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Quantitative analysis and time-resolved characterization of simulated tokamak exhaust gas by laser-induced breakdown spectroscopy

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Plasma Science and Technology 2022年第4期24卷 188-197页

作者：何亚雄许涛张勇柯川赵勇刘曙 School of Physics and Energy Fujian Normal UniversityFuzhou 350117People's Republic of China Center for Superconducting and New Energy Research and Development Southwest Jiaotong UniversityChengdu 610031People's Republic of China Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering Fuzhou 350117People's Republic of China Shandong Dong Yi Optoelectronic Instrument Co. LtdYantai 264670People's Republic of China Technical Center for Industrial Product and Raw Material Inspection and Testing Shanghai CustomsShanghai 200135People's Republic of China

Tokamak exhaust is an important part of the deuterium-tritium fuel cycle system in fusion reactions.In this work,we present a laser-induced breakdown spectroscopy(libs)-based method to monitor the gas compositions from the exhaust system in the tokamak device.Helium(He),a main impurity in the exhaust gas,was mixed with hydrogen(H_(2))in different ratios through a self-designed gas distribution system,and sealed into a measurement chamber as a standard specimen.A 532 nm wavelength laser pulse with an output power of 100 mJ was used for plasma excitation.The time-resolved libs is used to study the time evolution characteristics of the signal strength,signal-to-background ratio(SBR),signal-to-noise ratio(SNR)and relative standard deviation(RSD)of the helium and hydrogen characteristic lines.The Boltzmann twoline method was employed to estimate the plasma temperature of laser-induced plasma(LIP).The Stark-broadened profile of He I 587.56 nm was exploited to measure the electron density.From these studies,an appropriate time was determined in which the low RSD%was consistent with the high signal-to-noise ratio.The He I 587.56 nm and Hαemission lines with good signalto-noise ratio were extracted from the spectrum and used in the external standard method and internal standard method for quantitative analysis.The test results for mixed gas showed that the average relative error of prediction was less than 11.15%,demonstrating the great potential of libs in detecting impurities in plasma exhaust gas.

关键词： exhaust gas plasma diagnostics libs quantitative analysis

Recent progress of advanced anode materials of lithium-ion batteries

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Journal of Energy Chemistry 2021年第6期30卷 451-468,I0011页

作者： Hui Cheng Joseph G.Shapter Yongying Li Guo Gao Key Laboratory for Thin Film and Micro Fabrication of the Ministry of Education Department of Instrument Science and TechnologySchool of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Australian Institute of Bioengineering and Nanotechnology(AIBN) University of QueenslandSt.LuciaQueensland 4072Australia

The rapid development of electric vehicles and mobile electronic devices is the main driving force to improve advanced high-performance lithium ion batteries(libs).The capacity,rate performance and cycle stability of libs rely directly on the electrode materials.As far as the development of the advanced libs electrode is concerned,the improvement of anode materials is more urgent than the cathode materials.Industrial production of anode materials superior to commercial graphite still faces some challenges.This review sets out the most basic libs anode material design.The reaction principles and structural design of carbon materials,various transition metal oxides,silicon and germanium are summarized,and then the progress of other anode materials are analyzed.Due to the rapid development of metal organic frameworks(MOFs)in energy storage and conversion in recent years,the synthesis process and energy storage mechanism of nanostructures derived from MOF precursors are also discussed.From the perspective of novel structural design,the progress of various MOFs-derived materials for alleviating the volume expansion of anode materials is discussed.Finally,challenges for the future development of advanced anode materials for libs will be considered.

关键词： Anode materials libs Nanomaterials Metal organic frameworks

Spatio-temporal evaluation of Zr plasma parameters in a single-beam-splitting double-pulse laser-induced plasma

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Plasma Science and Technology 2021年第2期23卷 47-56页

作者： Arnab SARKAR Manjeet SINGH Fuel Chemistry Division Bhabha Atomic Research CentreMumbai 400085India Homi Bhabha National Institute AnushaktinagarMumbai 400094India

The plasma shielding effect is one of the major weaknesses of laser-induced breakdown spectroscopy(libs)as it causes non-linearity in signal strength.Although libs is typically carried out in constant laser energy,this non-linearity causes a reduction in sensitivity.In this work,we systematically examine laser-induced plasma,formed by two different excitation source modes,i.***.single pulse(SP)-excitation and single-beam-splitting double-pulse(SBS-DP)-excitation over Zr-2.5%Nb alloy.The two most important plasma parameters influencing the emission line intensity,plasma temperature(Te)and electron density(Ne)were studied and compared for both modes of laser excitation.Comparison of the results conclusively demonstrates that due to the splitting of the laser energy in the SBS-DP mode,the plasma shielding effect is significantly reduced.The reduced plasma shielding translates to an increased laser–sample coupling under SBS-DP mode.Temporal imaging of the total intensity of the laser-induced plasma in both excitation modes was also studied.The study shows how the plasma shielding effect can be reduced to improve the analytical quality of the libs methodology.

关键词： libs single-beam-splitting double pulse spatial-temporal evolution plasma temperature electron density

Rapid identification of volatile organic compounds and their isomers in the atmosphere

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Plasma Science and Technology 2022年第8期24卷 15-22页

作者：张兴龙葛一凡万恩来刘玉柱姚金平 Jiangsu Key Laboratory for Optoelectronic Detection of Atmosphere and Ocean Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology(CICAEET)Nanjing University of Information Science&TechnologyNanjing 210044People's Republic of China Jiangsu International Joint Laboratory on Meteorological Photonics and Optoelectronic Detection Nanjing University of Information Science&TechnologyNanjing 210044People's Republic of China State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800People's Republic of China

Isomers are widely present in volatile organic compounds(VOCs),and it is a tremendous challenge to rapidly distinguish the isomers of VOCs in the atmosphere.In this work,laserinduced breakdown spectroscopy(libs)technology was developed to online distinguish VOCs and their isomers in the air.First,libs was used to directly detect halogenated hydrocarbons(a typical class of VOCs)and the characteristic peaks of the related halogens were observed in the libs spectra.Then,comparing the libs spectra of various samples,it was found that for VOCs with different molecular formulas,although the spectra are completely the same in elemental composition,there are still significant differences in the relative intensity of the spectral lines and other information.Finally,in light of the shortcomings of traditional libs technology in identifying isomers,machine learning algorithms were introduced to develop the libs technique to identify the isomers of atmospheric VOCs,and the recognition results were very good.It is proved that libs combined with machine learning algorithms is promising for online traceability of VOCs in the atmospheric environment.

关键词： libs VOCs isomer machine learning

Diagnostics of First Wall Materials in a Magnetically Confined Fusion Device by Polarization-Resolved Laser-Induced Breakdown Spectroscopy

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Plasma Science and Technology 2014年第2期16卷 149-154页

作者：赵栋烨纳扎海然吴鼎丁洪斌 School of Physics and Optical Engineering Key Laboratory of Materials Modification by LaserIon and Electron BeamsChinese Ministry of EducationDalian University of Technology

Laser-induced breakdown spectroscopy （libs） is a powerful analytical tool for real- time diagnostics and detection of multiple elements deposited at the first wall of magnetically confined plasma ft^sion devices. Recently, we have tested libs in our laboratory for application to in situ real-time diagnostics in the fusion device EAST. In this study, we applied polarization- resolved libs （PR-libs） to reduce the background continuum and enhance the resolution and sensitivity of libs. We used aluminium （A1）（as a substitute for Be） and the first wall materials tungsten （W） and molybdenum （Mo） to investigate polarized continuum emission and signal-to- background ratio （SBR）. A Nd：YAG laser with first, second and third harmonics was used to produce plasma. The effects of the laser polarization plane, environmental pressure and polarizer detection angle were investigated. The spectra obtained without using a polarizer （i.e. libs） were compared with those obtained with a polarizer （PR-libs）. Distribution of emission spectral intensity was observed to follow Malus＇ law with respect to variation in the angle of detection of the polarizer. The spectra obtained by PR-libs had a higher SBR and greater stability than those obtained by libs, thereby enhancing the reliability of libs for quantitative analyses. A comparison of A1, Mo and W showed that W exhibited a higher continuum with stronger polarization than the low-Z elements.

关键词： libs PR-libs EAST first wall laser-produced plasma

Microanalysis of Multi-Element in Juncus effusus L. by libs Technique

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Plasma Science and Technology 2015年第11期17卷 904-908页

作者：刘晓娜黄建梅吴志生张乔史新元赵娜贾帅芸乔延江 College of Chinese Medicine Beijing University of Chinese Medicine Research Center of TCM-information Engineering State Administration of Traditional Chinese Medicine of the People's Republic of China

Laser-induced breakdown spectroscopy （libs） was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental microanalysis via libs. Microanalysis and multimode sampling methodologies were designed in this study. The relative standard deviation （RSD） approach was performed to optimize the multi-shot measurements. Taking advantage of the capability with no or minimal sample pre-treatment of libs, a thermodynamic chart of four elements （Mg, Ca, Ba, and Na） was created from twelve collection regions. The diagram of elemental distribution on a micro-scale was generated to explore the nature of Juncus effusus L. by libs. The results demon- strated that libs is a promising technique for rapid elemental microanalysis of heterogeneous samples.

关键词： libs Juncus effusus L. RSD approach thermodynamic chart elemental microanalysis micro-scale

Reaction kinetics modeling for lithium and cobalt recovery from spent lithium-ion batteries using acetic acid

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International Journal of Minerals,Metallurgy and Materials 2019年第1期26卷 98-107页

作者： Hendrik Setiawan Himawan Tri Bayu Murti Petrus Indra Perdana Sustainable Mineral Processing Research Group Department of Chemical Engineering Faculty of Engineering Universitas Gadjah Mada

Lithium and cobalt recovery from spent lithium-ion batteries(libs) is a major focus because of their increased production and usage. The conventional method for recycling spent libs using inorganic acids produces harmful byproducts. In this work, the leaching agent was substituted with a less expensive and more environmentally friendly alternative—acetic acid—and a mathematical model was developed to describe the kinetics of the recovery process. The variables used were the pH value, temperature, H_2O_2 concentration, and the solid-to-liquid(S/L) ratio. The mathematical model used was the shrinking core model, which was modified to accommodate an equilibrium reaction. The experimental results show that the rate of recovery of Li and Co over time was only affected by temperature. The leaching behaviors of Li and Co were found to oppose each other. An increase in temperature resulted in increased recovery of Li but decreased recovery of Co because of the product-favoring endothermic reaction of Li and the reactant-favoring exothermic reaction of Co. The product of Li has a lower entropy value than the reactant as a free-moving ion, whereas the product of Co leaching has a higher entropy value as a stiff crystal complex. Thus, temperature conditioning is a pivotal factor in the leaching of spent libs.

关键词： spent libs lithium cobalt kinetics modeling recovery equilibrium

Influence of polarization of laser beam on emission intensity of femtosecond laser-induced breakdown spectroscopy

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Chinese Physics B 2020年第6期29卷 314-320页

作者：杨岚刘淼刘奕彤李庆雪李苏宇姜远飞陈安民金明星 Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China College of Physics Jilin UniversityChangchun 130012China

Laser-induced breakdown spectroscopy(libs)is an important technique which is widely used to analyze element composition.In order to improve the sensitivity of libs,much effort has been made to enhance the spectral intensity of libs by proposing a number of methods.In addition,we find that laser polarization has great influence on the emission intensity of femtosecond libs.By comparing the emission intensity of femtosecond libs in the circular polarization with that in the linear polarization,the spectral intensity in the case of circular polarization is stronger than that in the case of linear polarization.Moreover,this phenomenon is more obvious as laser energy increases.The polarization plays an important role in libs signal intensity.Based on the observation,the enhanced mechanism of the laser polarization for the spectral intensity is discussed in this paper,which will be helpful in spectral analysis and component analysis.

关键词： libs femtosecond laser laser polarization spectral enhancement

Plasma Properties of 532 nm Laser-Ablated Aluminum E414d Target with Different Power Densities

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Plasma Science and Technology 2010年第4期12卷 385-390页

作者：罗文峰孙启兵高存孝汤洁王浩静赵卫 State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Sciences

Optical emission spectra of the plasma generated by a 532 nm Nd：YAG laser irra- diation onto a standard aluminum alloy （E414d） was recorded and analyzed. The electron tem- perature was determined using the Boltzmann plot method with three aluminum spectral lines at 236.71 nm, 257.509 nm and 308.215 nm, whereas the electron density was inferred by measuring the Stark broadening line profile of Al（II） 281.619 nm. The experimental results confirmed that the local thermodynamic equilibrium was valid and the plasma was optically thin. The spectral line intensity increased initially with the increase in laser irradiance and saturated at higher Jr- radiance levels. Results showed that the energy losses due to the reflection of laser beam from the plasma itself were insignificant. The absorption in the plasma through inverse bremsstrahlung and two-photon ionization were studied. At the same timer the variation of transition probability ratio of Al（I） 309.28 nm to Al（I） 308.21 nm with laser power density was also studied.

关键词： libs plasma emission spectroscopy