Composite neutron beam device
By partially sharing key components and optimizing the shielding structure, the problem of beamlines not being able to be used simultaneously was solved, proton utilization was improved, and costs and space requirements were reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA INSTITUTE OF ATOMIC ENERGY
- Filing Date
- 2026-01-30
- Publication Date
- 2026-05-08
AI Technical Summary
In existing technologies, quasi-monoenergetic neutron beamlines and white light neutron beamlines cannot be used simultaneously, resulting in low proton utilization and significant waste. Independent construction costs are high, and space occupies a large area.
Design a composite neutron beamline device that improves two beamlines to be partially independent and partially shared, sharing key components such as deflection magnets and focusing magnets, and optimizing the shielding wall structure to achieve flexible control of the proton beam and switching of neutron production modes.
This technology enables the simultaneous operation of two beamlines, improving proton utilization, reducing shielding costs and space requirements, and significantly saving material costs.
Smart Images
Figure CN122000107A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of neutron beamline devices, and particularly relates to a composite neutron beamline device. Background Technology
[0002] Neutrons are one of the fundamental building blocks of the atomic nucleus, possessing electrical neutrality, a magnetic moment, and strong penetrating power. They can precisely distinguish light elements, isotopes, and adjacent elements, making them a unique and irreplaceable advanced tool in cutting-edge scientific research. Meanwhile, neutron technology is increasingly permeating daily life, demonstrating its broad application value in fields such as radiation biology research, neutron cancer therapy, neutron activation analysis, neutron imaging, non-destructive testing, and isotope production. Accelerator-based neutron sources are crucial facilities for current neutron science and applications, boasting advantages such as high pulse flux, flexible operation, and low safety risks, showing significant potential in dynamic process research, multidisciplinary applications, and medical industrialization.
[0003] Quasi-monoenergetic neutrons and white-light neutrons generated by neutron sources based on medium- and high-energy accelerators have different focuses in practical applications. Quasi-monoenergetic neutrons have energies concentrated in a narrow range and are mainly used for detector calibration, research on device irradiation effects, and performance testing of shielding materials. White-light neutrons have a continuous energy spectrum covering a wider range and play an important role in imaging and non-destructive testing, isotope production, and neutron activation analysis.
[0004] One of the current problems in the design, construction, and application of quasi-monoenergetic neutron beamlines and white-light neutron beamlines is that the two beamlines cannot be used simultaneously. When two beamlines are built based on the same accelerator, protons are accelerated to a certain energy in the accelerator and then, depending on the actual application, enter one of the two beamlines to bombard the target material to produce neutrons for use. Therefore, if the same accelerator is used, only one beamline can be used at any given time.
[0005] The second problem in the design, construction, and application of quasi-monoenergetic neutron beamlines and white-light neutron beamlines is that only a very small number of protons are utilized, while the vast majority are wasted. Furthermore, this wasted portion of protons increases the cost of the dedicated shielding walls. The reason is as follows: due to considerations of neutron monochromaticity, the quasi-monoenergetic neutron target sheet made of lithium or beryllium is very thin, with protons depositing only about 2 MeV of energy within it. The vast majority of protons that do not participate in the neutron production reaction pass through the target sheet with energy close to their initial value. These protons need to be guided out to the beam collection barrel by deflecting magnets for measurement, blocking, and collection. Therefore, these blocked and collected protons are not only wasted but also react with the beam collection barrel to generate a large number of stray neutrons, affecting the original experimental results. To avoid this effect, a shielding structure is needed to block these neutrons. The shielding effect is better when the beam collection barrel is located deep in the shielding structure. However, deep shielding results in a larger shielding structure size, which increases the space cost and shielding material cost.
[0006] The third problem in the design, construction, and application of quasi-monoenergetic neutron beamlines and white-light neutron beamlines is that material and space costs increase significantly when the two beamlines are constructed independently. Two beamlines require two sets of deflecting magnets, two sets of focusing magnets, and two sets of shielding structures. One set of deflecting magnets costs approximately 800,000 yuan and occupies about 2 square meters; one set of focusing magnets costs approximately 200,000-300,000 yuan and occupies about 1 square meter; one set of shielding structures costs approximately 100,000 yuan and occupies about 4-5 square meters. Summary of the Invention
[0007] To address the shortcomings of existing technologies, this invention proposes a composite neutron beamline device. The first objective is to solve the problem that existing technologies cannot use two beamlines simultaneously. The second objective is to address the issue that when using quasi-monoenergetic neutron beamlines, only a very small number of protons are utilized, while the majority are wasted, and this wasted protons also increase the cost of the dedicated shielding walls. The third objective is to address the problem that material and space costs increase significantly when the two beamlines operate independently.
[0008] The present invention adopts the following technical solution to solve its technical problem: A composite neutron beamline device is characterized by comprising a composite beamline and a composite shielding wall. The composite beamline improves the original two independent beamlines into a partially independent and partially shared beamline after composite formation. The composite shielding wall improves the original two independent shielding walls into a partially independent and partially shared shielding wall after composite formation. Through the combination of the composite beamline and the composite shielding wall, a composite neutron beamline device capable of simultaneously generating quasi-monoenergetic neutrons and white light neutrons, a composite neutron beamline device capable of generating only quasi-monoenergetic neutrons, and a composite neutron beamline device capable of generating only white light neutrons are formed. The two beamlines are a quasi-monoenergetic neutron beamline and a white light neutron beamline.
[0009] Furthermore, the improvement of the two originally independent beamlines before recombination into a partially independent and partially shared beamline after recombination is as follows: the recombination beamline reduces the two focusing magnets on the two beamlines before recombination to a shared focusing magnet after recombination; the quasi-monoenergetic neutron target and white light neutron target that operate in a time-division manner on the two beamlines before recombination are changed to a quasi-monoenergetic neutron target and white light neutron target that operate simultaneously after recombination; the three Faraday lamps on the two beamlines before recombination are reduced to two Faraday lamps after recombination; and the two deflecting magnets on the two beamlines before recombination are improved to a single shared deflecting magnet after recombination.
[0010] Furthermore, the composite shielding wall improves the two independent shielding walls before the composite into a shielding wall that is partly independent and partly shared after the composite. Specifically, the white light neutron target and the white light neutron target shielding wall before the composite are moved to the exit (4) of the quasi-monoenergetic neutron target beam deflection magnet, and the white light neutron target shielding wall and the quasi-monoenergetic neutron target shielding wall are superimposed. The upper edge of the white light neutron target shielding wall at the superposition point is flush with the inner edge of the shielding wall on the side of the quasi-monoenergetic neutron target near the beam deflection magnet beam exit. The shielding wall at the superposition point is the shielding wall saved by the composite beamline shielding wall compared with the two independent beamline shielding walls.
[0011] Furthermore, in the composite neutron beamline device, a focusing magnet, a first Faraday tube, and a quasi-monoenergetic neutron target are sequentially arranged along the proton beam direction on the beam inlet side of the deflecting magnet, and a second Faraday tube and a white light neutron target are sequentially arranged along the proton beam direction on the beam outlet side of the deflecting magnet.
[0012] Furthermore, the composite neutron beamline device that simultaneously generates quasi-monoenergetic neutrons and white light neutrons is specifically configured such that, during the proton beam intensity detection stage, the cross-sections of the first and second Faraday tubes are in a state of blocking or collecting the proton beam; and during the stage of simultaneously generating quasi-monoenergetic neutrons and white light neutrons, the cross-sections of the first and second Faraday tubes are in a state of being raised or shifted to the side to allow the proton beam to pass through.
[0013] Furthermore, the composite neutron beamline device that only generates quasi-monoenergetic neutrons specifically comprises: during the proton beam intensity detection stage, the cross-sections of the first Faraday tube and the second Faraday tube are both in the state of collecting proton beams; during the stage of generating only quasi-monoenergetic neutrons, the cross-section of the first Faraday tube is in the state of being raised to allow the proton beam to pass through, and the cross-section of the second Faraday tube is in the state of being blocked to prevent the proton beam from passing through.
[0014] Furthermore, in the composite neutron beamline device that only produces white-light neutrons, during the beam intensity detection stage, the cross-sections of both the first and second Faraday tubes are in a state of collecting proton beams; during the stage of producing only white-light neutrons, the first Faraday tube is raised to allow the proton beam to pass through, and the second Faraday tube is moved laterally to allow the proton beam to pass through; and during the stage of producing only white-light neutrons, the quasi-monoenergetic neutron target is also raised to allow the proton beam to pass through. At this time, the beam no longer passes through the quasi-monoenergetic neutron target, but directly produces white-light neutrons through the deflection magnet and the white-light neutron target. Advantages and effects of the invention
[0015] 1. Achieving simultaneous operation of two beamlines. By modifying the previously completely independent quasi-monoenergetic neutron beamline and white-light neutron beamline into a partially independent and partially shared composite structure, the problem of their inability to operate simultaneously was solved. Specifically, by sharing the deflection magnet and focusing magnet, adjusting the operating states of the first and second Faraday lamps, changing the time-sharing target materials to simultaneous operation, and by stacking shielding walls and aligning the white-light neutron target in the stacked shielding wall with the beam outlet of the deflection magnet, the proton beam simultaneously bombards the quasi-monoenergetic neutron target and the white-light neutron target, thereby achieving the synchronous production of quasi-monoenergetic neutrons and white-light neutrons.
[0016] 2. Improved proton utilization and reduced shielding costs: By changing the time-sharing target material to simultaneous operation and optimizing the beamline and shielding structure, the utilization efficiency of the proton beam is significantly improved. Specifically, after bombarding the quasi-monoenergetic neutron target, the remaining protons can continue to bombard the white light neutron target via deflecting magnets, avoiding the waste caused by the beam collection tube blocking them. Simultaneously, by spatially superimposing the shielding walls of the white light neutron target and the quasi-monoenergetic neutron target, the total volume of shielding materials is effectively reduced, thereby lowering manufacturing costs and space requirements.
[0017] 3. Significantly Reduced Material and Space Costs: This invention achieves equipment integration and structural compactness by sharing key components such as the focusing magnet and deflecting magnet, and optimizing the original three Faraday cylinders into two. Furthermore, the integrated design of the composite shielding wall further reduces the overall volume. These integrated optimization measures work together to significantly reduce the system's construction costs and required space while ensuring beam performance. Attached Figure Description
[0018] Figure 1 This is a traditional design based on two independent beamlines; Figure 2 This invention relates to a composite neutron beamline device that simultaneously generates quasi-monoenergetic neutrons and white-light neutrons; Figure 3 This invention relates to a composite neutron beamline device that generates only quasi-monoenergetic neutrons. Figure 4 This invention relates to a composite neutron beamline device that generates only white light neutrons.
[0019] 1: Focusing magnet; 2: First Faraday tube; 3: Quasi-monoenergetic neutron target; 4: Deflecting magnet; 5: Second Faraday tube; 6: White light neutron target; 7: Composite shielding wall. Detailed Implementation Innovation of this invention
[0020] 1. Composite beamline and shielding wall collaborative design: Integrating quasi-monoenergy and white light neutron beamlines, sharing key components such as focusing and deflection magnets, and optimizing the shielding wall structure to achieve resource sharing and space intensification, reduce material and space costs, and support flexible switching between the two neutron beams.
[0021] 2. Target layout and beam path integration optimization: The white light neutron target is placed downstream of the quasi-monoenergetic neutron target at the deflection magnet exit, making full use of the deflected high-energy protons and avoiding energy waste and additional shielding requirements. Through the stacked design of the shielding walls, shielding costs are further reduced, forming a compact structure.
[0022] 3. Faraday Cylinder Dynamic Control Mechanism: By adjusting the cross-sectional state of the first and second Faraday cylinders, the on / off state of the proton beam can be flexibly controlled, enabling the switching of three working modes: simultaneously producing two types of neutrons, producing only quasi-monoenergetic neutrons, or producing only white light neutrons, significantly enhancing the device's multifunctionality and application adaptability.
[0023] 4. Liftable quasi-monoenergetic target design: By lifting the quasi-monoenergetic neutron target, the proton beam can directly bombard the white light neutron target through the deflection magnet, realizing a single white light neutron mode, further improving operational flexibility and mode switching efficiency. Design principle of the invention
[0024] This invention aims to address three major pain points in traditional neutron beamline devices: resource waste, inability to operate in parallel, and high construction costs. The fundamental solution is "composite"—through ingenious physical design and beam control, key components of two originally independent beamlines (a quasi-monoenergetic neutron beamline and a white light neutron beamline) are integrated and shared, achieving "one beam for two uses," thereby significantly reducing costs while improving efficiency.
[0025] 1. Beamline Combination and Resource Sharing: ① Tandem Target Design: Quasi-monoenergetic neutron targets (thin targets) and white-light neutron targets (thick targets) are placed in series on the beamline. ② Energy Cascade Utilization: The proton beam first passes through the quasi-monoenergetic target, producing quasi-monoenergetic neutrons. Then, its remaining energy is used to guide the beam to the white-light target by deflecting magnets, where it bombards the target again to produce white-light neutrons. This solves the problem of wasted proton energy in traditional schemes. ③ Sharing of Key Equipment: Shared Deflecting Magnets: One magnet serves both beamlines simultaneously, responsible for deflecting the remaining proton beam to the white-light target. Shared Focusing Magnets: The focusing elements upstream of the beamline are combined. Reduction of Faraday Cylinders: Reduced from three to two, with precise beam mode control achieved by manipulating their rise and fall.
[0026] 2. Composite Shielding Structure: Through optimized layout, the shielding body is integrated, saving space and cost. The white light neutron target and its shielding wall are moved near the exit of the quasi-monoenergetic target beam deflection magnet. The shielding walls of the two targets are physically connected or overlapped, sharing a portion of the shielding body, thus reducing the overall amount of shielding material used, floor space occupied, and construction cost.
[0027] 3. Flexible beam control and operating modes. Three operating modes are achieved through simple mechanical control, greatly improving the flexibility of the device.
[0028] Based on the above principles, this invention designs a composite neutron beamline device, such as... Figure 1-4 As shown, its features are: it includes a composite beamline and a composite shielding wall; the composite beamline improves the two originally independent beamlines before fusion into a beamline that is partly independent and partly shared after fusion; the composite shielding wall improves the two originally independent shielding walls into a shielding wall that is partly independent and partly shared after fusion; through the combination of the composite beamline and the composite shielding wall, a composite neutron beamline device capable of simultaneously producing quasi-monoenergetic neutrons and white light neutrons, a composite neutron beamline device capable of producing only quasi-monoenergetic neutrons, and a composite neutron beamline device capable of producing only white light neutrons are formed; the two beamlines are a quasi-monoenergetic neutron production beamline and a white light neutron production beamline; Supplementary Note 1 ① Focusing magnet: Composed of a set of alternating horizontal and vertical focusing quadrupole magnets, located at the very front of the entire composite neutron beamline device. The front end is directly connected to the pipe leading from the accelerator, and the rear end is connected to the Faraday cage through a pipe. The internal vacuum level is relatively high. By changing the input current value of the magnet, its magnetic field strength can be changed, thereby achieving beam confinement and beam spot size control, and maintaining beam quality.
[0029] ② Faraday Cylinder: Used to measure proton current intensity. The inner layer is a collecting cup made of copper or graphite, isolated from the pipes and ground potential by insulating materials such as ceramics. This ensures that all the collected particle charge can form a measurement current loop. A water-cooling structure is also included to promptly remove the heat deposited by the protons. Negatively charged metal rings or grids are placed in front of and inside the collecting cup as suppression electrodes to suppress secondary electron emission effects and ensure the accuracy of the proton current intensity. An outer shielding shell surrounds the entire body and is grounded to shield against external electromagnetic interference. A cylinder is connected above the collecting cup, allowing it to be raised and lowered. When raised, the proton beam can pass directly through; when lowered, the proton beam is cut off, enabling proton current intensity measurement. This device has two Faraday cylinders: one located at the front of the quasi-monoenergetic neutron target chamber, and the other at the front of the white light neutron target.
[0030] ③ Quasi-monoenergetic neutron target chamber: This is a sealed chamber made of aluminum alloy, titanium alloy, or other materials with high structural strength. The front end is connected to a vacuum pipeline via a flange. Both the beam inlet at the front and the beam outlet at the rear are sealed with thin titanium films. The interior is filled with argon as a protective gas. A movable copper target holder is installed inside, which can be moved to different working positions by a drive device. Different working positions correspond to target plates of different thicknesses or empty target positions. The target plate is relatively thin, made of lithium or beryllium targets, and produces quasi-monoenergetic neutrons under bombardment by a high-energy proton beam. Water-cooling channels are arranged on the side of the movable target holder to promptly remove the heat from the protons deposited on the target plate.
[0031] ④ Deflecting magnet: Generally a two-stage magnet, its core function is to provide a uniform static magnetic field, causing the proton beam to be deflected at a fixed angle. It is located at the rear end of the quasi-monoenergetic neutron target chamber. Protons that have passed through the quasi-monoenergetic neutron target chamber and have not participated in the neutron production reaction enter the deflecting magnet and are deflected to a certain angle to bombard the white light neutron target.
[0032] ⑤ White light neutron target: The main target sheet is made of tungsten, tantalum or other heavy metals, and a cooling copper cavity is set on the back, which is connected to external pipes for the inflow and outflow of cooling water. When protons bombard the white light neutron target, white light neutrons are generated. At the same time, the energy is completely deposited in it and converted into heat. The heat is carried away by the cooling water in the cooling copper cavity to ensure the safe operation of the white light neutron target.
[0033] ⑥ Shielding: The shielding is made of concrete or other shielding materials such as polyethylene, boron-containing polyethylene, graphite, or lead, and is arranged around the quasi-monoenergetic neutron target chamber and the white light neutron target to shield quasi-monoenergetic neutrons and white light neutrons emitted from angles other than the extraction position. An inner shielding made of iron is also installed around the white light neutron target.
[0034] ⑦ Collimator: Made of iron or graphite, it is a long and narrow cylinder or long cube with a circular opening inside. It is embedded behind the deflection magnet and the white light neutron target to control the divergence angle of the neutron beam and reduce background noise.
[0035] like Figure 2 As shown, the improvement of the two originally independent beamlines before recombination into a beamline that is partly independent and partly shared after recombination is as follows: the recombination beamline reduces the two focusing magnets on the two beamlines before recombination to a shared focusing magnet 1 after recombination; the quasi-monoenergetic neutron target and white light neutron target that operate in a time-division manner on the two beamlines before recombination are changed to a quasi-monoenergetic neutron target 3 and a white light neutron target 5 that operate simultaneously after recombination; the three Faraday cylinders on the two beamlines before recombination are reduced to two Faraday cylinders after recombination; and the two deflecting magnets on the two beamlines before recombination are improved to a shared deflecting magnet 4 after recombination.
[0036] like Figure 2 As shown, the composite shielding wall improves the two independent shielding walls before the composite by making one part independent and the other part shared after the composite. Specifically, the white light neutron target and the white light neutron target shielding wall are moved to the exit of the quasi-monoenergetic neutron target beam deflector magnet 4, so that the white light neutron target shielding wall and the quasi-monoenergetic neutron target shielding wall overlap. The upper edge of the white light neutron target shielding wall at the overlap point is flush with the inner edge of the shielding wall on the side of the quasi-monoenergetic neutron target near the beam deflector magnet beam exit. The shielding wall at the overlap point is the shielding wall saved by the composite beamline shielding wall compared to the two independent beamline shielding walls.
[0037] like Figure 2 As shown, the composite neutron beamline device has a focusing magnet 1, a first Faraday cylinder 2, and a quasi-monoenergetic neutron target 3 arranged sequentially along the proton beam direction on the beam inlet side of the deflecting magnet 4, and a second Faraday cylinder 5 and a white light neutron target 6 arranged sequentially along the proton beam direction on the beam outlet side of the deflecting magnet 4.
[0038] like Figure 2 As shown, the composite neutron beamline device that simultaneously generates quasi-monoenergetic neutrons and white light neutrons is specifically configured such that, during the proton beam intensity detection stage, the cross-sections of the first Faraday tube 2 and the second Faraday tube 5 are in a state of blocking or collecting the proton beam; and during the stage of simultaneously generating quasi-monoenergetic neutrons and white light neutrons, the cross-sections of the first Faraday tube and the second Faraday tube are in a state of being raised or shifted to the side to allow the proton beam to pass through.
[0039] Supplementary Note 2 like Figure 2The diagram shows a composite neutron beamline device that simultaneously generates quasi-monoenergetic neutrons and white-light neutrons in the neutron generation state. The composite neutron beamline device has a beam intensity detection state and a neutron generation state. In the beam intensity detection state, the first and second Faraday tubes are lowered or moved to the position to block the beam using a simple mechanical device in order to collect and measure the beam. In the neutron generation state, the first and second Faraday tubes are both raised or moved out to allow the beam to pass through and for the proton beam to hit the corresponding neutron target to generate the corresponding neutrons.
[0040] like Figure 3 As shown, the composite neutron beamline device that only generates quasi-monoenergetic neutrons specifically operates as follows: during the proton beam intensity detection stage, the cross-sections of the first Faraday tube 2 and the second Faraday tube 5 are both in a state of collecting proton beams; during the stage of generating only quasi-monoenergetic neutrons, the cross-section of the first Faraday tube 2 is raised to allow the proton beam to pass through, and the cross-section of the second Faraday tube 5 is blocked from allowing the proton beam to pass through.
[0041] Supplementary Note 3 like Figure 3 The diagram shows a composite neutron beamline device that produces only quasi-monoenergetic neutrons in the neutron production state. The composite neutron beamline device has a beam intensity detection state and a neutron production state. In the beam intensity detection state, the first and second Faraday tubes are lowered or moved to the position to block the beam using a simple mechanical device in order to collect and measure the beam. In the quasi-monoenergetic neutron production state, the first Faraday tube is in a raised or moved-out state, and the second Faraday tube is in a state to block the beam from passing through. When the beam passes through the deflection magnet, only quasi-monoenergetic neutrons are produced, but when it reaches the white light neutron target, it is blocked by the second Faraday tube, and the beam cannot pass through.
[0042] like Figure 4 As shown, in the composite neutron beamline device that only produces white light neutrons, during the beam intensity detection stage, the cross-sections of the first Faraday tube 2 and the second Faraday tube 5 are both in a state of collecting proton beams; during the stage of producing only white light neutrons, the first Faraday tube 2 is raised to allow the proton beam to pass through, and the second Faraday tube is moved laterally to allow the proton beam to pass through; and during the stage of producing only white light neutrons, the quasi-monoenergetic neutron target 3 is also raised to allow the proton beam to pass through. At this time, the beam no longer passes through the quasi-monoenergetic neutron target 3, but directly produces white light neutrons through the deflecting magnet 4 and the white light neutron target 6.
[0043] Supplementary Note 4 like Figure 4The diagram shows a composite neutron beamline device that only produces white light neutrons in the neutron production state. In the white light neutron production state, both the first and second Faraday tubes are raised to allow the beam to pass through, and the quasi-monoenergetic neutron target is also raised to allow the beam to pass through. Since the quasi-monoenergetic neutron target placed at the beam inlet of the deflecting magnet does not contact the beam at this time, it cannot produce quasi-monoenergetic neutrons. Therefore, the beam can only hit the white light neutron target to produce white light neutrons. Example 1
[0044] After the accelerator accelerates the protons, they enter the entire composite neutron beamline device. First, the proton beam is constrained and controlled by a focusing magnet. Then, the protons bombard the first Faraday tube to measure the current intensity and compare it with the incident proton current intensity. If the difference is not significant, the Faraday tube is lifted to allow the proton beam to pass through. If the difference is too great, the beam is adjusted by the focusing magnet at the front end to improve its transmission efficiency.
[0045] 1. When quasi-monoenergetic neutrons and white-light neutrons are produced simultaneously (as shown in the attached document) Figure 2 As shown): Protons, passing through a focusing magnet and Faraday cylinder, enter the quasi-monoenergetic neutron target chamber and react with the target sheet to produce quasi-monoenergetic neutrons. Since neutrons are uncharged, the quasi-monoenergetic neutrons used in applications do not undergo directional deflection when passing through the deflecting magnet. After being collimated by the collimator, they reach the sample or detector position. Quasi-monoenergetic neutrons emitted in other directions are shielded, slowed down, and absorbed. The energy deposited by the incident protons in the target sheet is conducted through the target holder and carried away by the cooling water flowing in the side channel. Protons that do not participate in the reaction lose only a very small amount of energy, about 1-2 MeV, retaining most of their original energy. Furthermore, because the proportion of protons participating in the reaction is extremely small (approximately 0.2% for 50 MeV), after being deflected by the deflecting magnet (see attached diagram), they are significantly reduced in energy. Figure 2 (Taking a 90° angle as an example) The Faraday tube before bombarding the white light neutron target is used to measure the proton flux. The strength of the deflection magnet is adjusted according to the proton flux to ensure proton transport efficiency. Then, the Faraday tube is raised, allowing the protons to pass through and bombard the white light neutron target, generating white light neutrons. The white light neutrons used in the application are collimated by a collimator and reach the sample or detector. White light neutrons emitted in other directions are first slowed down by the inner shield, and then further slowed down and absorbed by the shield. The proton energy is completely deposited in the white light neutron target, and the heat is carried away by cooling water flowing through the cooling chamber within the target.
[0046] Since the proton energy decreases less and the flux change is not significant when passing through the quasi-monoenergetic neutron target chamber, the neutron yield decreases by only about 5% compared with direct bombardment of the white light neutron target, and the impact on the performance is not very obvious.
[0047] In traditional designs, the two bundles exist independently (as shown in the attached diagram). Figure 1As shown in the diagram, the proton beam is first deflected entirely by a deflecting magnet at the very front end to either the quasi-monoenergetic neutron beamline or the white-light neutron beamline. Therefore, only one beamline can operate at a time. For the quasi-monoenergetic neutron beamline, protons that pass through the target sheet without reacting are deflected by the deflecting magnet and then enter the Faraday tube at the rear end for deceleration and deposition. These protons not only fail to produce usable neutrons and are thus wasted, but if the Faraday tube is placed too shallow, the neutrons emitted in the opposite direction due to the reaction with the Faraday tube cannot be adequately shielded. If it is placed too deep, the shielding thickness must be increased to block neutrons emitted in other directions, which undoubtedly increases costs significantly. Furthermore, the need for deflecting magnets, focusing magnets, and Faraday tubes at the front ends of both beamlines results in a degree of equipment overlap and overuse.
[0048] 2. In addition to simultaneously generating quasi-monoenergetic neutrons and white light neutrons, the composite neutron beamline device in this application can also generate quasi-monoenergetic neutrons or white light neutrons individually.
[0049] When quasi-monoenergetic neutrons are produced alone (as shown in the attached document) Figure 3 As shown): The generated quasi-monoenergetic neutrons reach the sample or detector at the application location through the collimator. After passing through the quasi-monoenergetic neutron target chamber, the protons are still deflected into the Faraday tube in front of the white light neutron target for current measurement. However, after the measurement is completed, the tube is not lifted, but continues to block the protons to protect the white light neutron target behind it. The inner layer shield and the shield around the white light neutron target slow down and absorb the neutrons generated by the protons bombarding the Faraday tube. At the same time, the collimator is filled with an iron cylinder to block the neutrons generated by the protons bombarding the Faraday tube from being emitted.
[0050] When white light neutrons are produced alone (as shown in the attached image) Figure 4 As shown): In the quasi-monoenergetic neutron target chamber, the target holder is in the empty target position. At this time, the incident protons do not react with the target sheet to produce quasi-monoenergetic neutrons. They pass directly through the target chamber and bombard the Faraday tube in front of the white light neutron target with a deflecting magnet to determine the proton flux and transmission efficiency. Then, the Faraday tube in front of the white light neutron target is lifted, and the protons bombard the white light neutron target to produce white light neutrons. After being collimated by a collimator, they reach the sample or detector located at the application position. Since the protons do not lose energy on the target sheet in the quasi-monoenergetic neutron target chamber, the yield of white light neutrons is consistent with that of the independent white light neutron beamline in the traditional design.
[0051] Compared with traditional designs, the composite neutron beamline in this application can simultaneously generate quasi-monoenergetic neutrons and white light neutrons while retaining the ability to independently generate them. At the same time, it effectively utilizes protons that did not participate in the reaction and were originally wasted when passing through the quasi-monoenergetic neutron target chamber to generate white light neutrons. The shielding around the white light neutron target solves the shielding problem of the beam collection barrel in the quasi-monoenergetic neutron beamline, and also eliminates the need for the deflection magnet at the front end. The magnet at the front end of the beamline, the Faraday tube, and the shielding at the rear end can be shared, reducing economic and space costs.
[0052] It should be emphasized that the above specific embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to the above embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.
Claims
1. A composite neutron beamline device, characterized in that: It includes a composite beamline and a composite shielding wall; the composite beamline improves the two originally independent beamlines into a beamline that is partly independent and partly shared after composite; the composite shielding wall improves the two originally independent shielding walls into a shielding wall that is partly independent and partly shared after composite; by combining the composite beamline and the composite shielding wall, a composite neutron beamline device capable of simultaneously generating quasi-monoenergetic neutrons and white light neutrons, a composite neutron beamline device capable of generating only quasi-monoenergetic neutrons, and a composite neutron beamline device capable of generating only white light neutrons are formed; the two beamlines are a quasi-monoenergetic neutron beamline and a white light neutron beamline.
2. The composite neutron beamline device according to claim 1, characterized in that: The improvement of the two originally independent beamlines before the composite beamline into a beamline that is partly independent and partly shared after the composite beamline is as follows: the composite beamline reduces the two focusing magnets on the two beamlines before the composite beamline to a shared focusing magnet after the composite beamline (1); the quasi-monoenergetic neutron target and white light neutron target that operate in time division on the two beamlines before the composite beamline are changed to a quasi-monoenergetic neutron target (3) and a white light neutron target (5) that operate simultaneously after the composite beamline; the three Faraday cylinders on the two beamlines before the composite beamline are reduced to two Faraday cylinders after the composite beamline; and the two deflecting magnets on the two beamlines before the composite beamline are improved to a shared deflecting magnet after the composite beamline (4).
3. The composite neutron beam device according to claim 1, characterized in that: The composite shielding wall improves the two independent shielding walls before the composite into a shielding wall that is partly independent and partly shared after the composite. Specifically, the white light neutron target and the white light neutron target shielding wall before the composite are moved to the exit of the quasi-monoenergetic neutron target beam deflection magnet (4), so that the white light neutron target shielding wall and the quasi-monoenergetic neutron target shielding wall are superimposed. The upper edge of the white light neutron target shielding wall at the superposition point is flush with the inner edge of the shielding wall on the side of the quasi-monoenergetic neutron target near the beam deflection magnet beam exit. The shielding wall at the superposition point is the shielding wall saved by the composite beamline shielding wall compared with the two independent beamline shielding walls.
4. The composite neutron beamline device according to claim 1, characterized in that: The composite neutron beamline device has a focusing magnet (1), a first Faraday tube (2), and a quasi-monoenergetic neutron target (3) arranged sequentially along the proton beam direction on the beam inlet side of the deflecting magnet (4), and a second Faraday tube (5) and a white light neutron target (6) arranged sequentially along the proton beam direction on the beam outlet side of the deflecting magnet (4).
5. The composite neutron beamline device according to claim 4, characterized in that: The composite neutron beamline device that simultaneously generates quasi-monoenergetic neutrons and white light neutrons is specifically configured such that, during the proton beam intensity detection stage, the cross-sections of the first Faraday tube (2) and the second Faraday tube (5) are in a state of blocking or collecting the proton beam, and during the stage of simultaneously generating quasi-monoenergetic neutrons and white light neutrons, the cross-sections of the first Faraday tube (2) and the second Faraday tube (5) are in a state of being raised or shifted to the side to allow the proton beam to pass through.
6. The composite neutron beamline device according to claim 4, characterized in that: The composite neutron beamline device that only produces quasi-monoenergetic neutrons is specifically configured such that: during the proton beam intensity detection stage, the cross-sections of the first Faraday tube (2) and the second Faraday tube (5) are both in the state of collecting proton beams; during the stage of producing only quasi-monoenergetic neutrons, the cross-section of the first Faraday tube (2) is in the state of being raised to allow the proton beam to pass through, and the cross-section of the second Faraday tube (5) is in the state of being blocked from allowing the proton beam to pass through.
7. The composite neutron beamline device according to claim 4, characterized in that: In the beam intensity detection stage, the cross sections of the first Faraday tube (2) and the second Faraday tube (5) of the composite neutron beamline device that only generates white light neutrons are both in the state of collecting proton beams. In the stage of producing only white light neutrons, the first Faraday tube (2) is raised to allow the proton beam to pass through, and the second Faraday tube (5) is shifted to allow the proton beam to pass through. In the stage of producing only white light neutrons, the quasi-monoenergetic neutron target is also raised to allow the proton beam to pass through. At this time, the beam no longer passes through the quasi-monoenergetic neutron target (3), but directly produces white light neutrons through the deflection magnet (4) and the white light neutron target (6).