A neutron switch insert and neutron spectrometer beam splitting system

Abstract

A neutron switch insert and a neutron spectrometer beam splitting system. The neutron switch insert comprises a vacuum housing, a first neutron guide and a second neutron guide. The vacuum housing comprises a vacuum cavity having a first port and a second port in communication, and the first neutron guide and the second neutron guide are arranged at an angle in the vacuum cavity. Due to the first neutron guide and the second neutron guide arranged at an angle in the vacuum cavity of the vacuum housing, two angled neutron beam flows can be transmitted through the neutron switch insert, so that the neutron reactor or the target station can simultaneously output two neutron beam flows to two independent spectrometer halls, greatly improving the utilization rate of the reactor or the target station.

Description

Technical Field

[0001] This invention relates to the field of neutron spectrometer technology, and more specifically to a neutron switch insert. Background Technology

[0002] Neutron spectrometers primarily utilize neutrons as a detection method to study the microscopic structure and properties of various substances. Currently, spectrometers built worldwide can be divided into two categories: neutron spallation source spectrometers and neutron reactor spectrometers. The neutron beam in the target station or reactor is transmitted to the spectrometer hall and then to the sample via neutron optical components such as neutron conduits or collimators. Both reactors and target stations require radiation protection shielding; thus, the neutron conduit or collimator inevitably needs to pass through the radiation protection shielding layer. The neutron conduit or collimator located within this radiation protection shielding layer is called a neutron insert, and the neutron insert connected to the neutron switch in the target station or reactor is called a neutron switch insert.

[0003] Existing neutron switch inserts consist of a small-angle, single-channel neutron conduit that can only transmit one neutron beam to a spectrometer hall, resulting in low utilization of the reactor or target station. Summary of the Invention

[0004] The main technical problem solved by this invention is that only one neutron beam can be transmitted to a spectrometer hall via existing neutron switch inserts, resulting in low utilization of the reactor or target station.

[0005] According to a first aspect, one embodiment provides a neutron switch insert, comprising:

[0006] A vacuum enclosure having a vacuum cavity, the vacuum cavity having a first port and a second port, the first port being connected to the second port, a first neutron beam window being provided at the first port, and a second neutron beam window being provided at the second port;

[0007] A first neutron conduit is disposed within the vacuum cavity, and the first neutron conduit extends from the first port to the second port;

[0008] And a second neutron conduit, which is disposed in the vacuum cavity, extends from the first port to the second port, and is arranged at an angle to the first neutron conduit.

[0009] According to a second aspect, one embodiment provides a neutron spectrometer beam splitting system, including a neutron switch insert, a neutron target station insert, and a neutron chopper arranged sequentially, wherein the neutron switch insert is the neutron switch insert as described in any embodiment of this application.

[0010] According to the neutron switch insert of the above embodiment, since the vacuum chamber of the vacuum cover is provided with a first neutron conduit and a second neutron conduit arranged at an angle, two neutron beams at an angle can be transmitted through the neutron switch insert, so that the neutron reactor or target station can simultaneously output two neutron beams to two independent spectrometer halls, greatly improving the utilization rate of the reactor or target station. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of a neutron switch insert in one embodiment;

[0012] Figure 2 This is a schematic diagram of the structure of the first port (including the first neutron beam window) of a neutron switch insert in one embodiment;

[0013] Figure 3 This is a schematic diagram of the structure of the first port of the neutron switch insert in one embodiment;

[0014] Figure 4 This is a schematic diagram of the structure of the second port (including the second neutron beam window) of the neutron switch insert in one embodiment;

[0015] Figure 5 This is a schematic diagram of the structure of the second port of the neutron switch insert in one embodiment;

[0016] Figure 6 This is a schematic diagram of the structure of the first port of the vacuum chamber of a neutron switch insert in one embodiment;

[0017] Figure 7 This is a schematic diagram of the structure of the second port of the vacuum chamber of a neutron switch insert in one embodiment;

[0018] Figure 8 This is a schematic diagram of the structure of the first neutron conduit of the neutron switch insert in one embodiment;

[0019] Figure 9 This is a schematic diagram of the structure of the rolling ball marker of the neutron switch insert in one embodiment;

[0020] Figure 10 This is a schematic diagram of the target hole at the second port of the neutron switch insert in one embodiment;

[0021] Figure 11 This is a schematic diagram of the target hole at the first port of the neutron switch insert in one embodiment;

[0022] Figure 12 This is a schematic diagram of the structure of a neutron spectrometer beam splitting system in one embodiment.

[0023] Explanation of reference numerals in the attached drawings: 1. Vacuum enclosure; 11. Vacuum cavity; 111. First port; 1111. First neutron beam window; 112. Second port; 1121. Second neutron beam window; 12. Rolling ball; 13. Columnar positioning element; 14. Protruding end plate; 15. Target hole; 21. First neutron guide tube; 22. Second neutron guide tube; 201. Reflector layer; 202. Glass layer; 203. Metal layer; 23. Guide tube mounting bracket; 24. Pad; 3. Top screw; 31. Limiting plate; 32. Top screw plate; 100. Neutron switch insert; 200. Neutron target station insert; 300. Neutron chopper; 1000. Neutron spectrometer beam splitting system. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0025] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0026] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0027] In one embodiment of this application, the neutron switch insert is applied to an existing neutron target station. Therefore, the external dimensions of the vacuum chamber of the neutron switch insert can only be slightly adjusted compared to the external dimensions of the vacuum chamber of the neutron switch insert in the prior art. Furthermore, the neutron target station did not consider beam splitting in the initial design stage, and the space available for beam splitting is small. The first neutron duct and the second neutron duct can only be set in a relatively narrow space, and the angle range between the first neutron duct and the second neutron duct is quite limited (about 2°). In this embodiment, beam splitting operation is achieved in a narrow space.

[0028] In this embodiment of the invention, the neutron switch insert includes a vacuum chamber, a first neutron conduit, and a second neutron conduit. The vacuum chamber includes a vacuum cavity with a first port and a second port communicating with each other. The first neutron conduit and the second neutron conduit are arranged at an angle within the vacuum cavity. Because the vacuum chamber of the vacuum chamber contains the first and second neutron conduits arranged at an angle, two angled neutron beams can be transmitted via the neutron switch insert, allowing the neutron reactor or target station to simultaneously output two neutron beams to two independent spectrometer halls, significantly improving the utilization rate of the reactor or target station.

[0029] The present application will be described below through specific embodiments.

[0030] Example 1:

[0031] like Figures 1 to 11 According to one embodiment of this application, a neutron switch insert 100 is provided, including a vacuum chamber 1, a first neutron conduit 21, and a second neutron conduit 22. The vacuum chamber 1 has a vacuum cavity 11, which has a first port 111 and a second port 112. The first port 111 and the second port 112 are connected. A first neutron beam window 1111 is provided at the first port 111, and a second neutron beam window 1121 is provided at the second port 112. The first neutron beam window 1111 and the second neutron beam window 1121 allow neutron beams to pass through. The first neutron conduit 21 is disposed within the vacuum cavity 11 and extends from the first port 111 to the second port 112. The second neutron conduit 22 is disposed within the vacuum cavity 11 and extends from the first port 111 to the second port 112. The second neutron conduit 22 is set at an angle to the first neutron conduit 21. In this embodiment, a neutron switch is inserted into the first port 111 of the neutron switch inserter 100. When the neutron switch is turned on, a neutron beam is injected from the first neutron beam window 1111 at the first port 111 into the first neutron conduit 21 and the second neutron conduit 22. The neutron beam passes through the first neutron conduit 21 and the second neutron conduit 22 and exits from the second neutron beam window 1121 at the second port 112 to enter other components.

[0032] In this embodiment, the neutron switch insert 100 can transmit two angled neutron beams through the vacuum chamber 11 of the vacuum cover 1, allowing the neutron reactor or target station to simultaneously output two neutron beams to two independent spectrometer halls, thus greatly improving the utilization rate of the reactor or target station.

[0033] Both the first neutron conduit 21 and the second neutron conduit 22 are used to transmit neutron beams. In this embodiment, both the first neutron conduit 21 and the second neutron conduit 22 have a three-layer structure, including a reflective layer 201, a glass layer 202, and a metal layer 203 arranged sequentially from the inside out. The reflective layer 201 is deposited on the glass layer 202, and the glass layer 202 is suspended and fixed within the metal layer 203 by a set screw 3. To ensure the transmission effect of the neutron beam, in this embodiment, the reflective layer 201 is made of a Ni / Ti multilayer film with an m value of 3, and the glass layer 202 is made of boron-free float glass. To ensure the operational stability of the first neutron conduit 21 and the second neutron conduit 22, both adopt a soft metal sealing method, and sintered boron carbide is also provided at their ports to block leaked thermal neutrons.

[0034] The neutron switch insert 100 in this embodiment is applied in an existing neutron target station. Compared to the external dimensions of existing single-neutron-conduit neutron switch inserts, the external dimensions of the neutron switch insert 100 can only be finely adjusted. Furthermore, the neutron target station did not consider beam splitting requirements in its initial design, resulting in a small space available for beam splitting (i.e., the space within the vacuum chamber 11). The first neutron conduit 21 and the second neutron conduit 22 can only be placed in a relatively narrow space, and the angle range between them is quite limited. In this embodiment, the second neutron conduit 22 is set at a 2° angle to the first neutron conduit 21.

[0035] Because the space inside the vacuum chamber 11 in this embodiment is relatively small, in order to ensure that the first neutron conduit 21 and the second neutron conduit 22 can be successfully installed inside the vacuum chamber 11 to complete the beam splitting operation, the space inside the vacuum chamber 11 should be fully utilized and the dimensions of each component inside the vacuum chamber 11 should be reasonably set.

[0036] In this embodiment, the cross-sectional dimensions of the first neutron conduit 21 and the second neutron conduit 22 are different. The neutron beams transmitted via the first neutron conduit 21 and the second neutron conduit 22 are used in two independent spectrometer halls for experiments. Depending on the spectrometer hall specifications, the required neutron beam quality may also differ. Therefore, the cross-sectional dimensions of the first neutron conduit 21 and the second neutron conduit 22 can be determined based on the neutron beam quality, minimizing their cross-sectional dimensions as much as possible while still meeting the neutron beam quality requirements. In this embodiment, the cross-sectional dimension of the first neutron conduit 21 is larger than that of the second neutron conduit 22, ensuring that the neutron beam quality transmitted via the first neutron conduit 21 and the second neutron conduit 22 meets the neutron beam quality requirements of different spectrometer hall specifications. In this embodiment, the cross-sectional dimensions of the first neutron conduit 21 are 27mm (width) × 92mm (height), and the cross-sectional dimensions of the second neutron conduit 22 are 27mm (width) × 52mm (height).

[0037] In this embodiment, the first neutron conduit 21 and the second neutron conduit 22 are at different elevations, meaning they are positioned at different heights. This fully utilizes the space within the vacuum chamber 11, ensuring that the first and second neutron conduits 21 and 22 can be smoothly installed within the vacuum chamber 11 to complete the beam splitting operation. In this embodiment, the elevation difference between the first neutron conduit 21 and the second neutron conduit 22 in the height direction is 25 mm.

[0038] The first neutron conduit 21 and the second neutron conduit 22 allow the neutron beam to pass through in order to provide experimental neutron beams for different spectrometer halls. Therefore, the installation positions of the first neutron conduit 21 and the second neutron conduit 22 should be accurate to ensure accurate neutron beam conduction.

[0039] In this embodiment, the vacuum chamber 1 is provided with a plurality of set screws 3. Some of the set screws 3 abut against the first neutron conduit 21, and the remaining set screws 3 abut against the second neutron conduit 22. The set screws 3 abutting against the first neutron conduit 21 are used to adjust the vertical (height direction) and horizontal (width direction) position of the cross-section of the first neutron conduit 21. By fine-tuning through the cooperation of each set screw 3, the vertical and horizontal position of the cross-section of the first neutron conduit 21 can be adjusted. The set screws 3 abutting against the second neutron conduit 22 are used to adjust the vertical and horizontal position of the cross-section of the second neutron conduit 22. By fine-tuning through the cooperation of each set screw 3, the vertical and horizontal position of the cross-section of the second neutron conduit 22 can be adjusted.

[0040] In this embodiment, a first adjusting member is provided at the first port 111 and a second adjusting member is provided at the second port 112. The first adjusting member and the second adjusting member are used to adjust the position of the first neutron conduit 21 or the second neutron conduit 22 in the length direction.

[0041] In some embodiments, the first adjusting member and the second adjusting member are position plates that can slide within the vacuum chamber 11. The first neutron conduit 21 or the second neutron conduit 22 is mounted on the position plate, and the position adjustment of the first neutron conduit 21 or the second neutron conduit 22 in the length direction is achieved by sliding the position plate within the vacuum chamber 11.

[0042] In one embodiment, the first adjusting member includes a limiting plate 31, and the second adjusting member includes a set screw plate 32. The limiting plate 31 is located at the first port 111 and abuts against the first neutron conduit 21 along its length. The limiting plate 31 has a waist hole through which it is fixed, allowing adjustment of its position along the length of the neutron conduit. The set screw plate 32 is located at the second port 112 and has a set screw 3. One set screw 3 on the set screw plate 32 abuts against the first neutron conduit 21 along its length. Adjusting the set screw 3 on the set screw plate 32 allows adjustment of the first neutron conduit 21 along its length. The operating principle of the limiting plate 31 and the set screw plate 32 on the second neutron conduit 22 is the same as that on the first neutron conduit 21, and will not be described again here. Through the combined action of the set screw 3, the first adjusting member, and the second adjusting member, the positions of the first neutron conduit 21 and the second neutron conduit 22 within the vacuum cavity 11 can be accurately set. In this embodiment, to save installation space, the limiting plate 31 is disposed on the metal layer 203 of the neutron conduit and acts on the glass layer 202. Correspondingly, the set screw 3 on the set screw plate 32 also acts on the glass layer 202. Those skilled in the art will understand that the transmission effect of the neutron beam by the first neutron conduit 21 and the second neutron conduit 22 mainly depends on the glass layer 202 and the reflective layer 201. Therefore, adjusting only the position of the glass layer 202 in the length direction can meet the requirements.

[0043] Both the first neutron conduit 21 and the second neutron conduit 22 are located inside the vacuum chamber 11. That is, the installation position of the vacuum chamber 11 is the installation reference for the first neutron conduit 21 and the second neutron conduit 22. Therefore, the installation position of the vacuum chamber 11 should be accurate, which means that the installation position of the vacuum cover 1 should be accurate.

[0044] In this embodiment, at least three rolling ball bearings 12 are provided on one side of the vacuum chamber 1. All the rolling ball bearings 12 are not on the same straight line. That is, the installation and positioning of the side of the vacuum chamber 1 with the rolling ball bearings 12 can be completed using all the rolling ball bearings 12, thereby achieving the installation and positioning of the vacuum chamber 1. Those skilled in the art will understand that in this embodiment, the vacuum chamber 1 has a stepped appearance. Although the rolling ball bearings 12 on different steps are not in the same plane, the outer surfaces with the rolling ball bearings 12 are parallel. Therefore, the installation and positioning of the side of the vacuum chamber 1 with the rolling ball bearings 12 can be completed through the cooperation of the rolling ball bearings 12.

[0045] In this embodiment, to ensure accurate installation of the vacuum chamber 1, multiple columnar positioning elements 13 are provided on the vacuum chamber, with the axes of all columnar positioning elements 13 not in the same plane. This arrangement allows the multiple columnar positioning elements 13 to assist in the spatial positioning and installation of the vacuum chamber 1, facilitating its installation. Furthermore, the different front-end shapes of each columnar positioning element 13 serve as a preventative measure against mistaken identity. In this embodiment, a columnar positioning element 13 is located near the second port 112, and the axial direction of the columnar positioning element 13 is the same as the vertical direction of the vacuum chamber 1. Two columnar positioning elements 13 are located near the first port 111, where the axial directions of the two columnar positioning elements 13 are at an angle to the vertical direction of the vacuum chamber 1, and the axial directions of the two columnar positioning elements 13 are different. To facilitate the installation of the two columnar positioning elements 13, a protruding end plate 14 is provided at the first port 111. One end of the protruding end plate 14 extends out of the first port 111, and two inclined surfaces are provided at an angle on the protruding end plate 14. The two columnar positioning elements 13 are respectively located on the two inclined surfaces.

[0046] In this embodiment, since the cross-sectional dimensions of the first neutron conduit 21 and the second neutron conduit 22 are different, the installation space required in the vacuum chamber 11 is also different. If the installation channels required for the first neutron conduit 21 and the second neutron conduit 22 in the vacuum chamber 11 are processed separately, it will be difficult to process them. Therefore, in this embodiment, a conduit mounting bracket 23 is also provided in the vacuum chamber 11. The conduit mounting bracket 23 divides the vacuum chamber 11 into two chambers, which are used to install the first neutron conduit 21 and the second neutron conduit 22, respectively. At the same time, since there is an elevation difference between the installation of the first neutron conduit 21 and the second neutron conduit 22, a pad 24 is also provided in the vacuum chamber 11. The pad 24 is connected to the second neutron conduit 22 and is used to assist in fixing the second neutron conduit 22.

[0047] In this embodiment, the vacuum chamber 1 adopts a frame structure, which is assembled from carbon steel (including galvanized carbon steel) using threaded connections and pin fittings, and then welded at each joint. The vacuum chamber 1 is also provided with an evacuation port for vacuuming. After the first neutron beam window 1111 and the second neutron beam window 1121 are installed, vacuuming and leak detection are performed. In this embodiment, the vacuum level is required to be ≤0.1 mbar, and the leakage rate is required to be ≤5×10-7 mbar·L / s.

[0048] In this embodiment, the neutron switch insert 100 is connected to the neutron switch. The opening and closing of the neutron switch will impact the frame of the vacuum chamber 1, especially the outer wall in the switching direction, which will be subjected to a large impact force. Therefore, the outer wall subjected to the impact of the neutron switch can be set to a thicker thickness to withstand the impact, while the outer wall not subjected to the impact of the neutron switch can be set to a thinner thickness, only needing to support the pressure difference between the inside and outside of the vacuum chamber 11. In this embodiment, the neutron switch is switched in the up-down direction, the thickness of the upper and lower outer walls of the vacuum chamber 1 is 38mm, and the thickness of the left and right outer walls is 4-15mm.

[0049] To ensure accurate installation of the vacuum enclosure 1, several target holes 15 are provided at the first port 111 and the second port 112 on the vacuum enclosure 1. The target holes 15 are used for retesting after installation.

[0050] The collimation and installation steps of the neutron switch insert 100 in one embodiment are as follows: First, establish a local coordinate network for the vacuum chamber 1 on the installation platform (measuring 4 outer surfaces and 2 end faces), fit the center line of the vacuum cavity 11, and transfer the center line of the vacuum cavity 11 to the vacuum chamber 1; then, give the theoretical center lines of the first neutron conduit 21 and the second neutron conduit 22 (including the determination of the included angle and the distance between their starting positions); then, push the first neutron conduit 21 and the second neutron conduit 22 into the vacuum cavity 11 respectively, and measure... The center lines of the first neutron conduit 21 and the second neutron conduit 22 are fitted to the four inner surfaces and two end faces of each conduit. The center lines of the first neutron conduit 21 and the second neutron conduit 22 are adjusted to their respective theoretical center lines by using the set screw 3, the first adjustment member and the second adjustment member, respectively. Finally, the coordinate network is re-established and the installation of the first neutron conduit 21 and the second neutron conduit 22 is re-measured. After installation, the neutron switch insert 100 is installed on the neutron switch as a whole, thus completing the alignment installation of the neutron switch insert 100.

[0051] Example 2:

[0052] like Figure 12As shown, one embodiment of this application provides a neutron spectrometer beam splitting system 1000, including a neutron switch insert 100, a neutron target station insert 200, and a neutron chopper 300 arranged in sequence. The neutron switch insert 100 is the neutron switch insert described in any embodiment of this application.

[0053] According to the neutron switch insert in the above embodiments, since the vacuum chamber of the vacuum enclosure is equipped with a first neutron conduit and a second neutron conduit arranged at an angle, two angled neutron beams can be transmitted through the neutron switch insert. This allows the neutron reactor or target station to simultaneously output two neutron beams to two independent spectrometer halls, significantly improving the utilization rate of the reactor or target station. Furthermore, the vacuum enclosure is equipped with various structures for assisting in the installation or positioning of the neutron conduits and the vacuum enclosure, facilitating product installation.

[0054] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A neutron switch insert for use in an existing neutron target station that does not take beam splitting into account, characterized in that, The vacuum cover body has a vacuum cavity with a first port and a second port in communication, the first port is provided with a first neutron beam window, and the second port is provided with a second neutron beam window. A first neutron guide tube is arranged in the vacuum cavity and extends from the first port to the second port. A second neutron guide tube is arranged in the vacuum cavity and extends from the first port to the second port, and the second neutron guide tube is arranged at an angle with the first neutron guide tube. The first port is used for inserting a neutron switch, so that when the neutron switch is opened, a neutron beam is emitted from the first neutron beam window at the first port into the first neutron guide tube and the second neutron guide tube to transmit two angled neutron beam flows. The second neutron guide tube is arranged at an angle of 2° with the first neutron guide tube.

2. The neutron switch insert of claim 1, wherein, The cross-sectional size of the first neutron guide tube is larger than that of the second neutron guide tube.

3. The neutron switch insert of claim 2, wherein, The elevations of the first neutron guide tube and the second neutron guide tube are different.

4. The neutron switch insert of claim 3, wherein, The vacuum cover body is provided with a plurality of jacks, part of the jacks abut against the first neutron guide tube, and the remaining jacks abut against the second neutron guide tube.

5. The neutron switch insert of claim 1, wherein, The first port is provided with a first adjusting member, and the second port is provided with a second adjusting member, and the first adjusting member and the second adjusting member are used to adjust the position of the first neutron guide tube or the second neutron guide tube in the length direction.

6. The neutron switch insert of claim 5, wherein, The second adjusting member includes a jack abutting against the first neutron guide tube or the second neutron guide tube in the length direction, and the first adjusting member includes a limiting plate slidable along the first neutron guide tube or the second neutron guide tube in the length direction, and the limiting plate abuts against the first neutron guide tube or the second neutron guide tube.

7. The neutron switch insert of claim 6, wherein, At least three rolling ball marks are arranged on one side of the vacuum cover body, and all the rolling ball marks are not on the same straight line.

8. The neutron switch insert of any one of claims 1 to 7, wherein, The vacuum cover body is provided with a plurality of columnar positioning elements, and the axes of all the columnar positioning elements are not in the same plane.

9. The neutron switch insert of claim 8, wherein, The neutron switch insert is sequentially provided with a neutron switch insert, a neutron target station insert, and a neutron chopper, and the neutron switch insert is any one of claims 1-9.

10. A neutron spectrometer beam splitting system, characterized by, ​

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