A non-contact pressure distribution detection system, method and apparatus

Abstract

The embodiment of the application provides a kind of non-contact pressure distribution detection system, method and device, it is related to optical and optoelectronic field.The system includes laser, vacuum cavity, gas target, moving assembly and detector;Gas target, moving assembly and detector are placed in vacuum cavity;Laser is used to emit laser to detector;Gas target is set in moving assembly, and two oppositely arranged, detachable target blocks, and two oppositely arranged window pieces, two target blocks and two window pieces are enclosed to form flow channel;One target block is provided with gas inlet communicated with flow channel;Moving assembly is used to drive gas target to move between first position and second position, gas target is located outside the light path of laser when being located at first position, and two window pieces and flow channel are on the light path of laser when gas target is located at second position;Detector is used to detect the light intensity distribution of outgoing laser.Application of the application, realize the detection to the pressure distribution in small flow channel.

Description

Technical Field

[0001] This application relates to the fields of optics and optoelectronics, and in particular to a non-contact pressure distribution detection system, method and apparatus. Background Technology

[0002] Attosecond laser pulses are pulses whose duration reaches attoseconds (10^6). -18 Attosecond (ATM) ultrafast laser technology offers sufficient time resolution to capture the trajectory of electrons within atoms, enabling the observation and control of extremely fast processes such as electron motion in the atomic-to-subatomic microscopic world. Attosecond laser pulses are based on the principle of high-order harmonic generation. High-order harmonics are generated in an inert gas medium using a femtosecond laser, and the ultrashort pulses are separated using phase-matching techniques. In this process, inert gas is typically injected from the outside into a dedicated gas target. The gas target has a three-way or near-three-way structure, containing one or more injection ports and two outlet ports. The actual generation area of ​​the attosecond laser is located within a tiny gas channel at its center.

[0003] Gas targets are typically placed in a vacuum environment, where a powerful laser interacts with an inert gas. The operating conditions of the gas target involve the ejection of gas from high pressure into a vacuum environment, encompassing a complex flow transition from continuous to rarefied flow, with extreme pressure gradient changes. Simulating the internal flow requires a coupled CFD-DSMC (Computational Fluid Dynamics (CFD) and Direct Simulation Monte Carlo) method. However, fluid simulations often suffer from discretization errors, initialization errors, model errors, boundary condition setting errors, and iteration errors, all of which affect simulation accuracy. Furthermore, the CFD-DSMC coupled method is challenging to implement and its results are difficult to verify, necessitating verification and validation using experimental data to improve the reliability of the computational results.

[0004] However, due to the tiny size and complex structure of the flow channels inside the gas target, traditional contact pressure sensors are difficult to implant, and implanting pressure sensors into the flow channels would also interfere with the original flow field, destroying the true state of the measured target. Furthermore, single-point sensors cannot comprehensively reflect the pressure distribution across the entire flow field cross-section, thus failing to meet the requirement of detecting the pressure distribution over the entire domain of complex flow structures. Therefore, how to detect the pressure distribution in small flow channels is crucial for accurately verifying the fluid simulation results of the gas flow distribution state in the gas target, the core component for attosecond pulse generation. Summary of the Invention

[0005] The purpose of this application is to provide a non-contact pressure distribution detection system, method, and apparatus to detect pressure distribution in small flow channels and improve the accuracy of verifying fluid simulation results of airflow distribution in a gas target generating attosecond pulses. The specific technical solution is as follows:

[0006] A first aspect of this application provides a non-contact pressure distribution detection system, the system comprising a laser, a vacuum chamber, a gas target, a moving component, and a detector; the gas target, the moving component, and the detector are disposed within the vacuum chamber.

[0007] The laser is used to emit laser light towards the detector;

[0008] The gas target is disposed on the movable component and includes two opposing, detachable first target blocks and second target blocks, as well as two opposing windows. The first target blocks, the second target blocks, and the two windows surround and form a flow channel. An air inlet communicating with the flow channel is provided on the first target block.

[0009] The moving component is used to move the gas target between a first position and a second position. When the gas target is in the first position, it is outside the optical path of the laser. When the gas target is in the second position, the two windows and the flow channel are in the optical path of the laser.

[0010] The detector is used to detect the intensity distribution of the emitted laser light.

[0011] In one possible implementation, the system further includes a beam shaper disposed within the vacuum cavity and positioned before the second position in the optical path of the laser.

[0012] The beam shaper is used to shape and homogenize the laser beam emitted by the laser.

[0013] In one possible implementation, the system further includes an aperture disposed between the beam shaper and the gas target.

[0014] In one possible implementation, the system further includes a collimation system disposed between the laser and the vacuum cavity;

[0015] The collimation system is used to collimate the laser emitted by the laser.

[0016] In one possible implementation, the wavelength of the laser is determined in advance based on a preset pressure of the gas target.

[0017] A second aspect of this application provides a non-contact pressure distribution detection method, the method comprising:

[0018] A first light intensity and a second light intensity are obtained, wherein the first light intensity and the second light intensity are detected by a first pixel of a detector in the non-contact pressure distribution detection system described in the first aspect, and the first light intensity is detected when the gas target in the system is located at a first position, and the second light intensity is detected when the gas target is located at a second position and the flow channel is filled with inert gas.

[0019] Based on the first light intensity and the second light intensity, the transmittance of the laser incident on the first pixel in the inert gas is determined as the first transmittance;

[0020] Based on the first transmittance, calculate the air pressure at the spatial point through which the laser passes in the flow channel.

[0021] In one possible implementation, determining the transmittance of the laser incident on the first pixel in the inert gas based on the first light intensity and the second light intensity includes:

[0022] The third light intensity detected by the first pixel is obtained, wherein the third light intensity is detected when the gas target is located at the second position and the flow channel is not filled with gas;

[0023] An initial offset coefficient is determined based on the first light intensity and the third light intensity. The initial offset coefficient is used to represent the degree of absorption of the laser by the two windows of the gas target.

[0024] The second light intensity is corrected according to the initial offset coefficient, and the transmittance of the laser incident on the first pixel in the inert gas is determined according to the first light intensity and the corrected second light intensity.

[0025] In one possible implementation, calculating the air pressure at the spatial point through which the laser passes in the flow channel based on the transmittance includes:

[0026] The air pressure at the spatial point through which the laser passes in the flow channel is calculated using the following formula:

[0027]

[0028] in, This is the first light intensity. Let P be the second light intensity, and P be the pressure. For preset coefficients, , This is the inherent absorption cross section of the gas. The distance between the two window panes. Let Avogadro's constant be 1. For universal gas constants, The temperature of the inert gas.

[0029] In one possible implementation, the second target block of the gas target is provided with an insertion gas pressure gauge for detecting the pressure at a calibration point on the second target block, the calibration point being located at one end of the second target block facing the flow channel. The step of calculating the gas pressure at the spatial point through which the laser passes in the flow channel based on the first transmittance includes:

[0030] The first transmittance is mapped according to the mapping formula to obtain the air pressure at the spatial point through which the laser passes in the flow channel;

[0031] The parameters in the mapping formula are modified in the following way:

[0032] The fourth and fifth light intensities are obtained, wherein the fourth and fifth light intensities are detected by the second pixel of the detector, and the fourth light intensity is detected when the gas target in the system is located at the first position, and the fifth light intensity is detected when the gas target is located at the second position and the flow channel is filled with inert gas, and the second pixel is the pixel to which the laser is incident via the calibration point.

[0033] The parameters in the mapping formula are corrected based on the fourth light intensity, the fifth light intensity, and the gas pressure measured by the insertion gas pressure gauge.

[0034] A third aspect of this application provides a non-contact pressure distribution detection device, the device comprising:

[0035] A light intensity acquisition module is used to acquire a first light intensity and a second light intensity, wherein the first light intensity and the second light intensity are detected by a first pixel of a detector in the non-contact pressure distribution detection system described in the first aspect, and the first light intensity is detected when the gas target in the system is located at a first position, and the second light intensity is detected when the gas target is located at a second position and the flow channel is filled with inert gas.

[0036] The transmittance determination module is used to determine the transmittance of the laser incident on the first pixel in the inert gas based on the first light intensity and the second light intensity, as the first transmittance;

[0037] The air pressure calculation module is used to calculate the air pressure at the spatial point through which the laser passes in the flow channel, based on the first transmittance.

[0038] In one possible implementation, the transmittance determination module is specifically used for:

[0039] The third light intensity detected by the first pixel is obtained, wherein the third light intensity is detected when the gas target is located at the second position and the flow channel is not filled with gas;

[0040] An initial offset coefficient is determined based on the first light intensity and the third light intensity. The initial offset coefficient is used to represent the degree of absorption of the laser by the two windows of the gas target.

[0041] The second light intensity is corrected according to the initial offset coefficient, and the transmittance of the laser incident on the first pixel in the inert gas is determined according to the first light intensity and the corrected second light intensity.

[0042] In one possible implementation, the air pressure calculation module is specifically used for:

[0043] The air pressure at the spatial point through which the laser passes in the flow channel is calculated using the following formula:

[0044]

[0045] in, This is the first light intensity. Let P be the second light intensity, and P be the pressure. For preset coefficients, , This is the inherent absorption cross section of the gas. The distance between the two window panes. Let Avogadro's constant be 1. For universal gas constants, The temperature of the inert gas.

[0046] In one possible implementation, the second target block of the gas target is provided with an insertion gas pressure gauge for detecting the pressure at a calibration point on the second target block, the calibration point being located at one end of the second target block facing the flow channel. The step of calculating the gas pressure at the spatial point through which the laser passes in the flow channel based on the first transmittance includes:

[0047] The first transmittance is mapped according to the mapping formula to obtain the air pressure at the spatial point through which the laser passes in the flow channel;

[0048] The parameters in the mapping formula are modified in the following way:

[0049] The fourth and fifth light intensities are obtained, wherein the fourth and fifth light intensities are detected by the second pixel of the detector, and the fourth light intensity is detected when the gas target in the system is located at the first position, and the fifth light intensity is detected when the gas target is located at the second position and the flow channel is filled with inert gas, and the second pixel is the pixel to which the laser is incident via the calibration point.

[0050] Based on the fourth light intensity and the fifth light intensity, the transmittance of the laser incident on the second pixel in the inert gas is determined as the second transmittance;

[0051] The second transmittance is mapped according to a preset mapping formula to obtain the pressure at the calibration point, which is used as the calibration pressure.

[0052] The parameters in the mapping formula are corrected based on the calibrated gas pressure and the gas pressure measured by the insertion gas pressure gauge.

[0053] A fourth aspect of the embodiments of this application provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0054] Memory, used to store computer programs;

[0055] When the processor executes the program stored in the memory, it implements the steps of the non-contact pressure distribution detection method described in the second aspect.

[0056] A fifth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the non-contact pressure distribution detection method described in the second aspect.

[0057] This application also provides a computer program product containing instructions that, when run on a computer, cause the computer to execute any of the non-contact pressure distribution detection methods described above.

[0058] Beneficial effects of the embodiments in this application:

[0059] This application provides a non-contact pressure distribution detection system, method, and apparatus. Because laser light interacts with inert gas, some of its energy is absorbed, causing the laser intensity to attenuate after passing through the inert gas. Furthermore, the absorption rate of laser energy by the inert gas depends on the density of inert gas molecules or atoms, which in turn depends on the pressure at the point through which the laser passes. Therefore, the intensity attenuation of the laser light in the inert gas is exponentially or approximately exponentially related to the pressure at that point. In this application, the window and target block of the gas target form a flow channel. A moving component moves the gas target between a first position and a second position. When the gas target is in the first position, it is outside the laser's optical path, and the laser emitted by the laser passes directly through the vacuum cavity. When the gas target is in the second position, its two windows and the flow channel are in the laser's optical path. After entering the vacuum cavity, the laser emitted by the laser first enters the flow channel through the window of the gas target, then passes through the inert gas filled in the flow channel and exits through the other window of the gas target into the detector. In other words, the difference in light intensity measured by the detector when the gas target is in the first and second positions is the light intensity attenuation caused by the absorption of the laser as it passes through the flow channel. As mentioned above, the light intensity attenuation is related to the pressure. Therefore, by calculating the light intensity attenuation after the laser passes through the flow channel, the gas pressure at the spatial point through which the laser passes through the flow channel can be determined, thereby realizing the detection of the pressure distribution in the flow channel and improving the accuracy of the fluid simulation results for verifying the airflow distribution state in the gas target that generates attosecond pulses.

[0060] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0062] Figure 1 A schematic diagram of a first structure of a non-contact pressure distribution detection system provided in an embodiment of this application;

[0063] Figure 2 This is a schematic diagram of a first structure of a gas target provided in an embodiment of this application;

[0064] Figure 3 This is a schematic diagram of a second structure of a gas target provided in an embodiment of this application;

[0065] Figure 4This is a schematic diagram of a second structure of the non-contact pressure distribution detection system provided in the embodiments of this application;

[0066] Figure 5 A schematic diagram of a third structure of the non-contact pressure distribution detection system provided in the embodiments of this application;

[0067] Figure 6 A schematic diagram of a fourth structure of the non-contact pressure distribution detection system provided in the embodiments of this application;

[0068] Figure 7 A fifth structural schematic diagram of the non-contact pressure distribution detection system provided in the embodiments of this application;

[0069] Figure 8 A sixth structural schematic diagram of the non-contact pressure distribution detection system provided in the embodiments of this application;

[0070] Figure 9 This is a first schematic diagram of a non-contact pressure distribution detection method provided in an embodiment of this application.

[0071] Figure 10 A schematic diagram of the light spot on the sensor of the detector provided in an embodiment of this application;

[0072] Figure 11 Example graphs showing the relationship between pressure and absorptivity under different absorption cross sections provided in embodiments of this application;

[0073] Figure 12 This is a second schematic diagram of the non-contact pressure distribution detection method provided in the embodiments of this application;

[0074] Figure 13 This is a third schematic diagram of a non-contact pressure distribution detection method provided in an embodiment of this application.

[0075] Figure 14 This is a schematic diagram of a third structure of a gas target provided in an embodiment of this application;

[0076] Figure 15 A schematic diagram of the non-contact pressure distribution detection device provided in an embodiment of this application;

[0077] Figure 16 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0078] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0079] To detect the pressure distribution in a small flow channel and improve the accuracy of verifying the fluid simulation results of the gas flow distribution state in the gas target 30 that generates attosecond pulses, a first aspect of this application provides a non-contact pressure distribution detection system, such as... Figure 1 The diagram shows a first structural schematic of a non-contact pressure distribution detection system provided in this application embodiment. The system includes a laser 10, a vacuum chamber 20, a gas target 30, a moving component 40, and a detector 50. The gas target 30, the moving component 40, and the detector 50 are placed inside the vacuum chamber 20. The laser 10 is used to emit laser light to the detector 50, and the detector 50 is used to detect the intensity distribution of the laser light emitted to the detector 50. It is understood that the detector 50 can be any device capable of measuring the intensity distribution of laser light, such as a beam quality analyzer.

[0080] Gas target 30 is disposed on moving component 40, such as Figure 2 The diagram shows a first structural schematic of the gas target 30 provided in this application embodiment. The gas target 30 includes two detachable target blocks arranged opposite each other, namely a first target block 301 and a second target block 302, and two windows arranged opposite each other, namely a first window 303 and a second window 304. The first target block 301, the second target block 302, the first window 303 and the second window 304 surround to form a flow channel, and the first target block 301 is provided with an air inlet 305 communicating with the flow channel.

[0081] In one possible implementation, the first window 303 and the second window 304 are made of quartz glass and coated with an anti-reflective film, which improves the transmittance of the selected laser and avoids window contamination. The target block of the gas target 30 is detachable, and the inner surface shape of the target block can be designed into different shapes according to actual needs. That is, the shape of the flow channel can be designed according to actual needs to match the simulation situation. In this way, for different flow channel shapes, only the target block needs to be replaced, which improves the flexibility of the non-contact pressure distribution detection system. For ease of description, the target block with the air inlet 305 can also be called the upper target block, and the other target block can be called the lower target block. The end of the target block facing the flow channel can be called the upper part of the target block, and the end of the target block away from the flow channel can be called the lower part of the target block. It is understood that... Figure 2This is merely one possible schematic diagram of the gas target 30 provided in the embodiments of this application. In other possible embodiments, the air inlet 305 may also be provided on the second target block 302. The upper target block and the lower target block are merely names of the target blocks and do not limit the position of the target blocks.

[0082] The upper target block 301, lower target block 302, first window 303, and second window 304 can be bonded together with sealant to form a flow channel, or they can be arranged as follows: Figure 3 As shown, the two target blocks and two window plates are enclosed to form a flow channel by a fixed cover plate 306. Figure 3 The dashed line in the middle represents a window.

[0083] The moving component 40 is used to move the gas target 30 between a first position and a second position. The moving component 40 can be any component capable of moving the gas target 30, such as a displacement stage. The laser beam paths when the gas target 30 is in the first and second positions are as follows: Figure 4 and Figure 1 As shown, see Figure 4 When the gas target 30 is in the first position, it is outside the laser's optical path. After entering the vacuum cavity 20, the laser directly enters the detector 50. (See [reference]). Figure 1 When the gas target 30 is in the second position, after the laser enters the vacuum cavity 20, it passes through the first window 303, the flow channel, and the second window 304 of the gas target 30 before entering the detector 50. That is, the first window 303, the second window 304, and the flow channel are in the laser's optical path. In this application, the gas pressure in the vacuum cavity 20 is less than a preset pressure threshold. The preset pressure threshold is set according to requirements, but it should satisfy the following condition: when the gas pressure is less than the preset pressure drop threshold, the absorption of the laser by the residual gas in the vacuum cavity 20 can be ignored, such as a preset pressure threshold of 10 Pa.

[0084] In order to enable the laser beam to illuminate every position in the flow channel of the gas target 30, in one possible implementation, the moving component 40 is also used to move the gas target 30 along any direction perpendicular to the laser direction, so that the laser beam can illuminate every position in the flow channel of the gas target 30.

[0085] In this embodiment, because the laser interacts with the inert gas, some of its energy is absorbed by the gas, causing the laser intensity to attenuate after passing through the inert gas. Furthermore, the absorption rate of the laser energy by the inert gas depends on the density of the inert gas molecules or atoms, which in turn depends on the pressure at the point through which the laser passes. Therefore, the intensity attenuation of the laser in the inert gas is exponentially or approximately exponentially correlated with the pressure at that point (the derivation of this exponential or approximately exponential correlation is explained below). In this application, the window and target block of the gas target 30 form a flow channel. The moving component 40 moves the gas target 30 between a first position and a second position. When the gas target 30 is in the first position, it is outside the laser's optical path, and the laser emitted by the laser 10 directly enters the detector via the vacuum cavity 20. 50. When the gas target 30 is in the second position, the two windows and the flow channel of the gas target 30 are in the optical path of the laser. After the laser emitted by the laser 10 enters the vacuum cavity 20, it first enters the flow channel through the first window 303 of the gas target 30, and then passes through the inert gas filled in the flow channel and exits from the other window of the gas target 30 into the detector 50. That is to say, the difference in light intensity measured by the detector 50 when the gas target 30 is in the first position and the second position is the light intensity attenuation caused by the absorption of the laser when it passes through the flow channel. As mentioned above, the light intensity attenuation is related to the pressure. Therefore, by calculating the light intensity attenuation of the laser after it passes through the flow channel, the gas pressure at the spatial point through which the laser passes through the flow channel can be determined, thereby realizing the detection of the pressure distribution in the flow channel and improving the accuracy of the fluid simulation results of the airflow distribution state in the gas target 30 that generates attosecond pulses.

[0086] Understandably, since the laser emitted by laser 10 is typically a Gaussian beam, the intensity of the laser beam varies at different points along a cross-section, resulting in a large computational burden for pressure calculations described below. Therefore, in one possible implementation, the laser beam emitted by laser 10 can be shaped by beam shaper 60 to transform the Gaussian beam into a flat-bottomed beam with a square spot shape, ensuring that the intensity of the laser beam is uniform at different points along a cross-section, thus facilitating calculations.

[0087] See Figure 5 , Figure 5 This is a schematic diagram of a third structure of the non-contact pressure distribution detection system provided in the embodiments of this application. The system also includes a beam shaper 60, which is disposed in the optical path of the laser and before the second position, for shaping and homogenizing the laser beam emitted by the laser 10.

[0088] In this case, when the gas target 30 is in the first position, the laser beam emitted by the laser 10 enters the vacuum cavity 20, first enters the beam shaper 60, and after shaping and homogenization, is directly injected into the detector 50; when the gas target 30 is in the second position, the laser beam emitted by the laser 10 enters the vacuum cavity 20, first enters the beam shaper 60, and after shaping and homogenization, passes sequentially through the first window 303, the flow channel, and the second window 304 of the gas target 30. Figure 5 (Not shown in the image) is then injected into detector 50.

[0089] In the embodiment of this application, the laser beam is shaped by the beam shaper 60 so that the light intensity of the laser beam is equal at all points on a certain cross section before entering the gas target 30. In this way, the light intensity of the laser is equal at all points before attenuation in each measurement. Only the light intensity at each point after attenuation needs to be calculated to determine the gas pressure at the spatial points through which the laser passes when passing through the flow channel, without having to measure and store the light intensity of the laser at each point before attenuation separately, thus reducing the amount of data calculation and storage.

[0090] Since the laser beam is usually accompanied by some low-energy stray light, if the stray light also shines into the detector 50, it will interfere with the measurement results, causing the detector 50 to misjudge the boundary of the beam, and thus leading to distorted measurement results. In order to eliminate stray light and improve the signal-to-noise ratio and measurement accuracy, in one possible implementation, the light flux incident on the detector 50 can be controlled by the aperture 70.

[0091] See Figure 6 , Figure 6 This is a schematic diagram of a fourth structure of the non-contact pressure distribution detection system provided in the embodiments of this application. The system also includes an aperture 70, which is disposed in the optical path of the laser and before the second position.

[0092] In this case, when the gas target 30 is in the first position, the laser beam emitted by the laser 10 enters the vacuum cavity 20, first enters the aperture 70, and then directly enters the detector 50; when the gas target 30 is in the second position, the laser beam emitted by the laser 10 enters the vacuum cavity 20, first enters the aperture 70, and then sequentially passes through the first window 303, the flow channel, and the second window 304 of the gas target 30. Figure 6 (Not shown in the image) is then injected into detector 50.

[0093] In another possible implementation, the non-contact pressure distribution detection system may include both an aperture 70 and a beam shaper 60. Both the beam shaper 60 and the aperture 70 are disposed within the vacuum cavity 20 and positioned before the second position on the laser beam path. The beam shaper 60 can be located either before or after the aperture 70. Since the sensor of the detector 50 is typically rectangular, to facilitate establishing the correspondence between the sensor pixels and various points on the light spot, the beam shaper 60 can shape the laser beam into a beam with a rectangular cross-section. Furthermore, the aperture 70 is a square aperture 70 to ensure that the cross-section of the laser beam remains rectangular.

[0094] Understandably, if the divergence angle of the laser beam emitted by laser 10 is too large, after propagating a very short distance, the diameter of the light spot may become so large that it exceeds the receiving range of the sensor of detector 50. This divergence reduces the energy illuminating the sensor target surface of detector 50, resulting in a low signal-to-noise ratio and consequently a large error in the light intensity measured by detector 50. Therefore, in one possible implementation, a collimation system can be used to control the diameter of the laser beam emitted by laser 10 to reduce the divergence angle.

[0095] See Figure 7 , Figure 7 This is a fifth structural schematic diagram of the non-contact pressure distribution detection system provided in the embodiments of this application. The system also includes a collimation system 80, which is disposed between the laser 10 and the vacuum cavity 20 and in the optical path of the laser, for collimating the laser emitted by the laser 10.

[0096] Understandably, since laser beams typically propagate in a straight line, in the scheme of this application, the laser needs to pass sequentially through optical elements including laser 10, vacuum cavity 20, gas target 30, moving component 40, and detector 50. Therefore, these optical elements are usually arranged in a straight line. When the system contains a large number of optical elements, it may result in a large size of the non-contact pressure distribution detection system. To reduce the size of the non-contact pressure distribution detection system, in one possible implementation, the positions of the components in the non-contact pressure distribution detection system can be changed by introducing a reflector.

[0097] It is understood that in other possible implementations, in addition to the laser 10, vacuum cavity 20, gas target 30, moving component 40 and detector 50, the non-contact pressure distribution detection system may simultaneously include one or more of the aperture 70, beam shaper 60 and collimation system, and the embodiments of this application do not limit this.

[0098] For example, such as Figure 8The diagram shown is a sixth structural schematic of the non-contact pressure distribution detection system provided in this application embodiment. The system includes a laser 10, a vacuum cavity 20, a gas target 30, a moving component 40, a detector 50, a collimation system 80, a beam shaper 60, an aperture 70, and a reflector 90. The laser emitted by the laser 10 is first collimated by the collimation system 80 and then enters the vacuum cavity 20. In the vacuum cavity 20, the laser beam is first shaped and homogenized by the beam shaper 60, and then the shaped laser beam is propagated by the reflector 90 to the aperture 70. After the aperture 70 removes the edge of the light spot, the beam illuminates the detector 50.

[0099] Corresponding to the aforementioned non-contact pressure distribution detection system in the first aspect, the second aspect of this application provides a non-contact pressure distribution detection method, see [link to relevant documentation]. Figure 9 , Figure 9 A first schematic diagram of the non-contact pressure distribution detection method provided in this application embodiment includes the following steps:

[0100] Step S10: Obtain the first light intensity and the second light intensity;

[0101] The first light intensity and the second light intensity are obtained by detecting the first pixel of the detector 50 in the aforementioned non-contact pressure distribution detection system. The first light intensity is detected when the gas target in the system is located at the first position, and the second light intensity is detected when the gas target is located at the second position and the flow channel is filled with inert gas. Inert gas includes, but is not limited to, helium, neon, argon, etc. The embodiments of this application do not limit the type of inert gas.

[0102] Step S20: Determine the transmittance of the laser incident on the first pixel in the inert gas based on the first light intensity and the second light intensity, and use it as the first transmittance.

[0103] Step S30: Calculate the air pressure at the spatial point through which the laser passes in the flow channel based on the first transmittance.

[0104] Understandably, when the laser beam illuminates the sensor of detector 50, the light spot covers multiple pixels of the sensor, and each pixel independently measures the light intensity illuminating its photosensitive area. For example, as... Figure 10 The diagram shows a schematic of the laser spot on the sensor of detector 50. The sensor has multiple pixels, and the area indicated by the dashed box is the laser spot. The pixels covered by the laser spot are used to measure the light intensity of the laser covering that pixel. Figure 10 The pixel at position A is used to measure the intensity of the laser light illuminating position A.

[0105] In step S10 above, when the gas target 30 of the non-contact pressure distribution detection system is in the first position, the laser beam does not pass through the gas target 30. In this case, the light intensity detected by each pixel on the sensor of the detector 50 is the first light intensity. When the gas target is in the second position and the gas target 30 is filled with inert gas, the laser beam passes through the gas target 30. Therefore, the laser beam will be absorbed by the inert gas in the gas target. In this case, the light intensity detected by each pixel on the sensor of the detector 50 is the second light intensity.

[0106] In step S20 above, the transmittance of the laser in the inert gas is the ratio of the second light intensity to the first light intensity, reflecting the absorption capacity of the inert gas for the laser. It depends on the wavelength of the laser, the type of gas, and the molecular or atomic density of the gas, that is, it depends on the pressure of the laser at the spatial point through which the inert gas passes. Therefore, based on the Beer-Lambert law and the ideal gas equation, it can be deduced that the light intensity attenuation of the laser in the inert gas is exponentially or approximately exponentially related to the pressure of the laser at the spatial point through which the inert gas passes. The detailed derivation process is described below and will not be repeated here.

[0107] In step S30 above, calculating the gas pressure at the spatial point through which the laser passes in the flow channel based on the first transmittance means calculating the gas pressure at that spatial point based on the light intensity attenuation that occurs when the laser passes through the inert gas. It can be understood that since the thickness of the gas being detected is usually thin in the direction parallel to the optical path, the gas density of the flow field in the direction parallel to the optical path can be considered to be uniformly distributed, that is, the pressure of the laser at each spatial point through which it passes in the gas target 30 in the direction parallel to the optical path is equal.

[0108] It is understandable that in step S10 above, the first pixel is any pixel within the area covered by the light spot. That is, for each pixel, the first light intensity and the second light intensity of that pixel need to be obtained. However, as mentioned above, the light intensity of the laser beam is different at different points in each cross-section. Since the actual gray value is directly measured for each pixel of the detector 50, the first light intensity needs to be calculated separately for different pixels, resulting in a large amount of computation.

[0109] In the embodiments of this application, since the laser interacts with the inert gas, some of the laser energy is absorbed by the gas. Therefore, the intensity of the laser light is attenuated after passing through the inert gas. Furthermore, since the absorption rate of the laser energy by the inert gas depends on the density of the inert gas molecules or atoms, that is, on the pressure at the point through which the laser passes, the intensity attenuation of the laser light in the inert gas is exponentially or approximately exponentially related to the pressure at the point through which the laser passes. In this application, the difference in light intensity measured by the detector 50 when the gas target 30 is in the first position and the second position is the intensity attenuation caused by the absorption of the laser light as it passes through the flow channel. As mentioned above, the intensity attenuation of the laser light is related to the pressure. Therefore, by calculating the intensity attenuation of the laser light after passing through the flow channel, the gas pressure at the point through which the laser light passes through the flow channel can be determined, thereby realizing the detection of the pressure distribution in the flow channel and improving the accuracy of the fluid simulation results for verifying the airflow distribution state in the gas target that generates attosecond pulses.

[0110] The following derivation shows the relationship between the intensity attenuation of laser light in an inert gas and the pressure at the point through which the laser passes in the inert gas:

[0111] Since the intensity attenuation of laser light when passing through a gaseous medium follows Beer-Lambert law, its expression is:

[0112] (1)

[0113] in, For the incident light intensity, The intensity of the emitted light after passing through the gas. The absorption cross section of gas atoms / molecules. Let be the path length of light passing through the gas. This represents the number density of gas molecules.

[0114] And combining the ideal gas equation and the definition of molecular number density:

[0115] (2)

[0116] (3)

[0117] Wherein, formula (2) is the ideal gas equation, formula (3) is the definition of molecular number density, and in formula (2) For the amount of substance, For gas volume, For universal gas constant ( ), The temperature is the thermodynamic temperature of the gas, such as room temperature (298 K); in formula (3) is Avogadro's constant.

[0118] Combining formulas (2) and (3), we can obtain:

[0119] (4)

[0120] Combining formulas (1) and (4), we can obtain:

[0121] (5)

[0122] Furthermore, due to the absorption rate of gases for specific wavelengths of light... for:

[0123] (6)

[0124] Combining formulas (5) and (6), we can obtain:

[0125] (7)

[0126] From equation (7), it can be seen that under ideal gas conditions, the absorption rate of an inert gas for a specific wavelength of light increases exponentially with pressure, and the rate of increase is determined by the inherent absorption cross section of the gas ( ), path length ( ) and temperature ( This is jointly determined. Taking neon as an inert gas as an example, the absorption cross sections for four different gases are plotted, and the results are obtained. Figure 11 The diagram shows an example of the relationship between pressure and absorptivity under different absorption cross sections.

[0127] After a simple transformation of the above formula (7), we can obtain:

[0128] (8)

[0129] Combining formula (8) and Figure 11 It is known that the gas absorptivity is positively correlated with pressure. When the pressure is too low or too high, the change in gas absorptivity with pressure is not significant. Furthermore, since gases have different absorption cross-sections for laser beams of different wavelengths, the pressure range at which the absorptivity changes significantly with pressure varies for different laser wavelengths. To accurately determine the pressure based on the absorptivity during actual measurements, a laser wavelength whose absorptivity changes significantly with pressure should be selected based on the pressure range. When the pressure range is large, a wavelength corresponding to a smaller absorption cross-section should be selected; when the pressure range is small, a wavelength corresponding to a larger absorption cross-section should be selected. It can be understood that the pressure range refers to the pressure range within the gas target. Since the pressure range of the gas target when filled with inert gas is predictable, the wavelength of the laser to be emitted can be selected based on the preset pressure of the gas target, where the preset pressure is the estimated pressure range within the gas target.

[0130] Based on the above formula (7), it can be seen that after selecting the wavelength of the laser, it can be considered that the wavelength of the laser is known and the type of inert gas is constant, therefore the absorption cross section is... Given, and the path length and temperature Both can be measured. Therefore, by using the non-contact pressure distribution detection system provided in this application to measure the transmittance of the laser in the inert gas in the gas target (i.e., the incident light intensity and the attenuated light intensity), the pressure of the spatial point through which the laser passes through the inert gas can be determined.

[0131] Understandably, since the detector 50 typically measures the grayscale value of each pixel, and since the grayscale value is directly proportional to the light intensity, that is:

[0132] (9)

[0133] Where γ is the proportionality coefficient between gray value G and light intensity.

[0134] Transforming the above formula (9) yields:

[0135] (10)

[0136] in, This represents the grayscale value corresponding to the first light intensity. This is the grayscale value corresponding to the second light intensity. , This is the grayscale value corresponding to the third light intensity.

[0137] make After transforming formula (10), we get:

[0138] (11)

[0139] This establishes the relationship between the intensity attenuation of laser light in an inert gas and the pressure at the point in space through which the laser passes:

[0140] (12)

[0141] Based on this, in one possible implementation, the air pressure at the spatial point through which the laser passes in the flow channel can be quickly calculated using the above formula (12), thereby improving the rate of pressure distribution detection.

[0142] It is understandable that, since the first window 303 and the second window 304 of the gas target 30 also absorb the energy of the laser beam, when the second light intensity is when the gas target 30 is in the second position and the flow channel is filled with inert gas, the laser beam will not only be absorbed by the inert gas but also by the windows of the gas target 30 when it passes through the gas target 30. The second light intensity detected by the detector 50 is the light intensity after the light intensity is attenuated due to absorption by the windows and inert gas. The first light intensity is detected when the gas target 30 is in the first position. If the transmittance is directly calculated based on the first light intensity and the second light intensity, it will lead to a large error in the measurement result.

[0143] To improve measurement accuracy, the error caused by the absorption rate of the window of the gas target 30 should be eliminated during pressure distribution detection. Therefore, in step S20 above, when determining the transmittance of the laser incident on the first pixel in the inert gas based on the first and second light intensities, the second or first light intensity should be corrected first. Specifically, this can be achieved by removing the intensity attenuated by window absorption from the second light intensity or by adding the intensity attenuated by window absorption to the first light intensity.

[0144] Taking the increase in intensity due to light intensity attenuation caused by window absorption within the first light intensity as an example, see [link to relevant documentation]. Figure 12 , Figure 12 A second schematic diagram of the non-contact pressure distribution detection method provided in this application embodiment includes the following steps:

[0145] Step S10: Obtain the first light intensity and the second light intensity;

[0146] The first light intensity and the second light intensity are obtained by the first pixel of the detector 50 in the aforementioned non-contact pressure distribution detection system. The first light intensity is obtained when the gas target 30 in the system is in the first position, and the second light intensity is obtained when the gas target 30 is in the second position and the flow channel is filled with inert gas.

[0147] Step S201: Obtain the third light intensity detected by the first pixel;

[0148] Step S202: Determine the initial offset coefficient based on the first light intensity and the third light intensity;

[0149] Step S203: Correct the second light intensity according to the initial offset coefficient, and determine the transmittance of the laser incident on the first pixel in the inert gas according to the first light intensity and the corrected second light intensity.

[0150] Step S30: Calculate the air pressure at the spatial point through which the laser passes in the flow channel based on the first transmittance.

[0151] Steps S10 and S30 are described above and will not be repeated here. Steps S201 to S203 are one possible implementation of step S20.

[0152] The third light intensity is detected when the gas target 30 is in the second position and the flow channel is not filled with gas. The initial offset coefficient is used to represent the degree of absorption of the laser by the first window 303 and the second window 304 of the gas target 30. It can be represented by the difference between the third light intensity and the first light intensity, or by the ratio of the third light intensity to the first light intensity, or by other means. This application embodiment does not limit this.

[0153] For example, suppose the first light intensity obtained in step S10 above is The second light intensity is The third light intensity obtained after detection in step S301 is ,but( This is the initial offset coefficient, denoted as . Then, for the second light intensity After correction, the corrected second light intensity is ( Then calculate the ratio of the first light intensity to the corrected second light intensity. , which is the transmittance of the laser incident on the first pixel in the inert gas.

[0154] In this case, the aforementioned formula (12) can be transformed into:

[0155] (13)

[0156] In another possible embodiment, after determining the initial offset coefficient, the first light intensity can also be adjusted. After correction, the first light intensity after correction is ( Then calculate the ratio of the corrected first light intensity to the second light intensity. , which is the transmittance of the laser incident on the first pixel in the inert gas. In this case, the aforementioned formula (12) can be transformed into:

[0157] (14)

[0158] In one possible implementation, such as Figure 13 A third schematic diagram of the non-contact pressure distribution detection method provided in the embodiments of this application includes the following steps:

[0159] Step S10: Obtain the first light intensity and the second light intensity;

[0160] The first light intensity and the second light intensity are obtained by the first pixel of the detector 50 in the aforementioned non-contact pressure distribution detection system. The first light intensity is obtained when the gas target 30 in the system is in the first position, and the second light intensity is obtained when the gas target is in the second position and the flow channel is filled with inert gas.

[0161] Step S20: Determine the transmittance of the laser incident on the first pixel in the inert gas based on the first light intensity and the second light intensity, and use it as the first transmittance.

[0162] Step S301: Map the first transmittance according to the mapping formula to obtain the air pressure at the spatial point through which the laser passes in the flow channel.

[0163] The mapping formula can be any formula as described in Formula (7) or derived from Formula (7), or any formula derived from the ideal gas equation and Beer-Lambert law to express the relationship between the light intensity attenuation of the laser in an inert gas and the pressure of the laser at the spatial point through which the inert gas passes. The embodiments of this application do not limit the mapping formula.

[0164] The parameters in the mapping formula include, but are not limited to, one or more of the following: ambient temperature, absorption cross section, and light path length. For example, the parameters in the mapping formula can be the preset parameters in the above formula (13). .

[0165] Based on the above formulas (11) to (14), it can be seen that when calculating the air pressure at the spatial point through which the laser passes in the flow channel, due to the changes in ambient temperature and absorption cross section, the preset coefficient is... The pressure may change, leading to errors in the measurement results. In one possible implementation, the pressure in the relatively high-pressure zone can be considered relatively stable, so an insertion gas pressure gauge can be used to measure the pressure in the relatively high-pressure zone to calibrate the preset coefficient.

[0166] Based on this, in one possible implementation, such as Figure 14 The diagram shown is a third structural schematic of the gas target provided in this application embodiment. An insertion-type gas pressure gauge 307 is also provided on the second target block 302 of the gas target 30 to detect the pressure at a calibration point set at the end of the second target block 302 facing the flow channel. It can be understood that the calibration point is set in advance based on experience, and the calibration point is located in a relatively high-pressure zone.

[0167] The following section provides a detailed explanation of how to calibrate the parameters of the mapping formula:

[0168] Step 1: Obtain the fourth and fifth light intensities;

[0169] The fourth and fifth light intensities are detected by the second pixel of detector 50. The fourth light intensity is detected when the gas target 30 in the system is in the first position, and the fifth light intensity is detected when the gas target 30 is in the second position and the flow channel is filled with inert gas. The second pixel is the pixel to which the laser is incident via the calibration point. The second pixel is different from the first pixel mentioned above. This step 1 is similar to the aforementioned step S10, except that the light intensities detected by different pixels of detector 50 are obtained.

[0170] Step 2: Correct the parameters in the mapping formula based on the fourth light intensity, the fifth light intensity, and the gas pressure measured by the insertion gas pressure gauge.

[0171] The fourth light intensity in step 1 and the first light intensity in step S10 can be obtained in the same measurement or separately. Similarly, the fifth light intensity in step 1 and the second light intensity in step S10 can be obtained in the same measurement or separately. It is understood that, to reduce errors, if the fifth and second light intensities are obtained in the same measurement, the laser beam emitted by laser 10 during that measurement must pass through the calibration point or be sufficiently close to the calibration point.

[0172] By selecting the embodiments of this application and correcting the parameters in the mapping formula, the errors in the measurement results can be reduced and the accuracy of pressure measurement can be improved.

[0173] Corresponding to the second aspect mentioned above, a third aspect of the embodiments of this application provides a non-contact pressure distribution detection device, such as... Figure 15 The diagram shown is a structural schematic of a non-contact pressure distribution detection device provided in an embodiment of this application. The device includes:

[0174] The light intensity acquisition module 1501 is used to acquire a first light intensity and a second light intensity, wherein the first light intensity and the second light intensity are detected by a first pixel of a detector in the non-contact pressure distribution detection system described in the first aspect, and the first light intensity is detected when the gas target in the system is located at a first position, and the second light intensity is detected when the gas target is located at a second position and the flow channel is filled with inert gas.

[0175] Transmittance determination module 1502 is used to determine the transmittance of the laser incident on the first pixel in the inert gas based on the first light intensity and the second light intensity, as the first transmittance;

[0176] The air pressure calculation module 1503 is used to calculate the air pressure at the spatial point through which the laser passes in the flow channel based on the first transmittance.

[0177] In this embodiment, because the laser interacts with the inert gas, some of its energy is absorbed, causing the laser intensity to attenuate after passing through the inert gas. Furthermore, the absorption rate of a known wavelength of laser energy by the inert gas depends on the density of the inert gas molecules or atoms, which in turn depends on the pressure at the point through which the laser passes. Therefore, the intensity attenuation of the laser in the inert gas is exponentially or approximately exponentially related to the pressure at that point. In this application, the window and target block of the gas target form a flow channel. A moving component moves the gas target between a first position and a second position. When the gas target is in the first position, it is outside the laser's optical path, and the laser emitted by the laser directly enters the detector through the vacuum cavity. When the target is in the second position, the two windows of the gas target and the flow channel are in the optical path of the laser. After the laser emitted by the laser enters the vacuum cavity, it first enters the flow channel through the window of the gas target, and then passes through the inert gas filled in the flow channel and exits from the other window of the gas target into the detector. That is to say, the difference in light intensity measured by the detector when the gas target is in the first position and the second position is the light intensity attenuation caused by the absorption of the laser when it passes through the flow channel. As mentioned above, the light intensity attenuation is related to the pressure. Therefore, by calculating the light intensity attenuation of the laser after it passes through the flow channel, the gas pressure at the spatial point through which the laser passes through the flow channel can be determined, realizing the detection of the pressure distribution in the flow channel, thereby improving the accuracy of the fluid simulation results of the airflow distribution state in the gas target that generates attosecond pulses.

[0178] In one possible implementation, the transmittance determination module is specifically used for:

[0179] The third light intensity detected by the first pixel is obtained, wherein the third light intensity is detected when the gas target is located at the second position and the flow channel is not filled with gas;

[0180] An initial offset coefficient is determined based on the first light intensity and the third light intensity. The initial offset coefficient is used to represent the degree of absorption of the laser by the two windows of the gas target.

[0181] The second light intensity is corrected according to the initial offset coefficient, and the transmittance of the laser incident on the first pixel in the inert gas is determined according to the first light intensity and the corrected second light intensity.

[0182] In one possible implementation, the air pressure calculation module is specifically used for:

[0183] The air pressure at the spatial point through which the laser passes in the flow channel is calculated using the following formula:

[0184]

[0185] in, This is the first light intensity. Let P be the second light intensity, and P be the pressure. For preset coefficients, , For the preset wavelength, The distance between the two window panes. Let Avogadro's constant be 1. For universal gas constants, The temperature of the inert gas.

[0186] In one possible implementation, the second target block of the gas target is provided with an insertion gas pressure gauge for detecting the pressure at a calibration point on the second target block, the calibration point being located at one end of the second target block facing the flow channel. The step of calculating the gas pressure at the spatial point through which the laser passes in the flow channel based on the first transmittance includes:

[0187] The first transmittance is mapped according to the mapping formula to obtain the air pressure at the spatial point through which the laser passes in the flow channel;

[0188] The parameters in the mapping formula are modified in the following way:

[0189] The fourth and fifth light intensities are obtained, wherein the fourth and fifth light intensities are detected by the second pixel of the detector, and the fourth light intensity is detected when the gas target in the system is located at the first position, and the fifth light intensity is detected when the gas target is located at the second position and the flow channel is filled with inert gas, and the second pixel is the pixel to which the laser is incident via the calibration point.

[0190] Based on the fourth light intensity and the fifth light intensity, the transmittance of the laser incident on the second pixel in the inert gas is determined as the second transmittance;

[0191] The second transmittance is mapped according to a preset mapping formula to obtain the pressure at the calibration point, which is used as the calibration pressure.

[0192] The parameters in the mapping formula are corrected based on the calibrated gas pressure and the gas pressure measured by the insertion gas pressure gauge.

[0193] A fourth aspect of the embodiments of this application provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0194] Memory, used to store computer programs;

[0195] When the processor executes the program stored in the memory, it implements the steps of the non-contact pressure distribution detection method described in the second aspect.

[0196] A fifth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the non-contact pressure distribution detection method described in the second aspect.

[0197] This application also provides a computer program product containing instructions that, when run on a computer, cause the computer to execute any of the non-contact pressure distribution detection methods described above.

[0198] This application also provides an electronic device, such as... Figure 16 As shown, it includes a processor 1601, a communication interface 1602, a memory 1603, and a communication bus 1604, wherein the processor 1601, the communication interface 1602, and the memory 1603 communicate with each other through the communication bus 1604.

[0199] Memory 1603 is used to store computer programs;

[0200] When processor 1601 executes a program stored in memory 1603, it performs the following steps:

[0201] A first light intensity and a second light intensity are obtained, wherein the first light intensity and the second light intensity are detected by a first pixel of a detector in the non-contact pressure distribution detection system described in the first aspect, and the first light intensity is detected when the gas target in the system is located at a first position, and the second light intensity is detected when the gas target is located at a second position and the flow channel is filled with inert gas.

[0202] Based on the first light intensity and the second light intensity, the transmittance of the laser incident on the first pixel in the inert gas is determined as the first transmittance;

[0203] Based on the first transmittance, calculate the air pressure at the spatial point through which the laser passes in the flow channel.

[0204] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0205] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0206] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0207] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0208] In another embodiment provided in this application, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of any of the above-described non-contact pressure distribution detection methods.

[0209] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the non-contact pressure distribution detection methods described above.

[0210] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0211] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0212] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0213] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A non-contact pressure distribution detection system, characterized in that, The system includes a laser, a vacuum cavity, a gas target, a moving component, and a detector; the gas target, the moving component, and the detector are placed inside the vacuum cavity; The laser is used to emit laser light towards the detector; The gas target is disposed on the movable component and includes two detachable first target blocks and second target blocks arranged opposite each other, as well as two windows arranged opposite each other. The first target blocks, the second target blocks, and the two windows surround and form a flow channel. An air inlet communicating with the flow channel is provided on the first target block. The surface shapes of the first target blocks and the second target blocks are designed according to actual needs. The moving component is used to move the gas target between a first position and a second position. When the gas target is in the first position, it is outside the optical path of the laser. When the gas target is in the second position, the two windows and the flow channel are in the optical path of the laser. The detector is used to detect the intensity distribution of the emitted laser light.

2. The system according to claim 1, characterized in that, The system also includes a beam shaper, which is placed inside the vacuum cavity and located before the second position in the optical path of the laser; The beam shaper is used to shape and homogenize the laser beam emitted by the laser.

3. The system according to claim 2, characterized in that, The system also includes an aperture, which is placed inside the vacuum cavity and located before the second position in the optical path of the laser.

4. The system according to claim 1, characterized in that, The system also includes a collimation system disposed between the laser and the vacuum cavity; The collimation system is used to collimate the laser emitted by the laser.

5. The system according to claim 1, characterized in that, The wavelength of the laser is determined in advance based on the preset pressure of the gas target.

6. A non-contact pressure distribution detection method, characterized in that, The method includes: A first light intensity and a second light intensity are obtained, wherein the first light intensity and the second light intensity are detected by a first pixel of a detector in any of the non-contact pressure distribution detection systems of claims 1-5, and the first light intensity is detected when the gas target in the system is located at a first position, and the second light intensity is detected when the gas target is located at a second position and the flow channel is filled with inert gas. Based on the first light intensity and the second light intensity, the transmittance of the laser incident on the first pixel in the inert gas is determined as the first transmittance; Based on the first transmittance, calculate the air pressure at the spatial point through which the laser passes in the flow channel.

7. The method according to claim 6, characterized in that, Determining the transmittance of the laser incident on the first pixel in the inert gas based on the first light intensity and the second light intensity includes: The third light intensity detected by the first pixel is obtained, wherein the third light intensity is detected when the gas target is located at the second position and the flow channel is not filled with gas; An initial offset coefficient is determined based on the first light intensity and the third light intensity. The initial offset coefficient is used to represent the degree of absorption of the laser by the two windows of the gas target. The second light intensity is corrected according to the initial offset coefficient, and the transmittance of the laser incident on the first pixel in the inert gas is determined according to the first light intensity and the corrected second light intensity.

8. The method according to claim 6, characterized in that, The step of calculating the air pressure at the spatial point through which the laser passes in the flow channel based on the transmittance includes: The air pressure at the spatial point through which the laser passes in the flow channel is calculated using the following formula: ; in, This is the first light intensity. Let P be the second light intensity, and P be the pressure. For preset coefficients, , This is the inherent absorption cross section of the gas. The distance between the two window panes. Let Avogadro's constant be 1. For universal gas constants, The temperature of the inert gas.

9. The method according to claim 6, characterized in that, The second target block of the gas target is equipped with an insertion gas pressure gauge, which is used to detect the pressure at a calibration point on the second target block. The calibration point is located at one end of the second target block facing the flow channel. The step of calculating the gas pressure at the spatial point through which the laser passes in the flow channel based on the first transmittance includes: The first transmittance is mapped according to the mapping formula to obtain the air pressure at the spatial point through which the laser passes in the flow channel; The parameters in the mapping formula are modified in the following way: The fourth and fifth light intensities are obtained, wherein the fourth and fifth light intensities are detected by the second pixel of the detector, and the fourth light intensity is detected when the gas target in the system is located at the first position, and the fifth light intensity is detected when the gas target is located at the second position and the flow channel is filled with inert gas, and the second pixel is the pixel to which the laser is incident via the calibration point. The parameters in the mapping formula are corrected based on the fourth light intensity, the fifth light intensity, and the gas pressure measured by the insertion gas pressure gauge.

10. A non-contact pressure distribution detection device, characterized in that, The device includes: A light intensity acquisition module is used to acquire a first light intensity and a second light intensity, wherein the first light intensity and the second light intensity are detected by a first pixel of a detector in the non-contact pressure distribution detection system according to any one of claims 1-5, and the first light intensity is detected when the gas target in the system is located at a first position, and the second light intensity is detected when the gas target is located at a second position and the flow channel is filled with inert gas. The transmittance determination module is used to determine the transmittance of the laser incident on the first pixel in the inert gas based on the first light intensity and the second light intensity, as the first transmittance; The air pressure calculation module is used to calculate the air pressure at the spatial point through which the laser passes in the flow channel, based on the first transmittance.

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