Spin coating target and accelerator with same

Abstract

The utility model discloses a spin coating target and an accelerator with the spin coating target, and the spin coating target comprises a shell which is provided with a vacuum cavity; the target base body is rotatably arranged in the vacuum cavity, and an annular coating area is defined on one side of the target base body; the liquid target material is used for coating the coating area so as to enable the coating area to form a target surface which can be bombarded by a set beam to generate neutrons; at least one part of the coating device is arranged in the vacuum cavity, and the coating device is used for coating the coating area with the liquid target material; and the at least one cooling device is arranged close to the target base body to cool the target surface. According to the spin-coating target disclosed by the embodiment of the utility model, the spin-coating device is arranged to coat lithium on the coating area, so that the problem that the service life of a rotary lithium target is short under the condition that the power density of a proton accelerator is very large can be solved, the supply of lithium on the target surface can be maintained, and the service life of the spin-coating target can be prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of accelerator equipment, and particularly relates to a rotary coating target and an accelerator with the same. Background Art

[0002] Boron neutron capture therapy (BNCT) is an advanced radiotherapy technology in rapid development. The core elements of BNCT include a suitable neutron source and neutron capture drugs. After a proton accelerator accelerates protons or deuterium ions to a certain energy (above 2.5 MeV), it bombards a lithium target, and neutrons are generated through a nuclear reaction. The performance of the target determines the neutron conversion efficiency, energy spectrum, and the power that can be tolerated.

[0003] Currently, the neutron conversion targets used in proton accelerators are generally fixed targets. In order to increase the tolerable proton power, rotary coating targets have also been tried. For a low-melting-point lithium target (180 °C), when the power of the proton beam increases to dozens of kilowatts, such as 50 kW - 80 kW, due to certain constraints on the size of the proton beam spot (the diameter is generally less than 6 cm), even for a well-cooled rotary coating target, since the temperature at the position bombarded by protons rises very high instantaneously, the temperature of the target surface will rise sharply and cause the evaporation of lithium. Once the lithium is exhausted, the required neutrons can no longer be generated.

[0004] By controlling the power of the proton beam, the purpose of reducing the evaporation of lithium due to heat can be achieved. However, controlling the power of the proton beam will restrict the generation of the neutron beam, and the structure of the rotary coating target is not conducive to installing a complex liquid cooling system. The excessive heat on the rotary coating target accelerates the volatilization of lithium and shortens the service life of the rotary coating target. Although the currently used liquid target can provide a relatively sufficient amount of lithium, the fluidity of the liquid leads to the instability of the liquid target, and the liquid target is more likely to volatilize, which not only increases the consumption of the target material but also is more likely to cause pollution of the vacuum chamber. Summary of the Invention

[0005] The purpose of the embodiments of the utility model is to provide a rotary coating target to solve the problems in the prior art that in an accelerator under high power density, the rotary lithium conversion target is prone to evaporation due to heat, the lithium supply on the target surface is insufficient, and the service life of the rotary coating target is short.

[0006] The utility model provides a rotary coating target.

[0007] The utility model also provides an accelerator with the above rotary coating target.

[0008] The rotary coating target according to the first aspect embodiment of the utility model includes:

[0009] A housing defining a vacuum chamber;

[0010] A target substrate, rotatably disposed in the vacuum chamber, and an annular coating region is defined on one side of the target substrate;

[0011] A liquid target material for coating the coating region so that the coating region is formed into a target surface from which neutrons can be bombarded by a set beam current;

[0012] A coating device, at least a part of which is disposed in the vacuum chamber, and the coating device is used to coat the liquid target material on the coating region;

[0013] At least one cooling device, disposed adjacent to the target substrate to cool the target surface.

[0014] Further, the coating region is formed into an annular inclined surface that is inclined in a direction from the outer edge of the target substrate toward the central axis of the target substrate, and the height of the coating region on the side adjacent to the outer edge of the target substrate is greater than the height of the other side of the coating region.

[0015] Further, the coating device includes:

[0016] A main body, at least a part of which is disposed in the vacuum chamber, and a receiving cavity is defined in the main body for receiving the liquid target material;

[0017] A coating part, disposed in the vacuum chamber, the coating part communicates with the receiving cavity and is disposed toward the coating region to coat the liquid target material on the coating region;

[0018] A pump, disposed in the receiving cavity to pump the liquid target material to the coating part.

[0019] Further, the coating device further includes:

[0020] A heating assembly, connected to the main body to heat the liquid target material in the receiving cavity;

[0021] A temperature control assembly, respectively connected to the coating part and the heating assembly to adjust the heating temperature of the heating assembly according to the viscosity of the liquid target material at the coating part.

[0022] Further, the target surface includes a plurality of target surface units, and each target surface unit is composed of a first surface and a bottom surface, and the area of the first surface is larger than the area of the bottom surface. Among them, the first surface is used to be bombarded by the set beam current, and the bottom surface is used to be connected to the target substrate.

[0023] Further, the ratio of the area of the first surface to the area of the corresponding bottom surface of each target surface unit is greater than 2.

[0024] Further, the target surface unit is formed into a conical shape and / or a pyramidal shape and / or a curved surface shape and / or a triangular prism.

[0025] Further, at least two of the cooling devices are included. After the coating area is coated into a target surface by the coating device, it passes through one of the cooling devices to be cooled. After the target surface is bombarded by the set beam current, it passes through another cooling device to be cooled; the cooling device cools the target substrate by spraying droplets onto the target substrate to vaporize the droplets into gas and extracting the gas from the vacuum chamber; and / or,

[0026] The rotary coating target further includes:

[0027] A liquid metal bearing, connected to one side or the other side of the target substrate to drive the rotation of the target substrate.

[0028] Further, the rotary coating target further includes:

[0029] A beam current pipeline, communicating with the vacuum chamber, and the set beam current passes through the beam current pipeline to bombard the target surface;

[0030] A differential pumping device, connected to the beam current pipeline to evacuate the beam current pipeline.

[0031] The accelerator according to the second aspect embodiment of the present invention includes the rotary coating target described in the above embodiment.

[0032] According to the rotary coating target of the embodiment of the present invention, by arranging a spin coating device to coat lithium on the coating area, the problems that lithium volatilizes due to heat and the service life of the rotary lithium target is short under the condition of a very high power density of the proton accelerator can be solved. The rotary coating target according to the embodiment of the present invention can maintain the supply of lithium and extend the service life of the rotary coating target. Description of the Drawings

[0033] Figure 1 FIG. is a schematic diagram of a rotary coating target according to an embodiment of the present invention;

[0034] Figure 2 FIG. is another schematic diagram of a rotary coating target according to an embodiment of the present invention;

[0035] Figure 3 FIG. is a schematic diagram of a target substrate and a target surface according to an embodiment of the present invention;

[0036] Figure 4 FIG. is still another schematic diagram of a rotary coating target according to an embodiment of the present invention;

[0037] Figure 5 FIG. is a schematic diagram of a target surface in the prior art;

[0038] Figure 6 It is a schematic diagram of a target surface unit according to an embodiment of the present utility model;

[0039] Figure 7 It is another schematic diagram of a target surface unit according to an embodiment of the present utility model;

[0040] Figure 8 It is a schematic diagram of the arrangement positions of the beam bombardment position, the cooling position, and the lithium paste coating position according to an embodiment of the present utility model;

[0041] Figure 9 It is another schematic diagram of the arrangement positions of the beam bombardment position, the cooling position, and the lithium paste coating position according to an embodiment of the present utility model.

[0042] Attached drawings

[0043] Rotary coating target 100;

[0044] Shell 10; Vacuum chamber 11;

[0045] Target substrate 21; Target surface 22; Coating area 23; Target surface unit 221;

[0046] Liquid target material 30;

[0047] Coating device 40; Body 41; Smearing part 42; Heating component 43; Temperature control component 44;

[0048] Coil 50;

[0049] Liquid metal bearing 60;

[0050] Beam pipe 70; Small hole 71;

[0051] Differential pumping device;

[0052] Moderator 90. Detailed implementation manners

[0053] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0054] In the description and claims of the present utility model, terms such as "first" and "second" are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data used can be interchanged under appropriate circumstances, so that the embodiments of the present utility model can be implemented in an order other than those illustrated or described herein. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.

[0055] The following will be combined Figures 1 to 9 , and the rotary coating target 100 provided by the embodiments of the present utility model will be described in detail through specific embodiments and their application scenarios.

[0056] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0057] As Figure 1 shown, the rotary coating target 100 according to the embodiments of the present utility model includes a housing 10, a target substrate 21, a liquid target material 30, a coating device 40, and at least one cooling device (not shown).

[0058] Specifically, the housing 10 defines a vacuum chamber 11; the target substrate 21 is rotatably disposed in the vacuum chamber 11, and an annular coating area 23 is defined on one side of the target substrate 21; the liquid target material 30 is used to coat the coating area 23 so that the coating area 23 is formed into a target surface 22 that can be bombarded by a set beam a (such as a proton beam or an ion beam) to eject neutrons b; at least a part of the coating device 40 is disposed in the vacuum chamber 11, and the coating device 40 is used to coat the liquid target material 30 on the coating area 23; at least one cooling device is disposed adjacent to the target substrate 21 to cool the target surface 22. Among them, the liquid target material 30 can be liquid lithium.

[0059] According to the rotary coating target 100 of the embodiments of the present utility model, the target substrate 21 can rotate. Compared with the fixed target surface 22, the target surface 22 of the rotary coating target 100 is an annular structure, and the rotary coating target 100 can disperse the power to a large-area target surface 22, thereby withstanding greater power. However, for a lithium conversion target with a relatively large power, for example, 80 kW of proton injection, it is difficult for the target surface to maintain at 100 °C within a certain area and time, so there is serious lithium evaporation loss. In order to ensure the supply of lithium on the target surface 22, the embodiments of the present utility model coat lithium on the target surface 22 through the coating device 40 to timely supplement the lithium lost on the target surface 22. The coating device 40 of the embodiments of the present utility model is applicable to both reflective targets and transmissive targets.

[0060] Further, in order to fully reduce the temperature of the target surface 22, a material with high thermal conductivity such as copper, copper alloy, or graphene is used as the thermal conductive layer material between the target substrate 21 and the lithium target surface 22, so as to quickly conduct away the heat of the target surface 22. In addition, according to the experimental data and the parameter settings of the coating device 40, lithium can be continuously coated on the target surface 22, or lithium can be coated on the target surface 22 every once in a while, always keeping the target surface 22 covered with lithium and the thickness of the lithium not exceeding 0.2 mm.

[0061] Further, in order to export the heat of the target surface 22, a plurality of cooling devices are provided to cool the target surface 22, so that the rotary coating target 100 can not only withstand the bombardment of a proton beam or an ion beam with a higher power, avoiding overheating and damage of the target surface 22, but also the cooling device 40 can quickly form a film of the liquid target material 30 on the coating area 23. Compared with directly using a liquid target, it can greatly reduce the volatilization of lithium and reduce pollution.

[0062] Thus, according to the rotary coating target 100 of the embodiment of the present invention, by providing the coating device 40 to coat lithium on the coating area 23, the problem of short service life of the rotary lithium target under the condition of a very high power density of the proton accelerator can be solved, the supply of lithium on the target surface 22 can be maintained, and the service life of the rotary coating target 100 can be extended.

[0063] According to an embodiment of the present invention, the coating area 23 is formed as an annular inclined surface that is inclined in the direction of the central axis of the target substrate 21 from the outer edge of the target substrate 21, and the height of the coating area 23 near the outer edge of the target substrate 21 is greater than the height of the other side of the coating area 23.

[0064] That is to say, as Figure 3 shown, the coating area 23 adopts an inclined surface structure, so that the target surface 22 located on the coating area 23 also forms an inclined surface that conforms to the shape of the coating area 23. The inclined target surface 22 can provide centripetal force for the lithium film at a high rotation speed, so that the lithium film that is just coated on the coating area 23 and presents a liquid and gel-like state will not fly out of the target surface 22 due to centrifugal force, reducing the pollution caused by lithium splashing.

[0065] In an embodiment of the present invention, as Figure 1 shown, the coating device 40 includes a main body 41, an application part 42, and a pump (not shown).

[0066] Specifically, at least a part of the main body 41 is arranged in the vacuum chamber 11, and a receiving chamber is defined in the main body 41 for receiving the liquid target material 30; the application part 42 is arranged in the vacuum chamber 11, the application part 42 communicates with the receiving chamber and is arranged towards the coating area 23 for coating the liquid target material 30 on the coating area 23; the pump is arranged in the receiving chamber for pumping the liquid target material 30 to the application part 42.

[0067] Further, the coating device 40 further includes a heating component 43 and a temperature control component 44. The heating component 43 is connected to the main body 41 to heat the liquid target material 30 in the accommodation cavity, and the temperature control component 44 is respectively connected to the coating part 42 and the heating component 43 to adjust the heating temperature of the heating component 43 according to the viscosity of the liquid target material 30 at the coating part 42.

[0068] Specifically, a viscometer can be provided on the coating part 42. The temperature control device 44 is connected to the viscometer on the coating part 42, and at the same time, the temperature control device 44 is connected to the heating component 43. When the viscosity of lithium is relatively high, it indicates that the fluidity of lithium is poor, and the thickness of the coated target surface 22 will be relatively thick. At this time, the temperature control device 44 controls the heating component 43 to heat the lithium in the accommodation cavity, which can improve the fluidity of lithium, so as to coat lithium with an appropriate viscosity onto the target surface 22 located at the lithium paste coating position P and control the thickness of the lithium film.

[0069] Preferably, the coating part 42 is formed as a brush. As Figure 1 shown, the brush is a relatively thin fibrous brush, the nozzle is an elongated rectangular structure, and the length of the nozzle or the brush is the same as the width of the target surface 22. As Figure 2 shown, the coating part 42 can also be formed as a nozzle.

[0070] In the specific use process, set the supply speed of the pump and control the heating temperature of the heating component 43 to make the lithium layer on the target surface 22 as thin as possible at a specific rotation speed, and the thickness does not exceed 0.2 mm.

[0071] According to another embodiment of the present invention, as Figure 4 shown, the target surface 22 includes a plurality of target surface units 221. The target surface unit 221 is composed of a first surface and a bottom surface, and the area of the first surface is larger than the area of the bottom surface. Among them, the first surface is used to be bombarded by the set beam a, and the bottom surface is used to be connected to the target substrate 21.

[0072] In other words, for the rotary coating target 100 according to the embodiment of the present invention, the target surface 22 is not a planar structure, but is composed of many target surface units 221. Each target surface unit 221 can be regarded as a convex structure or a concave structure, and a lithium film is respectively coated on each target surface unit 221. That is to say, compared with the traditional planar target surface, the uneven structure increases the effective area of the target surface 22.

[0073] Further, as Figure 6 and Figure 7As shown, the target surface unit 221 is similar to rows of mountain-like structures protruding on the target substrate 21. Thus, each target surface unit 221 increases its contact area with the ion beam or proton beam as much as possible on the original basis, and can construct a high proportion of heat dissipation boundaries. Therefore, when the spin coating target 100 is bombarded by the proton beam or ion beam, the target surface unit 221 can reduce the power density by more than one order of magnitude, avoid the transient temperature rise of the target surface 22 caused by proton or ion deposition, reduce the power borne by the unit lithium film, enable the temperature of the target surface 22 to be within a safe range, and the heat deposited during the continuous operation of the target substrate 21 can be taken away by the cooling device, further improving the service life of the spin coating target 100. The target surface unit 221 can be formed by machining, and the processing technology is simple.

[0074] According to an embodiment of the present invention, the ratio of the area of the first surface of each target surface unit 221 to the area of its bottom surface is greater than 2.

[0075] Specifically, the larger the area of the first surface of the target surface unit 221, the larger the effective area of its contact with the proton beam or ion beam. However, due to process and target surface 22 size limitations, the ratio of the area of the first surface to the area of the bottom surface should be controlled within a reasonable range. Compared with the smooth target surface 22, the target surface 22 according to the embodiment of the present invention can greatly reduce the power density of the target surface 22, and the instantaneous heat tolerance of the target surface 22 itself has also been greatly improved without relying on an external heat dissipation device.

[0076] Furthermore, the target surface unit 221 is formed into a conical shape and / or a pyramidal shape and / or a curved surface shape and / or a triangular prism.

[0077] That is to say, the target surface unit 221 can be composed of a single conical shape or pyramidal shape or curved surface shape or triangular prism structure, or can be composed of any combination of the above structures. As Figures 5 to 7 shown, Figure 5 is the planar target surface 1 in the prior art, Figure 6 and Figure 7 is the target surface 22 formed by the target surface unit 221 according to the embodiment of the present invention. Compared with the planar target surface 1, the target surface 22 formed by the target surface unit 221 can greatly increase the contact area of the target surface 22 with the set beam current a on the same target substrate 21. Taking Figure 6 as an example, the target surface 22 is composed of multiple horizontally placed triangular prism-shaped target surface units 221, and multiple target surface units 221 are combined into multiple triangular groove structures, and the lithium film is coated on the Figure 6 first surface (represented by thicker lines in Figure 6 ). Assuming that the ratio of the first surface area to the bottom area of the target surface unit 221 is Ks .

[0078] ThenKs The expression is: where , h is the height of the target surface unit 221, and T is the bottom width of the target surface unit 221.

[0079] When the cross-sectional power density of the implanted ion beam is , the actual power density on the target surface is:

[0080] Thus, when k hT > 5, the power density of the target surface 22 according to the embodiment of the present invention is reduced by more than one order of magnitude compared to the smooth target surface 1. The combination of multiple target surface units 221 and the rotating target structure can significantly reduce the transient temperature rise caused by proton or ion deposition.

[0081] According to an embodiment of the present invention, the height of each target surface unit 221 is equal, and the bottom area of each target surface unit 221 is also equal, so as to facilitate the unified processing of the target surface units 221 and facilitate the calculation of the power density of the target surface 22.

[0082] In an embodiment of the present invention, when the rotary coating target 100 is operating continuously, the high-power ion beam is finally deposited on the rotary coating target 100 in the form of heat. In order to conduct away the heat of dozens of kilowatts on the rotary coating target 100, a cooling device can also be provided to cool the rotary coating target 100. Preferably, the present invention uses a phase change cooling device to dissipate heat from the target surface 22. The phase change cooling device does not need to be directly connected to the target surface units 221 on the target surface 22. The phase change cooling device and the target surface units 221 work independently without complex connection relationships. Specifically, the phase change cooling device sprays liquid droplets onto the target surface 22 through an atomizer. The liquid droplets absorb the heat of the target surface 22 and then evaporate into high-temperature gas. The high-temperature gas is drawn away through the exhaust pipe, or the high-temperature gas is condensed into liquid through the condenser tube and discharged, thereby realizing the cooling of the rotary coating target 100 and avoiding the pollution of the vacuum chamber 11.

[0083] According to an embodiment of the present invention, as Figure 8As shown, the position on the target surface 22 bombarded by the set beam current a is the beam current bombardment zone. On the beam current bombardment zone of the set beam current a, along the rotation direction of the target substrate 21, a cooling position N and a lithium paste coating position P are sequentially arranged downstream of the beam current bombardment position M. The emission device of the set beam current a corresponds to the beam current bombardment position M, the cooling device corresponds to the cooling position N, and the coating device 40 corresponds to the lithium paste coating position P. When a large amount of lithium evaporates due to the bombardment of the target surface 22 by high-power protons, it rotates to the cooling position N, and the cooling device quickly cools the target surface 22 to room temperature. When the low-temperature target surface 22 passes through the lithium paste coating position P, the pump in the coating device 40 pumps lithium to the coating part 42, and the coating part 42 applies a lithium liquid film or a cooled solid film with a fixed thickness to the target surface 22. The coated target surface 22 then rotates to the beam current bombardment position M and continuously circulates.

[0084] In an embodiment of the present invention, there are at least two cooling devices. After the coating area 23 is coated into the target surface 22 by the coating device 40, it passes through one cooling device to be cooled. After the target surface 22 is bombarded by the set beam current a, it passes through another cooling device to be cooled; the cooling device cools the target surface 22 by spraying mist onto the target surface 22 to condense the mist into droplets and discharge them from the vacuum chamber 11.

[0085] Specifically, as Figure 9 shown, the target surface 22 passing through the beam current bombardment position M sequentially rotates to the first cooling position N1, the lithium paste coating position P, and the second cooling position N2. The set beam current a corresponds to the beam current bombardment position M, one cooling device corresponds to the first cooling position N1, the coating device 40 corresponds to the lithium paste coating position P, and another cooling device corresponds to the second cooling position N2. When the target surface 22 is bombarded by an ion beam or a proton beam, the temperature of the bombarded position is relatively high. It rotates to the first cooling position N1, and the cooling device quickly cools the target surface 22 to reduce the evaporation of lithium. Then it rotates to the lithium paste coating position P, and the coating device 4 coats the target surface 22. Then it rotates to the second cooling position N2, and another cooling device further dissipates the heat of the target surface 22 to solidify lithium in the coating area 23 and avoid the splashing of lithium. Among them, in order to improve the heat dissipation effect and facilitate installation, the cooling device can be arranged on any side of the target substrate 21. That is to say, multiple cooling devices can be arranged on both sides of the target surface 22 to ensure the heat dissipation effect.

[0086] In an embodiment of the present invention, as Figure 1 shown, the rotary coating target 100 further includes a beam pipe 70. The beam pipe 70 communicates with the vacuum chamber 11, and the set beam current a passes through the beam pipe 70 to bombard the target surface 22. In addition, a focusing device (not shown) and a small hole 71 for isolating pollution are provided at the end of the beam pipe 70. Among them, the focusing device is used to focus the proton beam or ion beam, and the proton beam or ion beam bombards the target surface 22 to generate neutrons b, and the neutrons b pass through the moderator 90 to reduce the energy of the neutrons b.

[0087] Furthermore, the rotary coating target 100 further includes a differential pumping device which is connected to the differential pumping port 80 to evacuate the beam pipe 70, thereby further reducing the contamination of the beam pipe 70 caused by lithium evaporation and reducing the risks such as high-voltage insulation breakdown caused by the contamination.

[0088] Preferably, the rotary coating target 100 further includes a liquid metal bearing 60. As shown in Figure 1 , Figure 2 , Figure 8 and Figure 9 , when the liquid metal bearing 60 is installed, it is correspondingly arranged with the bearing position O. The liquid metal bearing 60 is driven by a coil 50 to drive a mover coil (not shown) sleeved on the liquid bearing 60. The liquid metal bearing 60 is connected to one side or the other side of the target substrate 21 to drive the target substrate 21 to rotate. Among them, the liquid metal bearing 60 can select a metal material with high thermal conductivity and radiation resistance to conduct the heat of the target surface 22, further improving heat dissipation and increasing the average thermal conductivity of the rotary coating target 100.

[0089] The accelerator according to the second aspect embodiment of the present invention includes the rotary coating target 100 described in the above embodiment. Since the rotary coating target 100 according to the embodiment of the present invention has the advantage of long service life, therefore, the accelerator according to the embodiment of the present invention also has the advantage of long service life.

[0090] The other structures and technologies of the accelerator according to the embodiment of the present invention belong to the prior art and will not be elaborated here.

[0091] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims, and all of them belong to the protection scope of the present invention.

Claims

1. A spin coating target, characterized in that: include: a housing defining a vacuum chamber; A target substrate is rotatably disposed in the vacuum chamber, and one side of the target substrate defines an annular coating area; A liquid target material is used to coat the coating area so that the coating area is formed into a target surface that can be bombarded with neutrons by a set beam; a coating device, at least a portion of which is disposed in the vacuum chamber, the coating device being used to coat the liquid target material on the coating area; At least one cooling device is disposed adjacent to the target substrate to cool the target surface.

2. The spin coating target according to claim 1, characterized in that The coating area is formed as an annular inclined surface inclined from the outer edge of the target substrate toward the direction of the central axis of the target substrate, and the height of the coating area on one side adjacent to the outer edge of the target substrate is greater than the height of the other side of the coating area.

3. The spin coating target according to claim 1, characterized in that The coating device comprises: A body, at least a portion of which is disposed in the vacuum chamber, wherein a receiving cavity is defined in the body for receiving the liquid target material; A coating part is arranged in the vacuum chamber, the coating part is connected to the containing chamber and is arranged toward the coating area to coat the liquid target material on the coating area; A pump is disposed in the accommodating chamber and is used to pump the liquid target material to the coating portion.

4. The spin coating target according to claim 3, characterized in that: The coating device also includes: A heating component connected to the body for heating the liquid target material in the containing cavity; A temperature control component is connected to the coating part and the heating component respectively to adjust the heating temperature of the heating component according to the viscosity of the liquid target material at the coating part.

5. The spin coating target according to claim 1, characterized in that: The target surface includes a plurality of target surface units, each of which consists of a first surface and a bottom surface, wherein the area of ​​the first surface is larger than the area of ​​the bottom surface, wherein the first surface is used to be bombarded by the set beam, and the bottom surface is used to be connected to the target substrate.

6. The spin coating target according to claim 5, characterized in that The ratio of the area of ​​the first surface of each target surface unit to the area of ​​the corresponding bottom surface is greater than 2.

7. The spin coating target according to claim 5, characterized in that The target surface unit is formed in a cone shape and / or a pyramid shape and / or a curved surface shape and / or a triangular prism shape.

8. The spin coating target according to claim 1, characterized in that The cooling device comprises at least two cooling devices. After the coating area is coated by the coating device to form a target surface, it passes through one cooling device to be cooled. After the target surface is bombarded by the set beam, it passes through another cooling device to be cooled. The cooling device sprays droplets onto the target substrate to vaporize the droplets into gas and extracts the gas out of the vacuum chamber to cool the target substrate. and / or, The spin coating target further comprises: A liquid metal bearing is connected to one side or the other side of the target substrate to drive the target substrate to rotate.

9. The spin coating target according to claim 1, characterized in that: Also includes: A beam pipe connected to the vacuum chamber, wherein the set beam passes through the beam pipe to bombard the target surface; A differential pumping device is connected to the beam pipeline to evacuate the beam pipeline.

10. An accelerator, characterized in that: The invention comprises the spin coating target according to any one of claims 1 to 9.

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