In-situ laser diagnosis system and method for plasma fuel thermal desorption / impurity deposition in wall material

Abstract

The invention belongs to the technical field of magnetic confinement controllable thermonuclear fusion, and particularly relates to an in-situ laser diagnosis system and method for plasma fuel thermal desorption / impurity deposition in a wall material. The long-pulse laser module emits a long-pulse laser beam, and the long-pulse laser beam sequentially passes through the dichroscope I, the convex lens, the dichroscope II and quartz glass on the vacuum chamber and is irradiated to the surface of the sample to be detected; the short-pulse laser module emits a short-pulse laser beam, and the short-pulse laser beam sequentially passes through the dichroscope I, the convex lens, the dichroscope II and quartz glass on the vacuum chamber of the fusion device and is irradiated to the surface of the sample to be detected; the irradiated radiation light of the to-be-detected sample sequentially passes through the focusing lens, and a spectral signal is transmitted to the spectrum acquisition system. According to the system, high-efficiency in-situ laser thermal desorption can be carried out on fuel gas retained in a wall material, in-situ laser diagnosis of impurity deposition can also be carried out, the two methods are flexibly coupled into one set of system and can be independently used or simultaneously carried out, and a reference basis is provided for fusion reactor divertor operation control and wall material research and development in the future.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic confinement controllable thermonuclear fusion, and in particular relates to an in-situ laser diagnosis system and method for thermal desorption / impurity deposition of plasma fuel in a wall material. Background Art

[0002] Entering the 21st century, energy issues have become increasingly important. Traditional energy sources such as coal, oil, and natural gas have limited reserves, are non-renewable, and cause certain pollution to the environment when used; new energy sources such as solar energy and wind energy have flourished in recent years, but their total power generation is limited and far from meeting the production and living needs of industrial society; nuclear fusion energy has been in the ascendant in the past decade, but people are increasingly concerned about its safety issues in operation and nuclear waste pollution; nuclear fusion energy has gradually entered people's field of vision due to its advantages such as low pollution, safe operation, and no nuclear waste. At present, the most likely device to achieve magnetic confinement controlled thermonuclear fusion is the tokamak device.

[0003] During the operation of the Tokamak device, the plasma facing wall materials (Plasma Facing Materials, PFM) may be impacted by the steady-state / transient heat flow and particle flow from the core plasma, and the wall materials will be physically sputtered and chemically etched, resulting in various material damages and changes in the wall surface morphology. In addition, during the interaction between plasma and wall materials (Plasma Wall Interaction, PWI), impurities generated by the sputtering of the wall materials and fuel particles can be co-deposited on the first wall surface, and the fuel will be retained on the wall surface, which will change the elemental composition of the first wall surface. Changes in the state of the wall surface will affect the control of impurities and recycling, affect the plasma confinement performance, lead to various plasma instabilities, and reduce the plasma quality. Therefore, the research and development of diagnostic technology for the elemental composition of the wall material surface is one of the key scientific issues that urgently need to be solved in PFM research. At the first wall of the tokamak, deuterium and tritium ions are converted into neutral atoms through charge exchange and escape the magnetic field confinement. They are then injected or adsorbed on the wall surface to form retention. The impurity particles sputtered out during the PWI process are transported by the core plasma and then deposited on the wall material surface with the fuel deuterium and tritium to form a co-deposition layer. The co-deposition layer falls off to form large impurity particles, which directly affects the confinement performance of the plasma and even causes a "big rupture". In addition, the co-deposition layer will cause a large amount of deuterium and tritium isotopes to accumulate and release on the wall for a long time, which will seriously affect the fuel efficiency, tritium cycle process and stability control of the fusion plasma. Therefore, it is necessary to conduct in-depth research on the distribution characteristics of deuterium and tritium retention on the surface of the first wall material, reveal the mechanism of the retention process, and explore new methods to inhibit and eliminate fuel / helium ash retention.

[0004] At present, the diagnosis of tokamak PFM is mainly through offline analysis method. After a period of plasma irradiation experiment, the experimental sample is taken out and analyzed. At present, the commonly used offline diagnostic methods in the world are: secondary ion mass spectrometry, thermal desorption spectrum, nuclear reaction analysis method, X-ray photoelectron spectroscopy, etc. Although the offline PFM analysis means are very rich, the information of most samples is obtained by offline analysis method after the fusion device ends a round of experiments and the PFM is exposed to the atmosphere, so the result is the integral of the whole experimental process. In this way, the overall situation of the sample can be observed, but the PWI process under different experimental conditions cannot be optimized in real time. Therefore, it is very necessary to use in-situ analysis means in the PWI research of tokamak. The in-situ diagnostic method can directly avoid the pollution caused by the sampling and sample preparation process. The more real PFM monitoring information is of great significance to our in-depth understanding and effective control of the PWI process. The development of in-situ wall material detection method is a key link on the road of PWI research, and it is also an important step on the road of magnetic confinement fusion technology development. Summary of the invention

[0005] The present invention provides an in-situ laser diagnostic method for thermal desorption / impurity deposition of plasma fuel in wall materials, which provides a reference for future fusion reactor divertor operation control and wall material research and development.

[0006] The invention provides an in-situ laser diagnosis system for thermal desorption of plasma fuel / impurity deposition in a wall material, which is used to realize an in-situ laser diagnosis method for thermal desorption of plasma fuel / impurity deposition in a wall material.

[0007] The present invention is achieved through the following technical solutions:

[0008] An in-situ laser diagnostic system for thermal desorption / impurity deposition of plasma fuel in a wall material, wherein the long pulse laser module 1 emits a long pulse laser beam, and the long pulse laser beam sequentially passes through a magnifying glass system 5, a dichroic mirror I 8, a convex lens 19, a dichroic mirror II 22, and a quartz glass 13 on a vacuum chamber 10 to irradiate the surface of a sample 100 to be tested;

[0009] The short pulse laser module 3 emits a short pulse laser beam, which sequentially passes through the dichroic mirror 8, the dichroic mirror II 22, the convex lens 19, and the quartz glass 13 on the vacuum chamber 10 to irradiate the surface of the sample 100 to be tested;

[0010] The long pulse laser module 1, the short pulse laser module 3, the temperature measurement module 7 and the spectrum acquisition system 4 are respectively connected to the timing system 20, and the timing system 20 is connected to the computer terminal 21. The radiation light of the sample 100 to be tested is sequentially transmitted to the spectrum acquisition system 4 through the focusing lens 9 and the spectrum signal 6;

[0011] The vacuum chamber 10 is provided with a standard leak hole 17 , and the standard leak hole 17 is connected to a gas cylinder 18 .

[0012] Furthermore, four flange quartz windows 13 are evenly distributed on the vacuum chamber 10, a three-dimensional numerically controlled high-precision moving slide 14 is arranged in the vacuum chamber 10, a sample 100 to be tested is placed on the three-dimensional numerically controlled high-precision moving slide 14, and a high-performance mass spectrometer module 2 and a high-vacuum measurement sensor probe 15 are also inserted into the vacuum chamber 10;

[0013] A digital control gate valve 11 is also provided at the bottom end of the vacuum chamber 10 , and a vacuum pump 12 is provided below the digital control gate valve 11 .

[0014] Furthermore, the sample to be tested 100 is facing one of the flange quartz windows 13 of the vacuum chamber 10, and the flange quartz window 13 and the convex lens 19 are arranged in a straight line;

[0015] The focusing lens 9 is also arranged outside the flange quartz window 13;

[0016] A dichroic mirror II 22 and a convex lens 19 are arranged between the dichroic mirror I 8 and the flange quartz window 13 .

[0017] Furthermore, the standard gas in the gas cylinder 18 is used to calibrate the high-performance mass spectrometer module 2 .

[0018] Furthermore, the temperature measurement module 7 is coupled into the laser optical path 5 through a dichroic mirror and is coaxially transmitted with the long pulse laser module 1 .

[0019] Furthermore, the long pulse laser module 1 provides long pulse laser to achieve laser induced desorption;

[0020] The high-performance mass spectrometer module 2 collects the charge-to-mass ratio information of the laser desorption gas, which is used to analyze the composition and content of the retained fuel gas in the plasma-facing component material;

[0021] The short pulse laser module includes a short pulse laser 3 and a spectrum collection system 4, which is used to provide short pulse laser, collect spectrum information and analyze the residual gas inventory after desorption;

[0022] The optical module is used to realize the transmission of the laser light path 5 and the transmission of the spectrum signal 6;

[0023] A numerically controlled gate valve 11 is installed inside the vacuum chamber 10 to separate the vacuum chamber 10 and the vacuum pump 12 to achieve the negative pressure environment pressure maintenance function inside the vacuum chamber.

[0024] The vacuum chamber 10 is circumferentially provided with four flange quartz windows 13 for transmitting laser light during the laser diagnosis process and facilitating spectrum collection.

[0025] The vacuum chamber 10 is provided with a three-dimensional numerically controlled high-precision moving slide 14 for moving samples to simulate different positions of wall materials in a real tokamak device.

[0026] A high vacuum measurement sensor probe 15 is installed at the bottom of the vacuum chamber 10 to achieve real-time high-precision measurement of the internal pressure of the vacuum chamber 10;

[0027] The dichroic mirror I8 transmits laser in the visible light band of 300-800nm ​​and reflects laser in the infrared band greater than 800nm, and the dichroic mirror II22 transmits laser in the visible light band of 300-1100nm and reflects laser in the far-infrared light band greater than 1100nm. It can be used to achieve different experimental requirements, and can respectively realize the diagnosis of impurity deposition and the in-situ real-time diagnosis of fuel thermal desorption efficiency.

[0028] An in-situ laser diagnostic method for thermal desorption of plasma fuel / impurity deposition in a wall material, the method using the in-situ laser diagnostic system for thermal desorption of plasma fuel / impurity deposition in a wall material as described above, the method comprising:

[0029] After laser transmission and focusing the long pulse laser on the surface of the wall material to be tested, the mass spectrometer is used to collect the charge-to-mass ratio information of the desorbed gas, and the composition and content of the fuel retained in the wall material are obtained through analysis. Then the short pulse laser module is triggered, and the short pulse laser is transmitted through the same optical path and focused on the same position. The laser ablation plasma spectrum is collected by the spectrometer, and the gas charge-to-mass ratio information is collected by the mass spectrometer. The residual gas content after desorption is analyzed, and then the real-time desorption efficiency is obtained, realizing in-situ online real-time measurement and monitoring.

[0030] Furthermore, the method specifically comprises the following steps:

[0031] Step 1: Assemble the in-situ laser diagnosis system, use the computer terminal 21 to control and set the timing control system 20, the long pulse laser module 1 and the short pulse laser 3 in the short pulse module, and the spectrum acquisition system 4 to a working state;

[0032] Step 2: After the timing control system 20 receives the trigger signal of the long pulse laser module 1, the timing control system 20 sends a signal instruction to the short pulse laser 3 and the spectrum acquisition system 4 according to the set timing, triggering the long pulse laser module 1 and the high-performance mass spectrometer module 2, the short pulse laser 3 in the short pulse module, the spectrum acquisition system 4, and the temperature measurement module 7 to work and synchronize with the timing of the long pulse laser module 1;

[0033] Step 3: the long pulse laser module 1 emits a long pulse laser beam, irradiating the surface of the sample 100 to cause laser thermal desorption;

[0034] Step 4: The timing control system synchronously turns on the high-performance mass spectrometer module 2 and the temperature measurement module 7 to perform qualitative and quantitative detection of the gas components generated by the laser thermal desorption in step 4, and at the same time, performs real-time measurement of the surface temperature of the sample 100 to be tested;

[0035] Step 5: the short pulse laser module 3 emits a short pulse laser beam, which irradiates the surface of the sample 100 to be tested at the same position as the long pulse laser irradiation in step 3, and laser ablation occurs;

[0036] Step 6: After the surface material of the sample 100 to be tested is ablated by the short pulse laser beam, the ablated particles are excited and ionized by the high-energy laser to form a laser ablation plasma; after being focused by the plasma collection lens 9, they are coupled to the optical fiber and further transmitted to the spectrum collection system 4 by the optical fiber to record the emission spectrum;

[0037] Step 7: The spectrum acquisition system 4 transmits the acquired emission spectrum to the computer terminal 21 for data analysis, thereby realizing in-situ, online, and real-time measurement of the composition and content of impurity deposits on the sample surface.

[0038] Furthermore, the method further comprises:

[0039] Step 8: After one diagnosis is completed, if multiple diagnoses are required at the same spatial position of the sample to be tested, repeat steps 1 to 7 to obtain the surface element composition and content of fuel retention / impurity deposition on the sample surface at different ablation depths. After multiple measurements, the composition and content of the entire sample surface material can be analyzed, thus completing the in-situ diagnosis.

[0040] Further, the step 3 is specifically as follows: the long pulse laser module 1 emits a long pulse laser beam, which is irradiated onto the convex lens 19 through the dichroic mirror I8, and then passes through the dichroic mirror II22 and the quartz glass 13 window embedded in the vacuum chamber 10 of the fusion device, and then irradiates the surface of the sample 100 to cause laser thermal desorption;

[0041] The step 5 is specifically as follows: the short pulse laser module 3 emits a short pulse laser beam, which is irradiated onto the convex lens 19 through the dichroic mirror I8, and then passes through the dichroic mirror II22 through the quartz glass 13 window embedded in the vacuum chamber 10 of the fusion device, and irradiates the surface of the sample to be tested 100 at the same position as the long pulse laser irradiation in step 3, and laser ablation occurs.

[0042] The beneficial effects of the present invention are:

[0043] 1. The main components of the present invention are made of non-magnetic materials, and all components connected to the vacuum chamber are made of completely sealed non-magnetic stainless steel, which is not affected by the magnetic field of the tokamak device and can be used for in-situ laser diagnostic research on fuel retention / impurity deposition of the later tokamak device.

[0044] 2. The overall unique design of the present invention has a more reasonable layout, more efficient experiments and more complete functions.

[0045] 3. The present invention realizes the efficient linkage of long-pulse laser thermal desorption, short-pulse laser diagnosis of impurity deposition, and mass spectrometry qualitative and quantitative analysis through unique design of the optical path structure, thus expanding the research method of a single system.

[0046] 4. The present invention adds a temperature measurement module in the optical path to measure the surface temperature of the sample in real time, thereby effectively obtaining the heating effect of different laser parameters on different samples.

[0047] 5. The present invention designs a CF35 manipulator interface on the vacuum chamber window flange, which can effectively expand the laser scanning range and facilitate large-scale measurement in the tokamak device in the later stage.

[0048] 6. The present invention designs a quartz glass window on the vacuum chamber window flange, which can efficiently transmit the optical path and visually observe the laser ablation.

[0049] 7. The present invention opens an exhaust hole and a gate valve at the bottom of the vacuum chamber, which can be connected to a vacuum pump to achieve a negative pressure environment inside the reactor. Closing the gate valve puts the chamber in a negative pressure holding state, which can reduce the broadening of the absorption spectrum and stabilize the mass spectrum data, facilitating data post-processing.

[0050] 8. The present invention designs an optical path in the plasma action area to achieve transient measurement of the target product by spectroscopy technology.

[0051] 9. The present invention installs a dichroic mirror on each optical path branch, and can arrange 4 lasers to achieve simultaneous measurement of multiple measurement methods.

[0052] 10. The present invention adopts spectral technology of collecting spectral signals by optical fiber. When fixed firmly, the whole optical path is not affected by the outside world. It has the advantages of simple system, low device cost, strong anti-interference ability, in-situ non-contact measurement, wide range of measurement species, strong selectivity and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a structural schematic diagram of the present invention.

[0054] Figure 2 It is a schematic diagram of the interior of the vacuum chamber used in the present invention.

[0055] Figure 3 It is a work flow chart of the present invention.

[0056] Explanation of reference numerals: 1. long pulse laser module; 2. high performance mass spectrometer module; 3. short pulse laser; 4. spectrum acquisition system; 5. magnifying glass system; 6. spectrum signal transmission; 7. temperature measurement module; 8. dichroic mirror I; 9. focusing lens; 10. vacuum chamber; 11. CNC gate valve; 12. vacuum pump; 13. flange quartz window; 14. three-dimensional CNC high-precision moving slide; 15. high vacuum measurement sensor probe; 16. Swagelok ferrule connector; 17. standard leak hole; 18. gas cylinder; 19. convex lens; 20. timing system; 21. computer terminal; 22. dichroic mirror II; 100. sample DETAILED DESCRIPTION

[0057] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0058] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0059] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.

[0060] The following is attached to this application specification Figure 1-3 , the technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0061] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0062] Implementation Method 1

[0063] like Figure 1 and Figure 2 As shown, this embodiment provides an in-situ laser diagnostic system for thermal desorption / impurity deposition of plasma fuel in wall materials, wherein the long pulse laser module 1 emits a long pulse laser beam, and the long pulse laser beam sequentially passes through the magnifying glass system 5, the dichroic mirror I 8, the convex lens 19, the dichroic mirror II 22, and the quartz glass 13 on the vacuum chamber 10 to irradiate the surface of the sample 100 to be tested; the magnifying glass system 5 is composed of a reflector, a convex lens and a concave lens;

[0064] The short pulse laser module 3 emits a short pulse laser beam, which is sequentially irradiated to the surface of the sample 100 through the dichroic mirror I 8, the convex lens 19, the dichroic mirror II 22, and the quartz glass 13 on the vacuum chamber 10 of the fusion device;

[0065] The long pulse laser module 1, the short pulse laser module 3, the temperature measurement module 7 and the spectrum acquisition system 4 are respectively connected to the timing system 20, and the timing system 20 is connected to the computer terminal 21. The radiation light of the sample 100 to be tested is sequentially transmitted to the spectrum acquisition system 4 through the focusing lens 9 and the spectrum signal 6;

[0066] The vacuum chamber 10 is provided with a standard leak hole 17 , and the standard leak hole 17 is connected to a gas cylinder 18 via a Swagelok ferrule joint 16 .

[0067] Furthermore, four flange quartz windows 13 are evenly distributed on the vacuum chamber 10, a three-dimensional numerically controlled high-precision moving slide 14 is arranged in the vacuum chamber 10, a sample 100 to be tested is placed on the three-dimensional numerically controlled high-precision moving slide 14, and a high-performance mass spectrometer module 2 and a high-vacuum measurement sensor probe 15 are also inserted into the vacuum chamber 10;

[0068] A digital control gate valve 11 is also provided at the bottom end of the vacuum chamber 10 , and a vacuum pump 12 is provided below the digital control gate valve 11 .

[0069] Furthermore, the sample to be tested 100 is facing one of the flange quartz windows 13 of the vacuum chamber 10, and the flange quartz window 13 and the convex lens 19 are arranged in a straight line;

[0070] The focusing lens 9 is also arranged outside the flange quartz window 13;

[0071] A dichroic mirror II 22 and a convex lens 19 are arranged between the dichroic mirror I 8 and the flange quartz window 13 .

[0072] The position of the dichroic mirror I 8 is a position where the long pulse laser and the short pulse laser emitted by the long pulse laser module 1 and the short pulse laser module 3 can be coupled.

[0073] Specifically, the long pulse laser module 1 and the short pulse laser module 3 use the same optical path for coaxial transmission 5, and the two are coupled through a dichroic mirror Ⅰ8. A convex lens 19 is used in a small angle range on the other side of the front end to transmit the spectral information generated on the sample surface after the laser action to the spectral acquisition system 4. At the same time, a high-performance mass spectrometer module collects the mass-to-charge ratio information of the fuel gas to realize real-time detection of thermal desorption of the fuel inside the vacuum chamber 10.

[0074] Furthermore, the vacuum chamber 10 is equipped with a dedicated Swagelok ferrule connector 16 for connecting to a standard leak hole 17 , and the high-performance mass spectrometer module 2 is calibrated by using the standard gas in the gas cylinder 18 , thereby improving the accuracy of the qualitative and quantitative results of the high-performance mass spectrometer module 2 .

[0075] Furthermore, the temperature measurement module 7 is coupled into the laser transmission optical path through the dichroic mirror II 22 and is coaxially transmitted with the long pulse laser module 1 to achieve real-time transient measurement of the sample surface temperature.

[0076] Furthermore, the long pulse laser module 1 provides long pulse laser to achieve laser induced desorption;

[0077] Specifically, the main function of the long pulse laser module is to provide a high-power long pulse width laser beam, which can release the fuel gas trapped in the sample through irradiation heating. Figure 1 As shown, after the laser beam is emitted from the laser port, it passes through the first reflector and a group of lens groups with a magnifying glass structure, eliminates aberrations through a double cemented lens, reflects the beam through a dichroic mirror and focuses through a lens, and then the beam passes through a quartz window and is adjusted by the reflector of the manipulator to adjust the beam focus position, and finally focuses on the sample surface to achieve the laser irradiation heating function. The final focus position of the focused laser beam is achieved by adjusting the manipulator, thereby realizing the laser wide-range scanning function. The fuel gas generated by laser thermal desorption diffuses in the vacuum chamber and is captured by the mass spectrometer detector head, and finally the fuel gas composition and content information is obtained through mass spectrometer analysis;

[0078] The high-performance mass spectrometer module 2 collects the charge-to-mass ratio information of the laser desorption gas, which is used to analyze the composition and content of the retained fuel gas in the plasma-facing component material;

[0079] Specifically, the main function of the high-performance mass spectrometry module is to first ionize the substance, separate it according to the mass-to-charge ratio of the ions, and then measure the intensity of various ion spectrum peaks to achieve the purpose of analysis. The quadrupole mass analyzer consists of four parallel cylindrical metal rods, which are arranged equidistantly from the central axis. In order to ensure that only the required m / z ions can pass through the quadrupole smoothly and reach the detector, the quadrupole is simultaneously acted upon by both direct current and alternating current. The number of ions entering the detector generates a signal that is displayed on the computer. The mass spectrometer is calibrated in combination with standard leaks of different leak rates, and the mass spectrometry signal can finally be quantitatively analyzed.

[0080] The short pulse laser module includes a short pulse laser 3 and a spectrum collection system 4, which is used to provide short pulse laser, collect spectrum information and analyze the residual gas inventory after desorption;

[0081] Specifically, the main function of the short pulse laser module is to provide a short pulse width laser beam with high energy density, and the spectrum acquisition system collects the spectrum information of the laser ablation plasma. After the laser beam is emitted from the laser port, it transmits the beam through the dichroic mirror and is focused by the lens. Then, after the beam passes through the quartz window, the beam focusing position is adjusted by the reflector of the manipulator, and finally it is focused on the sample surface to realize the laser irradiation ablation function. The final focusing position of the focused laser beam is achieved by adjusting the manipulator, thereby realizing the laser large-scale scanning function. The impurity particles deposited in the sample are ablated by the laser to generate plasma groups. The emission spectrum information of the plasma groups is analyzed to obtain the composition information of the impurity particles for qualitative analysis. At the same time, the composition and content information of the impurity particles can also be obtained by mass spectrometer analysis.

[0082] The optical module is used to realize the transmission of the laser transmission optical path and the spectrum signal 6;

[0083] A numerically controlled gate valve 11 is installed inside the vacuum chamber 10 to separate the vacuum chamber 10 and the vacuum pump 12 to achieve the negative pressure environment pressure maintenance function inside the vacuum chamber.

[0084] The vacuum chamber 10 is circumferentially provided with four flange quartz windows 13 for transmitting laser light during the laser diagnosis process and facilitating spectrum collection.

[0085] The vacuum chamber 10 is provided with a three-dimensional numerically controlled high-precision moving slide 14 for moving samples to simulate different positions of wall materials in a real tokamak device.

[0086] A high vacuum measurement sensor probe 15 is installed at the bottom of the vacuum chamber 10 to achieve real-time high-precision measurement of the internal pressure of the vacuum chamber 10;

[0087] The dichroic mirror I8 transmits laser light in the visible light band of 300-800nm ​​and reflects laser light in the infrared band greater than 800nm, and the dichroic mirror II22 transmits laser light in the visible light band of 300-1100nm and reflects laser light in the far-infrared light band greater than 1100nm. They can be used to achieve different experimental requirements, and can respectively realize the diagnosis of impurity deposition and the in-situ real-time diagnosis of fuel thermal desorption efficiency.

[0088] The high-performance mass spectrometer module 2 is connected to the vacuum chamber 10 via a CF35 flange at one end, and is sealed with the vacuum chamber 10 using a vacuum sealing copper flat gasket.

[0089] Specifically, the main function of the temperature measurement module is to observe the surface temperature of the material surface in real time during the laser irradiation process. The infrared pyrometer determines the surface temperature of the object by measuring the infrared energy radiated by the object itself. The workflow of the temperature measurement module usually includes the following steps: first, the infrared radiation of the object to be measured is captured by the optical system; then, these radiations are sent to the infrared detector, which converts the thermal radiation into a voltage signal; finally, the voltage signal is converted into temperature after being processed by the readout circuit and output. In more advanced applications, by receiving and analyzing the infrared radiation emitted by the object, a thermal map of the temperature distribution can be generated, which helps to understand the temperature distribution of the object in more detail. By detecting the surface temperature of the material in real time, the relationship between the surface temperature of the sample and the laser parameters can be controlled, so as to obtain the relationship between the thermal desorption efficiency of the fuel gas and the laser parameters, and then provide data support for selecting different laser parameters for different materials.

[0090] Specifically, a high-precision standard leak is used to quantitatively calibrate the mass spectrometer, and a standard light source and a standard sample are used to calibrate the spectrometer spectral line and intensity to ensure good repeatability and accuracy of the fuel gas thermal desorption / impurity deposition data measurement. A mass spectrometer is used to qualitatively and quantitatively test the fuel gas components generated by laser thermal desorption, and an optical path is designed in the laser irradiation area. A quartz optical fiber is used to connect the spectrometer to perform transient measurements of impurity particles, and a high-temperature measurement module is used to measure the sample surface temperature in real time. The present invention forms a new set of fully functional in-situ laser diagnostic methods for fuel retention / impurity deposition and material temperature measurement by coupling a long pulse laser module, a short pulse laser module, a high-performance mass spectrometer, and a temperature measurement module. The method has the advantages of a stable and simple measurement system, strong resistance to external interference, and complete measurement functions.

[0091] Implementation Method 2

[0092] This embodiment provides an in-situ laser diagnosis method for thermal desorption of plasma fuel / impurity deposition in a wall material. The method uses the in-situ laser diagnosis system for thermal desorption of plasma fuel / impurity deposition in a wall material as described in Embodiment 1. The method is:

[0093] After laser transmission and focusing the long pulse laser on the surface of the wall material to be tested, the mass spectrometer is used to collect the charge-to-mass ratio information of the desorbed gas, and the composition and content of the fuel retained in the wall material are obtained through analysis. Then the short pulse laser module is triggered, and the short pulse laser is transmitted through the same optical path and focused on the same position. The laser ablation plasma spectrum is collected by the spectrometer, and the gas charge-to-mass ratio information is collected by the mass spectrometer. The residual gas content after desorption is analyzed, and then the real-time desorption efficiency is obtained, realizing in-situ online real-time measurement and monitoring.

[0094] Furthermore, the method specifically comprises the following steps:

[0095] Step 1: Assemble the in-situ laser diagnosis system, use the computer terminal 21 to control and set the timing control system 20, the long pulse laser module 1, the short pulse laser 3 (with a pulse width of less than 10 nanoseconds) in the short pulse module, and the spectrum acquisition system 4 to a working state;

[0096] Step 2: After the timing control system 20 receives the trigger signal of the long pulse laser module 1, the timing control system 20 sends a signal instruction to the short pulse laser 3 and the spectrum acquisition system 4 according to the set timing, triggering the long pulse laser module 1 and the high-performance mass spectrometer module 2, the short pulse laser 3 (with a pulse width of less than 10 nanoseconds) in the short pulse module, the spectrum acquisition system 4, and the temperature measurement module 7 to work and synchronize with the timing of the long pulse laser module 1;

[0097] Step 3: After receiving the trigger signal, the long pulse laser module 1 emits a long pulse laser beam, which passes through the dichroic mirror I8 and irradiates the convex lens 19, passes through the dichroic mirror II22 and the quartz glass 13 window embedded in the vacuum chamber 10 of the fusion device, and then irradiates the surface of the sample 100 to cause laser thermal desorption;

[0098] Step 4: After the long pulse laser module 1 is triggered, the high performance mass spectrometer module 2 and the temperature measurement module 7 are synchronously turned on through the timing control system to perform qualitative and quantitative detection on the gas components generated by the laser thermal desorption in step 4, and at the same time, the surface temperature of the sample 100 to be tested is measured in real time;

[0099] Step 5: After the long pulse laser module 1 is triggered, the timing control system 20 sends a signal to the short pulse laser 3, the spectrum acquisition system 4 and the high-performance mass spectrometer module 2 according to the set timing instruction; after receiving the trigger signal, the short pulse laser module 3 emits a short pulse laser beam, which is irradiated onto the convex lens 19 through the dichroic mirror I8, and then passes through the dichroic mirror II 22 through the quartz glass 13 window embedded in the vacuum chamber 10 of the fusion device, and irradiates the surface of the sample 100 to be tested at the same position as the long pulse laser irradiation in step 3, and laser ablation occurs;

[0100] Step 6: After the surface material of the sample 100 to be tested is ablated by the short-pulse laser beam, the ablated particles are excited and ionized by the high-energy laser to form a laser ablation plasma; the radiation light of the laser ablation plasma passes through the quartz glass 13 and is focused by the plasma collection lens 9, coupled to the optical fiber and further transmitted to the spectrum collection system 4 by the optical fiber to record the emission spectrum;

[0101] Step 7: The spectrum acquisition system 4 transmits the acquired emission spectrum to the computer terminal 21 for data analysis, thereby realizing in-situ, online, and real-time measurement of the element composition and content of impurity deposition on the sample surface. The emission spectrum is a mature technology in spectral analysis and will not be described in detail here.

[0102] Furthermore, the method further comprises:

[0103] Step 8: After one diagnosis is completed, if multiple diagnoses are required at the same spatial position of the sample to be tested, repeat steps 1 to 7 to obtain the surface element composition and content of fuel retention / impurity deposition on the sample surface at different ablation depths. After multiple measurements, the composition and content of the entire sample surface material can be analyzed, thus completing the in-situ diagnosis.

[0104] This method can accurately measure the gas composition and concentration of fuel thermal desorption during laser irradiation in a transient state, and the real-time observation response of the temperature in the action area is less than 0.1ms, and the impurity deposition and fuel recycling can be diagnosed in real time. A database of key information such as fuel gas composition, concentration, material temperature, impurity distribution, fuel recycling, etc. is established and improved to obtain the fuel / impurity retention rules at different locations, and understand and reveal the fuel retention mechanism during the PWI process. It provides a reference for the operation control and wall material research and development of the divertor of the future fusion reactor.

Claims

1. An in-situ laser diagnostic system for plasma fuel thermal desorption / impurity deposition in wall materials, characterized in that: The long pulse laser module (1) emits a long pulse laser beam, and the long pulse laser beam sequentially passes through the magnifying glass system (5), the dichroic mirror I (8), the convex lens (19), the dichroic mirror II (22), and the quartz glass (13) on the vacuum chamber (10) to irradiate the surface of the sample to be tested (100); The short pulse laser module (3) emits a short pulse laser beam, and the short pulse laser beam sequentially passes through a dichroic mirror I (8), a convex lens (19), a dichroic mirror II (22), and a quartz glass (13) on a vacuum chamber (10) to irradiate the surface of a sample to be tested (100); The long pulse laser module (1), the short pulse laser module (3), the temperature measurement module (7) and the spectrum acquisition system (4) are respectively connected to the timing system (20), the timing system (20) is connected to the computer terminal (21), and the radiation light irradiated by the sample to be tested (100) is sequentially transmitted to the spectrum acquisition system (4) through the focusing lens (9) and the spectrum signal (6); The vacuum chamber (10) is provided with a standard leak hole (17), and the standard leak hole (17) is connected to the gas cylinder (18).

2. The in-situ laser diagnostic system according to claim 1, characterized in that: Four flange quartz windows (13) are evenly distributed on the vacuum chamber (10), a three-dimensional numerically controlled high-precision moving slide (14) is arranged in the vacuum chamber (10), a sample to be tested (100) is placed on the three-dimensional numerically controlled high-precision moving slide (14), and a high-performance mass spectrometer module (2) and a high-vacuum measurement sensor probe (15) are also inserted into the vacuum chamber (10); A digitally controlled gate valve (11) is also provided at the bottom end of the vacuum chamber (10), and a vacuum pump (12) is provided below the digitally controlled gate valve (11).

3. The in-situ laser diagnostic system according to claim 2, characterized in that: The sample to be tested (100) is facing one of the flange quartz windows (13) of the vacuum chamber (10), and the flange quartz window (13) and the convex lens (19) are arranged in a straight line; The focusing lens (9) is also arranged outside the flange quartz window (13); A dichroic mirror II (22) and a convex lens (19) are arranged between the dichroic mirror I (8) and the flange quartz window (13).

4. The in-situ laser diagnostic system according to claim 1, characterized in that: The standard gas in the gas cylinder (18) is used to calibrate the high-performance mass spectrometer module (2).

5. The in-situ laser diagnostic system according to claim 1, characterized in that: The temperature measurement module (7) is coupled into the laser transmission optical path via a dichroic mirror and is coaxially transmitted with the long pulse laser module (1).

6. The in-situ laser diagnostic system according to claim 1, characterized in that: The long pulse laser module (1) provides long pulse laser to achieve laser induced desorption; The high-performance mass spectrometer module (2) collects the charge-to-mass ratio information of the laser desorption gas, and is used to analyze the composition and content of the retained fuel gas in the plasma-facing component material; The short pulse laser module comprises a short pulse laser (3) and a spectrum collection system (4), which is used to provide short pulse laser, collect spectrum information and analyze the residual gas inventory after desorption; The optical module is used to realize the transmission of the laser transmission optical path and the spectrum signal (6); A digitally controlled gate valve (11) is installed inside the vacuum chamber (10) and is used to separate the vacuum chamber (10) and the vacuum pump (12) so as to realize the negative pressure environment pressure maintenance function inside the vacuum chamber. The vacuum chamber (10) is annularly provided with four flange quartz windows (13) for transmitting laser light during the laser diagnosis process and facilitating spectrum collection. A three-dimensional numerically controlled high-precision moving slide (14) is installed inside the vacuum chamber (10) and is used to move samples to simulate different positions of wall materials in a real tokamak device. A high vacuum measurement sensor probe (15) is installed at the bottom of the vacuum chamber (10) to achieve real-time high-precision measurement of the internal pressure of the vacuum chamber (10); The dichroic mirror I (8) transmits laser light in the visible light band of 300-800nm ​​and reflects laser light in the infrared band greater than 800nm, and the dichroic mirror II (22) transmits laser light in the visible light band of 300-1100nm and reflects laser light in the far infrared band greater than 1100nm, and is used to achieve different experimental requirements, namely, to achieve the diagnosis of impurity deposition and the in-situ real-time diagnosis of fuel thermal desorption efficiency respectively.

7. An in-situ laser diagnostic method for thermal desorption of plasma fuel / impurity deposition in wall materials, characterized in that: The method uses an in-situ laser diagnostic system for plasma fuel thermal desorption / impurity deposition in a wall material as claimed in any one of claims 1 to 6, and the method is: After laser transmission and focusing the long pulse laser on the surface of the wall material to be tested, the mass spectrometer is used to collect the charge-to-mass ratio information of the desorbed gas, and the composition and content of the fuel retained in the wall material are obtained through analysis. Then the short pulse laser module is triggered, and the short pulse laser is transmitted through the same optical path and focused on the same position. The laser ablation plasma spectrum is collected by the spectrometer, and the gas charge-to-mass ratio information is collected by the mass spectrometer. The residual gas content after desorption is analyzed, and then the real-time desorption efficiency is obtained, realizing in-situ online real-time measurement and monitoring.

8. The in-situ laser diagnosis method according to claim 7, characterized in that: The method specifically comprises the following steps: Step 1: Assemble the in-situ laser diagnostic system, use the computer terminal (21) to control and set the timing control system (20), the long pulse laser module (1), the short pulse laser (3) in the short pulse module, and the spectrum acquisition system (4) to a working state; Step 2: After the timing control system (20) receives the trigger signal from the long pulse laser module (1), the timing control system (20) sends a signal instruction to the short pulse laser (3) and the spectrum acquisition system (4) according to the set timing, triggering the long pulse laser module (1) and the high-performance mass spectrometer module (2), the short pulse laser (3) in the short pulse module, the spectrum acquisition system (4), and the temperature measurement module (7) to work and synchronize with the timing of the long pulse laser module (1); Step 3: The long pulse laser module (1) emits a long pulse laser beam to irradiate the surface of the sample to be tested (100), causing laser thermal desorption; Step 4: The timing control system synchronously turns on the high-performance mass spectrometry module (2) and the temperature measurement module (7), performs qualitative and quantitative detection on the gas components generated by the laser thermal desorption in step 4, and simultaneously performs real-time measurement on the surface temperature of the sample to be tested (100); Step 5: the short pulse laser module (3) emits a short pulse laser beam, which irradiates the surface of the sample to be tested (100) at the same position as the long pulse laser irradiation in step 3, and laser ablation occurs; Step 6: After the surface material of the sample to be tested (100) is ablated by the short pulse laser beam, the ablated particles are excited and ionized by the high energy laser to form a laser ablation plasma; after being focused by the plasma collection lens (9), the plasma is coupled to the optical fiber and further transmitted to the spectrum collection system (4) by the optical fiber to record the emission spectrum; Step 7: The spectrum acquisition system (4) transmits the acquired emission spectrum to the computer terminal (21) for data analysis, thereby achieving in-situ, online, and real-time measurement of the composition and content of impurity deposits on the sample surface.

9. The in-situ laser diagnosis method according to claim 7, characterized in that: The method further comprises: Step 8: After one diagnosis is completed, if multiple diagnoses are required at the same spatial position of the sample to be tested, repeat steps 1 to 7 to obtain the surface element composition and content of fuel retention / impurity deposition on the sample surface at different ablation depths. After multiple measurements, the composition and content of the entire sample surface material can be analyzed, thus completing the in-situ diagnosis.

10. The in-situ laser diagnosis method according to claim 7, characterized in that: The step 3 specifically comprises: the long pulse laser module (1) emits a long pulse laser beam, which is irradiated onto a convex lens (19) through a magnifying glass system (5) and a dichroic mirror I (8), and then passes through a dichroic mirror II (22) and a quartz glass (13) window embedded in a vacuum chamber (10) of a fusion device, and then irradiates the surface of a sample to be tested (100), causing laser thermal desorption; The step 5 specifically comprises: the short pulse laser module (3) emits a short pulse laser beam, which is irradiated onto the convex lens (19) through the dichroic mirror I (8), passes through the dichroic mirror II (22) and through the quartz glass (13) window embedded in the vacuum chamber (10) of the fusion device, and then irradiates the surface of the sample to be tested (100) at the same position as the long pulse laser irradiation in step 3, thereby causing laser ablation.

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