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Investigation of laser induced breakdown spectroscopy(LIBS)for the Differentiation of Nerve and Gland Tissue-A Possible Application for a laser Surgery Feedback Control Mechanism

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Plasma Science and Technology 2016年第6期18卷 654-660页

作者： F.MEHARI M.ROHDE C.KNIPFER R.KANAWADE F.KLAMPFL W.ADLER N.OETTER F.STELZLE M.SCHMIDT Clinical Photonics Lab Erlangen Graduate School in Advanced Optical Technologies(SAOT)Friedrich-Alexander-Universitat Erlangen-NurnbergPaul-Gordan-Str.691052 ErlangenGermany Institute of Photonic Technologies Friedrich-Alexander-Universitat Erlangen-NiirnbergKonrad-Zuse-Str.3/591052 ErlangenGermany Department of Oral and Maxillofacial Surgery University Hospital ErlangenFriedrich-Alexander-Universitat Erlangen-NurnbergGliickstrasse 1191054 ErlangenGermany Chair of Biometry and Epidemiology Friedrich-Alexander-Universitat Erlangen-Niirnberg Waldstrabe 691054 ErlangenGermany

laser surgery provides clean,fast and accurate modeling of ***,the inability to determine what kind of tissue is being ablated at the bottom of the cut may lead to the iatrogenic damage of structures that were meant to be *** this context,nerve preservation is one of the key challenges in any surgical *** example is the treatment of parotid gland pathologies,where the facial nerve（***） and its main branches run through and fan out inside the glands parenchyma.A feedback system that automatically stops the ablation to prevent nerve-tissue damage could greatly increase the applicability and safety of surgical laser *** the present study,laser induced breakdown spectroscopy（LIBS） is used to differentiate between nerve and gland tissue of an ex-vivo pig animal *** LIBS results obtained in this preliminary experiment suggest that the measured spectra,containing atomic and molecular emissions,can be used to differentiate between the two tissue *** measurements and differentiation were performed in open air and under normal stray light conditions.

关键词： laser induced breakdown spectroscopy plasma chemical composition nerveparotid gland

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Heavy Metal Detection in Soils by laser induced breakdown spectroscopy Using Hemispherical Spatial Confinement

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Plasma Science and Technology 2015年第8期17卷 632-637页

作者：孟德硕赵南京马明俊王寅胡丽余洋方丽刘文清 Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences

Spatial confinement has great potential for laser induced breakdown spectroscopy （LIBS） instruments after it has been proven that it has the ability to enhance the LIBS signal strength and repeatability. In order to achieve in-situ measurement of heavy metals in farmland soils by LIBS, a hemispherical spatial confinement device is designed and used to collect plasma spectra, in which the optical fibers directly collect the breakdown spectroscopy of the soil samples. This device could effectively increase the stability of the spectrum intensity of soil. It also has other advantages, such as ease of installation, and its small and compact size. The relationship between the spectrum intensity and the laser pulse energy is studied for this device. It is found that the breakdown threshold is 160 cm-2, and when the laser fluence increases to 250 J/cm2, the spectrum intensity reaches its maximum. Four different kinds of laser pulse energy were set up and in each case the limits of detection of Cd, Cu, Ni, Pb and Zn were calculated. The results show that when the laser pulse fluence was 2.12 GW/cm2, we obtained the smallest limits of detection of these heavy metals, which are all under 10 mg/kg. This device can satisfy the needs of heavy metal in-situ detection, and in the next step it will be integrated into a portable LIBS instrument.

关键词： laser induced breakdown spectroscopy hemispherical spatial confinement,laser fiuence limit of detection

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Aqueous ruthenium detection by microwave-assisted laser-induced breakdown spectroscopy

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Plasma Science and Technology 2022年第8期24卷 32-39页

作者： Abu Farhan ABU KASIM M A WAKIL Kevin GRANT Milton HEARN Zeyad T ALWAHABI School of Chemical Engineering The University of AdelaideAdelaide SA 5005Australia

Aqueous ruthenium was detected in real-time under ambient conditions using microwaveassisted laser-induced breakdown spectroscopy(MW-LIBS).A 10 mJ laser energy and 750 W microwave power were directed at an open liquid jet sample of *** was observed that,for liquid flow,the coupling efficiency between the microwave and the laser-induced plasma was limited to 43%.The improvement in the ruthenium’s signal-to-noise ratio with MW-LIBS,with respect to LIBS,was *** on MW-LIBS,the limit of detection for aqueous ruthenium was determined to be 957±84 ppb.

关键词： microwave-assisted laser induced breakdown spectroscopy ruthenium detection laser induced breakdown spectroscopy

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Quantitative Analysis of Cr in Milk Powder by laser induced breakdown spectroscopy( LIBS)

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Agricultural Biotechnology 2015年第6期4卷 66-69页

作者： Gangmeng GONG Jun YANG School of Information and Engineering Jiangxi Agricultural University School of Software Jiangxi Agricultural University

At present, heavy metal pollution in food occurs frequently, which requires a novel method for rapid detection. laser induced breakdown spectroscopy （LIBS） is a new technique for rapid and environmental friendly detection, but it lacks high sensitivity and stability which restrict its development. In this study, Cr-polluted infant milk powder was used as experimental material to explore the feasibility of the application of LIBS technique in food safety detection. Aiming at improving the precision and accuracy of Cr detection by LIBS technique, LIBS spectra of samples were collected by a spectrometer with an intensified charge-cou- pled device （ICCD） using three gratings with different resolutions to comprehensively compare and analyze the stability, sensitivity and quantitative analysis accura- cy of LIBS detection. The results showed that average relative standard deviation （RSD） of LIBS spectral intensity was below 10%, indicating good stability. LIBS signals were collected by three gratings for quantitative analysis, and the results demonstrated that the linear correlation coefficient R2 of fitting curves was 0. 248 87, 0.903 12 and 0.992 81, respectively; the relative errors between actual and predicted concentrations were 38.23%, 8.84% and 7.43%, respectively, indicating that gratings with higher resolutions could lead to higher linear correlation coefficient and better detection accuracy. According to the results, high-resolu- tion spectrometer could significantly improve the accuracy of LIBS detection of Cr concentration in milk powder, suggesting that it is feasible to detect heavy metals in food by LIBS technique with the improvement of core device performance.

关键词： laser induced breakdown spectroscopy Milk powder Spectral resolution Cr

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Spectral Enhancement of laser-induced breakdown spectroscopy in External Magnetic Field

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Plasma Science and Technology 2015年第11期17卷 919-922页

作者：李丞高勋李奇宋超林景全 School of Science Changchun University of Science and Technology School of Chemistry & Environmental Engineering Changchun University of Science and Technology

In this paper the spectral enhancement of laser-induced breakdown spectroscopy （LIBS） for copper plasma in the presence of a magnetic field is investigated and the temporal- and spatial-resolved plasma emission spectra are analyzed. Experimental results show that the copper plasma atomic and ion spectra have been enhanced in the presence of the external magnetic field. In addition, the Cu I 521.82 nm spectral intensity evolution with delay time appears to have a double peak around the delay time of 2 μs, but that of Cu II 507.57 nm has a sharp decrease because of the electron-atom three body recombination process. The plasma temperature with magnetic confinement is lower than that of the case in the absence of magnetic fields. Finally, the spectral enhancement mechanisms of laser induced breakdown spectroscopy with magnetic confinement are analyzed.

关键词： laser induced breakdown spectroscopy spectral enhancement magnetic confinement

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Quantitative analysis of metal elements in atmospheric sedimentation by laser induced breakdown spectroscopy（LIBS） coupled with machine learning

Quantitative analysis of metal elements in atmospheric sedim...

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2019中国化学会第十五届全国计算（机）化学学术会议

作者： Xin Zhang Jia Xue Ying Zhang Tianlong Zhang Hua Li Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education College of Chemistry & Materials Science Northwest University College of Chemistry and Chemical Engineering Xi'an Shiyou University

The laser induced breakdown spectroscopy（LIBS） technique coupled with random forest（RF） and least squares support vector machine（LSSVM） methods was proposed to perform quantitative analysis of atmospheric sedimentation. The LIBS spectra of 16 atmospheric sedimentation samples with different locations were collected by LIBS measurement system. For quantitative analysis, first, the best pretreatment method needs to be selected to process the LIBS spectra of the four metals（Pb, Cu, Zn and Al）. Then RF, LSSVM and PLS calibration models were constructed with the optimal pretreatment spectra as input variables. The performance of the three calibration models was compared by R2 CV and RMSECV to obtain an optimal model. Finally, the optimal model was verified by the R2 P and RMSEP. The satisfactory quantitative results of Pb is RF calibration model based on the 1 st derivative, the R2 and RMSE are 0.9500 and 0.0297. The satisfactory quantitative results of Zn is LSSVM calibration model based on the original spectral data, the R2 and RMSE are 0.9769 and 0.1068. The satisfactory quantitative results of Cu is RF calibration model based on the 1 st derivative, the R2 and RMSE are 0.9105 and 0.0201. The satisfactory quantitative results of Al is RF calibration model based on the maximum intensity normalization, the R2 and RMSE are 0.9610 and 0.3956. It has been confirmed that the LIBS technique coupled with RF and LSSVM methods is a promising approach to achieve the quantitative analysis of atmospheric sedimentation.

关键词： Atmospheric sedimentation laser induced breakdown spectroscopy Quantitative analysis Machine learning

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laser ablation assisted spark induced breakdown spectroscopy and its application

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Frontiers of physics 2020年第5期15卷 111-117页

作者： Wei-Dong Zhou Yu-Hui Guo Ran-Ran Zhang Key Laboratory of Optical Information Detection and Display Technology of Zhejiang Zhejiang Normal UniversityJinhua 321004China

Recently,laser ablation assisted spark induced breakdown spectroscopy(LA-SIBS)has been growing rapidly and continue to be extended to a broad range of materials *** by employ-ing a speifically designed high voltage and pulse discharge cireuit to generate a spark and used to enhance plasma emission produced by laser ablation,allows direct analysis of materials without prior sample *** paper reviews recent development and application of laser ablation assisted spark induced breakdown spectrosoopy for material *** a summary of fundamentals and instrumentation of the LA-SIBS analytical techmique,the development and applications of laser ablation assisted spark induced breakdown spectroscopy for the analysis of conducting materials and insulating materials is described.

关键词： laser induced breakdown spectroscopy laser ablation assisted spark induced breakdown spectroscopy discharge cireuit charactor

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Three-dimensionalization via control of laser-structuring parameters for high energy and high power lithium-ion battery under various operating con ditions

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Journal of Energy Chemistry 2022年第1期31卷 93-102,I0004页

作者： Junsu Park Hyeongi Song Inseok Jang Jaepil Lee Jeongwook Um Seong-guk Bae Jihun Kim Sungho Jeong Hyeong-Jin Kim Ground Technology Research Insutitute Agency for Defense Development.P.O.Box 35Yuseong-guDaejeon 34186Republic of Korea Graduate School of Energy Convergence Gwangju Institute of Science and Technology123 Cheomdangwagi-ro.Buk-guGwangju 61005Republic of Korea School of Mechanical Engineering Gwangju Institute of Science and Technology123 Cheomdangwagi-ro.Buk-gu.Gwangju 61005Republic of Korea

laser-structuring is an effective method to promote ion diffusion and improve the performance of lithium-ion battery(LIB)*** this work,the effects of laser structuring parameters(groove pitch and depth)on the fundamental characteristics of LIB electrode,such as interfacial area,internal resistances,material loss and electrochemical performance,are investigated,LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) cathodes were structured by a femtosecond laser by varying groove depth and pitch,which resulted in a material loss of 5%-14%and an increase of 140%-260%in the in terfacial area between electrode surface and *** is shown that the importance of groove depth and pitch on the electrochemical performance(specific capacity and areal discharge capacity)of laser-structured electrode varies with current *** pitch is more im porta nt at low current rate but groove depth is at high curre nt *** the mapping of lithium concentration within the electrodes of varying groove depth and pitch by laser-induced breakdown spectroscopy,it is verified that the groove functions as a diffusion path for lithium *** ionic,electronic,and charge transfer resistances measured with symmetric and half cells showed that these internal resistances are differently affected by laser structuring parameters and the changes in porosity,ionic diffusion and electronic *** is demonstrated that the laser structuring parameters for maximum electrode performance and minimum capacity loss should be determined in consideration of the main operating conditions of LIBs.

关键词： Lithium-ion battery laser structuring Energy density Power density laser induced breakdown spectroscopy Lithium-ion diffusion

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Temporal and spatial dynamics of optical emission from laser ablation of the first wall materials of fusion device

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Plasma Science and Technology 2018年第1期20卷 150-157页

作者：赵栋烨李聪王勇王志伟高亮胡振华吴婧罗广南丁洪斌 Key Laboratory of Materials Modification by laser Ion and Electron Beams Chinese Ministry of Education School of Physics Dalian University of Technology Institute of Plasma Physics Chinese Academy of Sciences

laser-induced breakdown spectroscopy （LIBS） has been developed to in situ diagnose the chemical compositions of the first wall in the EAST tokamak. However, the dynamics of optical emission of the key plasma-facing materials, such as tungsten, molybdenum and graphite have not been investigated in a laser produced plasma （LPP） under vacuum. In this work, the temporal and spatial dynamics of optical emission were investigated using the spectrometer with ICCD. Plasma was produced by an Nd：YAG laser （1064 nm） with pulse duration of 6 ns. The results showed that the typical lifetime of LPP is less than 1.4 #s, and the lifetime of ions is shorter than atoms at ~10-6mbar. Temporal features of optical emission showed that the optimized delay times for collecting spectra are from 100 to 400 ns which depended on the corresponding species. For spatial distribution, the maximum LIBS spectral intensity in plasma plume is obtained in the region from 1.5 to 3.0 mm above the sample surface. Moreover, the plasma expansion velocity involving the different species in a multicomponent system was measured for obtaining the proper timing （gate delay time and gate width） of the maximum emission intensity and for understanding the plasma expansion mechanism. The order of expansion velocities for various species is Vc＋〉 VH 〉 Vsi＋〉 VLi 〉 VMo 〉 Vw. These results could be attributed to the plasma sheath acceleration and mass effect. In addition, an optimum signal-to-background ratio was investigated by varying both delay time and detecting position.

关键词： laser induced breakdown spectroscopy EAST tokamak temporal and spatialdynamics

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Spatial Resolution Measurements of C,Si and Mo Using LIBS for Diagnostics of Plasma Facing Materials in a Fusion Device

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Plasma Science and Technology 2015年第8期17卷 638-643页

作者：李聪赵栋烨吴兴伟丁洪斌 Key Laboratory of Materials Modification by laser Ion and Electron BeamsChinese Ministry of EducationSchool of Physics and Optical Electronic TechnologyDalian University of Technology

Recently, a laser-induced breakdown spectroscopic （LIBS） system has been developed for in situ measurements of the chemical compositions of plasma facing materials （PFMs） in the Experimental Advanced Superconducting Tokamak （EAST）. In this study, a LIBS system, which was used in a similar optical configuration to the in situ LIBS system in EAST, has been developed to investigate the spatial distribution of PFM elements at 10-4 Pa. The aim of this study was to understand the nature of the spatial distribution of atoms or ions of different elements in the plasma plume and optimize the signal to background ratio for the in situ LIBS diagnosis in EAST. The spatial profiles of the LIBS signals of C, Si, Mo and the continuous background were measured. Moreover, the influence of laser spot size and laser energy density on the LIBS signals of C, Si, Mo and H was also investigated. The results show that the distribution of the C, Si and Mo peaks＇ intensities first increased and then decreased from the center to the edge of the plasma plume. There was a maximum value at R ≈ 1.5 mm from the center of the plasma plume. This work aims to improve the understanding of ablating plasma dynamics in very low pressure environments and give guidance to optimize the LIBS system in the EAST device.

关键词： laser induced breakdown spectroscopy plasma expansion spatial distribution EAST

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