An integrated target body moderator for a spallation neutron source

Abstract

This application discloses an integrated target moderator for a spallation neutron source, comprising a target container and multiple target plates. The target container has a sealed space including a liquid inlet channel, a target cavity, and a moderation cavity. The target container also has a liquid inlet hole and a liquid outlet hole, with the liquid inlet hole communicating with the liquid inlet channel and the liquid outlet hole communicating with the moderation cavity. Multiple target plates are stacked in the target cavity, and the liquid inlet channel communicates with the moderation cavity through the gap between adjacent target plates. High-energy protons bombard the target plates, and during the bombardment, the cooling liquid flowing through the gap between the target plates cools the target plates. The generated high-energy fast neutrons are slowed down by the cooling liquid in the moderation cavity. Since the moderation cavity and the target cavity are integrated, the high-energy fast neutrons are directly slowed down in the moderation cavity. The physical gap between the high-energy fast neutrons from their generation location and the liquid in the moderation cavity is small, shortening the moderation path of the high-energy fast neutrons, thereby effectively reducing the flux loss of high-energy fast neutrons and improving the coupling efficiency of high-energy fast neutrons.

Description

Technical Field

[0001] This application belongs to the field of heat dissipation neutron source technology, specifically relating to an integrated target moderator for spallation neutron sources. Background Technology

[0002] Spallation neutron sources are crucial scientific instruments for studying the microscopic structure of matter. They generate neutrons by bombarding heavy metal targets with high-energy protons, collect and extract these neutrons to use as a light source for testing materials and determining their internal structure. Currently, key components within spallation neutron source target sites, such as the target body, moderator, and shielding, are typically independent, functionally separated modules. For example, the target body usually includes a target container and a target sheet, with the target sheet placed inside the container. When the target sheet is bombarded by high-energy protons, it produces high-energy fast neutrons, and the resulting heat is carried away by a cooling liquid flowing within the target container. Although the cooling liquid provides some moderation, the high-energy fast neutrons are usually guided to an external moderator for sufficient slowing, transforming them into the low-energy neutrons required for the experiment. However, the coupling efficiency of high-energy fast neutrons in existing spallation neutron sources is relatively low. Summary of the Invention

[0003] The technical problem to be solved by this application is that the utilization rate of high-energy fast neutrons in existing spallation neutron sources is low. In order to solve this technical problem, an integrated target moderator for spallation neutron sources is provided, which can improve the coupling efficiency of high-energy fast neutrons.

[0004] The technical solution proposed in this application is as follows: An integrated target moderator for a spallation neutron source includes: The target container has a sealed space, which includes a liquid inlet channel, a target chamber, and a slowing chamber. The target container also has a liquid inlet hole and a liquid outlet hole. The liquid inlet hole is connected to the liquid inlet channel, and the liquid outlet hole is connected to the slowing chamber. Multiple target plates are stacked and installed in the target cavity, and the liquid inlet channel is connected to the slowing cavity through the gap between two adjacent target plates.

[0005] Furthermore, the sealed space is provided with two liquid inlet channels, which are located on both sides of the target cavity and the slowing cavity, respectively. Two liquid inlet holes are opened on the same side of the target container, and the two liquid inlet channels are respectively connected to the two liquid inlet holes.

[0006] Furthermore, the sealed space is also provided with a connecting channel, which is located on the side of the target cavity away from the slowing cavity. The end of the liquid inlet channel away from the liquid inlet hole is connected to the connecting channel, and the connecting channel is connected to the slowing cavity through the gap between two adjacent target pieces.

[0007] Furthermore, the sealed space is provided with two partitions, which are arranged opposite to each other to enclose a slowing chamber with one end open. The opening is located at the end of the slowing chamber away from the liquid outlet. The target chamber is connected to the opening, and multiple target plates can close the opening.

[0008] Furthermore, a positioning post is provided within the sealed space, and the positioning post and the end of the partition plate enclose the target cavity.

[0009] Furthermore, the inlet and outlet are located on the same side of the target container.

[0010] Furthermore, it also includes an installation assembly for connecting to the main shield. The target container is connected to one end of the installation assembly that extends into the main shield. The installation assembly has a first cooling channel and a second cooling channel that are respectively connected to the liquid inlet and the liquid outlet, and the installation assembly is capable of shielding neutrons.

[0011] Furthermore, the mounting assembly includes a mounting unit and a connector. The mounting unit is used to connect to the main shield, the connector is connected to one end of the mounting unit that extends into the main shield, and the target container is connected to the end of the connector that is away from the mounting unit.

[0012] Furthermore, the installation unit includes a front-end module and a back-end module. The back-end module is used to connect to the main shield. The front-end module is detachably connected to one end of the back-end module that extends into the main shield. The connector is connected to the end of the front-end module that is away from the back-end module.

[0013] Furthermore, the end faces where the front-end module and the back-end module are connected to each other are provided with a labyrinth sealing structure, and the labyrinth sealing structure is filled with flexible shielding material.

[0014] Using the aforementioned spallation neutron source with an integrated target moderator, high-energy protons bombard the target sheet from a direction perpendicular to the target sheet, generating a large number of neutrons through spallation reactions. During the bombardment process, cooling liquid flowing through the gaps between the target sheets cools the target sheet, and the cooling liquid flows out through the outlet holes after passing through the moderation chamber. The generated high-energy fast neutrons are slowed down by the cooling liquid within the moderation chamber. Because the moderation chamber and the target chamber are integrated, the high-energy fast neutrons are directly slowed down within the moderation chamber. The physical gap between the high-energy fast neutrons and the cooling liquid within the moderation chamber is small, shortening the slowing path of the high-energy fast neutrons. This effectively reduces the flux loss of high-energy fast neutrons and improves the coupling efficiency.

[0015] Furthermore, it is understandable that the cooling liquid flowing through the target plate can also moderate some high-energy fast neutrons. Since in this embodiment, both the moderation cavity and the target plate are located within the target container, the high-energy fast neutrons moderated during the target plate cooling process can be further utilized, improving neutron coupling efficiency. It should be explained that during target cooling, some high-energy fast neutrons are directly absorbed and moderated by the cooling liquid. In existing systems where the target and moderator are separated, the absorbed neutrons have difficulty entering the moderator, affecting neutron coupling efficiency. Attached Figure Description

[0016] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0017] Figure 1 A schematic diagram of the structure of an integrated target moderator for a spallation neutron source provided in an embodiment of this application; Figure 2 for Figure 1 The diagram shows the internal structure of the target. Figure 3 This application provides a schematic diagram of the structure of a spallation neutron source according to an embodiment of the present application.

[0018] Label Explanation: 110. Target container; 111. Liquid inlet channel; 112. Target chamber; 113. Slowing chamber; 114. Liquid outlet; 115. Connecting channel; 116. Body; 117. Cover plate; 118. Partition plate; 119. Positioning post; 120. Target piece; 130. Mounting assembly; 140. Mounting unit; 141. Front-end module; 142. Rear-end module; 150. Connector. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0020] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0022] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0024] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0025] To facilitate understanding of the technical solution of this application, the reasons for the low coupling efficiency of high-energy fast neutrons in existing spallation neutron sources are explained here: In existing spallation neutron sources, the target and moderator are usually set separately. Due to the separation of the two, there is a large physical gap between the high-energy fast neutrons and the moderation medium of the moderator, resulting in a large flux loss of high-energy fast neutrons, which leads to a low coupling efficiency of high-energy fast neutrons.

[0026] Based on the above-mentioned technical problems, on the one hand, this application provides an integrated target moderator for spallation neutron sources. Using this target can reduce the flux loss of high-energy fast neutrons from the generation location to the moderator, thereby improving the coupling efficiency of high-energy fast neutrons.

[0027] like Figure 1 and Figure 2 As shown, in one embodiment, the target 100 includes a target container 110 and a plurality of target plates 120. The target container 110 has a sealed space, which includes a liquid inlet channel 111, a target cavity 112, and a moderation cavity 113. The plurality of target plates 120 are stacked in the target cavity 112, and the liquid inlet channel 111 communicates with the moderation cavity 113 through the gap between two adjacent target plates 120. In this way, cooling liquid, preferably water, can be introduced into the liquid inlet channel 111 and enter the moderation cavity 113 through the gap between the target plates 120, and can dissipate heat from the target plates 120 as it passes through them. In addition, after the cooling liquid enters the moderation cavity 113, the generated neutrons can be moderated in the cooling liquid within the moderation cavity 113. Therefore, it can be determined that in this embodiment, the moderation cavity 113 is equivalent to a moderator in the prior art.

[0028] Furthermore, the target container 110 is also provided with a liquid inlet and a liquid outlet 114. The liquid inlet is connected to the liquid inlet channel 111, and the liquid outlet 114 is connected to the moderation chamber 113. In this way, cooling liquid can be introduced into the liquid inlet channel 111 through the liquid inlet, and the cooling liquid flows into the moderation chamber 113 through the gap between the target plates 120, and then is discharged through the liquid outlet 114.

[0029] Using the aforementioned integrated target moderator 100 for spallation neutron source, high-energy protons bombard the target plate 120 from a direction perpendicular to the target plate 120, generating a large number of neutrons through spallation reactions. During the bombardment process, cooling liquid flowing through the gaps in the target plate 120 cools the target plate 120. The cooling liquid flows through the moderation chamber 113 and exits through the outlet hole 114. The generated high-energy fast neutrons are slowed down by the cooling liquid within the moderation chamber 113. Since the moderation chamber 113 and the target chamber 112 are integrated, the high-energy fast neutrons are directly slowed down within the moderation chamber 113. The physical gap between the high-energy fast neutrons from their generation location and the cooling liquid within the moderation chamber 113 is small, shortening the moderation path of the high-energy fast neutrons. This effectively reduces the flux loss of high-energy fast neutrons and improves their coupling efficiency. In addition, the target cavity 112 and the moderation cavity 113 are integrated into one unit, which is equivalent to integrating the original target body and moderator equipment, which is conducive to the subsequent replacement of the equipment and reduces the difficulty of maintenance.

[0030] It is understandable that the cooling liquid flowing through the target plate 120 can also moderate some high-energy fast neutrons. Since in this embodiment, both the moderation cavity 113 and the target plate 120 are located within the target container 110, the high-energy fast neutrons moderated during the cooling process of the target plate 120 can be further utilized, improving the neutron coupling efficiency. It should be explained that during the cooling process of the target body 100, some high-energy fast neutrons are directly absorbed by the cooling liquid. The existing separate setting of the target body 100 and the moderator makes it difficult for the neutrons absorbed by the moderator to enter the moderator, affecting the neutron coupling efficiency.

[0031] In one embodiment, the target container 110 includes a body 116 and a cover 117. The cover 117 is capable of covering the body 116 to form the aforementioned sealed space. It is also determined that the aforementioned inlet and outlet ports 114 are preferably located on the body 116.

[0032] In one embodiment, the sealed space is provided with two liquid inlet channels 111, which are located on both sides of the target cavity 112 and the moderation cavity 113, respectively. It can also be determined that two liquid inlet holes are opened on the same side of the target container 110, and the two liquid inlet channels 111 are respectively connected to the two liquid inlet holes.

[0033] In one embodiment, the sealed space is further provided with a connecting channel 115. The connecting channel 115 is located on the side of the target cavity 112 away from the moderating cavity 113. The end of the liquid inlet channel 111 away from the liquid inlet hole is connected to the connecting channel 115. The connecting channel 115 is connected to the moderating cavity 113 through the gap between two adjacent target plates 120. Specifically... Figure 1 In the embodiment shown, the two liquid inlet channels 111 are connected to both ends of the connecting channel 115.

[0034] In one embodiment, two partitions 118 are provided within the sealed space. The two partitions 118 are arranged opposite to each other to enclose a moderating chamber 113 with one end open within the sealed space. The opening is located at the end of the moderating chamber 113 away from the liquid outlet 114, i.e., the opening communicates with the target chamber 112. Multiple target plates 120 can close the opening, so that multiple target plates 120 are stacked and installed after the target chamber 112. The liquid inlet channel 111 and the connecting channel 115 communicate with the moderating chamber 113 through the gaps between the target plates 120, ensuring that the cooling liquid flows through the gaps between the target plates 120.

[0035] Furthermore, a positioning post 119 is also provided within the sealed space. The positioning post 119 and the end of the partition 118 enclose each other to form a target cavity 112. Figure 1 It can be understood that the target cavity 112 is used to position the cavity of the stacked target pieces 120. The target cavity 112 is rectangular in shape and its four surfaces are all through, so that the slowing cavity 113, the connecting channel 115 and the liquid inlet channel 111 can communicate with the gap between the stacked target pieces 120 in the target cavity 112.

[0036] like Figure 3 As shown, in one embodiment, the integrated target moderator further includes a mounting assembly 130 for connection to the main shield. The target container 110 is connected to one end of the mounting assembly 130 that extends into the main shield. It is understood that the mounting assembly 130 is detachably connected to the main shield, for example, via a flange and quick-release structure, to facilitate assembly and disassembly.

[0037] Furthermore, the mounting assembly 130 has a first cooling channel and a second cooling channel. The first cooling channel is connected to the liquid inlet, and the second cooling channel is connected to the liquid outlet 114. Specifically, there are two first cooling channels, each connected to one of the two liquid inlets. In addition, both the first and second cooling channels are connected to a liquid supply mechanism, allowing the liquid supply mechanism to deliver cooling liquid into the target container 110.

[0038] In practical applications, mounting component 130 can also shield neutrons to prevent generated neutrons from leaking through it. Specifically, mounting component 130 can be made of stainless steel to achieve neutron shielding.

[0039] In one embodiment, the mounting assembly 130 includes a mounting unit 140 and a connector 150. The mounting unit 140 is used to connect to the main shield, the connector 150 is connected to one end of the mounting unit 140 that extends into the main shield, and the target container 110 is connected to the end of the connector 150 that is away from the mounting unit 140.

[0040] Furthermore, the installation unit 140 includes a front-end module 141 and a rear-end module 142. The front-end module 141 has a maintenance handle and a hoisting irradiation test port on its side. The rear-end module 142 is used to connect to the main shield, and the front-end module 141 is detachably connected to one end of the rear-end module 142 that extends into the main shield. A connector 150 is connected to the end of the front-end module 141 furthest from the rear-end module 142. Similarly, the connector 150 can also be detachably connected to the front-end module 141, for example, through a quick-lock flange for rapid assembly and disassembly. Thus, the modular design of the installation assembly 130 allows for the replacement of corresponding components as needed without damaging or discarding the entire installation assembly 130, reducing maintenance difficulty and long-term operating costs, minimizing resource consumption, and facilitating the minimization and classified management of radioactive waste.

[0041] It needs further explanation that the front-end module 141 is closer to the target container 110 and receives more radiation. Therefore, after operation, it is usually necessary to replace the front-end module 141, connector 150, and target container 110. The front-end module 141 is detached from the back-end module 142 for processing. After testing, if the back-end module 142 is undamaged or the damage is within the allowable range and the shielding effect still meets the requirements, then the back-end module 142 can be reused.

[0042] In practical applications, the end faces connecting the front-end module 141 and the back-end module 142 are provided with a labyrinth sealing structure. For example, multiple concentric annular protrusions can be provided on the end face of one of the front-end module 141 and the back-end module 142, and multiple concentric annular grooves can be provided on the end face of the other. When the two end faces are connected, the annular protrusions are inserted into the corresponding annular grooves. In other embodiments, the labyrinth sealing structure can also be mesh-like or stepped, which is not limited here. In addition, in a preferred embodiment, the labyrinth sealing structure is filled with a flexible shielding material to ensure that the connection between the front-end module 141 and the back-end module 142 still has excellent shielding effect after multiple disassemblies and reassemblies, avoiding neutron leakage. The flexible shielding material can be a rubber-based neutron shielding material, a flexible boron nitride nanotube film, a soft boron-containing polyethylene, etc.

[0043] In summary, the integrated target moderator 100 for spallation neutron sources and the spallation neutron source provided in this application have at least the following advantages: 1. Integrating the original target and moderator equipment into one unit facilitates subsequent equipment replacement and reduces maintenance difficulty.

[0044] 2. After cooling the target plate 120, the cooling liquid enters the moderation chamber 113 and flows out through the outlet hole 114. Since the target chamber 112 and the moderation chamber 113 are connected as one unit, the neutrons generated on the target plate 120 directly enter the moderation chamber 113 and are slowed down by the cooling liquid in the moderation chamber 113. This shortens the moderation path of high-energy fast neutrons, reduces the flux loss of high-energy fast neutrons, and improves the coupling efficiency of high-energy fast neutrons.

[0045] 3. When the cooling liquid flows through the target plate 120, it can also slow down and absorb some high-energy fast neutrons. The cooling liquid that absorbs high-energy fast neutrons will flow directly into the moderation chamber 113, so that the neutrons that are slowed down and absorbed during the cooling process can be further utilized, thereby further improving the neutron coupling efficiency.

[0046] 4. Mounting component 130 can shield neutrons to prevent generated neutrons from leaking out of the main shield through mounting component 130.

[0047] 5. The modular design of the installation component 130 allows for the replacement of corresponding parts as needed without damaging or discarding the entire installation component 130. This reduces maintenance difficulty and long-term operating costs, minimizes resource consumption, and facilitates the minimization and classified management of radioactive waste.

[0048] 6. The end faces where the front-end module 141 and the back-end module 142 are connected are provided with a labyrinth sealing structure, and the labyrinth sealing structure is filled with flexible shielding material to ensure that the connection between the front-end module 141 and the back-end module 142 still has excellent shielding effect after multiple disassemblies and reassemblies.

[0049] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated target moderator for spallation neutron sources, characterized in that, include: The target container has a sealed space, which includes a liquid inlet channel, a target chamber, and a slowing chamber. The target container also has a liquid inlet hole and a liquid outlet hole. The liquid inlet hole is connected to the liquid inlet channel, and the liquid outlet hole is connected to the slowing chamber. Multiple target plates are stacked and installed in the target cavity, and the liquid inlet channel is connected to the slowing cavity through the gap between two adjacent target plates.

2. The integrated target moderator for spallation neutron sources according to claim 1, characterized in that, The sealed space is provided with two liquid inlet channels, which are located on both sides of the target cavity and the slowing cavity, respectively. Two liquid inlet holes are opened on the same side of the target container, and the two liquid inlet channels are respectively connected to the two liquid inlet holes.

3. The integrated target moderator for spallation neutron sources according to claim 1, characterized in that, The sealed space is also provided with a connecting channel, which is located on the side of the target cavity away from the slowing cavity. The end of the liquid inlet channel away from the liquid inlet hole is connected to the connecting channel, and the connecting channel is connected to the slowing cavity through the gap between two adjacent target pieces.

4. The integrated target moderator for spallation neutron sources according to claim 1, characterized in that, The sealed space is provided with two partitions, which are arranged opposite to each other to form a slowing chamber with one end open. The opening is located at the end of the slowing chamber away from the liquid outlet. The target chamber is connected to the opening, and multiple target plates can close the opening.

5. The integrated target moderator for spallation neutron sources according to claim 4, characterized in that, The sealed space is also provided with a positioning post, which, together with the end of the partition, forms the target cavity.

6. The integrated target moderator for spallation neutron sources according to claim 1, characterized in that, The inlet and outlet are located on the same side of the target container.

7. The integrated target moderator for spallation neutron sources according to claim 1, characterized in that, It also includes an installation component for connecting to the main shield. The target container is connected to one end of the installation component that extends into the main shield. The installation component has a first cooling channel and a second cooling channel that are respectively connected to the liquid inlet and the liquid outlet. The installation component is capable of shielding neutrons.

8. The integrated target moderator for spallation neutron sources according to claim 7, characterized in that, The installation assembly includes an installation unit and a connector. The installation unit is used to connect to the main shield. The connector is connected to one end of the installation unit that extends into the main shield. The target container is connected to the end of the connector that is away from the installation unit.

9. The integrated target moderator for spallation neutron sources according to claim 8, characterized in that, The installation unit includes a front-end module and a back-end module. The back-end module is used to connect to the main shield. The front-end module is detachably connected to one end of the back-end module that extends into the main shield. The connector is connected to the end of the front-end module that is away from the back-end module.

10. The integrated target moderator for a spallation neutron source according to claim 9, characterized in that, The end faces where the front-end module and the back-end module are connected are provided with a labyrinth sealing structure, and the labyrinth sealing structure is filled with flexible shielding material.

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