate a neutron beam, and a charged particle beam Located behind the working layer along the incident direction of the beam, and in the process of generating the particle beam. A foam suppression layer that can suppress foaming of the working layer, and a heat release layer that releases the heat accumulated in the working layer. Particles characterized by comprising a heat conduction layer that conducts heat to a heat layer and a heat dissipation layer that releases heat. A target used in a beam generator.

2. The heat conduction layer is located between the working layer and the foam suppression layer and is connected to the heat dissipation layer. The target according to feature 1.

3. The heat conduction layer and the heat dissipation layer surround the foam suppression layer, and the heat conduction layer or the heat dissipation layer The present invention is characterized in that a containment space for containing the foam suppression layer is formed therein. The target of the article.

4. The aforementioned containment space includes a bottom surface and side walls connected to the bottom surface, and the foam suppression layer is front It is characterized by having a top surface that contacts the bottom surface and an outer wall that contacts the side wall. The target described in 3.

5. The material of the working layer is Li, a compound thereof, or an alloy thereof, characterized in that The target described in 1.

6. The energy of the charged particle beam is 2.2 MeV to 3 MeV, and the thickness of the working layer is The target according to claim 5, characterized in that it is 49 μm to 189 μm in size.

7. The material of the foam suppression layer is a small amount of Nb, Ta, Pd, V, their alloys and compounds. The target according to claim 1, which includes at least one type.

8. The materials of the heat conductive layer and the heat dissipation layer are Cu, Fe, Al, their alloys and compounds. The target according to claim 1, characterized in that it includes at least one of our species.

9. The system further includes an antioxidant layer that prevents oxidation of the working layer, and the antioxidant layer, working layer, and heat conduction The guide layer, foam suppression layer, and heat dissipation layer are installed in order along the direction of incidence of the charged particle beam. The target according to claim 1, characterized by the following.

10. The target is flat and has a central perpendicular line perpendicular to the surface of the plate, and perpendicular to the central perpendicular line. In a straight radial direction, the maximum distance from the working layer to the central axis is the foam suppression. The maximum distance from the layer to the central axis and the maximum distance from the oxidation prevention layer to the central axis The smaller the distance from the foam suppression layer to the central axis, the smaller the distance from the heat conduction layer to the This is smaller than the maximum distance to the central axis and the maximum distance from the heat dissipation layer to the central axis. The target according to claim 9, characterized by the following.

11. The thickness of the foam suppression layer is 5 μm to 50 μm, and the thickness of the heat conduction layer and the heat dissipation layer The thickness is 5 μm to 50 μm, and the thickness of the oxidation-preventive layer is greater than 5 nm. The target described in claim 9, which is characterized by this feature.

12. The material of the aforementioned oxidation-preventive layer is Al, Ti, their alloys and compounds, or stainless steel. The target according to claim 9, characterized in that it includes at least one of the following.

13. The oxidation prevention layer, the working layer, the heat conduction layer, and the foam suppression layer form a film. The target according to claim 12 is characterized by being processed sequentially on the heat dissipation layer in the manner described above. 。

14. The aforementioned antioxidant layer is a polymer film, and the aforementioned effect is achieved by a film coating process. The target according to claim 9, characterized in that it is processed into layers.

15. The polymer film is characterized in that it is a polyimide having the following molecular structure. The target according to claim 14. 【Chemistry 1】

Images