Spatial and Spectral Evolution of Laser Induced Plasma On/near the Surface of an Aqueous Solution

Spatial and Spectral Evolution of Laser Induced Plasma On/near the Surface of an Aqueous Solution PDF Author: Daniel L. Helfman
Publisher:
ISBN:
Category : Laser plasmas
Languages : en
Pages : 0

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Spatial and Spectral Evolution of Laser Induced Plasma On/near the Surface of an Aqueous Solution

Spatial and Spectral Evolution of Laser Induced Plasma On/near the Surface of an Aqueous Solution PDF Author: Daniel L. Helfman
Publisher:
ISBN:
Category : Laser plasmas
Languages : en
Pages : 0

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Experimental and Theoretical Studies of Laser-induced Plasma Spectra Formed on a Graphite Surface and in Gases

Experimental and Theoretical Studies of Laser-induced Plasma Spectra Formed on a Graphite Surface and in Gases PDF Author: Parthasarathi Shah
Publisher:
ISBN:
Category : High power lasers
Languages : en
Pages : 310

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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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Remote Compositional Analysis

Remote Compositional Analysis PDF Author: Janice L. Bishop
Publisher: Cambridge University Press
ISBN: 110718620X
Category : Language Arts & Disciplines
Languages : en
Pages : 655

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Book Description
Comprehensive overview of the spectroscopic, mineralogical, and geochemical techniques used in planetary remote sensing.

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.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 456

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Laser Interaction and Related Plasma Phenomena

Laser Interaction and Related Plasma Phenomena PDF Author: Helmut J. Schwarz
Publisher: Springer
ISBN: 1468409018
Category : Science
Languages : en
Pages : 510

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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 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.

Laser-induced Plasmas as an Analytical Source for Quantitative Analysis of Gaseous and Aerosol Systems

Laser-induced Plasmas as an Analytical Source for Quantitative Analysis of Gaseous and Aerosol Systems PDF Author: Prasoon K. Diwakar
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Critical understanding of plasma-particle interactions includes study of the plasma evolution, analyte atomization, and the particle dissociation and diffusion. In this dissertation, temporal and spatial studies have been done to understand the fundamentals of the LIBS processes including the breakdown of gases by the laser pulse, plasma inception mechanisms, plasma evolution, analyte introduction and plasma-particle interactions and their influence on LIBS signal. Spectral measurements were performed in a laser-induced plasma and the results reveal localized perturbations in the plasma properties in the vicinity of the analyte species, for first 60 [mu]s. The measurements provide direct evidence of matrix effects in the LIBS plasma at early times. Electron density measurements at very early times in the plasma reveal deviations from the Local Thermodynamic Equilibrium conditions (LTE). The data from various experiments suggests a complex interaction between the plasma and the aerosol particle, during which the finite time-scales of particle dissociation, and heat and mass transfer are fundamental processes.