Material composition analysis system

Abstract

A material composition analysis system comprises: a neutron source (10) configured to generate neutrons acting on an inspected material (IM); a neutron moderation structure (20) surrounding the neutron source (10) and configured to moderate the neutrons generated by the neutron source (10); a material holding cavity (30) configured to hold the inspected material (IM); and a detector assembly (40) configured to capture characteristic signals generated by the inspected material (IM) after being bombarded by neutrons; wherein at least a portion of the neutron moderation structure (20) is located in the material holding cavity (30), so that at least a portion of the neutron moderation structure (20) is buried in the inspected material (IM). This can improve the utilization rate of neutrons emitted by the neutron source.

Description

Technical Field

[0001] The present disclosure relates to material analysis technology, and in particular to a material composition analysis system. Background Art

[0002] In some related technologies for material analysis equipment, a neutron source located below a conveyor belt emits neutrons, which interact with the material being conveyed along the conveyor belt to produce gamma rays. A scintillator detector generates a spectrum based on the received signals, allowing the energy peaks in the spectrum to be used to determine the elemental composition of the material. Summary of the Invention

[0003] Research has found that in some related technologies of material analysis equipment, the utilization rate of neutrons emitted by the neutron source is low, which not only affects the analysis efficiency, but also leads to waste of energy and operating costs.

[0004] In view of this, an embodiment of the present disclosure provides a material composition analysis system that can improve the utilization rate of neutrons emitted by a neutron source.

[0005] In one aspect of the present disclosure, a material composition analysis system is provided, comprising:

[0006] a neutron source configured to generate neutrons for acting on a material to be inspected;

[0007] a neutron moderating structure, surrounding the neutron source and configured to moderate neutrons generated by the neutron source;

[0008] a material holding chamber, configured to hold the inspected material; and

[0009] a detector assembly configured to capture characteristic signals generated by the inspected material after being bombarded by neutrons;

[0010] Wherein, at least a portion of the neutron moderating structure is located in the material containing cavity, so that at least a portion of the neutron moderating structure is buried in the inspected material.

[0011] In some embodiments, the neutron moderating structure comprises:

[0012] a first moderator structure comprising an inelastic moderator material; and

[0013] a second moderator structure comprising a first elastic moderator material and disposed around the first moderator structure;

[0014] The first moderator structure is located between the neutron source and the second moderator structure, and the second moderator structure is located in the material holding cavity, so that the second moderator structure is at least partially buried in the inspected material.

[0015] In some embodiments, the neutron moderating structure further comprises:

[0016] The third moderator structure includes a second elastic moderator material and is located between the detector assembly and the second moderator structure.

[0017] In some embodiments, at least one of the first elastic moderator material and the second elastic moderator material is an elastic moderator material that does not contain carbon.

[0018] In some embodiments, the elastic moderator material containing no carbon element includes no carbon and contains hydrogen H, deuterium D, and lithium isotope with a mass number of 7. 7 Li, beryllium Be, boron isotope with mass number 11 11 An elastic moderator material of at least one of B and oxygen O.

[0019] In some embodiments, the elastic moderator material containing no carbon element comprises at least one of water H2O, heavy water D2O, and dry water.

[0020] In some embodiments, at least one of the second moderator structure and the third moderator structure comprises a container configured to contain and seal the elastic moderator material that does not contain carbon, and the thermal neutron capture cross section of the material of the container does not exceed 0.3b.

[0021] In some embodiments, the material of the container includes at least one of magnesium Mg, zirconium Zr, aluminum Al, and aluminum oxide Al2O3.

[0022] In some embodiments, the detector assembly comprises:

[0023] The first detector is located in the material containing cavity so that the first detector is buried in the inspected material.

[0024] In some embodiments, the material holding chamber is configured to form a flow channel for the inspected material, and the detector assembly includes two groups of first detectors, which are located on both sides of the neutron source along a first direction, and the first direction is parallel to the extension direction of the flow channel.

[0025] In some embodiments, a portion of the first detector that contacts the inspected material is provided with a wear-resistant structure.

[0026] In some embodiments, the material holding cavity is configured to form a flow channel for the inspected material, at least a portion of the third moderation structure is coated on an inner wall of the material holding cavity, and the detector assembly includes:

[0027] a second detector located along the second direction on a side of the third moderator structure away from the neutron source;

[0028] Wherein, the second direction intersects with the extension direction of the flow channel.

[0029] In some embodiments, the detector assembly includes two groups of second detectors, and the two groups of second detectors are located on both sides of the neutron source along the second direction.

[0030] In some embodiments, the detector assembly further comprises:

[0031] a first detector, located in the material containing cavity, so that the first detector is buried in the inspected material;

[0032] The third moderation structure further has a portion located between the first detector and the second moderation structure.

[0033] In some embodiments, the material composition analysis system further includes:

[0034] The neutron absorption structure is located between the detector assembly and the third moderator structure and is used for absorbing neutrons.

[0035] In some embodiments, the scintillator material of the detector assembly includes at least one of sodium iodide (NaI) and bismuth germanate (BGO).

[0036] In some embodiments, the material composition analysis system further includes:

[0037] Shielding materials, used for radiation shielding;

[0038] The neutron source, the neutron moderation structure and the detector assembly are located within the shielding material.

[0039] In some embodiments, a wear-resistant structure is provided at a portion where the neutron moderating structure contacts the inspected material.

[0040] According to an embodiment of the present disclosure, at least a portion of the neutron moderating structure is disposed in a material holding cavity that holds the material to be inspected, so that at least a portion of the neutron moderating structure is buried in the material to be inspected. This allows the neutrons emitted by the neutron source surrounded by the neutron moderating structure to act more on the material to be inspected after being slowed down by the neutron moderating structure, thereby improving the utilization rate of the neutrons emitted by the neutron source. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0042] The present disclosure can be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0043] Figure 1 is a schematic structural diagram of some embodiments of the material composition analysis system according to the present disclosure;

[0044] Figure 2 is a schematic diagram of carbon C-related peaks in a background gamma spectrum obtained according to some embodiments of the material composition analysis system disclosed herein;

[0045] Figure 3 is a schematic diagram of the structural principle of the second moderator structure or the third moderator structure in some embodiments of the material composition analysis system according to the present disclosure;

[0046] Figure 4 is a schematic structural diagram of other embodiments of the material composition analysis system according to the present disclosure;

[0047] Figure 5 Schematic diagram of the structure of some further embodiments of the material composition analysis system according to the present disclosure.

[0048] It should be understood that the size of each part shown in the drawings is not drawn according to the actual proportional relationship.In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0049] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure, its application, or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions, and numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0050] The terms "first", "second" and similar terms used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The terms "include" or "comprises" and similar terms mean that the elements before the term include the elements listed after the term, and do not exclude the possibility of also including other elements. The terms "upper", "lower", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0051] In the present disclosure, when a specific device is described as being located between a first device and a second device, an intervening device may or may not be present between the specific device and the first device or the second device. When a specific device is described as being connected to another device, the specific device may be directly connected to the other device without an intervening device, or may be not directly connected to the other device but with an intervening device.

[0052] All terms (including technical or scientific terms) used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein.

[0053] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0054] In some related technologies for material analysis equipment, a neutron source located below a conveyor belt emits neutrons, which interact with the material being conveyed along the conveyor belt to produce gamma rays. A scintillator detector generates a spectrum based on the received signals, allowing the energy peaks in the spectrum to be used to determine the elemental composition of the material.

[0055] Research has found that the neutron source and moderator structure in this type of material composition analysis equipment are typically placed outside the material being tested. Due to factors such as relative positioning, some neutrons emitted by the neutron source successfully reach the material being tested and interact with the atomic nuclei therein, stimulating high-energy radiation. However, some neutrons, due to factors such as the relative positioning of the neutron source and moderator structure to the material being tested, fail to reach the material being tested. Alternatively, they lose sufficient energy due to excessive energy attenuation during propagation, preventing them from effectively reacting with the material. This results in low neutron utilization from the neutron source, impacting analysis efficiency and leading to wasted energy and operating costs.

[0056] In view of this, an embodiment of the present disclosure provides a material composition analysis system that can improve the utilization rate of neutrons emitted by a neutron source.

[0057] Figure 1 Schematic diagram of the structure of some embodiments of the material composition analysis system according to the present disclosure. Figure 1 The embodiment of the present disclosure provides a material composition analysis system, including: a neutron source 10, a neutron moderation structure 20, a material holding cavity 30 and a detector assembly 40.

[0058] The material composition analysis system can be used to perform offline or online testing on the inspected material IM to analyze the material composition of the inspected material IM. The material composition analysis system can be a prompt gamma neutron activation analysis (PGNAA) material composition analysis system.

[0059] The neutron source 10 is configured to generate neutrons that act on the inspected material IM. The neutron source 10 can generate a neutron beam through a nuclear reaction such as nuclear fusion or nuclear fission, or can generate neutrons by bombarding a target with high-energy particles. The neutron source 10 can include a radioactive neutron source, such as an (α, n) neutron source, a (γ, n) neutron source, or californium-252, or an accelerator neutron source.

[0060] The neutron moderation structure 20 surrounds the neutron source 10 and is configured to moderate the neutrons generated by the neutron source 10. Figure 1 Neutron moderator structure 20 completely surrounds neutron source 10, thereby being able to moderate all neutrons generated by neutron source 10. Neutron moderator structure 20 can reduce neutron energy and decelerate neutrons by using an elastic moderator material that achieves elastic scattering and / or an inelastic moderator material that achieves inelastic scattering, thereby obtaining neutrons of a desired number and energy that can act on inspected material IM.

[0061] The material holding chamber 30 is configured to hold the inspected material IM. During the inspection process, the inspected material IM can be stationary within the material holding chamber 30 or can be moved within the material holding chamber 30, for example, by causing a liquid, powder, or granular material to flow within the material holding chamber 30 to achieve continuous inspection of the material.

[0062] At least a portion of the neutron moderator structure 20 is located within the material holding chamber 30, so that at least a portion of the neutron moderator structure 20 is buried within the inspected material IM. Preferably, the entire neutron moderator structure 20 is located within the material holding chamber 30. The inspected material IM occupies a certain volume within the material holding chamber 30. Partial or complete burial of the neutron moderator structure 20 within the inspected material IM allows more moderated neutrons to act on the inspected material IM.

[0063] The detector assembly 40 is configured to capture characteristic signals generated by the inspected material IM after being bombarded by neutrons. For example, the detector assembly 40 can capture gamma-ray signals generated by the inspected material IM after being bombarded by neutrons, or it can capture other signals such as neutrons. In some embodiments, the detector assembly 40 can also perform signal conversion and processing on the captured characteristic signals.

[0064] In this embodiment, at least a portion of the neutron moderator structure 20 is disposed in the material holding cavity 30 that holds the inspected material IM, so that at least a portion of the neutron moderator structure 20 is buried in the inspected material IM. This allows the neutrons emitted by the neutron source 10 surrounded by the neutron moderator structure 20 to act more on the inspected material IM after being slowed down by the neutron moderator structure 20, thereby improving the utilization rate of the neutrons emitted by the neutron source 10.

[0065] refer to Figure 1 In some embodiments, the portion of the neutron moderator structure 20 that contacts the inspected material IM is provided with a wear-resistant structure 70. The wear-resistant structure 70 minimizes wear of the neutron moderator structure 20 when in contact with the inspected material IM, or when in contact and in contact with the inspected material IM, thereby improving the reliability and service life of the neutron moderator structure 20. The wear-resistant structure 70 can be in the form of a wear-resistant coating or a wear-resistant shell. Materials with high hardness and a relatively limited impact on the analytical accuracy of the material composition analysis system can be used, such as aluminum oxide (Al2O3) ceramics.

[0066] refer to Figure 1 In some embodiments, neutron moderator structure 20 includes a first moderator structure 21 and a second moderator structure 22. First moderator structure 21 includes an inelastic moderator material. The inelastic moderator material can reduce neutron energy by inelastic scattering of neutrons. For example, the inelastic moderator material may include a bismuth-containing Bi material.

[0067] Second moderator structure 22 includes a first elastic moderator material and is disposed around first moderator structure 21. First moderator structure 21 is located between neutron source 10 and second moderator structure 22. Second moderator structure 22 is located in material holding cavity 30 such that at least a portion of second moderator structure 22 is buried within inspected material IM.

[0068] The first moderator structure 21 is arranged between the neutron source 10 and the second moderator structure 22. It can quickly reduce the energy of the high-energy neutrons emitted by the neutron source 10 and reduce the number of neutrons reaching the second moderator structure 22 by absorbing some of the neutrons, which is beneficial to reducing the requirements of the second moderator structure 22 for factors such as materials and distance required for neutron moderation.

[0069] Second moderator structure 22 includes a first elastic moderator material that can reduce neutron energy by elastically scattering neutrons. Examples of such materials include graphite, polyethylene (PE), paraffin wax, water, and heavy water. Second moderator structure 22 can be disposed within material holding chamber 30, with a portion or the entirety of the second moderator structure 22 embedded within inspected material IM.

[0070] exist Figure 1In the embodiment, the second moderator structure 22 can be entirely wrapped around the outside of the first moderator structure 22, and the first moderator structure 21 can be entirely wrapped around the outside of the neutron source 10. Figure 1 The second moderator structure 22 can be designed as a cylindrical structure with a cylindrical inner cavity, and the first moderator structure 21 is located within the cylindrical inner cavity and is also cylindrical. A hole extending along the axis of the first and second moderator structures 21, 22 can be provided, and the neutron source 10 is located within the hole.

[0071] refer to Figure 1 In some embodiments, the neutron moderator structure 20 further includes a third moderator structure 23 , which includes a second elastic moderator material and is located between the detector assembly 40 and the second moderator structure 22 .

[0072] The third moderator structure 23 includes a second elastic moderator material that can reduce neutron energy through elastic scattering of neutrons. Examples include materials containing graphite, polyethylene (PE), paraffin, water, heavy water, etc. The third moderator structure 23 is disposed between the detector assembly 40 and the second moderator structure 22. This allows neutrons moderated by the second moderator structure 22 to not directly enter the detector assembly 40, but instead act on the surrounding material under inspection IM or be further moderated and absorbed by the third moderator structure 22. This allows for more precise control of neutron energy, reduces interference with characteristic signals from neutrons that directly enter the detector assembly 40, and reduces the risk of neutron leakage to the external environment by absorbing excess neutrons. Figure 1 For example, when the second moderator structure 22 can be designed as a cylindrical shape, the third moderator structure 23 can be designed as two cylindrical shapes with the same diameter and coaxially arranged at both ends of the second moderator structure 22 respectively.

[0073] According to the elastic moderation theory of neutrons, for the first elastic moderator material and the second elastic moderator material, the selection of moderator material can examine two indicators: the moderation capacity and the moderation ratio of the material. Both high moderation capacity is pursued to use less material, and high moderation ratio is pursued to reduce neutron loss.

[0074] Based on the goal of maximizing the thermal neutron flux, the neutron flux can be obtained from deuterium D, oxygen O, beryllium Be, and boron isotopes with a mass number of 11. 11 B, carbon C, lithium isotope with mass number 7 7 The moderator material is selected from the materials of Li and hydrogen H.

[0075] In some embodiments, at least one of the first elastic moderator material and the second elastic moderator material may be a carbon-containing C material, such as graphite, paraffin, polyethylene, etc. Such materials have excellent mechanical properties and a moderation ratio second only to deuterium D and oxygen O.

[0076] For some embodiments in which the detector assembly 40 includes a scintillator detector, for example, the scintillator material of the detector assembly 40 includes at least one of sodium iodide NaI and bismuth germanium oxide BGO, the use of a material rich in the element C near the neutron source 10 and the detector may result in the appearance of significant neutron capture gamma peaks, neutron inelastic gamma peaks, neutron capture gamma single escape peaks, neutron inelastic gamma single escape peaks, and neutron capture gamma double escape peaks of the element C in the background gamma spectrum (i.e., when there is no material to be tested) measured by the material composition analysis system, which may affect the measurement accuracy of some analyzed elements that rely on the positions of these energy peaks.

[0077] Figure 2 Schematic diagram of carbon C related peaks in the background γ spectrum obtained according to some embodiments of the material composition analysis system disclosed in the present invention. Figure 2 As can be seen, using a large amount of carbon-containing material as the moderator introduces three peaks at 4.945 MeV, 4.44 MeV, and 3.93 MeV. Research has shown that for devices using crystals such as NaI or BGO as detector materials, this can affect the measurement accuracy of analytes that rely on the positions of these three energy peaks. These analytes include neon (γ peak energy 4.374 MeV), magnesium (γ peak energy 3.917 MeV), phosphorus (γ peak energy 3.900 MeV), barium (γ peak energy 4.096 MeV), lanthanum (γ peak energy 4.847 MeV and 5.098 MeV), cerium (γ peak energy 4.766 MeV), and uranium (γ peak energy 4.060 MeV).

[0078] Based on the above research, in some embodiments of the present disclosure, at least one of the first elastic moderator material and the second elastic moderator material is an elastic moderator material that does not contain carbon. In this case, the first elastic moderator material can be an elastic moderator material that does not contain carbon, the second elastic moderator material can be an elastic moderator material that does not contain carbon, or both the first elastic moderator material and the second elastic moderator material can be elastic moderator materials that do not contain carbon.

[0079] This effectively reduces the count rate of carbon-related peaks, improving the accuracy of analysis of elements such as neon (Ne), magnesium (Mg), phosphorus (P), barium (Ba), lanthanum (La), cerium (Ce), and uranium (U). This can further improve the economic benefits of companies such as mining, batching, and smelting.

[0080] Regarding the selection of elastic moderator materials that do not contain carbon, in some embodiments, the elastic moderator materials that do not contain carbon may include materials that do not contain carbon (C) and contain hydrogen (H), deuterium (D), and lithium isotopes with a mass number of 7. 7 Li, beryllium Be, boron isotope with mass number 11 11An elastic moderator material of at least one of B and oxygen O.

[0081] Among these elastic moderator materials, hydrogen H has the highest elastic scattering cross section, and materials containing hydrogen H and no carbon C have the strongest moderation ability. According to the moderation ratio, the most preferred materials are those containing deuterium D and no carbon C, followed by those containing oxygen O, beryllium Be, and boron isotopes with a mass number of 11. 11 B. Lithium isotope with mass number 7 7 Materials of Li and hydrogen H.

[0082] From an economical point of view, it is most economical to choose a material that does not contain carbon C and contains hydrogen H. From the perspective of machinability, beryllium Be has the best machinability.

[0083] Select lithium isotope with mass number 7 7 When Li material is used as a moderator, the lithium isotope with a mass number of 6 is taken into account. 6 Li undergoes a (n, t) reaction and strongly absorbs thermal neutrons, so not only does the material contain no carbon C, but it also does not contain lithium isotopes with a mass number of 6. 6 Li.

[0084] Select a boron isotope with mass number 11 11 When the material of B is used as a moderator, considering the boron isotope with mass number 10 10 B undergoes (n, α) reaction and strongly absorbs thermal neutrons, so not only does the material contain no carbon C, but also no boron isotope with mass number 10. 10 B.

[0085] Based on the above research and analysis, in some embodiments, the carbon-free elastic moderator material includes at least one of water (H2O), heavy water (D2O), and dry water. Dry water is a special powdered material composed of tiny water droplets encapsulated in hydrophobic silica nanoparticles. (Although it looks like a dry powder, it actually contains approximately 95% water, hence the name "dry water").

[0086] Compared to boron isotopes that require isotopic separation 11 B and lithium isotopes 7 Li, relatively expensive beryllium Be and toxic Be compounds, at least one of water H2O, heavy water D2O and dry water has better safety, economy and moderation effect.

[0087] Figure 3 Schematic diagram of the structure principle of the second moderator structure or the third moderator structure in some embodiments of the material composition analysis system according to the present disclosure. Figure 3For embodiments in which at least one of the first and second elastic moderating materials uses at least one of water (H2O), heavy water (D2O), and dry water as the elastic moderating material, in order to enable such fluid or fluid-like material to be maintained in a corresponding position, in some embodiments, at least one of the second moderating structure 22 and the third moderating structure 23 includes a container 20b, and the container 20b is configured to contain and seal the elastic moderating material 20a that does not contain carbon elements, and the thermal neutron capture cross section of the material of the container 20b does not exceed 0.3b.

[0088] Container 20b can hold a fluid or fluid-like elastic moderator material, such as water (H2O), heavy water (D2O), or dry water. Its thermal neutron capture cross section (CCS) should not exceed 0.3b, reducing the probability of neutron capture by container 20b and minimizing neutron loss. When measurement accuracy can be guaranteed, a carbon-containing material can be appropriately selected as the material for container 20b.

[0089] In some embodiments, the material of the container includes at least one of magnesium Mg, zirconium Zr, aluminum Al, and aluminum oxide Al2O3. These materials do not contain carbon C, which can reduce the impact of the energy peak of C on other analyzed elements and have high material strength.

[0090] refer to Figure 1 In some embodiments, the material composition analysis system further includes a neutron absorption structure 50, located between the detector assembly 40 and the third moderator structure 23, for absorbing neutrons. For detector assembly 40 performing composition analysis using gamma spectroscopy, the neutron absorption structure 50 can reduce the number of neutrons reaching the detector assembly 40 by absorbing neutrons, thereby minimizing the impact on the analysis results of the material composition analysis system.

[0091] The neutron absorbing structure 50 may be made of a lithium isotope having a mass number of 6. 6 Li material can effectively absorb thermal neutrons and basically does not emit gamma rays, thereby reducing the interference of neutrons on the detector assembly 40 and reducing the interference of gamma rays that are not generated by the interaction between the inspected material IM and neutrons.

[0092] refer to Figure 1 In some embodiments, the material composition analysis system further includes a shielding material 60 . The shielding material 60 is used for radiation shielding, and the neutron source 10 , the neutron moderation structure 20 , and the detector assembly 40 are located within the shielding material 60 .

[0093] The shielding material 60 can be used to shield neutrons, gamma rays or other radiation in the material composition analysis system from the external environment to prevent contamination of the external environment. The shielding material 60 can be made of lead Pb, tungsten W, concrete, boron-containing polyethylene, etc.

[0094] In the above embodiments, by burying at least part of the neutron source 10 and the neutron moderator structure 20 in the material to be inspected IM, the utilization rate of the neutrons emitted by the neutron source 10 can be effectively improved, and the structure of the material composition analysis system can be made compact, reducing space occupancy.

[0095] On this basis, reference Figure 1 In some embodiments, the detector assembly 40 includes a first detector 41. The first detector 41 is located in the material receiving chamber 30 so that the first detector 41 is buried in the inspected material IM.

[0096] exist Figure 1 In the embodiment, the neutron source 10, the neutron moderator structure 20 and the first detector 41 are all buried in the inspected material IM. This structure can make the material composition analysis system more compact and reduce space occupation to a greater extent.

[0097] refer to Figure 1 In some embodiments, the material holding chamber 30 is configured to form a flow channel for the inspected material IM, and the detector assembly 40 includes two groups of first detectors 41. The two groups of first detectors 41 are located on both sides of the neutron source 10 along a first direction dr1, and the first direction dr1 is parallel to the extension direction of the flow channel.

[0098] exist Figure 1 In the embodiment, the inspected material IM can flow along the vertically drawn axis of the material holding chamber 30, allowing the material composition analysis system to perform material composition analysis on the continuously flowing inspected material IM at different time frames. Two sets of first detectors 41 are disposed on either side of the neutron source 10 along a first direction dr1. Each set may include one or more first detectors 41. The two sets of first detectors 41 can capture characteristic signals along the first direction dr1 at the front and rear sides of the neutron source 10, thereby increasing the probability of detecting the characteristic signals.

[0099] refer to Figure 1 In some embodiments, the portion of the first detector 41 that contacts the inspected material IM is provided with a wear-resistant structure 70. The wear-resistant structure 70 minimizes wear on the first detector 41 when in contact with the inspected material IM, or when both contact and friction occur, thereby improving the reliability and service life of the first detector 41. The wear-resistant structure 70 can be in the form of a wear-resistant coating or a wear-resistant shell. Materials with high hardness and a limited impact on the analytical accuracy of the material composition analysis system can be used, such as aluminum oxide (Al2O3) ceramics.

[0100] Figure 4 Schematic diagram of the structure of some other embodiments of the material composition analysis system according to the present disclosure. Figure 4In some embodiments, the material holding cavity 30 is configured to form a flow channel for the inspected material IM. At least a portion of the third moderator structure 23 is coated on the inner wall of the material holding cavity 30. Preferably, the third moderator structure 23 is coated on the entire inner wall of the material holding cavity 30. The detector assembly 40 includes a second detector 42. The second detector 42 is located along a second direction dr2 on a side of the third moderator structure 23 away from the neutron source 10. The second direction dr2 intersects the extension direction of the flow channel.

[0101] exist Figure 4 In the embodiment, the third moderator structure 23 may include a tubular portion covering the inner wall of the material holding chamber 30 to form a tubular flow channel with the second moderator structure 22 and the shielding material 60. The third moderator structure 23 may moderate neutrons and absorb excess neutrons.

[0102] exist Figure 4 In the embodiment, the inspected material IM can flow within the material holding chamber 30 along a vertically drawn axis, so that the material composition analysis system can perform material composition analysis on the continuously flowing inspected material IM over different timeframes. The second detector 42 is located along a second direction dr2 on a side of the third moderator structure 23 away from the neutron source 10. The second direction dr2 can intersect the extension direction of the flow channel, for example, perpendicular to, or at an acute or obtuse angle to, the first direction dr1.

[0103] refer to Figure 4 In some embodiments, the detector assembly 40 includes two groups of second detectors 42, and the two groups of second detectors 42 are located on both sides of the neutron source 10 along the second direction dr2. There can be more than one second direction dr2, that is, the two groups of second detectors 42 can be located on both sides of the neutron source 10 in one or more second directions dr2 that intersect with the first direction dr1.

[0104] For the two groups of second detectors 42, each group may include one or more second detectors 42. The two groups of second detectors 42 may capture characteristic signals at the front and rear sides of the neutron source 10 along the second direction dr2 to increase the probability of detecting the characteristic signals. Figure 4 The center lines drawn vertically are symmetrical or staggered.

[0105] In this embodiment, multiple second detectors 42 can be provided in the third moderation structure 23 as needed, with these detectors distributed around the material IM being measured. This effectively increases the probability of detecting characteristic signals, thereby improving measurement accuracy. Furthermore, this arrangement facilitates component analysis of the material IM being measured in a fluid or fluid-like state.

[0106] Figure 5Schematic diagram of the structure of some further embodiments of the material composition analysis system according to the present disclosure. Figure 5 ,and Figure 4 Compared to the illustrated embodiment, in some embodiments, the detector assembly 40 further includes a first detector 41, which is located in the material receiving cavity 30 so that the first detector 41 is buried in the inspected material IM. The third moderator structure 23 further includes a portion located between the first detector 41 and the second moderator structure 22.

[0107] In this embodiment, the first detector 41 and the second detector 42 are located outside the neutron source 10 and the neutron moderator structure 20 in the first direction dr1 and the second direction dr2. This can achieve a compact structure while further increasing the probability of detecting the characteristic signal, thereby achieving higher analysis accuracy.

[0108] In the above embodiment, the detectors included in the detector assembly 40 can be housed in a container containing a heat-insulating material to prevent the detectors from failing or being damaged due to excessive temperature, thereby improving the reliability of the detector assembly 40.

[0109] For example, the material IM is magnesium ore, and the material composition analysis system is used to analyze the Mg content in the Mg ore. The particle size of the Mg ore is 50 mm. Figure 4 In the arrangement structure shown, the first elastic moderator material of the second moderator structure 22 and the second elastic moderator material of the third moderator structure 23 are both made of H2O, the inelastic moderator material of the first moderator structure 21 is made of bismuth Bi, and the neutron absorption structure 50 is made of lithium isotope with a mass number of 6. 6 Li material. The thickness of the first moderator structure 21 is 2-3 cm, the thickness of the second moderator structure 22 is 2-3 cm, the thickness of the third moderator structure is 8-10 cm, and the thickness of the neutron absorption structure 50 is 3-4 cm. Testing has shown that the analytical accuracy of the Mg content can be improved from 0.45% to 0.30%.

[0110] For example, the material IM to be inspected is phosphate ore, and the material composition analysis system is used to analyze the P content in the phosphate ore. The particle size of the inspected phosphate ore is 1 mm. Figure 5 In the arrangement structure shown, the first elastic moderator material of the second moderator structure 22 and the second elastic moderator material of the third moderator structure 23 are both made of H2O, the inelastic moderator material of the first moderator structure 21 is made of bismuth Bi, and the neutron absorption structure 50 is made of lithium isotope with a mass number of 6. 6Li material. The thickness of the first moderator structure 21 is 2-3 cm, the thickness of the second moderator structure 22 is 2-3 cm, the thickness of the third moderator structure is 8-10 cm, and the thickness of the neutron absorption structure 50 is 3-4 cm. Testing has shown that the analytical accuracy of the phosphorus component has increased from 0.90% to 0.60%.

[0111] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0112] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A material composition analysis system, comprising: a neutron source (10) configured to generate neutrons for acting on an inspected material (IM); a neutron moderation structure (20), surrounding the neutron source (10), and configured to moderate neutrons generated by the neutron source (10); A material containing cavity (30) is configured to contain the inspected material (IM) and form a flow channel for the inspected material (IM); and A detector assembly (40) configured to capture characteristic signals generated by the inspected material (IM) after being bombarded by neutrons; wherein at least a portion of the neutron moderation structure (20) is located in the material holding cavity (30), so that at least a portion of the neutron moderation structure (20) is buried in the inspected material (IM); the neutron moderation structure (20) comprises a first moderation structure (21), a second moderation structure (22), and a third moderation structure (23), wherein the first moderation structure (21) is entirely wrapped around the outside of the neutron source (10); the second moderation structure (22) is entirely wrapped around the outside of the first moderation structure (21); the second moderation structure (22) is located in the material holding cavity (30) and is entirely buried in the inspected material (IM); the third moderation structure (23) is located between the detector assembly (40) and the second moderation structure (22), and covers the entire inner wall of the material holding cavity (30); Wherein, the detector assembly (40) comprises: Two groups of first detectors (41) are located in the material containing cavity (30), so that the first detectors (41) are buried in the inspected material (IM) and are located on both sides of the neutron source (10) along a first direction (dr1); A second detector (42) is located along a second direction (dr2) on a side of the third moderation structure (23) away from the neutron source (10), The first direction (dr1) is parallel to the extension direction of the flow channel, and the second direction (dr2) intersects with the extension direction of the flow channel.

2. The material composition analysis system according to claim 1, wherein: The first moderation structure (21) comprises an inelastic moderation material, and the second moderation structure (22) comprises a first elastic moderation material.

3. The material composition analysis system according to claim 2, wherein: The third moderation structure (23) comprises a second elastic moderation material.

4. The material composition analysis system according to claim 3, wherein: At least one of the first elastic moderator material and the second elastic moderator material is an elastic moderator material that does not contain carbon elements.

5. The material composition analysis system according to claim 4, wherein: The elastic moderator material containing no carbon element includes no carbon and contains hydrogen H, deuterium D, and lithium isotope with a mass number of 7. 7 Li, beryllium Be, boron isotope with mass number 11 11 An elastic moderator material of at least one of B and oxygen O.

6. The material composition analysis system according to claim 5, wherein: The elastic moderator material containing no carbon element includes at least one of water H2O, heavy water D2O and dry water.

7. The material composition analysis system according to claim 4, wherein: At least one of the second moderator structure (22) and the third moderator structure (23) includes a container configured to contain and seal the elastic moderator material that does not contain carbon elements, and the thermal neutron capture cross section of the material of the container does not exceed 0.3b.

8. The material composition analysis system according to claim 7, wherein: The material of the container includes at least one of magnesium Mg, zirconium Zr, aluminum Al and aluminum oxide Al2O3.

9. The material composition analysis system according to claim 1, wherein: A wear-resistant structure (70) is provided on the portion of the first detector (41) that contacts the inspected material (IM).

10. The material composition analysis system according to claim 1, wherein: The detector assembly (40) includes two groups of second detectors (42), and the two groups of second detectors (42) are located on both sides of the neutron source (10) along the second direction (dr2).

11. The material composition analysis system according to claim 1, wherein: The third moderator structure (23) further has a portion located between the first detector (41) and the second moderator structure (22).

12. The material composition analysis system according to claim 1, further comprising: The neutron absorption structure (50) is located between the detector assembly (40) and the third moderation structure (23) and is used for absorbing neutrons.

13. The material composition analysis system according to claim 1, wherein: The scintillator material of the detector assembly (40) includes at least one of sodium iodide (NaI) and bismuth germanium oxide (BGO).

14. The material composition analysis system according to claim 1, further comprising: Shielding material (60) for radiation shielding; The neutron source (10), the neutron moderation structure (20), and the detector assembly (40) are located within the shielding material (60).

15. The material composition analysis system according to claim 1, wherein: A wear-resistant structure (70) is provided at a portion of the neutron moderation structure (20) that contacts the inspected material (IM).

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