CN114894779A - Laser-induced breakdown spectroscopy measurement system - Google Patents

Abstract

The application provides a laser-induced breakdown spectroscopy measurement system. The laser-induced breakdown spectroscopy measurement system comprises a spectroscopy measurement device, a laser-induced breakdown spectroscopy measurement device and a spectrum measurement device, wherein the spectroscopy measurement device comprises a light path unit structure, a sample platform and a spectrometer, the light path unit structure is used for emitting laser to a measured sample, and the sample platform is used for bearing the measured sample; the spectrometer is used for collecting a plasma spectrum generated on the surface of the tested sample by the laser and acquiring the components of the tested sample according to the spectrum; and the driving device is used for realizing the relative movement of the optical path unit structure and the sample carrying platform so as to enable the spectrum measuring device to emit laser to different positions on the surface of the measured sample.

Description

Laser-induced breakdown spectroscopy measurement system

technical field

The present application relates to the field of spectral measurement, in particular to a laser-induced breakdown spectroscopy measurement system capable of multi-point excitation.

Background technique

Laser-induced breakdown spectroscopy (LIBS) is an atomic spectroscopy technique used for element detection. It is mainly based on high-energy pulsed laser ablation of samples to obtain information such as the intensity and position of spectral lines in the luminescence spectrum of laser plasma. Elements and the ratio of each element have the advantages of simplicity, rapidity, no need for sample pretreatment, simultaneous measurement of multiple elements, in-situ real-time detection in complex environments, etc. Has huge application prospects.

Due to the limitation of laser energy and optical system design, the current laser-induced breakdown spectroscopy technique adopts single-point excitation. Due to the small area of the single-point excitation focus point, when the measured powder has a certain degree of particle composition dispersion, single-point excitation The measured spectrum of the sub-shot does not represent the average value of the powder composition.

Therefore, developing a new method of laser-induced breakdown spectroscopy, making full use of laser pulse energy, and realizing multi-element measurement of samples will be of great significance to the development and application of laser-induced breakdown spectroscopy.

SUMMARY OF THE INVENTION

In view of the above-mentioned difficulties in the prior art, the present application provides a laser-induced breakdown spectroscopy measurement system, which realizes multi-point excitation of a sample on the premise of ensuring laser energy.

A laser-induced breakdown spectroscopy measurement system, comprising:

Spectral measurement device, including an optical path unit structure, a sample carrier and a spectrometer, the optical path unit structure is used to emit laser light to the sample to be tested, the sample carrier is used to carry the sample to be tested; the spectrometer is used to collect the laser light The plasma spectrum generated on the surface of the sample to be tested and the composition of the sample to be tested is obtained according to the spectrum; and

A driving device is used to realize the relative movement of the optical path unit structure and the sample stage, so that the spectrum measuring device emits laser light to different positions on the surface of the sample to be measured.

In one embodiment, the driving device is fixed to the optical path unit structure to drive the optical path unit structure to move.

In one embodiment, the driving device is fixed with the sample stage to drive the sample stage to move.

In one of the embodiments, the laser-induced breakdown spectroscopy measurement system further includes a track structure, the track structure includes a first annular guide rail located at the innermost side and at least one second annular guide rail concentric with the first annular guide rail, at least One of the second annular guide rails surrounds the first annular guide rail, and the driving device is used to drive the spectral measuring device to move on the first annular guide rail and/or the second annular guide rail.

In one embodiment, the track structure further includes a linear guide rail that connects the first annular guide rail and the second annular guide rail, and the driving device can move between the first annular guide rail and the second annular guide rail through the linear guide rail. movement between rails.

In one embodiment, the first annular guide rail and the second annular guide rail are both square guide rails.

In one embodiment, the optical path unit structure includes a laser transmitter and an optical unit, the optical unit includes a mesoscopic mirror, a first focusing lens, a second focusing lens and an optical fiber, the focusing lens, the mesoscopic reflector The mirror and the first focusing lens are sequentially arranged on the laser light path emitted by the laser emitter, the sample stage is arranged at the focal position of the first focusing lens, and the laser beam emitted by the laser emitter passes through the mesoporous mirror Then, it is focused on the surface of the sample to be tested by the first focusing lens to form a plasma; the first focusing lens, the middle hole mirror, the second focusing lens, the optical fiber and the spectrometer are respectively located in the luminous light of the plasma on the way.

In one embodiment, the laser-induced breakdown spectroscopy measurement system further includes an atmosphere protection cover, and the atmosphere protection cover seals the optical unit and the sample stage.

In one embodiment, the atmosphere protection cover connects the first focusing lens and the sample stage to seal the space between the first focusing lens and the sample stage.

In one embodiment, the atmosphere protective cover is made of flexible material.

Compared with the related art, in the present application, a driving device is provided in the laser-induced breakdown spectroscopy measurement system, and the relative movement between the optical path unit structure and the sample stage is realized by the driving device, so that the spectroscopy measurement device moves toward the measured object. The laser is emitted from different positions on the surface of the sample to realize the impact of different positions of the sample, and then the spectral analysis of different positions on the surface of the tested sample is realized to obtain the composition of the powder at multiple positions, and the composition of the multiple positions is used to obtain the average value. Finally, the accuracy of multi-element measurement of powder samples is achieved.

Description of drawings

1 is a schematic structural diagram of a laser-induced breakdown spectroscopy measurement system provided by the application;

FIG. 2 is a schematic diagram of a track structure included in the laser-induced breakdown spectroscopy measurement system provided in FIG. 1 .

In the figure, 100, laser-induced breakdown spectroscopy measurement system; 1, spectroscopy measurement device; 2, drive device; 3, track structure; 10, optical path unit structure; 12, sample stage; 14, spectrometer; 30, first ring guide rail; 32, second annular guide rail; 34, linear guide rail; 110, laser transmitter; 120, optical unit; 122, middle hole mirror; 124, first focusing lens; 126, second focusing lens; 128, optical fiber 4. Atmosphere protective cover.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, but not to limit the present application. In this application, unless otherwise stated, the directional words used such as "upper" and "lower" generally refer to the upper and lower sides of the device in actual use or working state, specifically the drawing direction in the accompanying drawings ; while "inside" and "outside" refer to the outline of the device.

Please refer to Fig. 1-2, Fig. 1-2 is a laser-induced breakdown spectroscopy measurement system 100 provided by the present application. The laser-induced breakdown spectroscopy measurement system 100 includes a spectroscopy measurement device 1 , a driving device 2 and a track structure 3 .

The spectral measurement device 1 includes an optical path unit structure 10, a sample carrier 12 and a spectrometer 14, the optical path unit structure 10 is used for emitting laser light to the sample to be measured, and the sample carrier 12 is used to carry the sample to be tested; the spectrometer 14 It is used to collect the plasma spectrum generated by the laser on the surface of the sample to be tested, and to obtain the composition of the sample to be tested according to the spectrum.

The driving device 2 is used to realize the relative movement of the optical path unit structure 10 and the sample stage 12 so that the spectral measurement device 1 emits laser light to different positions on the surface of the sample to be measured.

In this embodiment, the driving device 2 is fixed to the optical path unit structure 10 to drive the optical path unit structure 10 to move.

In this embodiment, the track structure 3 includes a first annular guide rail 30 located at the innermost side and at least one second annular guide rail 32 concentric with the first annular guide rail 30 , and at least one of the second annular guide rails 32 surrounds the The first annular guide rail 30 , the driving device 2 is used to drive the optical path unit structure 10 included in the spectrum measurement device 1 to move on the first annular guide rail 30 and/or the second annular guide rail 32 .

In the present embodiment, the track structure 3 further includes a linear guide rail 34 connecting the first annular guide rail 30 and the second annular guide rail 32 , and the driving device 2 can pass the linear guide rail 34 in the first annular guide rail 34 . There is movement between the guide rail 30 and the second annular guide rail 32 .

In this embodiment, the first annular guide rail 30 and the second annular guide rail 32 are both square guide rails. The driving device 2 drives the optical path unit structure 10 to move on the first annular guide 30 or the second annular guide 32, which is determined by the size of the sample to be tested. When the size of the sample to be tested is small, the first annular guide 30 is selected. When the size of the sample to be tested is larger, choose to move on the second annular guide rail 32 . The sizes of the second annular guide rails 32 may be multiple, and are arranged in a direction from close to the first annular guide rail 30 to away from the first annular guide rail 30 in sequence.

In this embodiment, the optical circuit unit structure 10 includes a laser transmitter 110 and an optical unit 120 . The optical unit 120 includes a hole mirror 122, a first focusing lens 124, a second focusing lens 126 and an optical fiber 128. The laser transmitter 110, the hole mirror 122 and the first focusing lens 124 are sequentially arranged at the laser emitter. On the optical path of the laser light emitted by the laser transmitter 110, the sample stage 12 is set at the focal position of the first focusing lens 124. The laser beam emitted by the laser transmitter 110 passes through the mesoporous mirror 122 and is captured by the first focusing lens. 124 is focused on the surface of the sample to be tested, and a plasma is formed on the surface of the sample to be tested; the first focusing lens 124, the middle hole mirror 122, the second focusing lens 126, the optical fiber 128 and the spectrometer 14 are respectively located in the luminescence of the plasma light road. In this embodiment, since the laser light emitted by the laser transmitter 110 directly passes through the light-transmitting hole 125 of the meso-hole mirror 122, there is no energy loss.

When the laser-induced breakdown spectroscopy measurement system provided in the present application is in use, the mesoporous mirror 122 has a light-transmitting hole 125 in the center for the laser to pass through, so that the laser light emitted by the laser transmitter 110 forms a first optical path. Specifically, the light beam emitted by the laser transmitter 110 passes through the light-transmitting hole 125 of the mesoporous mirror 122 to the first focusing lens 124 on the first optical path, and focuses the light on the surface of the tested sample on the first optical path, The sample to be tested may be a solid substance or a liquid substance, and the surface of the sample to be tested is excited by the energy of the laser to form a plasma state.

The luminescence of the plasma substance passes through the first focusing lens 124, and is condensed into parallel light, which changes its direction through the mesoporous reflector 122 to form a second optical path, which is parallel injected into the second focusing lens 126 on the second optical path, and focused on the second optical path. At the end of the optical fiber 128 on the optical path, the light is conducted to the spectrometer 14 through the optical fiber 128, and the spectrometer 14 measures the emission spectrum, thereby realizing the composition analysis of the solid substance.

In the related art, the laser emitted by the laser transmitter 110 generally realizes the multiplex transmission of light through a semi-transparent and semi-reflective film. When the laser beam is reflected by the mirror formed by the coating, the film is easy to be damaged because the film has to withstand the high-energy density laser beam. Therefore, the laser beam needs to be expanded before the reflection to reduce the energy density, so the laser energy loss is large, and the energy required by the laser-induced breakdown spectrum is often not reached.

In the related art, there is also a method of splitting the beam emitted by the laser transmitter 110 through a diffraction grating to form a plurality of parallel beams, and finally achieving multi-clicking of the sample at the same time. However, in this scheme, the diffraction grating forms a split beam, The light beam finally passes through the first focusing lens 124 and then reaches the sample to be tested. Since the incident beam is a sub-beam, the energy required for the laser-induced breakdown spectrum is bound to be reduced, and the impact effect is poor, which is not conducive to bombardment to generate plasma Since the laser beam emitted by the laser transmitter 110 is directly incident on the diffraction grating, the diffraction grating will be heated, and the high heat will inevitably cause the expansion of the diffraction grating, which will cause the beam splitting and thus affect the transmission of the transmitted beam. Overrate will also affect the final hitting effect.

In this embodiment, the laser-induced breakdown spectroscopy measurement system 100 further includes an atmosphere protection cover 4 , and the atmosphere protection cover 4 seals the optical unit 120 and the sample stage 12 .

In this embodiment, the atmosphere protection cover 4 connects the first focusing lens 124 and the sample stage 12 to seal the space between the first focusing lens 124 and the sample stage 12 .

In this embodiment, the atmosphere protection cover 4 is made of flexible material. Using a flexible material to form the atmosphere protection cover 4 can ensure that the optical path unit structure 10 can still achieve atmosphere protection when moving, and can reduce the weight of the optical path unit structure 10 , thereby reducing the driving force required by the driving device 2 .

In other embodiments, the driving device 2 is fixed to the sample stage 12 to drive the sample stage 12 to move relative to the optical path unit structure 10 .

To sum up, the laser-induced breakdown spectroscopy measurement system 100 provided by the present application has at least the following technical effects:

1. There is a light-transmitting hole 125 in the middle of the middle-hole mirror 122, and the laser light passes through the light-transmitting hole 125, and it is not necessary to expand the beam to reduce the energy density.

2. The plasma emission excited by the collection laser adopts the same two focal points of the same lens as the laser beam focusing, which simplifies the optical path structure and improves the reliability.

3. The optical path structure is simple and firm, with complete functions, suitable for high load, long-term work, and at the same time to withstand the impact of environmental vibration.

4. Use the driving device 2 to drive the optical path unit structure 10 to move, so as to realize multi-clicking on the same sample to be tested, so as to realize the acquisition of spectra of multiple positions of the sample to be tested, and to make the composition of the sample to be tested. Analysis is more precise.

5. When the sample to be tested is excited by the plasma to generate a spectrum, the atmosphere protection cover 4 is used to protect the sample, so that the composition measurement of the sample is not affected by the environmental medium, and the environmental medium does not affect the measurement results; since the atmosphere protection cover 4 is only connected to the sample carrier 12 With the first focusing lens 124, the atmosphere protection space covered by the atmosphere protection cover 4 is small, and the vacuuming of the atmosphere protection space can be carried out quickly, or when the atmosphere protection gas is filled, the required protection gas is less, and the atmosphere is reduced. Protection cost; the use of flexible materials to form the atmosphere protection cover 4 can reduce the weight of the optical path unit structure 10 , thereby reducing the driving force required by the driving device 2 .

The above are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore: all equivalent changes made according to the structure, shape and principle of the present application should be covered within the scope of the present application. Inside.

Claims (10)

1. A laser induced breakdown spectroscopy measurement system, comprising:

the spectrum measuring device comprises a light path unit structure, a sample platform and a spectrometer, wherein the light path unit structure is used for emitting laser to a measured sample, and the sample platform is used for bearing the measured sample; the spectrometer is used for collecting a plasma spectrum generated on the surface of the tested sample by the laser and acquiring the components of the tested sample according to the spectrum; and

and the driving device is used for realizing the relative movement of the optical path unit structure and the sample carrying platform so as to enable the spectrum measuring device to emit laser to different positions on the surface of the measured sample.

2. The system according to claim 1, wherein the driving device is fixed with the optical path unit structure to drive the optical path unit structure to move.

3. The system according to claim 2, wherein the driving device is fixed to the sample stage to drive the sample stage to move.

4. The laser-induced breakdown spectroscopy measurement system of claim 2, further comprising a track structure, wherein the track structure comprises a first ring-shaped guide rail positioned at the innermost side and at least one second ring-shaped guide rail concentric with the first ring-shaped guide rail, at least one of the second ring-shaped guide rails surrounds the first ring-shaped guide rail, and the driving device is used for driving the spectroscopy device to move on the first ring-shaped guide rail or the second ring-shaped guide rail.

5. The laser-induced breakdown spectroscopy measurement system of claim 4, wherein the rail structure further comprises a linear guide connecting the first and second endless guides, and wherein the drive device is movable between the first and second endless guides via the linear guide.

6. The laser-induced breakdown spectroscopy measurement system of claim 5, wherein the first and second annular rails are each a square rail.

7. The laser-induced breakdown spectroscopy measurement system of claim 6, wherein the optical path unit structure comprises a laser emitter and an optical unit, the optical unit comprises a mesoporous reflector, a first focusing lens, a second focusing lens and an optical fiber, the focusing lens, the mesoporous reflector and the first focusing lens are sequentially arranged on a laser path emitted by the laser emitter, the sample stage is arranged at a focal position of the first focusing lens, and a laser beam emitted by the laser emitter is focused on the surface of the sample to be measured by the first focusing lens after passing through the mesoporous reflector to form plasma on the surface of the sample to be measured; the first focusing lens, the middle hole reflector, the second focusing lens, the optical fiber and the spectrometer are respectively positioned on a light-emitting light path of the plasma.

8. The laser-induced breakdown spectroscopy measurement system according to any one of claims 1 to 7, further comprising an atmosphere protection cover that seals the optical unit and the sample stage.

9. The laser-induced breakdown spectroscopy measurement system of claim 8, wherein the atmospheric protective cover connects the first focusing lens and the sample stage to seal a space between the first focusing lens and the sample stage.

10. The laser-induced breakdown spectroscopy measurement system of claim 9, wherein the atmospheric protective cover is made of a flexible material.

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