Radiation ray generating device

Abstract

The embodiment of the present specification provides a radiation ray generating device, which comprises a first target assembly for generating radiation rays under irradiation of an electron beam at a preset energy, and a first heat dissipation layer arranged on the back of the first target assembly; wherein the thickness of the first target assembly is determined by the energy deposition peak thickness of a target material of the first target assembly at the preset energy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radiation rays, in particular to a radiation ray generating device. BACKGROUND

[0002] In an electron linear accelerator, the role of the target is to react with bremsstrahlung produced by the electron beam emitted from the accelerating tube to generate X-rays for treatment. The target structure is generally a composite target, that is, a heat-conducting material is covered on the target material. The role of the target material is mainly to produce photons under the irradiation of the electron beam, and the role of the heat-conducting material is to conduct the heat generated in the target material out to reduce the temperature of the target and to absorb the electrons that do not react to reduce electron leakage.

[0003] In order to ensure sufficient dose rate and less electron leakage, the thickness of the target material is usually thick, so that more energy is deposited in the target and the temperature is high. When the target material is thick, the heat dissipation layer is far away from the point with the highest temperature in the target material, and the farther the heat dissipation layer is from the position with the highest temperature in the target material, the worse the heat dissipation effect is. The poor heat dissipation effect of the target further leads to the over-high temperature of the target material, which makes the target material easy to be oxidized and seriously shortens the service life of the target. Therefore, solving the heat dissipation problem of the target will greatly improve the service life and stability. SUMMARY

[0004] One of the embodiments of the present application provides a radiation ray generating device. The radiation ray generating device comprises: a first target assembly for generating radiation rays under the irradiation of an electron beam with a preset energy; and a first heat dissipation layer arranged on the back of the first target assembly; wherein the thickness of the first target assembly is determined by the energy deposition peak thickness of the target material of the first target assembly under the preset energy.

[0005] In some embodiments, the thickness of the first target assembly is the same as or substantially the same as the energy deposition peak thickness of the target material of the first target assembly under the preset energy.

[0006] In some embodiments, the first target assembly comprises a plurality of first target material layers arranged in the thickness direction and a sub-heat dissipation layer arranged between the plurality of first target material layers.

[0007] In some embodiments, the device further comprises a second target assembly arranged on the back of the first heat dissipation layer.

[0008] In some embodiments, the target material of the second target assembly is the same as the target material of the first target assembly, and the total thickness of the target material of the second target assembly is determined by the radiation dose rate peak thickness of the target material.

[0009] In some embodiments, the sum of the total thickness of the target material of the first target assembly and the second target assembly is not less than the radiation dose rate peak thickness of the target material under the preset energy.

[0010] In some embodiments, the first target assembly comprises one or more second target material layers distributed along a radial direction and a second heat dissipation layer disposed adjacent to the one or more second target material layers.

[0011] In some embodiments, a minimum inner diameter of the second heat dissipation layer is determined by a diameter of a beam spot generated by the electron beam on the first target assembly.

[0012] In some embodiments, the second heat dissipation layer is in physical communication with the first heat dissipation layer.

[0013] In some embodiments, the target material comprises tungsten; and a material of the first heat dissipation layer and / or the second heat dissipation layer comprises copper or diamond.

[0014] One of the embodiments of the present specification provides a radiation ray generating apparatus. The radiation ray generating apparatus comprises: a first target assembly for generating a radiation ray under irradiation of an electron beam of a preset energy; the first target assembly comprises one or more second target material layers distributed along a radial direction and a second heat dissipation layer disposed adjacent to the one or more second target material layers.

[0015] In some embodiments, a minimum inner diameter of the second heat dissipation layer is determined by a diameter of a beam spot generated by the electron beam on the first target assembly.

[0016] In some embodiments, a thickness of the first target assembly is determined by an energy deposition peak thickness of a target material of the first target assembly at the preset energy; and the radiation ray generating apparatus further comprises: a first heat dissipation layer disposed on a back surface of the first target assembly.

[0017] In some embodiments, the second heat dissipation layer is in physical communication with the first heat dissipation layer.

[0018] In some embodiments, the first heat dissipation layer comprises a plurality of sub-heat dissipation layers distributed along a radial direction and a target material layer disposed between the plurality of sub-heat dissipation layers. BRIEF DESCRIPTION OF DRAWINGS

[0019] The present specification will be further described in the manner of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent the same structures, in which:

[0020] Figure 1A is a structural schematic diagram of a radiation ray generating apparatus according to some embodiments of the present specification;

[0021] Figure 1B is an energy deposition curve diagram of a target material of a radiation ray generating apparatus according to some embodiments of the present specification;

[0022] Figure 2 is an exemplary thickness direction structure schematic diagram of a first target assembly according to some embodiments of the present specification;

[0023] Figure 3A is another exemplary radial direction structure schematic diagram of a first target assembly according to some embodiments of the present specification;

[0024] Figure 3B is an exemplary connection schematic diagram of a first target assembly and a first heat dissipation layer according to some embodiments of the present specification;

[0025] Figure 4A is an exemplary radial direction structure schematic diagram of a first heat dissipation layer according to some embodiments of the present specification;

[0026] Figure 4B is another exemplary connection schematic diagram of a first target assembly and a first heat dissipation layer according to some embodiments of the present specification;

[0027] Figure 5 is a structure schematic diagram of a substrate according to some embodiments of the present specification.

[0028] Label explanation: 100, radiation ray generating device; 110, first target assembly; 111, first target material layer; 112, first sub heat dissipation layer; 115, second target material layer; 116, second heat dissipation layer; 130, first heat dissipation layer; 132, third sub heat dissipation layer; 134, third target material layer; 150, second target assembly; 190, substrate; 192, cooling water pipe. DETAILED DESCRIPTION

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some examples or embodiments of the present specification, and for those skilled in the art, the present specification can also be applied to other similar scenarios without creative labor. Unless it is obvious from the language environment or otherwise stated, the same reference numbers in the drawings represent the same structure or operation.

[0030] It should be understood that the "system", "device", "unit" and / or "module" used herein is a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0031] As shown in the specification and claims herein, unless the context clearly indicates otherwise, the words "comprise", "comprising", "consist of" and "consisting of" do not preclude the inclusion of additional steps, elements, components, etc. In general, the terms "comprise", "comprising", "include", "including", "contain", "containing", "have", "having", "composed of", "comprised of", "consist of", "consisting of", and the like, are used in the detailed description and claims herein to indicate that the named elements are essential, but to not necessarily limit the number of instances of the named elements to those specifically recited.

[0032] Flow diagrams are used in the specification herein to illustrate the operation of systems in accordance with embodiments of the specification. It should be understood that the operations in the front or back of the operation are not necessarily performed in the exact order shown. Rather, various steps can be handled in reverse order, or at the same time. Other operations can also be added to, or removed from, these processes.

[0033] The radiation ray generating device is mainly used for generating radiation rays, such as X-rays, etc. The radiation ray generating device is mainly applied to medical electronic linear accelerators, security X-ray machines, etc. Since the radiation ray generating device mainly generates photons by accepting electron beam irradiation through a target material, the deposited energy in the target is usually high, the temperature of the target is high, and oxidation is very easy to occur, and the service life is not long. The present specification mainly describes a radiation ray generating device, which mainly comprises: a first target assembly for generating radiation rays under the irradiation of an electron beam at a preset energy; a first heat dissipation layer, the first heat dissipation layer is arranged on the back surface of the first target assembly; wherein the thickness of the first target assembly is determined by the energy deposition peak thickness of the target material of the first target assembly at the preset energy. The thickness of the first target assembly is determined by the energy deposition peak of the target material at the preset energy, so that the energy deposition of the first target assembly with the thickness is concentrated near the back surface opposite to the irradiation surface. When the first heat dissipation layer is arranged on the back surface of the first target assembly, the distance between the first heat dissipation layer and the position with the highest temperature in the first target assembly can be effectively reduced, the heat dissipation capacity of the first heat dissipation layer to the first target assembly is enhanced, and the service life of the radiation ray generating device is prolonged.

[0034] Figure 1A is a structural schematic diagram of a radiation ray generating device according to some embodiments of the specification.

[0035] As Figure 1AAs shown, the radiation ray generating device 100 can include a first target assembly 110 and a first heat dissipation layer 130. The first target assembly 110 is configured to generate radiation rays under irradiation of an electron beam at a preset energy. The first heat dissipation layer 130 is arranged on the back surface of the first target assembly 110 and is configured to dissipate heat from the first target assembly 110 to reduce the temperature of the first target assembly 110. The thickness of the first target assembly 110 is determined by the peak energy deposition thickness of the target material of the first target assembly 110 at the preset energy, so that the energy deposition of the first target assembly 110 is concentrated near the back surface. By arranging the first heat dissipation layer 130 on the back surface of the first target assembly 110, the distance between the first heat dissipation layer and the position with the highest temperature in the first target assembly can be reduced, thereby enhancing the heat dissipation capability. In some embodiments, the preset energy refers to the energy of the electron beam used to irradiate the radiation ray generating device 100. In some embodiments, the preset energy can be measured by the voltage value of the electron beam. In some embodiments, the preset energy can be 1-20 MV, preferably, the preset energy can be 6-15 MV.

[0036] In the embodiments of the present specification, the surface of the first target assembly 110 irradiated by the electron beam can be defined as the irradiation surface. The surface of the first target assembly 110 opposite to the irradiation surface along the irradiation direction of the electron beam can be defined as the back surface. The distance between the irradiation surface and the back surface is the thickness of the first target assembly 110. The direction from the irradiation surface to the back surface is the thickness direction of the first target assembly 110.

[0037] The first target assembly 110 is the main functional component of the radiation ray generating device 100 and is mainly used to accept irradiation of the electron beam to generate photons and thus generate radiation rays such as X-rays.

[0038] In some embodiments, since the first target assembly 110 needs to be irradiated by the electron beam to generate photons, the target material of the first target assembly 110 can include a material with a high atomic number as the target material of the first target assembly 110, such as molybdenum with an atomic number of 42, tungsten with an atomic number of 74, etc. Since a large amount of energy is deposited in the target material during irradiation of the electron beam to generate photons, the temperature of the target material increases, and therefore the target material needs to have good heat resistance. In some embodiments, the target material of the first target assembly 110 can include tungsten.

[0039] The first heat dissipation layer 130 is the main heat dissipation component of the radiation ray generating device 100 and can dissipate heat from the first target assembly 110 (or other components adjacent thereto, such as the second target assembly 150, etc.) to reduce the temperature of the first target assembly 110, avoid the temperature of the first target assembly 110 reaching the oxidation temperature of the first target assembly 110, thereby alleviating the oxidation of the first target assembly 110 and improving the service life of the radiation ray generating device 100.

[0040] Since the first heat dissipation layer 130 needs to dissipate heat from the first target assembly 110, the energy deposition of the first heat dissipation layer 130 should be less than that of the first target assembly 110, so the material of the first heat dissipation layer 130 can include a material with low atomic number. On the other hand, the material of the first heat dissipation layer 130 also needs to have good thermal conductivity to better conduct and dissipate the energy of the first target assembly 110. In some embodiments, the material of the first heat dissipation layer 130 can include copper or diamond.

[0041] In some embodiments, the material of the first heat dissipation layer 130 can adopt a material with a certain electron absorption capacity, and the electron absorption capacity of the material can be less than that of the target material of the first target assembly 110. In some embodiments, the material of the first heat dissipation layer 130 can adopt copper. Since copper can also generate photons after absorbing electrons, the first heat dissipation layer 130 can increase the radiation dose rate of the radiation ray generating apparatus 100 to a certain extent while dissipating heat.

[0042] In other embodiments, the material of the first heat dissipation layer 130 can adopt diamond. Compared with copper, diamond has better thermal conductivity, so the first heat dissipation layer 130 adopting diamond has stronger heat dissipation capacity. The periphery of the diamond can be provided with a high-thermal-conductivity metal material plating layer (such as copper or the like), and the first heat dissipation layer 130 can be welded to the base 190 through the metal material plating layer to fix the first heat dissipation layer 130. On the other hand, the metal material plating layer can also enable the diamond to maintain high-efficiency heat conduction with the base 190, so that the first heat dissipation layer 130 can quickly transfer the heat of the first target assembly 110 to the base 190, and then dissipate the heat to the outside, thereby enhancing the heat dissipation function of the radiation ray generating apparatus 100.

[0043] In some embodiments, the first target assembly 110 can include a single-layer structure along its thickness direction. In some embodiments, the single-layer structure can be a target material layer with high atomic number. In some embodiments, the thickness of the first target assembly 110 is the same as or approximately the same as the peak thickness of the energy deposition of the target material of the first target assembly 110 at a preset energy. Since the first heat dissipation layer 130 is connected to the back surface of the first target assembly 110, after the thickness of the first target assembly 110 is determined, the position of the first heat dissipation layer 130 relative to the first target assembly 110 can be determined.

[0044] Figure 1Bis a schematic diagram of an energy deposition curve of a target material of a radiation ray generating apparatus according to some embodiments of the present specification. The energy deposition peak thickness described in embodiments of the present specification refers to a thickness of the target material corresponding to an energy deposition peak in an energy deposition curve of the target material at a preset energy (e.g., 6-15 MV). In some embodiments, when the total thickness of the target material exceeds the energy deposition peak thickness, the position of the target material at which the energy deposition peak thickness corresponds is the position at which the energy deposition of the target material is the highest. In some embodiments, the energy deposition curve can be simulated using Monte Carlo software. In some embodiments, see Figure 1B , the target material of the first target assembly 110 is taken as tungsten, for example, the thickness of tungsten corresponding to the energy deposition peak of tungsten under the irradiation of an electron beam at 6-15 MV is 0.3-0.5 mm. In some embodiments, the energy deposition peak can be a range of energy deposition values not less than 80% of the maximum energy deposition value, and thus the energy deposition peak thickness of the target material corresponding to the energy deposition peak can also be a range of thickness values. In some embodiments, when the target material of the first target assembly 110 is tungsten, the thickness of the first target assembly 110 can be the same as the energy deposition peak thickness of tungsten. For example, the thickness of the first target assembly 110 can be 0.3-0.5 mm. In some embodiments, when the target material of the first target assembly 110 is tungsten, the thickness of the first target assembly 110 can be substantially the same as the energy deposition peak thickness of tungsten. For example, the thickness of the first target assembly 110 can be 0.2-0.6 mm. In some embodiments, the thickness of the first target assembly 110 can be any value within the above range. In some embodiments, the thickness of the first target assembly 110 can be 0.5 mm.

[0045] In embodiments of the present specification, substantially the same refers to a difference less than or equal to 10%, i.e., the thickness of the first target assembly 110 is 90%-110% of the energy deposition peak thickness. In the first target assembly 110 within the thickness range, the region with the highest temperature is concentrated on the back surface of the first target assembly 110, which facilitates heat dissipation through the first heat dissipation layer arranged on the back surface of the first target assembly 110.

[0046] Figure 2 is a schematic diagram of an exemplary thickness direction structure of the first target assembly 110 according to some embodiments of the present specification. As shown in Figure 2 , in some embodiments, the first target assembly 110 can include a plurality of first target material layers 111 arranged along the thickness direction thereof, and a first sub-heat dissipation layer 112 is arranged between adjacent first target material layers 111 in the plurality of first target material layers 111. The first target assembly 110 is further divided into a multi-layer structure in the thickness direction thereof through the first sub-heat dissipation layer 112, and the plurality of first target material layers 111 with a smaller thickness can further enhance the heat dissipation capacity of the first target assembly 110.

[0047] In some embodiments, the material of the first sub-heat dissipation layer 112 can be the same as that of the first heat dissipation layer 130, and can be a material with a smaller atomic number, such as copper, diamond, etc. In some embodiments, the material of the first sub-heat dissipation layer 112 can also be different from that of the first heat dissipation layer 130. For example, the first heat dissipation layer 130 is made of diamond, and the first sub-heat dissipation layer 112 is made of copper, etc.

[0048] In some embodiments, the total thickness of the plurality of first target material layers 111 can be determined according to the energy deposition peak thickness of the target material of the first target material layer 111 at a preset energy. In some embodiments, the total thickness of the plurality of first target material layers 111 can be 90%-110% of the energy deposition peak thickness corresponding to the target material thereof. In other embodiments, the total thickness of the plurality of first target material layers 111 can also be other proportion ranges (such as 95%-105%, etc.) of the corresponding energy deposition peak thickness. In some embodiments, the thickness of each of the plurality of first target material layers 111 can be the same or different. In some embodiments, the thickness of each of the plurality of first target material layers 111 can be distributed from thick to thin along the irradiation direction, so that the thickness of the first target material layer 111 near the position of the energy deposition peak thickness of the target material is thinner, the total energy deposited thereon is smaller, and the temperature is prevented from being too high; at the same time, the first sub-heat dissipation layer 112 connected to the first target material layer 111 at the position can more easily conduct heat out, achieving the purpose of rapid cooling. In some embodiments, the thickness of each of the plurality of first target material layers 111 can be distributed from thin to thick along the irradiation direction.

[0049] In some embodiments, the thickness of each first target material layer 111 is not less than 0.1 mm. If the thickness of the first target material layer 111 is too thin, it can cause the first target material layer 111 to absorb too few electrons, the radiation dose rate to be low, and the electron leakage to be more, resulting in more serious electron pollution.

[0050] Since the total thickness of the target material of the first target assembly 110 is certain, the more the number of the first target material layers 111 is, the thinner the thickness of the first target material layer 111 is, and the better the heat dissipation effect is. However, since the thickness of the first target material layer 111 can cause more negative effects of electron leakage, the number of the first target material layers 111 should not be too large. In some embodiments, the number of the first target material layers 111 can be 1-5 layers.

[0051] In some embodiments, when the first target assembly 110 is a multi-layer structure along the thickness direction thereof, the total thickness of the first target assembly 110 (including the thickness of the first target material layer 111 and the first sub-heat dissipation layer 112) can be greater than the energy deposition peak thickness corresponding to the target material of the first target assembly 110.

[0052] For example, under the condition of an electron beam with a 6MV energy, the first target assembly 110 can be divided into a three-layer structure, including two layers of first target material layers 111 and a first sub-cooling layer 112 between the two layers of first target material layers 111. Along the irradiation direction of the electron beam, the first layer is a first target material layer 111 (for example, which can be a tungsten layer) with a thickness of 0.3mm; the second layer is a first sub-cooling layer 112 (for example, which can be a copper layer) with a thickness of 0.6mm; and the third layer is another first target material layer 111 (for example, which can be a tungsten layer) with a thickness of 0.3mm. In some embodiments, when the first target assembly 110 includes a three-layer structure of two layers of first target material layers 111 and a first sub-cooling layer 112 between the two layers of first target material layers 111, the total thickness of the two layers of first target material layers 111 can be the same as or approximately the same as the peak thickness of the energy deposition curve corresponding thereto.

[0053] Figure 3A is another exemplary schematic diagram of the radial direction structure of the first target assembly 110 according to some embodiments of the present specification; Figure 3B is an exemplary connection schematic diagram of the first target assembly 110 and the first cooling layer 130 according to some embodiments of the present specification. As shown in Figure 3A and Figure 3B In some embodiments, the first target assembly 110 can further include one or more second target material layers 115 arranged along the radial direction thereof, and a second cooling layer 116 arranged adjacent to the one or more second target material layers 115. The first target assembly 110 is divided into a multi-ring structure in the radial direction thereof by the second cooling layer 116, and the multiple second target material layers 115 with a narrower width and the adjacent second cooling layer 116 can further enhance the heat dissipation capability of the first target assembly 110.

[0054] In some embodiments, the projection shape of the first target assembly 110 and the first cooling layer 130 in the projection plane perpendicular to the thickness direction thereof is circular, and the radial direction mentioned above refers to the radial direction of the circular cross section. In some embodiments, the projection shape of the first target assembly 110 and the first cooling layer 130 in the projection plane perpendicular to the thickness direction thereof can also be square or other shapes, and the radial direction mentioned above refers to the radial direction of the central axis of the projection shape. In some embodiments, the central region of the projection shape can be arranged as a second target material layer 115, and the periphery of the second target material layer 115 in the central region can be arranged as a second cooling layer 116, which surrounds the peripheral side of the second target material layer 115. In some embodiments, the periphery of the second cooling layer 116 can further be arranged to surround another second target material layer 115. In some embodiments, the periphery of the second target material layer 115 and the second cooling layer 116 can further be arranged as a multi-layer structure distributed along the radial direction, and the number of layers can be three, four, five, etc., and the present specification does not limit the specific number of layers.

[0055] In some embodiments, the material of the second heat dissipation layer 116 can be the same as that of the first heat dissipation layer 130, and can be a material with a small atomic number, such as copper or diamond. In some embodiments, the material of the second heat dissipation layer 116 can also be different from that of the first heat dissipation layer 130, for example, the first heat dissipation layer 130 is made of copper, and the second heat dissipation layer 116 is made of diamond.

[0056] It should be noted that when the material of the second heat dissipation layer 116 includes diamond, a metal material coating with high thermal conductivity (such as copper) can be provided around the diamond. The second heat dissipation layer 116 can be welded to the second target layer 115 or the substrate 190 through the metal material coating.

[0057] In some embodiments, the second heat dissipation layer 116 may be physically connected to the first heat dissipation layer 130 (e.g., Figure 3B As shown, the first heat dissipation layer 130 and the second heat dissipation layer 116 together dissipate heat from the second target material layer 115, enhancing the heat dissipation effect. On the other hand, in some embodiments, since the second heat dissipation layer 116 located between the two second target material layers 115 is difficult to directly connect to the substrate 190, it is difficult to directly conduct heat to the substrate 190 for dissipation. In this case, the heat of the second heat dissipation layer 116 can be guided to the substrate 190 through the first heat dissipation layer 130 by connecting it to the first heat dissipation layer 130, thereby completing the heat dissipation.

[0058] In some embodiments, the minimum inner diameter of the second heat dissipation layer 116 is determined by the diameter of the beam spot generated by the electron beam on the first target assembly 110. In some embodiments, the minimum inner diameter of the second heat dissipation layer 116 may refer to the inner diameter of the second heat dissipation layer 116 near the central region of the first target assembly 110. Since the radial energy distribution of the first target assembly 110 after electron beam irradiation follows a Gaussian curve, i.e., the closer to the center, the higher the energy and the higher the temperature. Therefore, the smaller the inner diameter of the second heat dissipation layer 116, the closer the second heat dissipation layer 116 is to the center of the first target assembly 110, i.e., the closer the second heat dissipation layer 116 is to the position with the highest temperature, the better the heat dissipation effect.

[0059] In the radial direction, since the photons of the first target assembly 110 are mainly generated by the electron beam irradiation of the second target layer 115, the second heat dissipation layer 116 should be kept away from electron beam irradiation as much as possible to avoid affecting the radiation dose rate of the first target assembly 110. That is, the second heat dissipation layer 116 should be located as far outside the beam spot generated by the electron beam on the first target assembly 110 as possible (e.g., Figure 3B (As shown). In some embodiments, the minimum inner diameter of the second heat dissipation layer 116 is greater than or equal to the diameter of the beam spot. Simultaneously, the second heat dissipation layer 116 is disposed outside the beam spot, which also prevents the second heat dissipation layer 116 from being directly irradiated by the electron beam and melting at high temperatures.

[0060] Since the radial energy distribution of the first target assembly 110 after electron beam irradiation follows a Gaussian curve—that is, the energy is higher closer to the center and lower further away from the center—and the energy decreases sharply after a certain distance from the center, in some embodiments, the second target layer 115 and the second heat dissipation layer 116 of the first target assembly 110 may each have only one layer. Of course, in other embodiments, the first target assembly 110 may include multiple second target layers 115 and multiple second heat dissipation layers 116, with the second target layers 115 and the second heat dissipation layers 116 spaced apart.

[0061] For example, under electron beam conditions with an energy of 6MV, the first target assembly 110 may include a second target layer 115 located at the center and a second heat dissipation layer 116 on the periphery. Along the radial direction of the first target assembly 110, the second target layer 115 (e.g., may be a circular tungsten layer, also called a tungsten circle) has a radius of 0-0.2mm; the second heat dissipation layer 116 (e.g., may be an annular copper layer, also called a copper ring) has a radius of 0.2-0.5mm.

[0062] Figure 4A This is a schematic diagram of the exemplary radial structure of the first heat dissipation layer according to some embodiments of this specification; Figure 4B This is another exemplary connection diagram of the first target component and the first heat dissipation layer according to some embodiments of this specification. Figure 4A and Figure 4B As shown, in some embodiments, the first heat dissipation layer 130 may also include one or more third sub-heat dissipation layers 132 distributed radially therein and a third target layer 134 disposed adjacent to the one or more third sub-heat dissipation layers 132. The radial structure of the first heat dissipation layer 130 is similar to the radial structure of the first target assembly 110, except that the center of the first target assembly 110 is the second target layer 115, and the center of the first heat dissipation layer 130 is the third sub-heat dissipation layer 132, and along the irradiation direction of the electron beam, each second target layer 115 corresponds to a third sub-heat dissipation layer 132 (e.g., ...). Figure 4B (As shown).

[0063] Exemplarily, under the condition of an electron beam with a 6MV energy, in the radial direction, the first target assembly 110 has a tungsten circle in the range of 0-0.2mm in radius of the first target material layer 115 (for example, which can be a tungsten circle), a copper circle in the range of 0-0.2mm in radius of the first heat dissipation layer 130 (for example, which can be a copper circle), the tungsten circle corresponding to the copper circle; the first target assembly 110 has a copper ring in the range of 0.2-0.5mm in radius of the second heat dissipation layer 116 (for example, which can be a copper ring), a tungsten ring in the range of 0.2-0.5mm in radius of the third target material layer 134 (for example, which can be a tungsten ring), the copper ring corresponding to the tungsten ring.

[0064] In some embodiments, the first target assembly 110 can have a multi-layer structure in the depth direction and a multi-ring structure in the radial direction, that is, the first target material layer 111 and the first heat dissipation layer 112 can also have a multi-ring structure in the radial direction. Exemplarily, under the condition of an electron beam with a 6MV energy, in the irradiation direction of the electron beam, the first layer of the first target assembly 110 is the first target material layer 111, which can have a thickness of 0.3mm; in the radial direction, the first target material layer 111 has a tungsten circle in the range of 0-0.2mm in radius and a copper ring in the range of 0.2-0.5mm in radius. The second layer of the first target assembly 110 is the first heat dissipation layer 112, which can have a thickness of 0.6mm; in the radial direction, the first heat dissipation layer 112 has a copper circle in the range of 0-0.2mm in radius and a tungsten ring in the range of 0.2-0.5mm in radius. The third layer of the first target assembly 110 is another first target material layer 111, which can have a thickness of 0.6mm; in the radial direction, the first target material layer 111 has a tungsten circle in the range of 0-0.2mm in radius and a copper ring in the range of 0.2-0.5mm in radius.

[0065] In some embodiments, the radiation ray generating apparatus 100 can further include a second target assembly 150 disposed on the back of the first heat dissipation layer 130. The second target assembly 150 can also absorb electrons of the electron beam to generate photons, thereby increasing the radiation dose rate of the radiation ray generating apparatus 100 and reducing the electron leakage rate.

[0066] In some embodiments, the target material of the second target assembly 150 can be the same as the target material of the first target assembly 110, and the total thickness of the target material of the second target assembly 150 is determined by the peak thickness of the target material at the radiation dose rate. The peak thickness of the target material at the radiation dose rate refers to the total thickness of the target material corresponding to the peak (i.e., the maximum) of the radiation dose rate of the photons generated by the target material when irradiated by the electron beam. In some embodiments, when the total thickness of the target material is less than the peak thickness of the target material at the radiation dose rate, the radiation dose rate of the radiation ray generating device 100 increases with the increase of the total thickness of the target material in the radiation ray generating device 100; when the total thickness of the target material is greater than the peak thickness of the target material at the radiation dose rate, the radiation dose rate of the radiation ray generating device 100 decreases with the increase of the total thickness of the target material in the radiation ray generating device 100.

[0067] The target material of the second target assembly 150 can be the same as the target material of the first target assembly 110, so that the second target assembly 150 and the first target assembly 110 absorb the photons generated by the electrons in the same way, facilitating the control of the radiation dose rate of the radiation ray generating device 100. In some embodiments, the target material of the second target assembly 150 can also include tungsten.

[0068] In some embodiments, the sum of the total thicknesses of the target materials of the first target assembly 110 and the second target assembly 150 is not less than the peak thickness of the target material at the radiation dose rate at a preset energy (e.g., 6-15 MV), so as to maximize the radiation dose rate of the first target assembly 110 and the second target assembly 150. In some embodiments, the sum of the total thicknesses of the target materials of the first target assembly 110 and the second target assembly 150 can be equal to the peak thickness of the target material at the radiation dose rate at a preset energy (e.g., 6-15 MV), so that the radiation dose rate of the radiation ray generating device 100 is at the highest level. In some embodiments, in order to further reduce the electron leakage rate of the radiation ray generating device 100, the total thicknesses of the target materials of the first target assembly 110 and the second target assembly 150 can be further increased. In some embodiments, the sum of the total thicknesses of the target materials of the first target assembly 110 and the second target assembly 150 can be greater than the peak thickness of the target material at the radiation dose rate at a preset energy (e.g., 6-15 MV). When the total thickness of the target material is greater than the peak thickness at the radiation dose rate, the radiation dose rate of the radiation ray generating device 100 decreases compared to the peak. In some embodiments, the decrease of the radiation dose rate of the radiation ray generating device 100 does not exceed 20% of the peak of the radiation dose rate, i.e., the radiation dose rate after the decrease is not less than 80% of the peak of the radiation dose rate, and the thickness of the target material corresponding to the radiation dose rate is the total thickness of the target materials of the first target assembly 110 and the second target assembly 150. By setting the total thicknesses of the target materials of the first target assembly 110 and the second target assembly 150 to be greater than the peak thickness at the radiation dose rate, the radiation ray generating device 100 can have a higher radiation dose rate while reducing the electron leakage rate and improving the overall performance of the radiation ray generating device 100.

[0069] In some embodiments, in order to make the radiation dose rate of the radiation ray generating apparatus 100 not less than 80% of the peak value of the radiation dose rate, while minimizing the electron emission rate, the total thickness of the target material of the second target assembly 150 can be set to be not more than 4 times the thickness of the peak value of the radiation dose rate of the target material at the preset energy according to the radiation dose rate curve.

[0070] In some embodiments, the second target assembly 150 can also include a multi-layer structure in the depth direction, and the thickness of each target material layer in the multi-layer structure is also not less than 0.1 mm. In some embodiments, the second target assembly 150 can also include a multi-ring structure in the radial direction. In some embodiments, the second target assembly 150 can include both a multi-layer structure in the depth direction and a multi-ring structure in the radial direction. The multi-layer structure in the depth direction and the multi-ring structure in the radial direction of the second target assembly 150 can refer to the above related content, which will not be repeated here.

[0071] Figure 5 is a structural schematic diagram of the base 190 according to some embodiments of the present specification. As shown in Figure 5 In some embodiments, the radiation ray generating apparatus 100 can also include a base 190 in physical communication with at least the first heat dissipation layer 130, and the base 190 is provided with a cooling water pipe 192. In some embodiments, the base 190 can be arranged around the first target assembly 110 and the first heat dissipation layer 130. In some embodiments, the base 190 can be arranged around the first target assembly 110, the first heat dissipation layer 130 and the second target assembly 150. In some embodiments, the base 190 can also be arranged around the first target assembly 110, the first heat dissipation layer 130 and the second target assembly 150, and the back of the second target assembly 150.

[0072] In some embodiments, the base 190 can provide a mounting and fixing platform for the first target assembly 110, the first heat dissipation layer 130 and the second target assembly 150, and the base 190 can conduct and dissipate the heat of the first heat dissipation layer 130 to the outside, enhancing the heat dissipation effect.

[0073] In some embodiments, the material of the base 190 can include copper. The base 190 made of copper has good heat conduction function on one hand, and on the other hand, it is convenient for welding and fixing the first target assembly 110, the first heat dissipation layer 130 and the second target assembly 150.

[0074] In some embodiments, the base 190 can be provided with a plurality of cooling water pipes 192, and deionized water can flow in the cooling water pipes 192. The deionized water can not corrode the base 190 and can take away the heat of the base 190, thereby enhancing the heat dissipation effect of the radiation ray generating apparatus 100. In some embodiments, the plurality of cooling water pipes 192 are located at the circumferential side of the first target assembly 110, the first heat dissipation layer 130, and the second target assembly 150, so as to avoid the cooling water pipes 192 from being irradiated by the electron beam and to avoid the cooling water pipes 192 and the deionized water inside the cooling water pipes 192 from adversely affecting the irradiation of the electron beam. In some embodiments, the cooling water pipes 192 can also be provided on the irradiation path of the electron beam, and the present specification does not limit the embodiments in this regard.

[0075] The beneficial effects that can be brought by the radiation ray generating apparatus disclosed in the present specification include, but are not limited to, (1) the thickness of the first target assembly determined by the energy deposition peak thickness of the target material at the preset energy, so that the energy deposition of the first target assembly is concentrated near the back surface thereof, the distance between the first heat dissipation layer and the position with the highest temperature in the first target assembly is reduced, the heat dissipation capacity of the radiation ray generating apparatus is enhanced, and the service life of the radiation ray generating apparatus is prolonged; (2) the setting of the deep multi-layer structure and the radial multi-ring structure of the first target assembly enhances the heat dissipation capacity of the first target assembly; and (3) the setting of the cooling water pipes enhances the heat dissipation capacity of the base without affecting the irradiation of the electron beam. It should be noted that the beneficial effects that can be brought by different embodiments are different, and in different embodiments, the beneficial effects that can be brought can be any one or a combination of the above, or any other beneficial effects that can be obtained.

[0076] The above has described the basic concepts, and it is obvious that the above detailed disclosure is only used as an example and does not limit the present specification. Although the above has not been explicitly described, those skilled in the art can make various modifications, improvements, and corrections to the present specification. Such modifications, improvements, and corrections are suggested in the present specification, so such modifications, improvements, and corrections still belong to the spirit and scope of the exemplary embodiments of the present specification.

[0077] Meanwhile, specific terms are used in the present specification to describe the embodiments of the present specification. For example, “one embodiment”, “an embodiment”, and / or “some embodiments” means a certain feature, structure, or characteristic related to at least one embodiment of the present specification. Therefore, it should be emphasized and noted that “an embodiment” or “one embodiment” or “an alternative embodiment” mentioned in different positions in the present specification does not necessarily refer to the same embodiment. In addition, some features, structures, or characteristics in one or more embodiments of the present specification can be properly combined.

[0078] Furthermore, the order of the processing elements and sequences described in this specification are not intended to be construed as a limitation, unless specifically stated, but are included to provide a complete description of one or more embodiments of the present specification. Regardless of the particular sequence of processing elements and sequences, however, the description herein of a process should be understood to include any and all combinations of one or more elements, and sequences that can be perceived as either open-ended or specific.

[0079] Similarly, it is to be noticed that the term "comprising", used in the description, should not be interpreted as being restricted only to the means listed thereafter. It is to be understood that the term "comprising" means "including, but not limited to". Furthermore, it is to be noted that the terms "a", "an" and "the" are not intended to exclude the plural, but rather to mean "one or more". The use of the term "about" in the description should not be construed as limiting the description to a precise operation, unless explicitly indicated. Similarly, "substantially" and "approximately" are used to indicate that the parameter so designated is very close to the stated reference, but can also allow for some variation outside of a strict interpretation of the parameter.

[0080] Some embodiments use numerals to describe components, quantities of attributes. It should be understood that such numerals used in the description of the embodiments are, in some examples, modified by the adjectives "about", "approximately", or "substantially". Unless otherwise stated, "about", "approximately", or "substantially" indicates that the number can vary by ±20%. Accordingly, numerical parameters such as those included in the description and claims are approximations, and can vary depending on the desired properties sought to be obtained in the individual embodiments. In some embodiments, numerical parameters are determined by the number of significant digits and by the general convention that numbers contained in the specification and claims are to be construed either as approximations when precision is not important, or as "open-ended" numerical parameters when the indicated number range is intended to encompass smaller numbers less than the lower stated limit, and also to encompass larger numbers greater than the upper stated limit. In some embodiments, numerical parameters are determined by the number of significant digits and by the general convention that numbers contained in the specification and claims are to be construed either as approximations when precision is not important, or as "open-ended" numerical parameters when the indicated number range is intended to encompass smaller numbers less than the lower stated limit, and also to encompass larger numbers greater than the upper stated limit.

[0081] Each patent, patent application, publication, and other material cited in this specification is incorporated herein by reference in its entirety. Nothing herein is to be construed as an admission that the application is not entitled to antedate such material by virtue of prior application. To the extent the material incorporated by reference contradicts or contradicts specifically, defines, or describes something in this specification that is not otherwise explicitly stated, such incorporation by reference is only addressed as provided by 37 C.F.R. § 1.57. It is expressly not admitted that any item of material, of any nature, other than those specifically and explicitly identified as being incorporated by reference, is incorporated by reference.

[0082] Finally, it should be understood that the embodiments described herein are only given by way of example and that other modifications can occur to persons skilled in the art. Therefore, the scope of the present description is not intended to be limited to the embodiments described herein but is only limited by the claims that follow.

Claims

1. A radiation ray generating device, characterized in that, include: The first target assembly is used to generate radiation rays under the irradiation of an electron beam of preset energy; A first heat dissipation layer is disposed on the back side of the first target assembly; The second target component is disposed on the back side of the first heat dissipation layer; The thickness of the first target component is determined by the peak thickness of the energy deposition of the target material of the first target component at the preset energy; the sum of the total thickness of the target materials of the second target component and the first target component is not less than the peak thickness of the radiation dose rate of the target material at the preset energy.

2. The radiation ray generating device according to claim 1, characterized in that, The thickness of the first target component is approximately the same as the peak thickness of the energy deposition of the target material of the first target component at the preset energy.

3. The radiation ray generating device according to claim 1, characterized in that, The first target assembly includes a plurality of first target material layers disposed along the thickness direction and a sub-heat dissipation layer disposed between the plurality of first target material layers.

4. The radiation ray generating device according to claim 1, characterized in that, The target material of the second target assembly is the same as that of the first target assembly, and the total thickness of the target material of the second target assembly is determined based on the peak thickness of the radiation dose rate of the target material.

5. The radiation ray generating device according to claim 1, characterized in that, The first target assembly includes one or more second target layers distributed radially and a second heat dissipation layer disposed adjacent to the one or more second target layers.

6. The radiation ray generating device according to claim 5, characterized in that, The minimum inner diameter of the second heat dissipation layer is determined by the diameter of the beam spot generated by the electron beam on the first target assembly.

7. The radiation ray generating device according to claim 5, characterized in that, The second heat dissipation layer is physically connected to the first heat dissipation layer.

8. The radiation ray generating apparatus according to any one of claims 1-7, characterized in that, The target material includes tungsten; the material of the first heat dissipation layer includes copper or diamond.

9. The radiation ray generating device according to claim 5, characterized in that, The material of the second heat dissipation layer includes copper or diamond.

10. A radiation ray generating device, characterized in that, include: A first target assembly is used to generate radiation rays under electron beam irradiation of a preset energy; the first target assembly includes one or more second target material layers distributed radially and a second heat dissipation layer disposed adjacent to the one or more second target material layers; A first heat dissipation layer is disposed on the back side of the first target assembly; The second target assembly is disposed on the back side of the first heat dissipation layer, and the sum of the target material thicknesses of the second target assembly and the first target assembly is not less than the peak thickness of the target material at the preset energy radiation dose rate.

11. The radiation ray generating device according to claim 10, characterized in that, The minimum inner diameter of the second heat dissipation layer is determined by the diameter of the beam spot generated by the electron beam on the first target assembly.

12. The radiation ray generating device according to claim 10 or 11, characterized in that, The thickness of the first target component is approximately the same as the peak thickness of the energy deposition of the target material of the first target component at the preset energy.

13. The radiation ray generating device according to claim 12, characterized in that, The second heat dissipation layer is physically connected to the first heat dissipation layer.

14. The radiation ray generating device according to claim 12, characterized in that, The first heat dissipation layer includes a plurality of sub-heat dissipation layers distributed radially and a target layer disposed between the plurality of sub-heat dissipation layers.

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