Rectangular scanning device for laser-induced breakdown spectroscopy

Abstract

The utility model belongs to the technical field of laser-induced breakdown spectroscopy detection, and particularly relates to a rectangular scanning device for laser-induced breakdown spectroscopy. The device comprises a three-dimensional mobile platform placed in a sample chamber, and further comprises a sample detection table fixedly connected with the three-dimensional mobile platform, and the sample detection table comprises an object placing table and a servo motor which are sequentially arranged from top to bottom; the object placing table is fixedly connected with an output shaft of the servo motor, and the servo motor and the object placing table are driven by the three-dimensional moving platform to move along a path set by the rectangular scanning device. According to the utility model, a rectangular scanning mode is adopted, so that higher flexibility and controllability are realized, element composition analysis results of different point positions can be obtained, and meanwhile, the condition that the point positions are relatively close to each other and slip is avoided. In addition, the rectangular scanning mode can reduce unnecessary scanning area, improve scanning efficiency and reduce energy consumption and cost.

Description

Technical Field

[0001] This invention belongs to the field of laser-induced breakdown spectroscopy analysis technology, and particularly relates to a rectangular scanning device for laser-induced breakdown spectroscopy. Background Technology

[0002] Laser-induced breakdown spectroscopy (LASPS) uses a high-peak-power pulsed laser to irradiate the sample, focusing the beam onto a very small analytical point. Within the laser-irradiated area, material in the sample is ablated and stripped away, forming a particle cloud above the sample. As the laser energy is significantly absorbed by this cloud, plasma gradually forms. The high-energy plasma melts the particles, exciting them and causing them to emit a spectrum. The light emitted by the atoms, ions, and molecules in the plasma can be received and recorded by a detector. By analyzing the characteristic wavelengths and intensity information of the spectrum, the composition and concentration of different elements present in the sample can be obtained.

[0003] However, traditional laser-induced breakdown spectroscopy (LASDS) faces several challenges and limitations in its application. Among these, the design and optimization of the scanning method are key factors affecting its effectiveness. Traditional scanning methods often employ circular trajectories, selecting points of varying radii for sequential spotting. However, since the samples are manually ground and pressed, different radii result in varying degrees of pressure, leading to significant deviations in the analytical results. To overcome the limitations of traditional scanning methods, some studies have proposed circular scanning methods, using different radii for multiple spotting operations to obtain sample analysis results. However, this method still has problems; when the radius is small, slippage can occur between points, leading to charring and affecting the analysis of elemental composition and concentration in the sample. Utility Model Content

[0004] The purpose of this invention is to solve the scanning problems and large deviations in analysis results of traditional technologies.

[0005] To achieve the above objectives, this utility model provides a rectangular scanning device for laser-induced breakdown spectroscopy, including a three-dimensional moving platform, on which a sample detection stage is fixedly connected. The sample detection stage includes a placement stage and a servo motor arranged sequentially from top to bottom, with the bottom surface of the placement stage fixedly connected to the output shaft of the servo motor. A through hole is opened at the center of the top wall of the sample chamber, a focusing lens is located directly above the through hole, a reflecting mirror is located directly above the focusing lens, and a pulsed laser is located to the right of the reflecting mirror.

[0006] The three-dimensional moving platform includes a vertical moving guide rail, a longitudinal moving guide rail, and a transverse moving guide rail; the transverse moving guide rail is used to control the left and right movement of the device; a longitudinal moving guide rail is installed on the transverse moving guide rail, and the longitudinal moving guide rail is used to control the forward and backward movement of the device; a vertical moving guide rail is installed on the longitudinal moving guide rail, and the vertical moving guide rail controls the up and down movement of the device.

[0007] The movement path of the 3D mobile platform is S-shaped, with 15 points per row in the S-shape, a distance of 1mm between each point, and a spacing of 5mm between rows.

[0008] Furthermore, the sample chamber is a closed rectangular cavity, with the sample testing stage and three-dimensional moving platform stably placed at the center of the bottom wall of the sample chamber.

[0009] Furthermore, the angle between the reflector and the horizontal plane is 45°, and the pulsed laser generated by the pulsed laser is located in the incident light path of the reflector.

[0010] Furthermore, there is a probe on the upper right side of the sample chamber, with one end of an optical fiber connected to the probe and the other end connected to the spectrometer.

[0011] Furthermore, the spectrometer is equipped with a detector, which is connected to a computer.

[0012] Beneficial effects:

[0013] The user operates the 3D moving platform to adjust the actual position of the sample to be tested, aligning the first point of the sample on the stage with the focal point of the laser beam. At this point, the optical path system for analysis and detection is activated, and the pulsed laser is focused onto the sample surface, exciting the sample to generate a plasma spectral signal. Then, a servo motor drives the stage to the next point on the sample, sequentially penetrating each point along the set path. The spectrometer continuously collects the sample's spectral information. After detection, the sample is moved from the laser focal point to a safe position, then removed from the stage and placed in the next sample for further analysis, or the device can be shut down to stop detection. This invention employs a rectangular scanning method, offering greater flexibility and controllability, enabling the acquisition of elemental composition analysis results from different points while avoiding slippage due to close proximity of points. Furthermore, the rectangular scanning method reduces unnecessary scanning area, improves scanning efficiency, and lowers energy consumption and cost. Attached Figure Description

[0014] Figure 1 This is an overall schematic diagram of the moving mechanism for laser-induced breakdown spectroscopy of this utility model;

[0015] Figure 2 This is a schematic diagram of the specific locations of the sample to be tested according to this utility model;

[0016] Figure 3 This is a sample dot movement trajectory diagram of this utility model.

[0017] Reference numerals: 1-Platform, 2-Servo motor, 3-Stage, 4-Sample to be tested, 5-Focusing lens, 6-Reflector, 7-Pulsed laser, 8-Probe, 9-Fiber optic cable, 10-Spectrometer, 11-Detector, 12-Computer, 101-Vertical moving track, 102-Longitudinal moving track, 103-Horizontal moving track. Detailed Implementation

[0018] To further understand the invention content, features and effects of this utility model, the following embodiments are provided, and detailed descriptions are given in conjunction with the accompanying drawings.

[0019] The structure of this utility model will now be described in detail with reference to the accompanying drawings.

[0020] like Figure 1 As shown, a rectangular scanning device for laser-induced breakdown spectroscopy includes a three-dimensional moving platform 1, a servo motor 2, a stage 3, a sample to be tested 4, a focusing lens 5, a reflector 6, a pulsed laser 7, a probe 8, an optical fiber 9, a spectrometer 10, a detector 11, a computer 12, a vertical moving guide rail 101, a longitudinal moving guide rail 102, and a transverse moving guide rail 103.

[0021] The moving mechanism for rectangular scanning of the laser-induced breakdown spectrum provided in this embodiment, such as... Figure 1 As shown, the sample chamber includes a three-dimensional moving platform 1 and a sample detection stage. The sample chamber is a sealable, closed cuboid cavity, with the sample detection stage and the three-dimensional moving platform 1 stably positioned at the center of the bottom wall of the sample chamber. The optical path device for laser-induced breakdown spectroscopy analysis is located outside the sample chamber. This optical path system includes a focusing lens 5, a reflecting mirror 6, a pulsed laser 7, a probe 8, an optical fiber 9, a spectrometer 10, a detector 11, and a computer 12.

[0022] A through-hole is located at the center of the top wall of the sample chamber. A focusing lens 5 is positioned directly above the through-hole, and a reflecting mirror 6 is positioned directly above the focusing lens 5. The angle between the reflecting mirror 6 and the horizontal plane is 45°. The pulsed laser generated by the pulsed laser 7 is located in the incident light path of the reflecting mirror 6. The pulsed laser 7 is positioned in the incident light path of the reflecting mirror 6.

[0023] like Figure 2As shown, the three-dimensional moving platform 1 includes a vertical moving guide rail 101, a longitudinal moving guide rail 102, and a transverse moving guide rail 103. The transverse moving guide rail 103 is located at the bottom and is the basic track of the entire system. This guide rail controls the left and right movement of the control device (X-axis direction) while supporting and fixing the longitudinal moving guide rail 102, allowing it to move in the transverse direction. The longitudinal moving guide rail 102 is installed on the transverse moving guide rail (103), controls the forward and backward movement of the control device (Y-axis direction), and is connected to the vertical moving guide rail 101, allowing the platform to move in the longitudinal direction. The vertical moving guide rail 101 is installed on the longitudinal moving guide rail 102, controls the up and down movement of the control device (Z-axis direction), allowing the entire moving platform to adjust its height in the vertical direction, ultimately driving the scanning device or laser head to perform three-dimensional scanning. This three-axis movement method ensures that the scanning device can flexibly adjust its position in the X, Y, and Z directions, achieving a precise laser scanning path.

[0024] The sample testing stage includes a platform 3 and a servo motor 2 arranged sequentially from top to bottom. The entire sample testing stage is fixed to a three-dimensional moving platform 1 and can be driven by the three-dimensional moving platform 1. The movement path of the three-dimensional moving platform 1 is S-shaped, with 15 points per row in the S-shape, a distance of 1mm between each point, and a spacing of 5mm between rows. The bottom surface of the platform 3 is fixedly connected to the output shaft of the servo motor 2. The servo motor 2 can drive the platform 3 to move. By controlling the distance the platform 3 moves each time through the servo motor 2, different points of the sample 4 to be analyzed can be sequentially moved to the irradiation position of the laser beam. The sample 4 to be analyzed is placed on the platform 3.

[0025] Probe 8 is located above and to the right of the sample chamber. One end of optical fiber 9 is connected to probe 8, and the other end is connected to spectrometer 10. Probe 8, optical fiber 9, and spectrometer 10 are used to receive signals from the optical path system. The plasma spectral signal generated by the pulsed laser beam exciting the sample is directly coupled from probe 8 to optical fiber 9 and transmitted to spectrometer 10 for analysis.

[0026] A detector 11 is installed on the spectrometer 10, and the detector 11 is connected to the computer 12.

[0027] In this embodiment, the three-dimensional moving platform 1 employs a motion mechanism including a grinding screw, guide rails, a moving platform, a drive motor, and a driver for each direction of movement. Such three-dimensional moving platforms 1 and motion mechanisms are very common in the prior art and are well-known to those skilled in the art, and will not be elaborated upon here. The operator starts the three-dimensional moving platform 1 to adjust the position of the sample 4 to be tested. First, a movement command is issued to the driver of the vertical moving guide rail 101, driving the stage to move to the horizontal height of the laser beam focal point via the servo motor. Then, the distance between the sample to be tested and the laser beam focal point in the X and Y directions is adjusted via the longitudinal moving guide rail 102 and the transverse moving guide rail 103. After reaching the first position of the sample to be tested, the following steps are taken... Figure 3 The dots are marked using the indicated movement trajectory.

[0028] Sample 4 to be tested is a representative rock cuttings sample collected from the drilling site or related geological exploration area. First, a crusher or grinder is used to grind the rock cuttings into an appropriate particle size to ensure uniform particle size. Then, the sample is compressed into tablets using a tablet press. The compressed sample should have appropriate thickness and uniformity to obtain a stable spectral signal during spectral acquisition. Sample 4 after tablet compression is shown below. Figure 2 As shown, the inner diameter of the sample groove is 28mm, the outer diameter is 44mm, the ring thickness is 8mm, and the interval between each point is 1mm.

[0029] The working process of this utility model for elemental analysis of rock fragments includes the following steps:

[0030] Step 1, Sample Pretreatment: First, collect representative rock cuttings samples from the drilling site or relevant geological exploration area. Use a crusher or grinder to grind the rock cuttings samples into appropriate particle sizes to ensure uniform particle size. Then, use a tablet press to compress the samples into tablets. The tableted samples should have appropriate thickness and uniformity so that a stable spectral signal can be obtained during spectral acquisition.

[0031] Step 2, Sample Loading: Place the pressed sample 4 on the stage 3. Adjust the vertical distance between the sample 4 and the pulsed laser and probe 8 using the three-dimensional moving platform 1. This adjustment is achieved by moving the stage 3 using the servo motor 2, ensuring the spectrometer 10 can maximize the absorption of the laser-excited plasma and the emitted spectrum. Simultaneously, the operator activates the three-dimensional moving platform 1 to adjust the position of the sample 4. First, a movement command is sent to the driver of the vertical moving guide rail 101, moving the stage to the horizontal level of the laser beam focal point via the servo motor. Then, the distances between the sample and the laser beam focal point in the X and Y directions are adjusted using the longitudinal moving guide rail 102 and the transverse moving guide rail 103. After reaching the first position of the sample, proceed according to... Figure 3 The laser is moved along the indicated dotting trajectory to mark dots, ensuring that the laser can effectively penetrate the sample 4 under test and generate plasma.

[0032] Step 3: Set the rectangular scanning area. Based on the dimensions of the sample 4 to be tested, set the size of the rectangular scanning area to 14mm × 15mm, as shown below. Figure 3 The starting point is the first point at the upper left corner of the sample 4 to be tested, and the ending point is the last point at the lower left corner of the sample 4 to be tested. The rectangular scanning path is S-shaped. The servo motor 2 and the stage 3 are moved along this path by the three-dimensional moving platform 1. Each row has 15 points, the distance between each point is 1mm, and the spacing between rows is 5mm.

[0033] Step 4, Equipment Start-up and Sample Detection: Start the three-dimensional moving platform 1 to reach the first point, start the pulsed laser 7 and spectrometer 10, the pulsed laser begins to penetrate the first point of the sample 4 to be tested, and then the servo motor 2 drives the stage 3 to reach the next point of the sample 4 to be tested, and penetrate each point in sequence according to the set path. The spectrometer 10 continuously collects the sample spectral information.

[0034] Step 5: End of detection and sample removal. Ensure that the laser pulse emission has stopped, turn off the pulsed laser 7 and the spectrometer 10, move the sample 4 to be tested from the laser focus point to a safe position, and then remove the sample 4 from the stage 3 and place the next sample to continue the detection, or turn off the equipment to stop the detection.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall fall within the scope of the technical solution of the present utility model.

Claims

1. A rectangular scanning device for laser-induced breakdown spectroscopy, characterized in that The three-dimensional moving platform is fixedly connected with a sample detection table, the sample detection table comprises a placing table and a servo motor arranged in sequence from top to bottom, and the bottom surface of the placing table is fixedly connected with the output shaft of the servo motor; a through hole is formed in the center of the top wall of the sample chamber, the focusing lens is located directly above the through hole, the reflecting mirror is located directly above the focusing lens, and the pulse laser is located to the right of the reflecting mirror; The three-dimensional moving platform comprises a vertical moving guide rail, a longitudinal moving guide rail and a transverse moving guide rail; the transverse moving guide rail is used for controlling the left-right movement of the device; the longitudinal moving guide rail is installed on the transverse moving guide rail and is used for controlling the front-rear movement of the device; and the vertical moving guide rail is installed on the longitudinal moving guide rail and is used for controlling the up-down movement of the device. The moving path of the three-dimensional moving platform is S-shaped, each row of point positions in the S-shaped path is 15, the distance between each point position is 1 mm, and the distance between rows is 5 mm.

2. The rectangular scanning device for laser-induced breakdown spectroscopy according to claim 1, characterized in that, The sample chamber is a closed cuboid cavity, and the sample detection table and the three-dimensional moving platform are stably placed at the center of the bottom wall in the sample chamber.

3. The rectangular scanning device for laser-induced breakdown spectroscopy according to claim 1, characterized in that, The included angle between the reflecting mirror and the horizontal plane is 45°, and the pulse laser generated by the pulse laser is located on the incident light path of the reflecting mirror.

4. The rectangular scanning device for laser-induced breakdown spectroscopy according to claim 1 or 2, characterized in that A probe is arranged above the right side of the sample chamber, one end of an optical fiber is connected with the probe, and the other end of the optical fiber is connected with a spectrometer.

5. The rectangular scanning device for laser-induced breakdown spectroscopy according to claim 4, characterized in that A detector is installed on the spectrometer and connected with a computer.

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