A material surface in-situ diagnosis rapid sampling device based on a cascaded local vacuum structure, a diagnosis device and a diagnosis method

Abstract

The application discloses a material surface in-situ diagnosis fast sampling device based on a cascaded local vacuum structure, a diagnosis device and a diagnosis method, and relates to the technical field of material surface in-situ diagnosis. The device comprises a sampling head assembly, a differential pumping system, a laser ablation module, a spectrum acquisition module and a gas sampling module. The sampling head assembly comprises two or more than two nested cavity structures. The differential pumping system comprises a plurality of pumping units, and each pumping unit corresponds to a sealed cavity. The laser ablation module is used for emitting a laser beam to the surface of a material to be measured in the innermost sealed cavity through an optical window arranged on each layer of cavity and coaxially aligned in the vertical direction by means of a laser device. The spectrum acquisition module is used for collecting the emission spectrum signal of plasma through the optical window. The gas sampling module is in communication with the sealed cavity. The application can detect the material surface on site by arranging the sampling head assembly on the material surface to form a local sealed structure.

Description

Technical Field

[0001] This invention relates to the field of in-situ diagnostic technology for material surfaces, and in particular to a rapid sampling device, diagnostic device, and diagnostic method for in-situ diagnostic of material surfaces based on a cascaded local vacuum structure. Background Technology

[0002] In nuclear fusion devices, aerospace equipment, and large industrial equipment, critical structural materials typically operate under prolonged conditions of high temperature, radiation, or complex atmospheres. Their surface elemental composition and gas retention behavior are crucial for material performance evaluation and service safety. Traditional material surface analysis methods usually require disassembling and transferring the component under test to a laboratory environment for analysis using thermal desorption spectroscopy, ion beam analysis, or other characterization equipment. However, these offline methods are not only time-consuming but also prone to introducing contamination or altering the material's surface state during disassembly, transport, and storage, making it difficult to accurately reflect the surface characteristics of materials under actual service conditions.

[0003] Laser-induced breakdown spectroscopy (LIBS) is a spectroscopic technique that enables rapid elemental analysis. It offers advantages such as no need for complex sample preparation, fast detection speed, and the ability to perform on-site analysis, thus attracting widespread attention in the field of rapid material surface detection. However, when directly ablating material surfaces with lasers in a conventional atmospheric environment, the background signal generated by air breakdown is strong, and the material surface is prone to oxidation, leading to reduced spectral detection sensitivity. Furthermore, the gaseous products released during laser ablation diffuse rapidly in the atmosphere, making them difficult to collect and analyze effectively. Therefore, it is challenging to simultaneously detect the elemental composition of the material and analyze the gas release characteristics.

[0004] To reduce air background and improve detection sensitivity, existing technologies propose conducting LIBS detection in a vacuum environment. However, current vacuum LIBS systems typically require the entire sample to be placed in a vacuum chamber for testing. This approach is difficult to implement for the internal structures of large equipment or non-removable components, limiting the application of this technology in in-situ testing.

[0005] In addition, the following technical problems exist in the local vacuum detection scheme: On the one hand, in order to establish a high vacuum environment in a local area on the material surface, it is usually necessary to evacuate the local cavity through a differential pumping structure. However, when the surface roughness of the material is high or the sealing conditions are limited under field conditions, gas leakage is likely to occur in the local sealed space, making it difficult to establish a stable high vacuum environment. On the other hand, when it is necessary to perform mass spectrometry detection on the gas released during laser ablation, the gas sampling process will disturb the local vacuum environment. If the sampling structure is not designed properly, it may lead to a decrease in the cavity vacuum, thereby affecting the stability of laser ablation and spectral detection.

[0006] Therefore, it is necessary to propose a material surface diagnostic technology that can rapidly establish a stable high vacuum environment in a local area of ​​the material surface without evacuating the entire device under test, and can effectively sample the gaseous products generated by laser ablation while maintaining the high vacuum state, thereby realizing in-situ analysis of combined spectral detection and gas mass spectrometry detection. Summary of the Invention

[0007] To address the problems in existing technologies, such as the difficulty in establishing a stable high vacuum environment on the material surface under on-site testing conditions, the easy disruption of the local vacuum state during gas sampling, and the difficulty in simultaneously acquiring elemental information and gas release information from the material surface, this invention provides a rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure.

[0008] Accordingly, the present invention also provides an in-situ diagnostic device and method for material surfaces based on a cascaded local vacuum structure. This device enables joint in-situ detection of the elemental composition and gas release characteristics of the material surface.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure includes a sampling head assembly, a differential pumping system, a laser ablation module, a spectral acquisition module, and a gas sampling module.

[0011] The sampling head assembly includes a cavity structure with two or more nested levels, wherein the cavity structure includes a cavity and a sealing structure; the cavity, the sealing structure, and the surface of the material to be tested form a sealed cavity;

[0012] The differential pumping system includes multiple pumping units, each corresponding to a sealed cavity;

[0013] The laser ablation module is used to emit a laser beam through an optical window arranged coaxially in the vertical direction on each cavity layer to the surface of the material to be tested in the innermost sealed cavity, so as to ablate the surface of the material to be tested and generate plasma.

[0014] The spectral acquisition module is used to acquire the emission spectral signal of the plasma through the optical window;

[0015] The gas sampling module is connected to the innermost sealed cavity. The gas sampling module is used to collect gaseous products released during or after laser ablation and transport them to the mass spectrometry analysis device for detection.

[0016] The sampling port of the gas sampling module is located in the innermost sealed cavity and faces the laser ablation area.

[0017] A flow-limiting structure is provided between the innermost sealed cavity and the gas sampling module. The flow-limiting structure is a flow-limiting orifice or a throttling channel. The flow-limiting structure maintains a high vacuum state in the innermost sealed cavity while performing gas sampling. The conductivity of the flow-limiting structure is matched with the pumping speed of the second pumping unit.

[0018] The diameter of the flow-limiting orifice is in the range of micrometers to millimeters.

[0019] The sampling head assembly is a two-level nested cavity structure, comprising an outer cavity structure and an inner cavity structure disposed within the outer cavity structure. The outer cavity structure includes an outer cavity and a first sealing structure disposed at the bottom of the outer cavity, the first sealing structure forming an outer sealed cavity with the surface of the material to be tested. The inner cavity structure includes an inner cavity and a second sealing structure disposed at the bottom of the inner cavity, the second sealing structure forming an inner sealed cavity with the surface of the material to be tested, the inner sealed cavity being located inside the outer sealed cavity.

[0020] The differential pumping system includes a first pumping unit and a second pumping unit.

[0021] Among them, the nested cavities are coaxially arranged.

[0022] The sealing structure is an elastic sealing ring, a flexible sealing gasket, or a deformable sealing structure, to adapt to the roughness or curvature of the surface of the material to be tested.

[0023] The pumping unit is a turbomolecular pump, a compound molecular pump, a dry vacuum pump, or a combination thereof.

[0024] The material surface in-situ diagnostic rapid sampling device based on the cascaded local vacuum structure also includes a pressure monitoring unit for real-time monitoring of the pressure and pressure rise rate of the sealed cavity; when the pressure of the outer sealed cavity drops to a preset pressure threshold and the pressure rise rate is not higher than the preset pressure rise rate threshold, the corresponding pumping unit is started to further pump air from the innermost sealed cavity to establish a high vacuum environment in the innermost sealed cavity.

[0025] The material surface in-situ diagnostic rapid sampling device based on a cascaded local vacuum structure also includes a control unit. The control unit is used to synchronously trigger the laser ablation module, the spectral acquisition module, and the gas sampling module to realize the time-correlated acquisition of laser ablation events with corresponding spectral and mass spectrometry signals.

[0026] A material surface in-situ diagnostic device based on a cascaded local vacuum structure includes the aforementioned rapid sampling device for material surface in-situ diagnostics based on a cascaded local vacuum structure; the material surface in-situ diagnostic device based on a cascaded local vacuum structure further includes a mass spectrometry analysis device for detecting gaseous products related to hydrogen, deuterium, or tritium isotopes.

[0027] The material surface in-situ diagnostic device based on the cascaded local vacuum structure also includes a movable platform; the material surface in-situ diagnostic rapid sampling device based on the cascaded local vacuum structure is installed on the movable platform to realize in-situ scanning detection at multiple locations on the surface of the material to be tested.

[0028] A method for in-situ diagnostics of a material surface using the aforementioned in-situ diagnostic device based on a cascaded local vacuum structure includes the following steps:

[0029] S1: Position and press the sampling head assembly onto the surface of the material to be tested, so that the outer cavity and the inner cavity form an outer sealed cavity and an inner sealed cavity with the surface of the material to be tested through corresponding sealing structures;

[0030] S2: Start the first air extraction unit connected to the outer sealing cavity to pre-extract air from the outer sealing cavity;

[0031] S3: When the pressure in the outer sealing cavity drops to a preset pressure threshold, the second pumping unit connected to the inner sealing cavity is activated to further evacuate the inner sealing cavity, thereby establishing a high vacuum environment within the inner sealing cavity; the atmospheric pressure of the high vacuum environment is not higher than 10. -3 Pa;

[0032] S4: A laser pulse is emitted to the surface of the material to be tested through the laser ablation module, plasma is generated in the high vacuum environment and its emission spectrum signal is collected;

[0033] S5: Collect gaseous products released during or after laser ablation through the gas sampling module and transport them to the mass spectrometry analysis device for analysis;

[0034] S6: Based on the time correlation results of spectral data and mass spectrometry data, the elemental composition and hydrogen isotope retention characteristics of the surface of the material to be tested are analyzed.

[0035] The beneficial effects of this invention are as follows:

[0036] (1) The device of the present invention enables in-situ detection of material surfaces. The present invention forms a locally sealed structure by setting a sampling head assembly on the material surface, which eliminates the need to disassemble the component to be tested or to evacuate the entire device under test, thereby improving detection efficiency and reducing the risk of contamination that may be introduced during sample disassembly, transportation and storage.

[0037] (2) The device of the present invention can rapidly establish a high vacuum environment in a localized area on the material surface. The present invention uses a cascaded local vacuum structure formed by the outer cavity and the inner cavity, and performs differential pumping through the first pumping unit and the second pumping unit, respectively, which can effectively reduce the impact of external gas leakage on the vacuum environment of the inner cavity, thereby rapidly establishing a stable high vacuum environment in a localized area on the material surface.

[0038] (3) The device of the present invention improves the stability of the local vacuum establishment process. The present invention monitors the pressure rise rate of the outer sealing cavity and determines whether to start the inner layer pumping accordingly, so as to make real-time judgment on the sealing status, thereby avoiding the start of high vacuum pumping under unstable sealing conditions and improving the stability and reliability of the local vacuum establishment process.

[0039] (4) The device of the present invention improves the sampling efficiency of gaseous products and maintains a high vacuum environment in the inner cavity. The present invention sets the gas sampling port close to the laser ablation area, and preferably controls the distance between the sampling port and the ablation area to be 1 to 10 mm, thereby improving the sampling efficiency of gaseous products generated by laser ablation. At the same time, a flow-limiting structure is set in the gas sampling channel to match its conductivity with the pumping speed of the pumping unit, thereby maintaining a high vacuum environment in the inner sealed cavity while performing gas sampling.

[0040] (5) The device and diagnostic method of the present invention realize the joint analysis of material surface elemental information and gas release information. The present invention combines laser-induced breakdown spectroscopy with gas mass spectrometry analysis to acquire plasma emission spectral signals and mass spectrometry signals of released gases while laser ablation of the material surface. The control unit performs time correlation analysis on the spectral data and mass spectrometry data, thereby realizing a comprehensive characterization of the material surface elemental composition and gas release characteristics.

[0041] (6) The device of the present invention has good field applicability. The device of the present invention has a compact structure and can be installed on a mobile platform or robotic arm system to realize multi-point scanning detection of material surface, thereby obtaining two-dimensional distribution information of material surface element composition or gas release characteristics, which is suitable for in-situ detection of large equipment or complex structural materials. Attached Figure Description

[0042] Figure 1This is a schematic diagram of the overall structure of the rapid sampling device for in-situ diagnosis of material surfaces based on a cascaded local vacuum structure according to the present invention.

[0043] The attached figures are labeled as follows: 1-surface of the material to be tested, 2-first sealing structure, 3-second sealing structure, 4-outer cavity, 5-inner cavity, 6-vacuum valve, 7-optical window, 8-mass spectrometer, 9-flow limiting orifice, 10-fore-stage dry vacuum pump, 11-second pumping unit, 12-turbomolecular pump, 13-isolation valve, 14-pressure monitoring unit, 15-laser beam, 16-laser, 17-first pumping unit. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0045] Example 1

[0046] like Figure 1 As shown, this embodiment provides a rapid sampling device for in-situ diagnosis of material surfaces based on a cascaded local vacuum structure, which includes a sampling head assembly, a differential pumping system, a laser ablation module, a spectral acquisition module, and a gas sampling module.

[0047] The sampling head assembly is used to press against the surface 1 of the material to be tested and form a locally sealed space. For details, see [link to documentation]. Figure 1 The sampling head assembly is a two-level nested cavity structure. Specifically, the sampling head assembly of this embodiment includes an outer cavity 4, an inner cavity 5 disposed inside the outer cavity 4, a first sealing structure 2, and a second sealing structure 3. The first sealing structure 2 is disposed at the bottom of the outer cavity 4 to form an outer sealed cavity with the surface 1 of the material to be tested. The second sealing structure 3 is disposed at the bottom of the inner cavity 5 to form an inner sealed cavity with the surface 1 of the material to be tested. The inner sealed cavity is located inside the outer sealed cavity, thereby forming a double-layer sealing structure in a local area of ​​the surface 1 of the material to be tested.

[0048] Preferably, the inner cavity 5 and the outer cavity 4 are coaxially arranged.

[0049] More preferably, the inner cavity 5 and the outer cavity 4 are coaxial cylindrical bodies of equal height.

[0050] The first sealing structure 2 and the second sealing structure 3 are elastic sealing rings, flexible sealing gaskets, or deformable sealing structures to adapt to the roughness or curvature of the surface 1 of the material to be tested.

[0051] See Figure 1 The differential pumping system includes a first pumping unit 17 connected to the outer sealing cavity and a second pumping unit 11 connected to the inner sealing cavity. The first pumping unit 17 is used to pre-pump the outer sealing cavity to reduce the gas leakage load of the first sealing structure 2. The second pumping unit 11 is used to pump the inner sealing cavity.

[0052] The first pumping unit 17 and the second pumping unit 11 may each include one or more of a turbomolecular pump 12, a compound molecular pump, and a backing dry vacuum pump 10, as well as corresponding valves and pipelines, for realizing differential pumping of the external sealed cavity and the internal sealed cavity.

[0053] In this embodiment, both the first pumping unit 17 and the second pumping unit 11 include a fore-stage dry vacuum pump 10, a turbomolecular pump 12, a vacuum valve 6, and an isolation valve 13.

[0054] Specifically, the rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure of the present invention further includes a pressure monitoring unit 14 for real-time monitoring of the pressure and pressure rise rate of the outer and inner sealed cavities; pressure monitoring units 14 are respectively installed on the outer cavity 4 and the inner cavity 5 to monitor the pressure changes within the corresponding cavities in real time and feed the detection signals back to the control unit. The control unit can control the evacuation process based on the pressure and pressure rise rate of the outer sealed cavity to determine whether the local sealing state meets the conditions for further evacuation of the inner layer. In this embodiment, the pressure monitoring unit 14 is a pressure sensor.

[0055] Preferably, when the pressure monitoring unit 14 detects that the pressure of the outer sealing cavity has dropped to a preset pressure threshold and the pressure rise rate is not higher than the preset pressure rise rate threshold, the second pumping unit 11 is started to further pump air from the inner sealing cavity to establish a high vacuum environment in the inner sealing cavity.

[0056] See Figure 1 Each cavity layer has an optical window 7 at its top. The optical windows 7 at the top of each cavity layer are arranged coaxially along the vertical direction and are used for the incident laser beam 15 and the acquisition of plasma emission spectra.

[0057] See Figure 1 The laser ablation module is used to emit a laser beam 15 through an optical window 7 disposed on the inner cavity 5 towards the surface 1 of the material to be tested within the inner sealed cavity, so as to ablate the surface 1 of the material to be tested and generate plasma. In this embodiment, the laser device is a laser 16. The laser 16 is preferably a pulsed laser.

[0058] The spectral acquisition module is used to acquire the emission spectral signal of the plasma through the optical window 7.

[0059] The gas sampling module is connected to the inner cavity 5 and is used to collect gaseous products released during or after laser ablation and transport them to the mass spectrometry analysis device 8 for detection.

[0060] The sampling port of the gas sampling module is located within the inner cavity 5 and faces the laser ablation area to improve the collection efficiency of ablation products. Preferably, the distance between the sampling port and the laser ablation area is 1–10 mm; in some embodiments, this distance can be 0.5–20 mm. By placing the sampling port close to the ablation area, the collection efficiency of gaseous products released during laser ablation can be improved, and signal loss caused by gas diffusion within the cavity can be reduced.

[0061] In this embodiment, a flow-limiting structure is provided between the inner cavity 5 and the gas sampling module. The flow-limiting structure is a flow-limiting orifice 9 or a throttling channel to maintain a high vacuum state in the inner sealed cavity while gas sampling is performed. The conductivity of the flow-limiting structure is matched with the pumping speed of the second pumping unit 11 to maintain the inner sealed cavity in the high vacuum environment during gas sampling.

[0062] Preferably, the diameter of the flow-limiting orifice 9 is in the range of micrometers to millimeters.

[0063] The rapid sampling device for in-situ diagnosis of material surfaces based on a cascaded local vacuum structure in this embodiment also includes a control unit, which is used to synchronously trigger the laser ablation module, the spectral acquisition module and the gas sampling module to realize the time-correlated acquisition of laser ablation events with corresponding spectral signals and mass spectrometry signals.

[0064] Example 2

[0065] In this embodiment, the sampling head assembly employs a cavity structure with two or more nested levels, thereby forming multi-level local sealed spaces to further improve the local vacuum establishment capability and reduce the impact of external gas leakage on the inner vacuum environment. The cavity structure includes the cavity itself and sealing components.

[0066] Specifically, in Figure 1 An additional cavity is set inside the inner cavity 5 shown.

[0067] Meanwhile, the differential pumping system includes a first pumping unit 17, a second pumping unit 11, and a third pumping unit.

[0068] Example 3

[0069] This embodiment provides a material surface in-situ diagnostic device based on a cascaded local vacuum structure, which includes the rapid sampling device for material surface in-situ diagnostic based on a cascaded local vacuum structure as described in Embodiment 1 or Embodiment 2 and a mass spectrometry analysis device 8. The mass spectrometry analysis device 8 is used to detect gaseous products related to hydrogen, deuterium, or tritium isotopes.

[0070] More preferably, the material surface in-situ diagnostic device based on the cascaded local vacuum structure further includes a movable platform; the material surface in-situ diagnostic rapid sampling device based on the cascaded local vacuum structure is installed on the movable platform to realize in-situ scanning detection of multiple locations on the surface of the material to be tested.

[0071] Example 3 describes a method for in-situ diagnostics of material surfaces using an in-situ diagnostic device, comprising the following steps:

[0072] S1: Position and press the sampling head assembly onto the surface 1 of the material to be tested, so that the outer cavity 4 and the inner cavity 5 form an outer sealed cavity and an inner sealed cavity with the surface 1 of the material to be tested through corresponding sealing structures; specifically, move the device to the surface 1 of the material to be tested, and press the first sealing structure 2 and the second sealing structure 3 onto the surface 1 of the material to be tested through the pressing mechanism, thereby forming an outer sealed cavity and an inner sealed cavity.

[0073] S2: Start the first air extraction unit 17 connected to the outer sealing cavity to pre-evacuate the outer sealing cavity; to reduce the gas leakage load across the first sealing structure 2. Typically, the outer sealing cavity can reach a low-pressure state within minutes.

[0074] S3: When the pressure of the outer sealing cavity drops to a preset pressure threshold, the second pumping unit 11 connected to the inner sealing cavity is started to further pump air from the inner sealing cavity to establish a high vacuum environment in the inner sealing cavity; preferably, the second pumping unit 11 is started when the pressure of the outer sealing cavity drops to no more than 100 Pa; more preferably, the second pumping unit 11 is started when the pressure of the outer sealing cavity drops to 10-30 Pa.

[0075] Before starting the second pumping unit 11, the pressure rise rate of the outer sealing cavity can be monitored within a time window of 30–60 s. When the pressure rise rate is no greater than 1 Pa / s, the sealing state of the outer sealing cavity is considered stable, meeting the conditions for further evacuation of the inner layer. Subsequently, the second pumping unit 11 evacuates the inner sealing cavity to a pressure no higher than 1 × 10⁻⁶ Pa / s. -3 Pa, preferably pumped to 5×10 -4 Pa.

[0076] S4: The laser ablation module emits laser pulses to the surface 1 of the material under test, generating plasma in the high vacuum environment and collecting its emission spectrum signal; specifically, when the inner sealed cavity reaches the high vacuum condition, the laser ablation module and the spectrum acquisition module are activated, and laser pulses are emitted to the surface 1 of the material under test through the optical window 7, forming laser ablation and generating plasma in a local area, while collecting its emission spectrum signal.

[0077] S5: The gaseous products released during or after laser ablation are collected by the gas sampling module and transported to the mass spectrometry analysis device 8 for analysis. Specifically, during or after laser ablation, the released gaseous products are collected by the gas sampling module connected to the inner cavity 5. Since the sampling port is close to the ablation area and connected to the inner cavity 5 through a flow-limiting structure, the gaseous products can be stably transported to the mass spectrometry analysis device 8 for detection while maintaining the high vacuum environment of the inner cavity 5.

[0078] S6: Based on the time correlation results of spectral and mass spectrometry data, the elemental composition and hydrogen isotope retention characteristics of the surface 1 of the test material are analyzed. Specifically, the control unit synchronously triggers and timestamps the laser ablation event, spectral acquisition data, and mass spectrometry acquisition data, thereby performing in-situ analysis of the elemental composition and hydrogen isotope retention characteristics of the material surface based on characteristic spectral lines and characteristic mass-to-charge ratio information.

[0079] The materials to be tested include materials for nuclear fusion devices, aerospace materials, or industrial metal materials.

[0080] The device of this invention can be used for in-situ detection of surfaces such as divertor tiles in nuclear fusion devices, first wall materials, aerospace thermal protection materials, and industrial metal materials. The device is particularly suitable for performing laser-induced breakdown spectroscopy (LIBS) analysis on material surfaces under on-site conditions while simultaneously conducting gas mass spectrometry detection, thereby achieving joint in-situ diagnosis of the elemental composition and gas release characteristics of the material surface.

[0081] Taking materials for nuclear fusion devices as an example, the elemental information of tungsten, carbon, deuterium and other elements on the material surface can be analyzed by laser-induced breakdown spectroscopy (LIBS) characteristic spectral lines. Combined with signals such as m / z = 2, 3, 4 and 6 in mass spectrometry, the gas release characteristics of hydrogen isotopes can be evaluated, thereby achieving a comprehensive analysis of the elemental composition of the material surface and the hydrogen isotope retention behavior.

[0082] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention. The above embodiments are provided only for the purpose of describing the present invention and are not intended to limit the present invention. Parts not described in detail in this specification are well-known in the art and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims. All equivalent substitutions and modifications made without departing from the spirit and principle of the present invention should be covered within the scope of the present invention.

Claims

1. A rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure, characterized in that, It includes a sampling head assembly, a differential pumping system, a laser ablation module, a spectral acquisition module, and a gas sampling module; The sampling head assembly includes a cavity structure with two or more nested levels, wherein the cavity structure includes a cavity and a sealing structure; the cavity, the sealing structure, and the surface of the material to be tested form a sealed cavity; The differential pumping system includes multiple pumping units, each corresponding to a sealed cavity; The laser ablation module is used to emit a laser beam through an optical window arranged coaxially in the vertical direction on each cavity to the surface of the material to be tested in the innermost sealed cavity, so as to ablate the surface of the material to be tested and generate plasma. The spectral acquisition module is used to acquire the emission spectral signal of the plasma through the optical window; The gas sampling module is connected to the innermost sealed cavity. The gas sampling module collects gaseous products released during or after laser ablation and transports them to a mass spectrometry analyzer for detection. The sampling port of the gas sampling module is located within the innermost sealed cavity and faces the laser ablation area. A flow-limiting structure, which is a flow-limiting orifice or throttling channel, is provided between the innermost sealed cavity and the gas sampling module. This flow-limiting structure maintains a high vacuum within the innermost sealed cavity while performing gas sampling. The conductivity of the flow-limiting structure is matched to the pumping speed of the second pumping unit. The material surface in-situ diagnostic rapid sampling device based on the cascaded local vacuum structure also includes a pressure monitoring unit for real-time monitoring of the pressure and pressure rise rate of the sealed cavity; when the pressure of the outer sealed cavity drops to a preset pressure threshold and the pressure rise rate is not higher than the preset pressure rise rate threshold, the corresponding pumping unit is started to further pump air from the innermost sealed cavity to establish a high vacuum environment in the innermost sealed cavity.

2. The rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure according to claim 1, characterized in that, The diameter of the flow-limiting orifice is in the range of micrometers to millimeters.

3. The rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure according to claim 1, characterized in that, The sampling head assembly is a two-level nested cavity structure, comprising an outer cavity structure and an inner cavity structure disposed within the outer cavity structure. The outer cavity structure includes an outer cavity and a first sealing structure at the bottom of the outer cavity, the first sealing structure forming an outer sealed cavity with the surface of the material to be tested. The inner cavity structure includes an inner cavity and a second sealing structure at the bottom of the inner cavity, the second sealing structure forming an inner sealed cavity with the surface of the material to be tested, the inner sealed cavity being located inside the outer sealed cavity. The differential pumping system includes a first pumping unit and a second pumping unit.

4. The rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure according to claim 1, characterized in that, Nested cavity coaxial setup.

5. The rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure according to claim 1, characterized in that, The sealing structure is an elastic sealing ring, a flexible sealing gasket, or a deformable sealing structure, to adapt to the roughness or curvature of the surface of the material to be tested. The pumping unit is a turbomolecular pump, a compound molecular pump, a dry vacuum pump, or a combination thereof.

6. The rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure according to any one of claims 1 to 5, characterized in that, The material surface in-situ diagnostic rapid sampling device based on a cascaded local vacuum structure also includes a control unit, which is used to synchronously trigger the laser ablation module, the spectral acquisition module, and the gas sampling module to realize the time-correlated acquisition of laser ablation events with corresponding spectral and mass spectrometry signals.

7. A material surface in-situ diagnostic device based on a cascaded local vacuum structure, characterized in that, The in-situ diagnostic device for material surfaces based on a cascaded local vacuum structure includes the rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure as described in any one of claims 1 to 6; the in-situ diagnostic device for material surfaces based on a cascaded local vacuum structure further includes a mass spectrometry analysis device for detecting gaseous products related to hydrogen, deuterium, or tritium isotopes.

8. The in-situ diagnostic device for material surfaces based on a cascaded local vacuum structure according to claim 7, characterized in that, The in-situ diagnostic device for material surfaces based on a cascaded local vacuum structure also includes a movable platform; the rapid sampling device for in-situ diagnostics of material surfaces based on a cascaded local vacuum structure is installed on the movable platform to achieve in-situ scanning detection at multiple locations on the surface of the material to be tested.

9. A method for in-situ diagnostics of a material surface using the material surface in-situ diagnostic device based on a cascaded local vacuum structure as described in claim 7 or 8, characterized in that, Includes the following steps: S1: Position and press the sampling head assembly onto the surface of the material to be tested, so that the outer cavity and the inner cavity form an outer sealed cavity and an inner sealed cavity with the surface of the material to be tested through corresponding sealing structures; S2: Start the first air extraction unit connected to the outer sealing cavity to pre-extract air from the outer sealing cavity; S3: When the pressure in the outer sealing cavity drops to a preset pressure threshold, the second pumping unit connected to the inner sealing cavity is activated to further evacuate the inner sealing cavity, thereby establishing a high vacuum environment within the inner sealing cavity; the atmospheric pressure of the high vacuum environment is not higher than 10. -3 Pa; S4: A laser pulse is emitted to the surface of the material to be tested through the laser ablation module, plasma is generated in the high vacuum environment and its emission spectrum signal is collected; S5: Collect gaseous products released during or after laser ablation through the gas sampling module and transport them to the mass spectrometry analysis device for analysis; S6: Based on the time correlation results of spectral data and mass spectrometry data, the elemental composition and hydrogen isotope retention characteristics of the surface of the material to be tested are analyzed.

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