A portable laser-induced breakdown spectroscopy acquisition device and control method

Abstract

The application relates to the field of laser-induced breakdown spectroscopy collection, in particular to a portable laser-induced breakdown spectroscopy collection device and a control method. The laser-induced breakdown spectroscopy collection device comprises a laser emission device, a sample bearing mechanism and a collection mechanism. The laser emission mechanism is used for emitting a laser beam. The sample bearing mechanism comprises a sample bearing plate. The collection mechanism comprises a support frame body provided with a laser channel axis through which the laser beam passes, a plurality of collection components and a plurality of adjusting units corresponding to the collection components. Each collection component comprises a collection head. Each adjusting unit comprises a linear driving mechanism for driving the collection head to perform linear reciprocating motion in a radial direction pointing to the laser channel axis, and an angle adjusting mechanism for adjusting the included angle between the optical axis of the collection head and the plane where the sample bearing plate is located. The application achieves the technical effects of comprehensively collecting signal light generated by plasma from multiple angles and improving the stability and comprehensiveness of signal light collection.

Description

Technical Field

[0001] This application relates to the field of laser-induced breakdown spectral acquisition technology, and in particular to a portable laser-induced breakdown spectral acquisition device and control method. Background Technology

[0002] Laser-induced breakdown spectroscopy (LAS) is an atomic emission spectroscopic analysis technique that uses a pulsed laser to excite plasma on the surface of a sample. The types and amounts of elements in the sample are then determined by analyzing the spectral wavelengths and intensities of the emitted plasma. This technique is characterized by its ability to perform analysis without sample preparation, its high speed, its remote and non-contact operation, and its capacity for simultaneous multi-element analysis of any substance. Therefore, it is widely used in numerous fields, including metal analysis, environmental monitoring, nuclear energy and engineering, life sciences, and cultural relic preservation.

[0003] In traditional laser-induced breakdown spectroscopy (LAS) acquisition, a fixture is used to hold the sample and the laser emitting mechanism in order to collect the signal light generated by the laser excitation. However, there is a lack of precise control over the laser beam path. This existing technology has significant drawbacks. Because the plasma formed by the laser beam on the sample is not perfectly uniform in space, and each excitation may involve minute morphological changes, if only a single acquisition component is used to collect the signal light from a single angle, the intensity of the collected signal light will fluctuate significantly due to this non-uniformity and instability, resulting in incomplete acquisition. Summary of the Invention

[0004] The purpose of this application is to overcome the above-mentioned technical problems and provide a portable laser-induced breakdown spectrum acquisition device.

[0005] A portable laser-induced breakdown spectrum acquisition device, comprising:

[0006] A laser emitting mechanism used to emit a laser beam;

[0007] A sample carrying mechanism, including a sample carrying plate for carrying the sample;

[0008] Data collection agencies include:

[0009] A support frame, wherein the support frame is provided with a laser channel axis through which the laser beam passes;

[0010] Multiple acquisition components are arranged in a circular array around the axis of the laser channel. Each acquisition component includes an acquisition head for acquiring the plasma signal light generated by the laser beam irradiating the sample; and

[0011] Multiple adjustment units are provided, each of which is respectively configured to correspond to one of the acquisition components and is used to adjust the position and orientation of the acquisition head corresponding to the device;

[0012] Each of the aforementioned adjustment units includes:

[0013] A linear drive mechanism for driving the acquisition head to perform linear reciprocating motion in a radial direction generally pointing towards the axis of the laser channel; and

[0014] An angle adjustment mechanism is used to adjust the angle between the optical axis of the acquisition head and the plane of the sample carrier plate.

[0015] By adopting the above scheme, since the plasma formed by the laser beam on the sample is not completely uniform in space, and there may be slight morphological changes with each excitation, if only a single acquisition component is used to collect the signal light from a single angle, the intensity of the collected signal light will fluctuate greatly due to this non-uniformity and instability, resulting in incomplete acquisition. Multiple acquisition components arranged in a circular array can collect the signal light generated by the plasma from multiple angles. At the same time, the angle and distance of the multiple acquisition components from the laser channel can be changed, increasing the acquisition range and thus enabling more comprehensive acquisition of the signal light.

[0016] In one embodiment, the linear drive mechanism includes:

[0017] A sliding frame, on which both the acquisition head and the angle adjustment mechanism are mounted; and

[0018] An adjusting screw driven by a power source is connected to the sliding frame to drive the sliding frame to move linearly.

[0019] By adopting the above scheme, since the position of the plasma will also change when analyzing samples of different shapes or when the distance between the entire device and the sample changes, the adjustment screw can drive the sliding frame and the collection head to move during the rotation process, so that the collection head can refocus on the plasma. When the sample being analyzed is curved or is blocked, the optimal collection point can also be found by adjusting the position of the collection head.

[0020] In one embodiment, a rotating frame is provided, the acquisition head is mounted on the rotating frame, and the rotating frame is rotatably connected to the sliding frame; and

[0021] A telescopic component, one end of which is hinged to the sliding frame and the other end of which is hinged to the rotating frame, is used to drive the rotating frame to rotate by changing its own length.

[0022] By adopting the above scheme, the telescopic component can drive the rotating frame to rotate around one end of the sliding frame during the telescopic process, thereby changing the angle of the acquisition head and enabling the acquisition head to aim at the acquisition signal light generated by plasma at different heights.

[0023] In one embodiment, the support plate assembly includes two parallel support plates, with an adjustment section formed between the two parallel support plates. The acquisition component is located in the adjustment section. A mounting frame with a "U"-shaped cross-section is provided on one side of the adjustment section. The adjustment screw passes through both ends of the mounting frame. A plurality of guide rods parallel to the adjustment screw are also fixed inside the mounting frame. The guide rods pass through the sliding block.

[0024] By adopting the above scheme, the adjustment unit separates multiple acquisition components, which serves to install and limit the acquisition components. The installation frame and guide rods are used to initially prevent the movement trajectory of the acquisition components from deviating.

[0025] In one embodiment, a first guide rail parallel to the adjusting screw is fixed on the side of the adjusting part away from the mounting bracket, a second guide rail parallel to the adjusting screw is fixed on the side of the lower plate facing the adjusting part, a first slider cooperating with the first guide rail is fixed on one side of the sliding frame, and a second slider cooperating with the second guide rail is provided at the bottom of the sliding frame.

[0026] By adopting the above scheme, the guide rod, the first guide rail and the second guide rail cooperate with each other to limit the sides and bottom of the sliding frame at the same time, and at the same time support the sliding frame to prevent the displacement trajectory from deviating due to the deformation of the sliding frame itself.

[0027] In one embodiment, the mounting groove is provided with a plurality of sleeve clamps that mate with the outer peripheral surface of the acquisition head. Each sleeve clamp has a mounting screw hole on the side facing the bottom of the mounting groove, and the end of the rotating frame opposite to the sleeve clamp is provided with a mounting bolt that mates with the mounting screw hole.

[0028] By adopting the above scheme, the sleeve clamp and the mounting bolt are used to fix the acquisition head.

[0029] In one embodiment, the rotating frame is provided with adjusting screws on both sides, the adjusting screws pass through the two sides of the rotating frame and abut against the two sides of the sleeve clamp, the bottom of the rotating frame is provided with an adjusting groove, the adjusting groove is arc-shaped, and the mounting bolt passes through the adjusting groove and engages with the mounting screw hole.

[0030] By adopting the above scheme, the adjusting screw is used to limit the sleeve clamp and prevent the sleeve clamp from swaying left and right. At the same time, the mounting bolt passes through different positions of the adjusting groove, and the acquisition head is fixed by the sleeve clamp at different angles, which further improves the degree of freedom of the acquisition head angle adjustment.

[0031] In one embodiment, the sample carrying mechanism further includes a carrying column, a first driving screw is disposed inside the carrying column, and the first driving screw passes through the sample carrying plate.

[0032] By adopting the above scheme, when the first drive screw rotates, it can drive the sample carrier plate to move along the carrier column, thereby adjusting the sample to the most suitable collection height.

[0033] In one embodiment, the sample carrying mechanism further includes an adjustment base located at the bottom of the carrying column. The adjustment base includes a first adjustment plate and a second adjustment plate arranged perpendicularly to each other. The first adjustment plate is provided with a second drive screw passing through the carrying column. The second drive screw is perpendicular to the first drive screw. The second adjustment plate is provided with a third drive screw passing through the first adjustment plate. The third drive screw is perpendicular to the plane where the first drive screw and the second drive screw are located.

[0034] By adopting the above scheme, when there are other observation needs for the sample, the adjustment base can be adjusted to adjust the working position of the sample detection, thereby facilitating the installation of other observation equipment.

[0035] This application also provides a control method for a portable laser-induced breakdown spectral acquisition device, which includes the following steps:

[0036] S1. Control the laser emitting mechanism to emit a laser beam, the laser beam irradiating the sample supported by the sample carrier plate along the preset laser channel axis, so as to generate plasma on the sample surface;

[0037] S2. Based on the position of the sample or plasma, control the linear drive mechanism in each adjustment unit to drive its corresponding acquisition head to move in a radial direction that is approximately pointing towards the axis of the laser channel, so as to align the focus of the acquisition head with the plasma.

[0038] S3. Based on the height or shape of the plasma, control the angle adjustment mechanism in each adjustment unit to adjust the angle between the optical axis of the corresponding acquisition head and the plane where the sample carrier plate is located, so that the acquisition head aims at the optimal acquisition area of ​​the plasma signal light;

[0039] S4. By using multiple acquisition heads arranged in a circular array around the axis of the laser channel, the signal light emitted by the plasma is simultaneously acquired from multiple different angles and positions to achieve comprehensive acquisition of the signal light.

[0040] By adopting the above scheme, the device can adapt to samples of different shapes or those that are obscured, and collect signals simultaneously from multiple angles, ultimately obtaining more comprehensive, stable and high-quality spectral data.

[0041] In summary, this application includes at least one of the following beneficial technical effects:

[0042] 1. Because the plasma formed by the laser beam on the sample is not completely uniform in space, and there may be slight morphological changes with each excitation, if only a single acquisition component is used to collect the signal light from a single angle, the intensity of the collected signal light will fluctuate significantly due to this non-uniformity and instability, resulting in incomplete acquisition. Multiple acquisition components arranged in a circular array can collect the signal light generated by the plasma from multiple angles, increasing the acquisition range and thus enabling more comprehensive acquisition of the signal light. At the same time, the two laser perforations can limit the path of the laser beam and prevent deviations in the laser irradiation position.

[0043] 2. During the extension and retraction process, the telescopic component can drive the rotating frame to rotate around one end of the sliding frame, thereby changing the angle of the acquisition head. This allows the acquisition head to aim at the acquisition signal light generated by the plasma at different heights. When analyzing samples of different shapes, or when the distance between the entire device and the sample changes, the position of the plasma will also change. During the rotation of the adjusting screw, the sliding block can be moved, which in turn can move the sliding frame and the acquisition head, allowing the acquisition head to refocus on the plasma. When the sample being analyzed is curved or obstructed, the optimal acquisition point can also be found by adjusting the position of the acquisition head.

[0044] 3. With the sample carrying mechanism in place, when there are other observation needs for the sample, the adjustable base can adjust the working position of the sample detection, which facilitates the installation of other observation equipment. When the first drive screw rotates, it can drive the sample carrying plate to move along the carrying column, thereby adjusting the sample to the most suitable collection height. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of a portable laser-induced breakdown spectrum acquisition device provided in this application.

[0046] Figure 2 This is a schematic diagram showing the connection relationship between the support frame and the data acquisition components.

[0047] Figure 3 This is a schematic diagram of the internal structure of the support frame.

[0048] Figure 4 This is a schematic diagram of the acquisition component.

[0049] Figure 5 This is an exploded view of the data acquisition component.

[0050] Explanation of reference numerals in the attached drawings: 1. Laser emitting mechanism; 2. Sample carrying mechanism; 21. Sample carrying plate; 22. Support column; 221. First drive screw; 23. Adjusting base; 231. First adjusting plate; 2311. Second drive screw; 232. Second adjusting plate; 2321. Third drive screw; 3. Acquisition mechanism; 31. Support frame; 311. Upper connecting plate; 312. Lower connecting plate; 3121. Observation hole; 313. Support plate assembly; 3131. Adjustment part; 3132. First guide rail; 3133. Second guide rail; 314. Laser perforation; 32 321. Acquisition Component; 33. Acquisition Head; 33. Adjustment Unit; 331. Sliding Frame; 3311. Sliding Block; 3312. First Sliding Block; 3313. Second Sliding Block; 332. Rotating Frame; 3321. Mounting Slot; 3322. Adjusting Top Screw; 3323. Adjustment Slot; 3324. Mounting Bolt; 333. Telescopic Part; 334. Adjusting Screw; 3341. Power Source; 335. Mounting Frame; 3351. Guide Rod; 336. Sleeve Clamp; 3361. Mounting Screw Hole; 34. Linear Drive Mechanism; 35. Angle Adjustment Mechanism; 4. Cage Structure Connecting Block. Detailed Implementation

[0051] Therefore, it is necessary to provide a laser-induced breakdown spectrum acquisition device that can accurately capture signal light.

[0052] Example 1: Please refer to Figure 1-2 , Figure 1 This is a schematic diagram of a portable laser-induced breakdown spectroscopy acquisition device provided in this application. The laser-induced breakdown spectroscopy acquisition device provided in this application includes a laser emitting mechanism 1, a sample carrying mechanism 2, and an acquisition mechanism 3. The laser emitting mechanism 1 emits a laser beam. The sample carrying mechanism 2 includes a sample carrying plate 21 for carrying the sample. The acquisition mechanism 3 includes a support frame 31 and multiple acquisition components 32. Each acquisition component 32 includes an acquisition head 321, and each acquisition component 32 is correspondingly equipped with an adjustment unit 33. The adjustment unit 33 includes a linear drive mechanism 34 and an angle adjustment mechanism 35. Since laser-induced plasma is a three-dimensional, non-uniform luminescent region, its shape, size, and luminescence intensity vary with time, spatial position, and subtle differences in each laser pulse. A single acquisition component 32 can only acquire the signal light generated by the plasma from a single angle, resulting in an unstable and incomplete signal. By setting multiple acquisition components 32, multiple acquisition components 32 can acquire the signal light generated by the plasma from multiple perspectives, making the measurement results more accurate.

[0053] The sample carrying mechanism 2 includes a sample carrying plate 21 and a carrying column 22. The sample carrying plate 21 is located below the support frame 31 and is slidably connected to the carrying column 22. The carrying column 22 contains a first drive screw 221 that drives the sample carrying plate 21 to move up and down. The first drive screw 221 can be driven by a motor. When the first drive screw 221 rotates, it can move the sample carrying plate 21 along the carrying column 22, thereby adjusting the sample to the most suitable collection height. The sample carrying mechanism 2 also includes an adjusting base 23, which includes a vertically arranged first adjusting plate 231 and a second adjusting plate 232. The first adjusting plate 231 contains a second drive screw 2311 that is perpendicular to the first drive screw 221, and the second adjusting plate 232 contains a third drive screw 2321 that is perpendicular to the first drive screw 221 and is planar. When there are other observation requirements for the sample, the working position of the sample detection can be adjusted by controlling the rotation of the second drive screw 2311 and the third drive screw 2321, thereby facilitating the installation of other observation equipment.

[0054] The support frame 31 includes an upper plate 311, a lower plate 312 parallel to the upper plate 311, and multiple support plate groups 313 arranged in a circular array. The upper plate 311 and lower plate 312 each have coaxial laser perforations 314. Multiple acquisition components 32 are arranged in a circular array with the axis of the laser perforations 314 as the center. Each acquisition component 32 is used to acquire the signal light generated by the laser beam acting on the sample, achieving the effect of increasing the acquisition range, comprehensively acquiring the signal light, and simultaneously limiting the laser beam path to avoid irradiation position deviation. This is because the plasma formed by the laser beam on the sample is not completely uniform in space, and each excitation may have slight morphological changes. The multiple acquisition components 32 arranged in a circular array can acquire the signal light generated by the plasma from multiple angles, while the two laser perforations 314 can limit the path of the laser beam.

[0055] Please refer to the following: Figure 3 , Figure 3This is a schematic diagram of the internal structure of the support frame. The upper plate 311 and lower plate 312 of the support frame 31 are generally made of metal, such as aluminum alloy, which has good strength and stability. The upper plate 311 and lower plate 312 are arranged in parallel to ensure the coaxiality of the laser perforation 314. Multiple support plate groups 313 are distributed in a circumferential array and are perpendicular to the upper plate 311, serving to connect and support the upper plate 311 and the lower plate 312. The support plate groups 313 can be made of steel plates or high-strength plastic plates, and the support plates in the support plate groups 313 can be fixed by welding or bolting. The laser emitting mechanism 1 includes a pulsed laser and a focusing lens. The pulsed laser can generate a high-energy laser beam to meet the needs of laser-induced breakdown spectroscopy analysis. The focusing lens is used to guide the laser beam through the two laser perforations 314 and focus the laser beam onto the sample to be tested, so that the surface of the sample to be tested is excited to generate plasma that emits signal light for detection.

[0056] In this application, a cage-like connecting block 4 can be installed on the side of the lower connecting plate 312 opposite to the support plate assembly 313. The cage-like connecting block 4 is used to connect with other cage-like connecting columns in the experimental equipment to connect the support frame 31 and multiple acquisition components 32 into the classic cage-like optical system, ensuring compatibility with traditional optical experimental systems. The center of the cage-like connecting block 4 is coaxial with the central axis of the two laser perforations 314. The lower connecting plate 311 on the lower surface of the connecting block is connected by bolts. The lower connecting plate 312 is also provided with an observation hole 3121 for observation of the acquisition components 32.

[0057] Please refer to the following: Figure 4-5 , Figure 4 This is a schematic diagram of the acquisition component. The acquisition head 321 is supported by the adjustment unit 33. The acquisition head 321 passes through the observation hole 3121 of the lower plate 312 and is used to collect the signal light generated by the plasma. The adjustment unit 33 is used to change the angle and orientation of the acquisition head 321. Since the signal light generated by the plasma is not uniform, and the intensity of the signal light generated in different regions is also different, if the acquisition direction of the acquisition head 321 is only focused on one point, it will lead to inaccurate quantitative analysis of the signal light. The angle and orientation of multiple acquisition heads 321 can be adjusted, and each acquisition head 321 can collect the signal light from different regions, thereby obtaining higher quality spectral data.

[0058] The linear drive mechanism 34 includes a sliding frame 331 and an adjusting screw 334 driven by a power source 3341. The power source 3341 can be a stepper motor, which has the advantage of no accumulated error and facilitates repeated positioning during horizontal movement. The adjusting screw 334 is parallel to the plane where the acquisition head 321 and the telescopic member 333 are located. A sliding block 3311 that cooperates with the adjusting screw 334 is provided on one side of the sliding frame 331. When the adjusting screw 334 rotates, the sliding block 3311 moves on the screw, thereby driving the sliding frame 331 and the acquisition head 321 to move. The adjusting screw 334 can be a ball screw, which has high transmission efficiency and accuracy.

[0059] The angle adjustment mechanism 35 includes a rotating frame 332 and a telescopic component 333. The rotating frame 332 has a mounting groove 3321, and the acquisition head 321 is disposed in the mounting groove 3321. One end of the rotating frame 332 is rotatably connected to one end of the sliding frame 331 via a rotating shaft, enabling the rotating frame 332 to rotate around the sliding shaft. The telescopic component 333 can be an electric push rod or a hydraulic telescopic rod, with its two ends rotatably connected to the rotating frame 332 and the sliding frame 331, respectively. During the extension and retraction of the telescopic component 333, it can drive the rotating frame 332 to rotate around one end of the sliding frame 331, thereby changing the angle of the acquisition head 321 and enabling the acquisition head 321 to aim at the acquisition signal light generated by plasma at different heights. The laser emitting mechanism 1 focuses the laser beam near the test point of the sample to be tested, generating high-temperature plasma at the test point. The plasma emits signal light, and the acquisition module in the acquisition head 321 acquires the signal light generated by the plasma.

[0060] In this application, the acquisition module of the acquisition head 321 is installed inside a lens sleeve. The lens sleeve serves as a standard interface for various optical signal acquisition devices, and can accommodate various lenses or optical sensors that meet size requirements. It acquires and processes plasma optical signals, including but not limited to focusing and color filtering. The sleeve also has threads at the tail end, allowing for convenient installation of connectors for various optical acquisition devices or connection of optical fibers.

[0061] The telescopic component 333 uses an electric linear actuator with a built-in encoder for precise closed-loop length control. The electric linear actuator driver and control module drive and control the actuator. Electric linear actuators typically use DC geared motors. The driver can be a classic H-bridge circuit composed of discrete components or an integrated motor control chip. The control section can simply lead out the control lines from the drive circuit; for circuit reliability, optocouplers can also be used for control. Control signals and actuator position feedback signals can be directly processed by a PLC or MCU, while providing digital signal interfaces such as serial ports to facilitate a host computer control structure and simplify system design.

[0062] The support plate assembly 313 includes two parallel support plates, with an adjustment section 3131 formed between them. A mounting frame 335 is provided within the adjustment section 3131, and the mounting frame 335 can be a metal frame structure. An adjusting screw 334 passes through the mounting frame 335 and is rotatably connected to it. A guide rod 3351, parallel to the adjusting screw 334, is fixed within the mounting frame 335, and the guide rod 3351 passes through a sliding block 3311 on the sliding frame 331. The guide rod 3351 can be a smooth metal rod, guiding the movement of the sliding block 3311 and preventing it from deviating. In this application, a position encoder such as a grating ruler can also be installed on the mounting frame 335 to detect the absolute horizontal position of the leveling frame, achieving closed-loop control and improving the motion accuracy of the acquisition head 321.

[0063] The adjusting part 3131 has a first guide rail 3132 on the side opposite to the mounting bracket 335, and the lower plate 312 has a second guide rail 3133 on the side corresponding to the adjusting part 3131. The sliding frame 331 has a first slider 3312 that cooperates with the first guide rail 3132 and a second slider 3313 that cooperates with the second guide rail 3133. The first guide rail 3132 and the second guide rail 3133 can be dovetail groove guide rails or linear guide rails. The first slider 3312 and the second slider 3313 are adapted to the guide rails and can slide smoothly on the guide rails. The guide rod 3351, the first guide rail 3132 and the second guide rail 3133 cooperate with each other to limit the sides and bottom of the sliding frame 331 at the same time, and also provide support for the sliding frame 331 to prevent the sliding frame 331 from deviating from its displacement trajectory due to deformation.

[0064] The rotating frame 332 is provided with a mounting groove 3321, and a sleeve clamp 336 that mates with the outer circumferential surface of the sampling head 321 is provided in the mounting groove 3321. The sleeve clamp 336 can be made of rubber or plastic and has a certain degree of elasticity, which can better fit the outer circumferential surface of the sampling head 321. The bottom of the sleeve clamp 336 is provided with a mounting screw hole 3361, and the rotating frame 332 is provided with a mounting bolt 3324 that mates with the mounting screw hole 3361. By tightening the mounting bolt 3324, the sampling head 321 is fixed on the rotating frame 332.

[0065] The rotating frame 332 has adjusting screws 3322 on both sides, which abut against the sleeve clamp 336. The adjusting screws 3322 can be metal screws; rotating them limits the position of the sleeve clamp 336, preventing it from wobbling. The bottom of the rotating frame 332 has an arc-shaped adjusting groove 3323, through which a mounting bolt 3324 passes and engages with a mounting screw hole 3361. By positioning the mounting bolt 3324 through the adjusting groove 3323, the sampling head 321 is fixed at different angles by the sleeve clamp 336, further increasing the freedom of angle adjustment for the sampling head 321.

[0066] The working principle of this embodiment is as follows: The laser-induced breakdown spectroscopy acquisition device collects signal light generated by plasma from multiple angles through multiple acquisition devices arranged in a circular array, increasing the acquisition range and enabling more comprehensive acquisition of signal light. Simultaneously, the two laser perforations 314 on the support frame 31 restrict the path of the laser beam, preventing deviations in the laser irradiation position. The adjustment unit 33 can adjust the position and angle of the acquisition head 321 to adapt to samples of different shapes and different acquisition requirements.

[0067] Example 2: This application also provides a control method for a portable laser-induced breakdown spectrum acquisition device, which includes the following steps:

[0068] S1. Control the laser emitting mechanism 1 to emit a laser beam, the laser beam irradiating the sample supported by the sample carrier plate 21 along the preset laser channel axis, so as to generate plasma on the sample surface;

[0069] S2. Based on the position of the sample or plasma, control the linear drive mechanism 34 in each adjustment unit 33 to drive its corresponding acquisition head 321 to move in a radial direction that is approximately pointing to the axis of the laser channel, so as to align the focus of the acquisition head 321 with the plasma.

[0070] S3. Based on the height or shape of the plasma, control the angle adjustment mechanism 35 in each adjustment unit 33 to adjust the angle between the optical axis of its corresponding acquisition head 321 and the plane where the sample carrier plate 21 is located, so that the acquisition head 321 aims at the optimal acquisition area of ​​the plasma signal light.

[0071] S4. Multiple acquisition heads 321 arranged in a circular array around the axis of the laser channel are used to synchronously acquire the signal light emitted by the plasma from multiple different angles and positions, so as to achieve comprehensive acquisition of the signal light.

[0072] This control method enables the laser-induced breakdown spectroscopy acquisition device to independently and precisely control multiple adjustment units 33 according to sample characteristics or plasma morphology. By controlling the linear drive mechanism 34, the acquisition head 321 can be adjusted to the optimal distance from the plasma for precise focusing; by controlling the angle adjustment mechanism 35, the pitch attitude of the acquisition head 321 can be changed to aim at the plasma region with the strongest signal. This flexible control strategy allows the device to adapt to samples of different shapes or those that are obstructed, and to acquire signals simultaneously from multiple angles, ultimately obtaining more comprehensive, stable, and high-quality spectral data.

[0073] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A portable laser-induced breakdown spectroscopy acquisition device, characterized in that, The application relates to a laser plasma sampling device. The device comprises: a laser emission mechanism (1) for emitting a laser beam; a sample bearing mechanism (2) comprising a sample bearing plate (21) for bearing a sample; a sampling mechanism (3) comprising: a support frame (31) provided with a laser passage axis for the laser beam to pass through; a plurality of sampling assemblies (32) arranged in a circumferential array around the laser passage axis, each of the sampling assemblies (32) comprising a sampling head (321) for collecting plasma signal light generated by the laser beam irradiating the sample; and a plurality of adjusting units (33), each of the adjusting units (33) being arranged correspondingly to one of the sampling assemblies (32) and being used for adjusting the position and posture of the corresponding sampling head (321); wherein each of the adjusting units (33) comprises: a linear driving mechanism (34) for driving the sampling head (321) to perform linear reciprocating motion in a radial direction approximately pointing to the laser passage axis; an angle adjusting mechanism (35) for adjusting the included angle between the optical axis of the sampling head (321) and the plane where the sample bearing plate (21) is located; a sliding frame (331), the sampling head (321) and the angle adjusting mechanism being mounted on the sliding frame (331); and an adjusting screw (334) driven by a power source (3341), the adjusting screw (334) being in transmission connection with the sliding frame (331) to drive the sliding frame (331) to linearly move; a rotating frame (332), the sampling head (321) being mounted on the rotating frame (332), and the rotating frame (332) being rotatably connected to the sliding frame (331); and 2.The portable LIBS acquisition device according to claim 1, wherein: an extension piece (333), one end of the extension piece (333) being hinged to the sliding frame (331), and the other end of the extension piece (333) being hinged to the rotating frame (332), the extension piece (333) being used for driving the rotating frame (332) to rotate by changing the length of the extension piece (333). The support frame comprises an upper connecting plate (311), a lower connecting plate (312) arranged in parallel with the upper connecting plate (311), and a plurality of support plate groups (313) arranged in a circumferential array, each of the support plate groups (313) comprising two parallel support plates, an adjusting portion (3131) being formed between the two parallel support plates, the sampling assemblies (32) and the adjusting units (33) being located in the adjusting portion (3131), one side of the adjusting portion (3131) being provided with a mounting frame (335) with a "U" shaped cross section, the adjusting screw (334) penetrating through the two ends of the mounting frame (335), a plurality of guide rods (3351) arranged in parallel with the adjusting screw (334) being fixedly arranged in the mounting frame (335), and the guide rods (3351) penetrating through the sliding frame (331).

3. The portable LIBS acquisition device of claim 2, wherein: The adjusting part (3131) is fixed with a first guide rail (3132) parallel to the adjusting screw rod (334) on the side away from the mounting frame (335), and the lower connecting plate (312) is fixed with a second guide rail (3133) parallel to the adjusting screw rod (334) on the side facing the adjusting part (3131), and the slide frame (331) is fixed with a first sliding block (3312) matched with the first guide rail (3132) on one side, and the slide frame (331) is provided with a second sliding block (3313) matched with the second guide rail (3133) on the bottom. 4.The portable LIBS acquisition device of claim 1, wherein: The rotating frame (332) is provided with a mounting groove (3321), and a plurality of sleeve clamps (336) matched with the outer circumferential surface of the collection head (321) are arranged in the mounting groove (3321), each sleeve clamp (336) is provided with a mounting screw hole (3361) on the surface facing the bottom of the mounting groove (3321), and the rotating frame (332) is provided with a mounting bolt (3324) matched with the mounting screw hole (3361) on the side away from the sleeve clamp (336).

5. The portable LIBS acquisition device of claim 4, wherein: The rotating frame (332) is provided with an adjusting top screw (3322) on both sides, the adjusting top screw (3322) penetrates the rotating frame (332) on both sides and abuts against both sides of the sleeve clamp (336), and the bottom of the rotating frame (332) is provided with an adjusting groove (3323), the adjusting groove (3323) is in a circular arc shape, and the mounting bolt (3324) penetrates the adjusting groove (3323) and is matched with the mounting screw hole (3361).

6. The portable LIBS acquisition device of claim 1, wherein: The sample carrying mechanism (2) further comprises a carrying column (22), and the carrying column (22) is provided with a first driving screw rod (221) penetrating the sample carrying plate (21).

7. The portable LIBS acquisition device of claim 6, wherein: The sample carrying mechanism (2) further comprises an adjusting base (23) at the bottom of the carrying column (22), and the adjusting base (23) comprises a first adjusting plate (231) and a second adjusting plate (232) arranged perpendicularly to each other, the first adjusting plate (231) is provided with a second driving screw rod (2311) penetrating the carrying column (22), the second driving screw rod (2311) is perpendicular to the first driving screw rod (221), and the second adjusting plate (232) is provided with a third driving screw rod (2321) penetrating the first adjusting plate (231), and the third driving screw rod (2321) is perpendicular to the plane in which the first driving screw rod (221) and the second driving screw rod (2311) are located. 8.The control method of the portable LIBS acquisition device according to claim 1, wherein: It comprises the following steps: S1. Control the laser emitting mechanism (1) to emit a laser beam, and the laser beam is irradiated to the sample carried by the sample carrying plate (21) along a preset laser channel axis, so as to excite plasma on the surface of the sample; S2. According to the position of the sample or the plasma, control the linear driving mechanism (34) in each adjusting unit (33) to drive its corresponding collection head (321) to move in a radial direction approximately pointing to the axis of the laser channel, so as to aim the focal point of the collection head (321) at the plasma; S3. According to the height or morphology of the plasma, control the angle adjusting mechanism (35) in each adjusting unit (33) to adjust the included angle between the optical axis of its corresponding collection head (321) and the plane where the sample carrier plate (21) is located, so as to aim the collection head (321) at the optimal collection area of the plasma signal light; S4. Through the multiple collection heads (321) arranged in a circumferential array around the axis of the laser channel, synchronously collect the signal light emitted by the plasma from multiple different angles and positions, so as to achieve comprehensive collection of the signal light.

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