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Xiaoyan Zeng - One of the best experts on this subject based on the ideXlab platform.
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multielemental Self Absorption reduction in laser induced breakdown spectroscopy by using microwave assisted excitation
Optics Express, 2018Co-Authors: Yun Tang, Xiaoyan Zeng, Jiaming Li, Shisong Tang, Xiangyou Li, Jun Duan, Yongfeng LuAbstract:The Self-Absorption effect seriously affects the accuracy of determination in laser-induced breakdown spectroscopy (LIBS). In this work, we proposed to reduce multielemental Self-Absorption within a wide spectral range (200-900 nm) by using microwave-assisted excitation in LIBS (MAE-LIBS). Self-Absorption reduction of sodium (Na), potassium (K), aluminum (Al), silicon (Si), and calcium (Ca) in potassium feldspar using MAE-LIBS was investigated. The mechanisms of Self-Absorption reduction in MAE-LIBS were also investigated. The results show that the serious Self-Absorption of spectral lines (Na and K) was reduced. The full widths at half maximum (FWHMs) of Na I 589.0 nm, Na I 589.6 nm, K I 766.5 nm, and K I 769.9 nm in potassium feldspar were reduced by 43%, 43%, 53%, and 47%, respectively. MAE-LIBS also has a little FWHM reduction for spectral lines with weak Self-Absorption. The results demonstrate that MAE-LIBS can simultaneously reduce multielemental Self-Absorption.
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accuracy improvement of boron by molecular emission with a genetic algorithm and partial least squares regression model in laser induced breakdown spectroscopy
Journal of Analytical Atomic Spectrometry, 2018Co-Authors: Zhihao Zhu, Lianbo Guo, Yun Tang, Yangmin Guo, Xiao Cheng, Xiaoyan ZengAbstract:Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectrometry technique for material component analysis. However, the spectral signal distortion and the low analytical accuracy remain as challenges due to the Self-Absorption effect of atomic lines in LIBS. Here, to overcome this flaw, we demonstrated a method to build calibration with molecular emission, which was measured from a mixture of H3BO3 and C6H12O6·H2O in powder form. We compared the calibration established by typical atomic emission and molecular emission of boron monoxide. The results showed that the Self-Absorption effect and R2 values were improved by using molecular spectra. Furthermore, to improve the accuracy of molecular emission content determination, a genetic algorithm and partial least squares regression (GA-PLSR) combination model was adopted. The achieved root mean square error of prediction (RMSEP) and the mean prediction error (MPE) for the GA-PLSR model were 0.8667 wt% and 10.9685%, respectively. The results demonstrated that it is a potential method to overcome the Self-Absorption effect with molecular emission and the accuracy of boron content determination of molecular emission can be improved with the GA-PLSR model.
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investigation on Self Absorption at reduced air pressure in quantitative analysis using laser induced breakdown spectroscopy
Optics Express, 2016Co-Authors: Lianbo Guo, Z Q Hao, Li Liu, Meng Shen, Xiao Yang, Xiaoyan ZengAbstract:The Self-Absorption at reduced air pressure for quantitative analysis of Mn and Cu elements in steel using laser-induced breakdown spectroscopy was investigated. The calibration curves of Mn and Cu elements at the air pressures of 100, 80, 50, 20, and 1 kPa were studied. The results show that, the nonlinearity of calibration curves which caused by Self-Absorption effects at atmosphere could be significantly improved by reducing the air pressure to 1 kPa, and the coefficients of determination (R2) of linear calibration curves of Mn and Cu lines are all higher than 0.99. The further study explored that the reason for the improvement was that the induced plasma became low density and the Self-Absorption coefficient was close to 1 when the air pressure reduced to 1 kPa.
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investigation of the Self Absorption effect using spatially resolved laser induced breakdown spectroscopy
Journal of Analytical Atomic Spectrometry, 2016Co-Authors: Lianbo Guo, Xinyan Yang, Xiaoyan ZengAbstract:The Self-Absorption effect will seriously influence the accuracy of quantitative analyses using laser-induced breakdown spectroscopy (LIBS). To reduce the Self-Absorption effect, elements Na and K (major elements) and Pb and Cu (minor elements) in soil plasmas have been studied by spatially resolved LIBS (SRLIBS). The 2-dimensional distributions of line intensities and Self-Absorption coefficients of lines in the plasmas were investigated and the influence parameters of the Self-Absorption effect were also studied. Results have shown that the Self-Absorption effect could be reduced greatly and the accuracy of quantitative LIBS could be improved obviously by selecting the collecting zones of the plasmas carefully. Meanwhile, a high laser energy and a short delay time could be useful to expand the region which is influenced slightly by the Self-Absorption effect.
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Self Absorption reduction in laser induced breakdown spectroscopy using laser stimulated Absorption
Optics Letters, 2015Co-Authors: Lianbo Guo, Xinyan Yang, Nan Zhao, Z Q Hao, Xiaoyan ZengAbstract:The Self-Absorption effect is one of the main bottlenecks for the laser-induced breakdown spectroscopy (LIBS) technique. In this Letter, LIBS assisted by laser-stimulated Absorption (LSA-LIBS) is proposed to solve this problem. The process of LSA in Self-Absorption reduction is discussed and confirmed. The serious Self-Absorption phenomena of spectral lines (K, Mn, and Al) were not observed in LSA-LIBS. The full width at half-maximum (FWHM) of K, Mn, and Al was reduced by about 58%, 25%, and 52%, respectively. The results demonstrate the capability of this approach to Self-Absorption reduction in the LIBS technique.
E Tognoni - One of the best experts on this subject based on the ideXlab platform.
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measurement of stark broadening of mn i and mn ii spectral lines in plasmas used for laser induced breakdown spectroscopy
Spectrochimica Acta Part B: Atomic Spectroscopy, 2007Co-Authors: F Bredice, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, F O Borges, H Sobral, M Villagranmuniz, H O Di Rocco, E TognoniAbstract:Abstract We present measurements of the Stark broadening of several Mn lines in the conditions of typical laser-induced plasmas. Single-and double-pulse Laser-Induced Breakdown spectroscopy (LIBS) configurations are studied on a series of Fe–Mn alloy samples with Mn concentration ranging from 6% to 30%. The effects of Self-Absorption on the measured line broadenings are discussed in detail. In particular, the experimental results evidence that Self-Absorption is much higher in laser-induced plasmas generated with double pulses, compared to the case of single pulse. After measurement of the electron density, the Stark coefficients of several neutral and ionic Mn lines are derived through the measure of the broadening in conditions of optically thin plasma. The results obtained for singly ionized Mn lines are compared with the theoretical and experimental data present in the literature. For the first time, experimental measurements of the Stark coefficient for several neutral Mn lines are also presented.
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evaluation of Self Absorption coefficients of aluminum emission lines in laser induced breakdown spectroscopy measurements
Spectrochimica Acta Part B: Atomic Spectroscopy, 2005Co-Authors: A El M Sherbini, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, L Pardini, Th El M Sherbini, H Hegazy, E TognoniAbstract:In quantitative Laser Induced Breakdown Spectroscopy (LIBS) measurements it is essential to account for the effect of Self-Absorption on the emission lines intensity. In order to quantify this effect, in this paper we propose a simple method for evaluating the ratio between the actual measured line intensity and the intensity expected in absence of Self-Absorption and, if necessary, correcting the effect of Self-Absorption on line intensity. The method, based on a homogeneous plasma model, is applicable when the plasma electron density is known and in particular to lines whose Stark broadening parameter is available.
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a procedure for correcting Self Absorption in calibration free laser induced breakdown spectroscopy
Spectrochimica Acta Part B: Atomic Spectroscopy, 2002Co-Authors: D Bulajic, M Corsi, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, E TognoniAbstract:Abstract A model of the Self-Absorption effect in laser-induced plasma has been developed, with the aim of providing a tool for its automatic correction in the Calibration-Free algorithm recently developed for standardless analysis of materials by LIBS (Laser Induced Breakdown Spectroscopy). As a test of the model, the algorithm for Self-Absorption correction is applied to three different certified steel NIST samples and to three ternary alloys (Au, Ag, Cu) of known composition. The experimental results show that the Self-Absorption corrected Calibration-Free method gives reliable results, improving the precision and the accuracy of the CF-LIBS procedure by approximately one order of magnitude.
Lianbo Guo - One of the best experts on this subject based on the ideXlab platform.
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accuracy improvement of boron by molecular emission with a genetic algorithm and partial least squares regression model in laser induced breakdown spectroscopy
Journal of Analytical Atomic Spectrometry, 2018Co-Authors: Zhihao Zhu, Lianbo Guo, Yun Tang, Yangmin Guo, Xiao Cheng, Xiaoyan ZengAbstract:Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectrometry technique for material component analysis. However, the spectral signal distortion and the low analytical accuracy remain as challenges due to the Self-Absorption effect of atomic lines in LIBS. Here, to overcome this flaw, we demonstrated a method to build calibration with molecular emission, which was measured from a mixture of H3BO3 and C6H12O6·H2O in powder form. We compared the calibration established by typical atomic emission and molecular emission of boron monoxide. The results showed that the Self-Absorption effect and R2 values were improved by using molecular spectra. Furthermore, to improve the accuracy of molecular emission content determination, a genetic algorithm and partial least squares regression (GA-PLSR) combination model was adopted. The achieved root mean square error of prediction (RMSEP) and the mean prediction error (MPE) for the GA-PLSR model were 0.8667 wt% and 10.9685%, respectively. The results demonstrated that it is a potential method to overcome the Self-Absorption effect with molecular emission and the accuracy of boron content determination of molecular emission can be improved with the GA-PLSR model.
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investigation on Self Absorption at reduced air pressure in quantitative analysis using laser induced breakdown spectroscopy
Optics Express, 2016Co-Authors: Lianbo Guo, Z Q Hao, Li Liu, Meng Shen, Xiao Yang, Xiaoyan ZengAbstract:The Self-Absorption at reduced air pressure for quantitative analysis of Mn and Cu elements in steel using laser-induced breakdown spectroscopy was investigated. The calibration curves of Mn and Cu elements at the air pressures of 100, 80, 50, 20, and 1 kPa were studied. The results show that, the nonlinearity of calibration curves which caused by Self-Absorption effects at atmosphere could be significantly improved by reducing the air pressure to 1 kPa, and the coefficients of determination (R2) of linear calibration curves of Mn and Cu lines are all higher than 0.99. The further study explored that the reason for the improvement was that the induced plasma became low density and the Self-Absorption coefficient was close to 1 when the air pressure reduced to 1 kPa.
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investigation of the Self Absorption effect using spatially resolved laser induced breakdown spectroscopy
Journal of Analytical Atomic Spectrometry, 2016Co-Authors: Lianbo Guo, Xinyan Yang, Xiaoyan ZengAbstract:The Self-Absorption effect will seriously influence the accuracy of quantitative analyses using laser-induced breakdown spectroscopy (LIBS). To reduce the Self-Absorption effect, elements Na and K (major elements) and Pb and Cu (minor elements) in soil plasmas have been studied by spatially resolved LIBS (SRLIBS). The 2-dimensional distributions of line intensities and Self-Absorption coefficients of lines in the plasmas were investigated and the influence parameters of the Self-Absorption effect were also studied. Results have shown that the Self-Absorption effect could be reduced greatly and the accuracy of quantitative LIBS could be improved obviously by selecting the collecting zones of the plasmas carefully. Meanwhile, a high laser energy and a short delay time could be useful to expand the region which is influenced slightly by the Self-Absorption effect.
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Self Absorption reduction in laser induced breakdown spectroscopy using laser stimulated Absorption
Optics Letters, 2015Co-Authors: Lianbo Guo, Xinyan Yang, Nan Zhao, Z Q Hao, Xiaoyan ZengAbstract:The Self-Absorption effect is one of the main bottlenecks for the laser-induced breakdown spectroscopy (LIBS) technique. In this Letter, LIBS assisted by laser-stimulated Absorption (LSA-LIBS) is proposed to solve this problem. The process of LSA in Self-Absorption reduction is discussed and confirmed. The serious Self-Absorption phenomena of spectral lines (K, Mn, and Al) were not observed in LSA-LIBS. The full width at half-maximum (FWHM) of K, Mn, and Al was reduced by about 58%, 25%, and 52%, respectively. The results demonstrate the capability of this approach to Self-Absorption reduction in the LIBS technique.
A Salvetti - One of the best experts on this subject based on the ideXlab platform.
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measurement of stark broadening of mn i and mn ii spectral lines in plasmas used for laser induced breakdown spectroscopy
Spectrochimica Acta Part B: Atomic Spectroscopy, 2007Co-Authors: F Bredice, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, F O Borges, H Sobral, M Villagranmuniz, H O Di Rocco, E TognoniAbstract:Abstract We present measurements of the Stark broadening of several Mn lines in the conditions of typical laser-induced plasmas. Single-and double-pulse Laser-Induced Breakdown spectroscopy (LIBS) configurations are studied on a series of Fe–Mn alloy samples with Mn concentration ranging from 6% to 30%. The effects of Self-Absorption on the measured line broadenings are discussed in detail. In particular, the experimental results evidence that Self-Absorption is much higher in laser-induced plasmas generated with double pulses, compared to the case of single pulse. After measurement of the electron density, the Stark coefficients of several neutral and ionic Mn lines are derived through the measure of the broadening in conditions of optically thin plasma. The results obtained for singly ionized Mn lines are compared with the theoretical and experimental data present in the literature. For the first time, experimental measurements of the Stark coefficient for several neutral Mn lines are also presented.
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evaluation of Self Absorption of manganese emission lines in laser induced breakdown spectroscopy measurements
Spectrochimica Acta Part B: Atomic Spectroscopy, 2006Co-Authors: F Bredice, G Cristoforetti, S Legnaioli, V Palleschi, F O Borges, H Sobral, M Villagranmuniz, H O Di Rocco, L Pardini, A SalvettiAbstract:This paper is part of a more general study aimed to the determination of the best experimental procedures for reliable quantitative measurements of Fe–Mn alloys by LIBS. In this work, attention is pointed on the Self-Absorption processes, whose effect deeply influences the LIBS measurements, reflecting in non-linear calibration curves. The effect of Self-Absorption on the line intensity can be quantified by defining a Self-Absorption coefficient, that measures the deviation of the line intensity from the linear extrapolation of the curve of growth in the optically thin regime. The authors demonstrated in a previous paper that Self-Absorption coefficients could be calculated once the electron density of the plasma is known and the Stark coefficients of the lines are available. However, when the Stark coefficients of the lines of interest are not known, a different approach is needed. In this work a new method for evaluation of Self-Absorption coefficients in LIBS measurements is presented, which does not require the knowledge of Stark coefficients. In order to understand the basic principles and setting out the theoretical tools that will be used for the analysis of the alloys, a preliminary study was done on pure Mn; LIBS spectra were acquired in different experimental conditions, at different laser energies and different delays after the laser irradiation of the sample. Moreover, collinear double pulse measurements were also performed. Analytical relations were derived and experimental procedures devised for evaluation of the Self-Absorption coefficients of several Mn lines, which are important for characterization and control of the experimental conditions in which the analysis is performed.
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evaluation of Self Absorption coefficients of aluminum emission lines in laser induced breakdown spectroscopy measurements
Spectrochimica Acta Part B: Atomic Spectroscopy, 2005Co-Authors: A El M Sherbini, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, L Pardini, Th El M Sherbini, H Hegazy, E TognoniAbstract:In quantitative Laser Induced Breakdown Spectroscopy (LIBS) measurements it is essential to account for the effect of Self-Absorption on the emission lines intensity. In order to quantify this effect, in this paper we propose a simple method for evaluating the ratio between the actual measured line intensity and the intensity expected in absence of Self-Absorption and, if necessary, correcting the effect of Self-Absorption on line intensity. The method, based on a homogeneous plasma model, is applicable when the plasma electron density is known and in particular to lines whose Stark broadening parameter is available.
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a procedure for correcting Self Absorption in calibration free laser induced breakdown spectroscopy
Spectrochimica Acta Part B: Atomic Spectroscopy, 2002Co-Authors: D Bulajic, M Corsi, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, E TognoniAbstract:Abstract A model of the Self-Absorption effect in laser-induced plasma has been developed, with the aim of providing a tool for its automatic correction in the Calibration-Free algorithm recently developed for standardless analysis of materials by LIBS (Laser Induced Breakdown Spectroscopy). As a test of the model, the algorithm for Self-Absorption correction is applied to three different certified steel NIST samples and to three ternary alloys (Au, Ag, Cu) of known composition. The experimental results show that the Self-Absorption corrected Calibration-Free method gives reliable results, improving the precision and the accuracy of the CF-LIBS procedure by approximately one order of magnitude.
G Cristoforetti - One of the best experts on this subject based on the ideXlab platform.
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measurement of stark broadening of mn i and mn ii spectral lines in plasmas used for laser induced breakdown spectroscopy
Spectrochimica Acta Part B: Atomic Spectroscopy, 2007Co-Authors: F Bredice, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, F O Borges, H Sobral, M Villagranmuniz, H O Di Rocco, E TognoniAbstract:Abstract We present measurements of the Stark broadening of several Mn lines in the conditions of typical laser-induced plasmas. Single-and double-pulse Laser-Induced Breakdown spectroscopy (LIBS) configurations are studied on a series of Fe–Mn alloy samples with Mn concentration ranging from 6% to 30%. The effects of Self-Absorption on the measured line broadenings are discussed in detail. In particular, the experimental results evidence that Self-Absorption is much higher in laser-induced plasmas generated with double pulses, compared to the case of single pulse. After measurement of the electron density, the Stark coefficients of several neutral and ionic Mn lines are derived through the measure of the broadening in conditions of optically thin plasma. The results obtained for singly ionized Mn lines are compared with the theoretical and experimental data present in the literature. For the first time, experimental measurements of the Stark coefficient for several neutral Mn lines are also presented.
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evaluation of Self Absorption of manganese emission lines in laser induced breakdown spectroscopy measurements
Spectrochimica Acta Part B: Atomic Spectroscopy, 2006Co-Authors: F Bredice, G Cristoforetti, S Legnaioli, V Palleschi, F O Borges, H Sobral, M Villagranmuniz, H O Di Rocco, L Pardini, A SalvettiAbstract:This paper is part of a more general study aimed to the determination of the best experimental procedures for reliable quantitative measurements of Fe–Mn alloys by LIBS. In this work, attention is pointed on the Self-Absorption processes, whose effect deeply influences the LIBS measurements, reflecting in non-linear calibration curves. The effect of Self-Absorption on the line intensity can be quantified by defining a Self-Absorption coefficient, that measures the deviation of the line intensity from the linear extrapolation of the curve of growth in the optically thin regime. The authors demonstrated in a previous paper that Self-Absorption coefficients could be calculated once the electron density of the plasma is known and the Stark coefficients of the lines are available. However, when the Stark coefficients of the lines of interest are not known, a different approach is needed. In this work a new method for evaluation of Self-Absorption coefficients in LIBS measurements is presented, which does not require the knowledge of Stark coefficients. In order to understand the basic principles and setting out the theoretical tools that will be used for the analysis of the alloys, a preliminary study was done on pure Mn; LIBS spectra were acquired in different experimental conditions, at different laser energies and different delays after the laser irradiation of the sample. Moreover, collinear double pulse measurements were also performed. Analytical relations were derived and experimental procedures devised for evaluation of the Self-Absorption coefficients of several Mn lines, which are important for characterization and control of the experimental conditions in which the analysis is performed.
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evaluation of Self Absorption coefficients of aluminum emission lines in laser induced breakdown spectroscopy measurements
Spectrochimica Acta Part B: Atomic Spectroscopy, 2005Co-Authors: A El M Sherbini, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, L Pardini, Th El M Sherbini, H Hegazy, E TognoniAbstract:In quantitative Laser Induced Breakdown Spectroscopy (LIBS) measurements it is essential to account for the effect of Self-Absorption on the emission lines intensity. In order to quantify this effect, in this paper we propose a simple method for evaluating the ratio between the actual measured line intensity and the intensity expected in absence of Self-Absorption and, if necessary, correcting the effect of Self-Absorption on line intensity. The method, based on a homogeneous plasma model, is applicable when the plasma electron density is known and in particular to lines whose Stark broadening parameter is available.
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a procedure for correcting Self Absorption in calibration free laser induced breakdown spectroscopy
Spectrochimica Acta Part B: Atomic Spectroscopy, 2002Co-Authors: D Bulajic, M Corsi, G Cristoforetti, S Legnaioli, V Palleschi, A Salvetti, E TognoniAbstract:Abstract A model of the Self-Absorption effect in laser-induced plasma has been developed, with the aim of providing a tool for its automatic correction in the Calibration-Free algorithm recently developed for standardless analysis of materials by LIBS (Laser Induced Breakdown Spectroscopy). As a test of the model, the algorithm for Self-Absorption correction is applied to three different certified steel NIST samples and to three ternary alloys (Au, Ag, Cu) of known composition. The experimental results show that the Self-Absorption corrected Calibration-Free method gives reliable results, improving the precision and the accuracy of the CF-LIBS procedure by approximately one order of magnitude.