CN116804628A - Device and method for improving LIBS quantitative detection precision and reducing self-absorption influence - Google Patents
Device and method for improving LIBS quantitative detection precision and reducing self-absorption influence Download PDFInfo
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Abstract
The invention discloses a device and a method for improving LIBS quantitative detection precision and reducing self-absorption influence, wherein a computer controls a femtosecond laser to work, pulse laser is focused on the surface of a standard sample to be detected after passing through a reflector and a focusing lens, a focusing light spot with high energy density is formed on the surface of the sample, the focusing light spot interacts with the surface of the sample to form a plasma spectrum, a single-opening triangular cavity is arranged on the surface of the sample to be detected, the laser focusing light spot is positioned in the single-opening triangular cavity, the cavity assists in generating a stable plasma spectrum, the plasma spectrum is transmitted to an echelle grating spectrometer for light splitting through a collecting optical fiber probe, an optical signal is converted into an electric signal through ICCD to realize signal imaging output, and the element content of the sample to be detected is calculated and analyzed according to spectrum information. The invention can effectively improve the LIBS quantitative detection precision, reduce the minimum detection limit and reduce the self-absorption effect of the plasma spectrum in the space cavity. The method has the characteristics of low cost and simple operation, and can be used for quantitatively detecting the element content of the sample.
Description
Technical Field
The invention relates to the technical field of laser-induced breakdown spectroscopy analysis. In particular to a device and a method for improving LIBS quantitative detection precision and reducing self-absorption influence.
Background
Laser-induced breakdown spectroscopy (Laser-Induced Breakdown Spectroscopy, LIBS) is an emission spectroscopy technique used to analyze elemental constituents of a sample. Compared with the traditional chemical analysis method, the technology has the characteristics of simple system structure, small destructiveness, capability of realizing rapid in-situ analysis, multi-element multi-form simultaneous on-line monitoring and the like, and is widely applied to various fields such as on-line analysis of steel components, coal quality analysis, universe exploration, monitoring of experimental environment and wastes, cultural heritage identification, industrial process control, geochemical analysis and the like. However, in practical application, due to the complexity of plasma spectrum on the surface of the sample, experimental environment, instrument noise and other factors, the accuracy of the LIBS quantitative detection result is affected.
In order to improve the LIBS quantitative detection precision, the current research is mainly divided into two aspects of optimizing experimental system conditions and improving a spectrum data processing method, wherein the two aspects are optimizing system instrument parameters, experimental environment conditions, improving detection distance, controlling laser pulses and the like; the latter such as a spectral preprocessing method, a spectral correction method, a quantitative detection algorithm, etc. The improvement of LIBS quantitative detection accuracy by the method is limited by the performance of experimental system instruments. On the basis of determining the instrument parameters of an experimental system, the detection precision of the LIBS can be further improved by introducing an auxiliary device, such as Raman spectrum auxiliary improvement, ultrasonic auxiliary improvement, microwave auxiliary improvement, discharge auxiliary improvement and the like. But these methods also add to the economic cost of the detection system and the complexity of the system operation. The space limitation auxiliary improvement technology is to use a small cavity to assist in limiting the diffusion direction and diffusion rate of plasma and shock wave, reduce the influence of experimental environment airflow on plasma formation, and further improve LIBS detection precision. Currently, the auxiliary cavity with limited space has a cylindrical shape, a square shape, a hemispherical shape, etc. The shape may be classified into a closed type and an open type. The research at present finds that although the cavity auxiliary technology can improve the detection performance of the LIBS technology, the self-absorption effect of the plasma spectrum is enhanced by introducing the cavity, and the self-absorption effect is mainly related to the geometry and design parameters of the cavity. Based on the above, the invention provides a device and a method for improving the LIBS quantitative detection precision and reducing the self-absorption influence, which utilize a single-opening triangular cavity to assist the LIBS to detect the element content of a sample to be detected, improve the LIBS quantitative detection precision and reduce the minimum detection limit. And the self-absorption effect of the plasma spectrum in the cavity is reduced by adjusting the opening angle of the cavity.
Disclosure of Invention
The invention aims to provide a device and a method for improving the LIBS quantitative detection precision and reducing the self-absorption influence, which have low cost and simple operation, can effectively improve the LIBS quantitative detection precision, reduce the lowest detection limit, reduce the self-absorption effect of plasma spectrum in a space cavity, and can quantitatively detect the element content of an actual sample.
In order to achieve the above purpose, the invention is realized by adopting the following technical scheme:
an apparatus for improving the accuracy of LIBS quantitative determination and reducing the effects of self-absorption comprising: the device comprises a femtosecond laser, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror, a focusing lens, a stainless steel standard sample, a single-opening triangular cavity, a collecting fiber probe, an echelle grating spectrometer, an ICCD, a level regulator, a height regulator, a bracket and a computer;
the sample is placed on a horizontal regulator, the horizontal regulator is placed on a height regulator, a single-opening triangular cavity is positioned on the surface of the sample, the single-opening triangular cavity is made of an aluminum alloy material and is in an opening shape, two walls form an acute angle theta with an adjustable angle, and the adjustment range theta=25-45 degrees;
the computer controls the femtosecond laser to work, the femtosecond laser adopts an internal triggering mode to work, a synchronous delay generator in the femtosecond laser outputs a clock signal to synchronously control the delay time between the echelle grating spectrometer and laser pulses of the femtosecond laser, the time is 2 mu s, pulse laser is focused on the surface of a sample to be detected through a first reflecting mirror, a second reflecting mirror, a third reflecting mirror and a focusing lens, a focusing light spot with high energy density is formed on the surface of the sample, the focusing light spot interacts with the surface of the sample to form a plasma spectrum, the single-opening triangular cavity is introduced and is arranged on the surface of the sample to be detected, the laser focusing light spot is arranged in the cavity, the vertical distance between the laser focusing light spot and the two inner walls of the cavity is 2mm, the cavity assists in generating a stable plasma spectrum, the plasma spectrum is transmitted to the echelle grating spectrometer through a collecting optical fiber probe for light splitting, the optical signal is converted into an electric signal through ICCD to realize signal imaging output, the element content of the sample to be detected is calculated and analyzed according to spectrum information, the LIBS quantitative detection of the element content of the sample to be detected is realized, the opening angle of the single-opening triangular cavity is adjusted, and the self-absorption effect of the plasma spectrum in the cavity is reduced.
The invention further discloses the following technology:
preferably, the laser wavelength emitted by the femtosecond laser is 1030nm, the energy is 400 mu J, the power is 10W, and the repetition frequency is 10kHz.
Preferably, the first reflecting mirror, the second reflecting mirror and the third reflecting mirror are all broadband medium reflecting mirrors, the wave band is 750-1100 nm, and the inclination angle is 45 degrees.
Preferably, the focusing lens is a K9 plano-convex lens, and the focal length is 100mm.
Preferably, the collecting optical fiber probe is a fused quartz optical fiber and is stably supported by a bracket, the included angle between the center of the collecting optical fiber probe shaft and the horizontal plane is 20 degrees, and the plasma light spot is positioned on the center line of the collecting optical fiber probe shaft.
Preferably, the pixel 1024×1024 pixels of the ICCD, the pixel 13.3 μm×13.3 μm, and the detection range is 200-700 nm.
Compared with the prior art, the invention has the following technical effects:
the invention introduces a single-opening triangular cavity into a plasma spectrum acquisition system, and is used as a simple auxiliary device for auxiliary limiting of the diffusion direction and diffusion rate of plasma and shock wave, reducing the influence of experimental environment air flow on plasma formation and obtaining stable plasma spectrum signals. Compared with other devices and methods for assisting in improving the LIBS quantitative detection precision, the LIBS quantitative detection method has the advantages of low cost, easiness in carrying, simplicity in operation and practicability.
The invention carries out parameter adjustment on the single-opening triangular cavity auxiliary device to determine the optimal opening angle. Compared with the research results of LIBS detection assisted by other space cavities, the invention determines the opening angle and direction of the cavity by adjusting the cavity parameters, and reduces the self-absorption effect of the plasma spectrum in the cavity. Compared with the LIBS system without the cavity under the same experimental condition, the quantitative detection precision of the LIBS is improved, the minimum detection limit is reduced, and the self-absorption effect of the plasma spectrum in the cavity is also reduced.
According to the invention, the single-opening triangular cavity is used for assisting in limiting the diffusion direction and diffusion rate of plasma and shock wave, so that the influence of experimental environment air flow on plasma formation is reduced. Compared with the method for improving the LIBS quantitative detection precision through a data processing algorithm, the method provided by the invention improves the stability of plasma emission light formation from a plasma formation physical mechanism and significance, and acquires a stable plasma spectrum, thereby improving the LIBS quantitative detection precision and reducing the minimum detection limit.
Drawings
FIG. 1 is a schematic view of the apparatus of the present invention.
FIG. 2 is a flow chart of a method according to an embodiment of the invention.
FIG. 3 is a graph of line intensity as a function of opening angle θ, with data normalized by the maximum.
Fig. 4 is a graph of spectral line self-absorption calibration. (a) is a cavity-free and (b) is a cavity-containing.
FIG. 5 is a graph of calibration for quantitative detection of Fe and Cr elements based on an internal standard method; the circular marks represent data without cavities, and the triangular marks represent data with cavities; (a) is Fe element and (b) is Cr element.
Detailed Description
In order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the present invention easy to understand, the present invention is further explained below with reference to the specific drawings.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in more detail with reference to the accompanying drawings.
In this embodiment, a device for improving the quantitative detection accuracy of LIBS and reducing the self-absorption influence is provided, and fig. 1 is a schematic diagram of a device of the present invention, including: the device comprises a femtosecond laser 1, a first reflecting mirror 2, a second reflecting mirror 3, a third reflecting mirror 4, a focusing lens 5, a sample 6, a single-opening triangular cavity 7, a collecting fiber probe 8, an echelle grating spectrometer 9, an enhanced charge coupled device (ICCD) 10, a level regulator 11, a height regulator 12, a bracket 13 and a computer 14;
the sample to be measured is placed on a horizontal regulator, the horizontal regulator is placed on a height regulator, a single-opening triangular cavity is positioned on the surface of the sample, the single-opening triangular cavity is made of an aluminum alloy material into an opening shape, two walls form an acute angle theta with an adjustable angle, and the adjustment range theta=25-45 degrees;
the femtosecond laser is used for emitting pulse laser with the laser energy of 400 mu J, the wavelength of 1030nm, the power of 10W and the repetition rate of 10 kHz; the first reflecting mirror, the second reflecting mirror and the third reflecting mirror are all 45 degrees in inclination angle and are all used for reflecting and transmitting laser beams; the focusing lens is a K9 plano-convex lens and is used for converging laser beams to form a focusing light spot with high energy density; the single-opening triangular cavity is used for assisting in limiting the diffusion direction and diffusion rate of plasma, reducing the influence of experimental environment air flow on plasma formation and generating a stable plasma spectrum; the collecting fiber optic probe is used for collecting the generated plasma spectrum; the echelle grating spectrometer is used for receiving and separating monochromatic light with different frequencies in the arranged light beams; the ICCD is used for receiving the optical signal processed by the echelle grating spectrometer, converting the optical signal into an enhanced electric signal and transmitting the enhanced electric signal to the computer to realize optical signal imaging; the level regulator is used for moving a sample to be detected to collect plasma spectrums at different points; the height adjuster is used for adjusting the height of the sample accurately so that the laser beam is focused on the surface of the sample to be detected accurately; the support is used for supporting the collecting optical fiber probe, so that the included angle between the axial center of the collecting optical fiber probe and the horizontal plane is 20 degrees, and the plasma light spot is positioned on the axial center line of the collecting optical fiber probe.
Fig. 2 is a flowchart of a method according to an embodiment of the present invention, in which a LIBS technology is used to detect the element content of a sample to be measured, first, a computer is used to control a femtosecond laser to work, the femtosecond laser works in an internal trigger mode, and an internal synchronous delay generator outputs a clock signal to synchronously control the delay time between an echelle grating spectrometer and a laser pulse, where the delay time is 2 μs. The femtosecond laser emits pulse laser with the energy of 400 mu J, the laser wavelength of 1030nm, the power of 10w and the repetition frequency of 10kHz, the pulse laser is focused on the surface of a sample to be detected through the first reflector, the second reflector, the third reflector and the focusing lens, a focusing light spot with high energy density is formed on the surface of the sample to be detected, and the focusing light spot interacts with the surface of the sample to form a plasma spectrum; and secondly, introducing a single-opening triangular cavity, placing the single-opening triangular cavity on the surface of a sample to be detected, placing a laser focusing light spot in the cavity, wherein the vertical distance between the laser focusing light spot and two inner walls of the cavity is 2mm, adjusting the opening angle of the single-opening triangular cavity, and reducing the self-absorption effect of plasma spectrum in the cavity. The diffusion direction and the diffusion rate of the plasmas and the shock waves are limited by using the cavity in an auxiliary way, the influence of the experimental environment air flow on the plasmas is reduced, and a stable plasma spectrum is generated; and finally, transmitting the plasma spectrum to an echelle grating spectrometer for light splitting through a collection optical fiber probe, converting an optical signal into an electric signal through ICCD to realize signal imaging output, calculating and analyzing the element content of a sample to be detected according to spectrum information, and realizing LIBS quantitative detection of the element content of the sample to be detected.
In this embodiment, the selected samples to be tested are six certified YSBS series stainless steels, but the method of the present invention is not limited to testing six certified YSBS series stainless steels in this embodiment, and any other samples to be tested that can be used for LIBS testing are within the scope of the present invention.
The technical effects of the invention are verified by specific experimental results:
the embodiment of the invention provides a device for improving the LIBS quantitative detection precision and reducing the self-absorption influence, which utilizes a single-opening triangular cavity as an auxiliary device to auxiliary limit the diffusion direction and diffusion rate of plasmas and shock waves, reduces the influence of experimental environment airflow on the plasmas, generates a stable plasma spectrum, improves the LIBS quantitative detection precision and reduces the minimum detection limit. However, according to related studies, it is found that the existing spatial cavity assisted LIBS analysis can improve the detection performance of LIBS, but can enhance the self-absorption effect of plasma spectrum. Therefore, in the implementation of the invention, the self-absorption effect of the plasma spectrum in the cavity is reduced by adjusting the opening angle of the single-opening triangular cavity while the LIBS quantitative detection precision is improved under the assistance of the single-opening triangular cavity. Thus, the present embodiment is divided into two parts: example 1 study of the adjustment of single opening triangular cavity opening angle parameters the optimum opening angle was determined by comparing the spectral intensities and stabilities of the different opening angles as the opening angle was changed. Finally, the spectral self-absorption coefficients of the non-cavity and the cavity (the optimal opening angle) are compared, and the influence of the parameter of the opening angle on the spectral self-absorption of the plasma in the cavity is analyzed and adjusted; in the embodiment 2, the diffusion direction and the diffusion rate of plasma and shock wave are limited by using the single-opening triangular cavity with the optimal opening angle in an auxiliary manner, the influence of experimental environment air flow on the plasma is reduced, stable plasma emission light is generated, quantitative analysis is performed by adopting an internal standard method according to spectrum data, the quantitative detection precision of the element with or without the cavity and the auxiliary cavity is compared, and the improvement effect of the single-opening triangular cavity on the LIBS quantitative detection precision and the influence on the minimum detection limit are determined.
The samples to be tested used in all the examples of the present invention were six certified YSBS series standard stainless steels, the contents of the elements Fe to be tested, cr and internal standard element Mn are shown in table 1, and the numbers 1 to 6 represent six samples.
TABLE 1 elemental content of Fe, cr, mn in six Standard stainless Steel samples
Example 1:
the geometry and design parameters of a single-opening triangular cavity affect the self-absorption effect of the plasma spectrum within the cavity. According to research, the spatial cavity limitation auxiliary LIBS detection can enhance the self-absorption effect of the plasma spectrum, and is mainly related to the cavity shape and design parameters. Therefore, the opening angle theta of the single-opening triangular cavity is adjusted, the change of the characteristic spectral line intensity when the opening angle is changed is analyzed, and the opening angle when the spectrum intensity is strongest and is stable is determined. The strongest angular fluctuation range of the spectral line intensity is experimentally studied to be 25-45 degrees, and the angular fluctuation range is gradually changed from 25 degrees at intervals of 5 degrees until the angular fluctuation range is increased to 45 degrees. According to two elements Fe and Cr with the largest element content in six stainless steel standard samples, a spectral line Fe I500.5703 nm and Cr I513.8852 nm with relatively stable intensity and good line profile are respectively selected, a curve of the intensity changing along with the angle theta is observed, as shown in figure 3, the characteristic spectral line intensity is gradually enhanced between theta=25-40 degrees, the maximum value is reached when theta is 40 degrees, and the fluctuation of the spectral line intensity between theta=35-45 degrees is very small, so that 40 degrees is selected as the optimal opening angle of the cavity.
After the optimal opening angle of the cavity is determined to be 40 degrees, the spectrum self-absorption coefficients of the cavity without the cavity and the spectrum self-absorption coefficients of the cavity with the cavity are compared, and the influence of the opening angle of 40 degrees on the spectrum self-absorption of the plasma in the single-opening triangular cavity is analyzed. The self-absorption effect of the spectrum is evaluated using the self-absorption coefficient. The self-absorption coefficient calculation formula is shown in formula (1):
wherein SA is self-absorption coefficient, and the value range is 0The smaller the SA value is, the stronger the self-absorption is; i is the measured spectral intensity, I 0 For the spectral intensity (theoretical intensity without self absorption) of an ideal optical thin plasma, lambda is spectral line wavelength, L is absorption path length, K (lambda) L is optical thickness, C is element content, alpha is proportionality coefficient, and can be obtained by a calibration curve fitted by an exponential function, wherein the formula is shown as formula (2):
I λ (C)＝A(1-e -αC )+I b (2)
wherein I lambda (C) is the spectral line intensity of lambda when the element content is C and the element spectral line wavelength is lambda; a and I b Is a constant; the larger α is, the smaller SA is, and the stronger self-absorption is, as is known from the formula (1).
The six standard stainless steel samples are the most Fe element, so the Fe element is selected to evaluate the self absorption of the spectrum most appropriately, the lower energy level and the upper energy level of Fe I388.6142 nm are 0.0516eV and 3.241eV respectively, the probability of resonance is high, and the method is suitable for evaluating the self absorption effect of the spectrum. Experiment evaluation of self-absorption effect of Fe I388.6142 nm analysis line of standard stainless steel sample without cavity and with cavity assistance, self-absorption correction fitting curve of the analysis line is shown in figure 4, and fitting coefficient R of the cavity is shown in figure 4 2 Is larger than the non-cavity. When the Fe content is more than 71%, the spectral intensity of the No. 5 and No. 6 samples without cavity assistance is slightly reduced compared with that of the No. 4 sample due to self-absorption, but when the Fe content is assisted by the cavity, the reduction trend is reduced. The proportionality coefficients alpha of the cavity and the cavity are 0.859 and 0.918 respectively, and the self-absorption effect of the cavity is slightly reduced compared with that of the cavity. Therefore, the single-opening triangular cavity adopted by the embodiment of the invention reduces the self-absorption effect of the plasma spectrum in the cavity by adjusting the opening angle parameter. The self-absorption effect is slightly smaller after the cavity is added than that when the cavity is not arranged, and the defect that the spectrum self-absorption effect is increased when the LIBS is assisted by the existing space cavity is overcome.
Example 2:
according to the embodiment, the single-opening triangular cavity (the opening angle is 40 ℃) is utilized to assist in limiting the diffusion direction and the diffusion rate of plasma and shock waves, the influence of experimental environment airflow on plasma formation is reduced, compared with the case that the cavity is not used for assisting, the cavity is introduced to obtain more stable spectrum signals, LIBS quantitative detection precision is improved, and the minimum detection limit is reduced. In the embodiment, the influence of the single-opening triangular cavity on the LIBS quantitative detection and the minimum detection limit is analyzed by adopting an internal standard method, and the quantitative detection precision and the minimum detection limit of the LIBS without the cavity and with the cavity are compared, wherein the scaling curve determining coefficient R is shown as the formula (3):
wherein I is 1 And I 2 Spectral intensities of analysis element and internal standard element, C 1 And C 2 Respectively their elemental content. C (C) 2 At lower self-absorption coefficient b 1 ＝b 2 ＝b≈1。a 1 、a 2 And a 0 Is a constant.
In the embodiment, a single-opening triangular cavity is introduced to assist in collecting LIBS spectra, and the contents of two elements Fe and Cr are analyzed by combining an internal calibration quantity detection method. As the standard deviation of Mn content in six stainless steel standard samples is 0.1%, the content fluctuation is small, and the Mn content is relatively low compared with the Fe and Cr content, mn is selected as an internal standard element. According to the requirements of the internal standard method: the analysis line and the internal marking line have independent spectral peaks, are not interfered by other spectral peaks, and the energy levels of the internal marking line and the analysis line are close. Analysis line Fe I384.0442 nm and internal marking Mn I380.6590 nm, analysis line Cr I370.9084 nm and internal marking Mn I370.5382 nm are selected, quantitative detection calibration curves are respectively established, and the results are shown in figure 5. The calibration curve evaluation parameters are fitting coefficients (R 2 ) The Root Mean Square Error (RMSE) and the limit of detection (LoD) are calculated as shown in table 2. R of quantitative detection calibration curve for Fe element content without cavity and cavity 2 0.958 and 0.990 respectively, root mean square errors of 0.0329 and 0.0224 respectively, and detection limits of 3.7042mg/kg and 1.6827mg/kg respectively; r of calibration curve for quantitative detection of Cr element content 2 0.941 and 0.991 respectively, root mean square errors of 0.0061 and 0.0055 respectively, and detection limits of 14.3571mg/kg and 6.2944mg/kg respectively. From the results of the two elements, it can be seen that a single-opening triangular cavity with an opening angle of 40 DEG is utilizedThe LIBS detection is assisted, so that the LIBS quantitative detection precision can be improved, and the minimum detection limit can be reduced.
Table 2 evaluation parameters of a quantitative detection calibration curve for the presence or absence of cavities.
According to the experimental results of the embodiment, the single-opening triangular cavity is introduced into the spectrum acquisition system to assist the LIBS to detect the element content of the sample, the self-absorption effect of the plasma spectrum in the cavity is reduced by adjusting the opening angle parameter of the single-opening triangular cavity, and the defect that the self-absorption effect of the spectrum is enhanced when the LIBS is assisted by the existing space cavity is overcome. Meanwhile, the quantitative detection result shows that the introduction of the single-opening triangular cavity can improve the LIBS quantitative detection precision and reduce the minimum detection limit.
The foregoing has outlined and described the basic principles, main features and features of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made therein without departing from the spirit and scope of the invention, which is defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (6)
1. A device for improving the accuracy of LIBS quantitative determination and reducing the effects of self-absorption comprising: the device comprises a femtosecond laser, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror, a focusing lens, a stainless steel standard sample, a single-opening triangular cavity, a collecting fiber probe, an echelle grating spectrometer, an ICCD, a level regulator, a height regulator, a bracket and a computer;
the sample is placed on a horizontal regulator, the horizontal regulator is placed on a height regulator, a single-opening triangular cavity is positioned on the surface of the sample to be measured, the single-opening triangular cavity is made of an aluminum alloy material and is in an opening shape, two walls form an acute angle theta with an adjustable angle, and the adjusting range theta=25-45 degrees;
the computer controls the femtosecond laser to work, the femtosecond laser works in an internal triggering mode, a synchronous delay generator in the femtosecond laser outputs a clock signal to synchronously control the delay time between the echelle grating spectrometer and laser pulses of the femtosecond laser, the delay time is 2 mu s, pulse laser is focused on the surface of a sample to be detected through a first reflecting mirror, a second reflecting mirror, a third reflecting mirror and a focusing lens, a focusing light spot with high energy density is formed on the surface of the sample, the focusing light spot interacts with the surface of the sample to form a plasma spectrum, a single-opening triangular cavity is introduced and is arranged on the surface of the sample to be detected, the laser focusing light spot is arranged in the cavity, the vertical distance between the laser focusing light spot and the two inner walls of the cavity is 2mm, the cavity assists in generating a stable plasma spectrum, the plasma spectrum is transmitted to the echelle grating spectrometer through a collecting fiber probe to split, an optical signal is converted into an electric signal through ICCD (integrated circuit device), imaging output of the optical signal is realized, and the element content of the sample to be detected is calculated and analyzed according to spectrum information.
2. The device for improving the quantitative detection accuracy of LIBS and reducing the effects of self-absorption according to claim 1 wherein: the laser wavelength emitted by the femtosecond laser is 1030nm, the energy is 400 mu J, the power is 10W, and the repetition frequency is 10kHz.
3. The device for improving the quantitative detection accuracy of LIBS and reducing the effects of self-absorption according to claim 1 wherein: the first reflecting mirror, the second reflecting mirror and the third reflecting mirror are broadband medium reflecting mirrors, the wave band ranges from 750 nm to 1100nm, and the inclination angles are 45 degrees.
4. The device for improving the quantitative detection accuracy of LIBS and reducing the effects of self-absorption according to claim 1 wherein: the focusing lens is a K9 plano-convex lens, and the focal length is 100mm.
5. The device for improving the quantitative detection accuracy of LIBS and reducing the effects of self-absorption according to claim 1 wherein: the collecting optical fiber probe is fused quartz optical fiber and is stably supported by the support, the included angle between the center of the collecting optical fiber probe shaft and the horizontal plane is 20 degrees, and the plasma light spot is positioned on the center line of the collecting optical fiber probe shaft.
6. The device for improving the quantitative detection accuracy of the LIBS and reducing the effects of self-absorption according to claim 1, wherein: the pixel 1024×1024pixel of the ICCD, the pixel 13.3 μm×13.3 μm, the detection range is 200-700 nm.
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| CN202310393141.3A CN116804628A (en) | 2023-04-13 | 2023-04-13 | Device and method for improving LIBS quantitative detection precision and reducing self-absorption influence |
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| CN202310393141.3A CN116804628A (en) | 2023-04-13 | 2023-04-13 | Device and method for improving LIBS quantitative detection precision and reducing self-absorption influence |
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