Laser-induced Plasma as a Function of the Laser Parameters and the Ambient Gas

Laser-induced Plasma as a Function of the Laser Parameters and the Ambient Gas PDF Author: Xueshi Bai
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Laser-induced breakdown spectroscopy (LIBS) has been invented for more than 50 years, which analyzes the spectrum of the laser-induced plasma to determine the elemental composition of the ablated sample. Recently, LIBS technique has been well developed and applied in different domains, for example oceanic exploration, pollution monitoring in the environment. LIBS uses the ablation plasma as a light source that contains the elemental composition information of the sample. However, the laser-induced plasma exhibits a transient behavior. Although time-resolved and gated detection can greatly improve the performance of the LIBS technique especially that of calibration-free LIBS (CF-LIBS) with a better determination of plasma temperature, the temporal evolution of the plasma is correlated to its morphology and its spatial inhomogeneity. The determination of the morphology as well as the internal structure of the plasma together with their evolution during plasma expansion into the ambient gas is therefore crucial for the optimization of the use of ablation plasma as a spectroscopic emission source. Evolutions of the morphology and the internal structure of the ablation plasma are considered as the consequence of its hydrodynamic expansion into the ambient gas. Following the thesis of Qianli Ma which has studied the effect of laser wavelength on the behavior of the plasma induced in an ambient gas of argon, the present thesis has used the same diagnostic techniques (time- and space-resolved emission spectroscopy and fast spectroscopic images) together with 1064 nm ns laser pulse ablation of a target of aluminum to investigate the effects of other parameters, such as the fluence and the duration of laser pulse, the effect of different ambient gases (argon and air), on the morphology and internal structure of the plasma. Furthermore, in order to understand the effects of these parameters on the properties of the plasma, the microscopic mechanisms during post ablation and the propagation of the plasma are also studied. While the plasma cools down in air, molecules are formed, AlO for instance. So the thesis also studied the condition for the formation of the molecules in the plasma. Beyond the practical interest of this study for LIBS, it provides also insights to the kinetics of the AlO molecule formation in laserinduced plasma.

Laser-induced Plasma as a Function of the Laser Parameters and the Ambient Gas

Laser-induced Plasma as a Function of the Laser Parameters and the Ambient Gas PDF Author: Xueshi Bai
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
Laser-induced breakdown spectroscopy (LIBS) has been invented for more than 50 years, which analyzes the spectrum of the laser-induced plasma to determine the elemental composition of the ablated sample. Recently, LIBS technique has been well developed and applied in different domains, for example oceanic exploration, pollution monitoring in the environment. LIBS uses the ablation plasma as a light source that contains the elemental composition information of the sample. However, the laser-induced plasma exhibits a transient behavior. Although time-resolved and gated detection can greatly improve the performance of the LIBS technique especially that of calibration-free LIBS (CF-LIBS) with a better determination of plasma temperature, the temporal evolution of the plasma is correlated to its morphology and its spatial inhomogeneity. The determination of the morphology as well as the internal structure of the plasma together with their evolution during plasma expansion into the ambient gas is therefore crucial for the optimization of the use of ablation plasma as a spectroscopic emission source. Evolutions of the morphology and the internal structure of the ablation plasma are considered as the consequence of its hydrodynamic expansion into the ambient gas. Following the thesis of Qianli Ma which has studied the effect of laser wavelength on the behavior of the plasma induced in an ambient gas of argon, the present thesis has used the same diagnostic techniques (time- and space-resolved emission spectroscopy and fast spectroscopic images) together with 1064 nm ns laser pulse ablation of a target of aluminum to investigate the effects of other parameters, such as the fluence and the duration of laser pulse, the effect of different ambient gases (argon and air), on the morphology and internal structure of the plasma. Furthermore, in order to understand the effects of these parameters on the properties of the plasma, the microscopic mechanisms during post ablation and the propagation of the plasma are also studied. While the plasma cools down in air, molecules are formed, AlO for instance. So the thesis also studied the condition for the formation of the molecules in the plasma. Beyond the practical interest of this study for LIBS, it provides also insights to the kinetics of the AlO molecule formation in laserinduced plasma.

Temporal and Spatial Characteristics of Laser-induced Plasma on Organic Materials and Quantitative Analysis of the Contained Inorganic Elements

Temporal and Spatial Characteristics of Laser-induced Plasma on Organic Materials and Quantitative Analysis of the Contained Inorganic Elements PDF Author: Wenqi Lei
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
This PhD work was devoted to the understanding of the laser-induced plasma on organic materials and theapplication of laser-induced breakdown spectroscopy (LIBS) to quantitative analysis of these materials. Itcontributes to deepen our knowledge on the physical mechanisms involved in laser-matter interaction, plasmageneration, evolution and expansion of the plasma into the ambient gas, with emphasis on plasmas induced onorganic targets. It also intends to improve the performance of LIBS for the analysis of organic materials. Thespecificity for organic targets fits the current focus of the international community working on LIBS, toimprove the control of the plasma induced on this kind of material which has a distinguished optical prosperitywith respect to that of metals, better known for laser ablation. It addresses also the growing need to apply theLIBS technique to organic materials for different applications in the environmental, food, or biomedicaldomains. The works in this thesis were therefore presented in this thesis document according to the followingorganization.After the General Introduction which introduces the scientific and technological contexts, Chapter Irecalls the basic theoretical elements necessary to understand the phenomenon of plasma generation by laserablation, and its evolution in the background gas. Ablation of organic material is emphasized. Procedures andtechniques of diagnostics of laser-induced plasma were then presented with a focus on the transient andinhomogeneous nature of the expanding plasma. Chapter II focuses on the generation and the evolution of theplasma induced on the skin of a potato, a typical sample of agricultural product. The characteristics of plasmainduced on a soft and wet organic target, such as a fresh potato, was something unknown when the thesis workstarted. These characteristics provide the necessary basis for the quantitative analysis of the trace andultra-trace metallic elements in these samples. Following this characterization, semi-quantitative analyticalresults were extracted from LIBS spectra corresponding to potato skin. Chapter III is presented in thecontinuity of Chapter II for the application of LIBS to the quantitative analysis of organic materials. Acomparative study on the analytical results with LIBS and ICP-AES for milk powders allows an assessment ofthe performances of quantitative analysis by LIBS for organic materials, and a validation of the CF-LIBSprocedure that we have developed. Different from Chapters II and III where attention was paid to trace metalelements, Chapter IV studies the behavior of the major elements that make up the matrix of organic material,which are 4 known organic elements: H, C, O, N. During the decomposition of organic material by laserablation, these elements can be found in the form of molecular fragments, or recombined into molecularspecies. We then study in this Chapter the evolution of these species as a function of the laser ablationparameters, the laser wavelength in particular. The thesis document ends with a general conclusion andoutlooks.

Pulsed Laser Ablation of Solids

Pulsed Laser Ablation of Solids PDF Author: Mihai Stafe
Publisher: Springer Science & Business Media
ISBN: 3642409784
Category : Science
Languages : en
Pages : 241

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Book Description
The book introduces ‘the state of the art' of pulsed laser ablation and its applications. It is based on recent theoretical and experimental studies. The book reaches from the basics to advanced topics of pulsed laser ablation. Theoretical and experimental fundamental phenomena involved in pulsed laser ablation are discussed with respect to material properties, laser wavelength, fluence and intensity regime of the light absorbed linearly or non-linearly in the target material. The energy absorbed by the electrons leads to atom/molecule excitation, ionization and/or direct chemical bond breaking and is also transferred to the lattice leading to material heating and phase transitions. Experimental non-invasive optical methods for analyzing these phenomena in real time are described. Theoretical models for pulsed laser ablation and phase transitions induced by laser beams and laser-vapour/plasma interaction during the plume expansion above the target are also presented. Calculations of the ablation speed and dimensions of the ablated micro- and nano-structures are performed. The validity and required refinement of different models in different experimental conditions is provided. The pulsed laser deposition process which bases on collecting the ablated particles on a surface is analyzed in terms of efficiency and quality of the deposited films as a function of ambient conditions, target material, laser parameters and substrate characteristics. The interaction between the incident laser and the ablation plasma is analyzed with respect to its influence on the structures of the deposited films and its capacity to generate high harmonics and single attosecond pulses which are highly desirable in pump-probe experiments.

Lasers-Induced Plasmas and Applications

Lasers-Induced Plasmas and Applications PDF Author: Leon J. Radziemski
Publisher: CRC Press
ISBN: 1000147371
Category : Technology & Engineering
Languages : en
Pages : 474

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Book Description
This book discusses the physics of plasma initiation and reviews the features of dissipating, propagating plasmas. It deals with advances in diagnostics for high-energy, laser-fusion plasmas. The book reviews the basic physical processes, plasma characteristics of the "continuous optical discharge".

Laser-Induced Breakdown Spectroscopy

Laser-Induced Breakdown Spectroscopy PDF Author: Reinhard Noll
Publisher: Springer Science & Business Media
ISBN: 3642206689
Category : Science
Languages : en
Pages : 547

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Book Description
This book is a comprehensive source of the fundamentals, process parameters, instrumental components and applications of laser-induced breakdown spectroscopy (LIBS). The effect of multiple pulses on material ablation, plasma dynamics and plasma emission is presented. A heuristic plasma modeling allows to simulate complex experimental plasma spectra. These methods and findings form the basis for a variety of applications to perform quantitative multi-element analysis with LIBS. These application potentials of LIBS have really boosted in the last years ranging from bulk analysis of metallic alloys and non-conducting materials, via spatially resolved analysis and depth profiling covering measuring objects in all physical states: gaseous, liquid and solid. Dedicated chapters present LIBS investigations for these tasks with special emphasis on the methodical and instrumental concepts as well as the optimization strategies for a quantitative analysis. Requirements, concepts, design and characteristic features of LIBS instruments are described covering laboratory systems, inspections systems for in-line process control, mobile systems and remote systems. State-of-the-art industrial applications of LIBS systems are presented demonstrating the benefits of inline process control for improved process guiding and quality assurance purposes.

Laser-induced Breakdown Spectroscopy (LIBS)

Laser-induced Breakdown Spectroscopy (LIBS) PDF Author: Andrzej W. Miziolek
Publisher:
ISBN: 9780511246692
Category : Laser spectroscopy
Languages : en
Pages : 640

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Book Description
This is the first comprehensive reference explaining the fundamentals of the LIBS phenomenon, its history and its fascinating applications across eighteen chapters written by recognized leaders in the field. This book will be of significant interest to researchers in chemical and materials analysis within academia and industry.

Space and Time Characterization of Laser-induced Plasmas for Applications in Chemical Analysis and Thin Film Deposition

Space and Time Characterization of Laser-induced Plasmas for Applications in Chemical Analysis and Thin Film Deposition PDF Author: Mahmoud Dawood
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Plasmas at High Temperature and Density

Plasmas at High Temperature and Density PDF Author: Heinrich Hora
Publisher: Springer Science & Business Media
ISBN: 3540543120
Category : Science
Languages : en
Pages : 455

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Book Description
This advanced textbook on fundamental macroscopic plasma physics emphasizes the nonlinear and relativistic effects due to laser-plasma interactions. Experiments with lasers of high intensity helped to discover new quantum effects and the longitudinal components of optical radiation in vacuum, and this in turn led to an extension of basic plasma physics, which is presented here together with its impact on classical topics such asinstabilities, solitons, resonance absorpption, etc. The reader will also find sections on energy problems and nuclear fusion.

Handbook of Laser-Induced Breakdown Spectroscopy

Handbook of Laser-Induced Breakdown Spectroscopy PDF Author: David A. Cremers
Publisher: John Wiley & Sons
ISBN: 1118567366
Category : Science
Languages : en
Pages : 452

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Book Description
Starting from fundamentals and moving through a thorough discussion of equipment, methods, and techniques, the Handbook of Laser-Induced Breakdown Spectroscopy provides a unique reference source that will be of value for many years to come for this important new analysis method. The authors, with a total of over 60 years of experience in the LIBS method, use a combination of tutorial discussions ranging from basic principles up to more advanced descriptions along with extensive figures and photographs to clearly explain topics addressed in the text. In this second edition, chapters on the use of statistical analysis and advances in detection of weapons of mass destruction have been added. Tables of data related to analysis with LIBS have been updated. The Handbook of Laser-Induced Breakdown Spectroscopy, Second Edition: provides a thorough but understandable discussion of the basic principles of the method based on atomic emission spectroscopy, including recently available data leading to better characterization of the LIBS plasma; presents a discussion of the many advantages of the method along with limitations, to provide the reader a balanced overview of capabilities of the method; describes LIBS instrumentation ranging from basic set-ups to more advanced configurations; presents a comprehensive discussion of the different types of components (laser, spectrometers, detectors) that can be used for LIBS apparatuses along with suggestions for their use, as well as an up-to-date treatment of the newest advances and capabilities of LIBS instruments; presents the analytical capabilities of the method in terms of detection limits, accuracy, and precision of measurements for a variety of different sample types; discusses methods of sampling different media such as gases, liquids, and solids; presents an overview of some real-world applications of the method, with new emphasis on sampling of biologically and physically dangerous materials; provides an up-to-date list of references to LIBS literature along with the latest detection limits and a unique list of element detection limits using a uniform analysis method; provides annotated examples of LIBS spectra which can serve as references for the general reader and will be especially useful for those starting out in the field.

Laser Processing and Chemistry

Laser Processing and Chemistry PDF Author: Dieter Bäuerle
Publisher: Springer Science & Business Media
ISBN: 3662040743
Category : Science
Languages : en
Pages : 788

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Book Description
Laser Processing and Chemistry gives an overview of the fundamentals and applications of laser-matter interactions, in particular with regard to laser material processing. Special attention is given to laser-induced physical and chemical processes at gas-solid, liquid-solid, and solid-solid interfaces. Starting with the background physics, the book proceeds to examine applications of laser techniques in micro-machining, and the patterning, coating, and modification of material surfaces. This third edition has been revised and enlarged to cover new topics such as the synthesis of nanoclusters and nanocrystalline films, ultrashort-pulse laser processing, laser polishing, cleaning, and lithography. Graduate students, physicists, chemists, engineers, and manufacturers alike will find this book an invaluable reference work on laser processing.