Download or read book Space and Time Characterization of Laser induced Plasmas for Applications in Chemical Analysis and Thin Film Deposition written by Mahmoud Dawood and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Laser induced Plasma and Application to Surface assisted LIBS for Powder and Liquid Samples written by Ye Tian and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-induced breakdown spectroscopy (LIBS) is an analytical method with optical emission spectroscopy that uses a laser pulse to vaporize, atomize, and excite a hot plasma as the spectroscopic emission source. Although LIBS has demonstrated its versatility and attractive features in many fields, the quantitative analysis ability of LIBS is considered as its Achilles' heel. From a fundamental point of view, this can be due to the complex nature of laserinduced plasma as the spectroscopic emission source for LIBS application. The temporal and spatial characterization of laser-induced plasma is considered as one of the key points for the LIBS technique. On the other hand, from the analytical point of view, LIBS is usually characterized by direct laser ablation. This can be however quite limiting, especially for some types of materials such as powders or liquids. Proper sample preparation or treatment allowing the deposition of a thin homogeneous film on a metallic surface could greatly improve the analytical performance of LIBS for these types of materials. Since the metallic surface is expected to contribute to increase the temperature and the density of the plasma and, consequently, to a better overall sensitivity, we call this technique surface-assisted LIBS. The present thesis work is therefore motivated by two basic aspects of LIBS analysis: the need of an improved knowledge of laser-induced plasma as a spectroscopic emission source, and new methods to improve the analytical performance of LIBS, including a higher sensibility and a reduced matrix effect. The first part of this thesis (Chapter 2) is dedicated to an extensive characterization of the plasma induced on glass samples, as a function of the laser wavelength, infrared (IR) or ultraviolet (UV), and the ambient gas, air or argon. Both the spectroscopic imaging and time- and space-resolved emission spectroscopy are used for plasma diagnostics in this work. The second part of this thesis is to develop a surface-assisted LIBS method for the elemental analysis in powders, and in wines as examples of liquids. We applied the surface-assisted LIBS for the quantitative elemental analysis in cellulose powders, alumina powders, and soils (Chapter 3). Special attentions are paid on the figures-of-merit, matrix effects, and normalization approaches in LIBS analysis. We also used the surfaceassisted LIBS for the classification of French wines according to their production regions (Chapter 4). Two classification models based on the principal component analysis (PCA) and random forest (RF) are used for the classification. Through these applications, this thesis work demonstrates the efficiency of the surface-assisted LIBS method for the analysis of powders (cellulose, alumina and soils) and of liquids (wines), with ppm or sub-ppm sensitivities and a reduced matrix effect.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Laser Produced Plasmas in Liquid Environments written by Nichola Walsh and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the interaction of an intense laser pulse with a solid metal target, a high temperature, high density plasma is formed. Pulsed laser ablation has attracted much interest over the past fifty years with experimental and theoretical work largely focussed on the study of laser produced plasmas in vacuum. The study of pulsed laser ablation has been largely motivated from a materials processing perspective, with the characterisation of thin films using pulsed laser deposition of particular interest. Another application resulting from the study of laser produced plasmas is the use of laser-induced breakdown spectroscopy (LIBS) for elemental composition and quantitative analysis of samples. LIBS is now a widely used technique employed in various fields including environmental analysis, forensics and biomedical applications. While much work has been carried out on pulsed ablation of materials in vacuum and gas ambient, comparatively little research has been done on ablation in liquid media. As a result, the fundamental understanding of laser produced plasmas in liquids remains insufficient. Using techniques such as time resolved imaging and spectroscopy, a full characterisation of the plasma formed in air was undertaken as a comparison to the subsequent investigation of the plasma formed in water ambient. Single pulse studies revealed information on the dynamic evolution of a laser plasma formed in the liquid phase where strong confinement and broadband emission were the main observations. Shadowgraphy measurements were performed to examine the dynamic behaviour of the cavitation bubble that eventually forms post plasma ignition. The results of time resolved optical emission measurements from within the cavitation bubble using a second laser pulse reveal for the first time the full dynamic evolution of the plasma formed in such an environment.
Download or read book Laser Induced Plasma Spectroscopy and Applications written by and published by . This book was released on 2002 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Ablation written by Tatiana Itina and published by BoD – Books on Demand. This book was released on 2017-12-21 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shortly after the demonstration of the first laser, the most intensely studied theoretical topics dealt with laser-matter interactions. Many experiments were undertaken to clarify the major ablation mechanisms. At the same time, numerous theoretical studies, both analytical and numerical, were proposed to describe these interactions. These studies paved the ways toward the development of numerous laser applications, ranging from laser micro- and nanomachining to material analysis, nanoparticle and nanostructure formation, thin-film deposition, etc. Recently, more and more promising novel fields of laser applications have appeared, including biomedicine, catalysis, photovoltaic cells, etc. This book intends to provide the reader with a comprehensive overview of the current state of the art in laser ablation, from its fundamental mechanisms to novel applications.
Download or read book Space Time Characterization of Laser Plasma Interactions in the Warm Dense Matter Regime written by and published by . This book was released on 2008 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser plasma interaction experiments have been performed using a fs Titanium Sapphire laser. Plasmas have been generated from planar PMMA targets using single laser pulses with 3.3 mJ pulse energy, 50 fs pulse duration at 800 nm wavelength. The electron density distributions of the plasmas in different delay times have been characterized by means of Nomarski Interferometry. Experimental data were compared with hydrodynamic simulation. First results to characterize the plasma density and temperature as a function of space and time are obtained. This work aims to generate plasmas in the warm dense matter (WDM) regime at near solid-density in an ultra-fast laser target interaction process. Plasmas under these conditions can serve as targets to develop x-ray Thomson scattering as a plasma diagnostic tool, e.g., using the VUV free-electron laser (FLASH) at DESY Hamburg.
Download or read book Investigation of Physical and Spectral Characteristics of Laser induced Plasmas written by Vincent P. Hohreiter and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: The physical and optical characteristics of laser-induced plasmas (LIP) and the precision of measurements using laser-induced breakdown spectroscopy (LIBS) for aerosol and gas phase species are explored. In a series of coherent experiments properties of the LIP and the temporal, spatial, and energetic variations of interactions with entrained particles (aerosols) are evaluated from both a standpoint of basic plasma science and applied atomic spectroscopy. First, the evolution of a LIP is characterized in terms of its temporally-resolved spectral absorptivity, spectral emissivity, and free electron density during the first 500 nanoseconds. Transmission measurements reveal near opacity of the LIP at early times (10-50 ns) and essential transparency at longer times (500 ns).
Download or read book Characteristics of Ultrafast Laser Produced Plasma and Its Application in Thin Film Deposition written by Zhiyu Zhang and published by . This book was released on 2003 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser induced Plasmas written by Ethan J. Hemsworth and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the theory and applications of laser-induced plasmas. Topics discussed include the application of laser-induced plasma expansion models for thin film deposition; cluster-containing plasma fumes for high-order harmonic generation laser radiation; pulsed laser deposition of nanocrystalline V2O5 thin films; nanosecond and femtosecond laser ablation of TeO2 crystals; resonant harmonic generation of short pulse laser in plasma and the influence of the heterogeneous nature of laser ablation on near-surface plasma formation and propagation.
Download or read book SIOEL 99 written by Teodor Necsoiu and published by SPIE-International Society for Optical Engineering. This book was released on 2000 with total page 874 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temporal and Spatial Characteristics of Laser induced Plasma on Organic Materials and Quantitative Analysis of the Contained Inorganic Elements written by Wenqi Lei and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Energy a Continuing Bibliography with Indexes written by and published by . This book was released on 1983 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Laser Induced Plasmas written by David Scott Jebens and published by . This book was released on 1990 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conference Papers Index written by and published by . This book was released on 1988 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monthly. Papers presented at recent meeting held all over the world by scientific, technical, engineering and medical groups. Sources are meeting programs and abstract publications, as well as questionnaires. Arranged under 17 subject sections, 7 of direct interest to the life scientist. Full programs of meetings listed under sections. Entry gives citation number, paper title, name, mailing address, and any ordering number assigned. Quarterly and annual indexes to subjects, authors, and programs (not available in monthly issues).
Download or read book Simultaneously Time and Space resolved Spectroscopic Characterization of Laser produced Plasmas written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The CHROMA laser facility at KMS Fusion has been used to irradiate a variety of microdot targets. These include aluminum dots and mixed bromine dots doped with K-shell (magnesium) emitters. Simultaneously time- and space-resolved K-shell and L-shell spectra have been measured and compared to dynamic model predictions. The electron density profiles are measured using holographic interferometry. Temperatures, densities, and ionization distributions are determined using K-shell and L-shell spectral techniques. Time and spatial gradients are resolved simultaneously using three diagnostics: a framing crystal x-ray spectrometer, an x-ray streaked crystal spectrometer with a spatial imaging slit, and a 4-frame holographic interferometer. Significant differences have been found between the interferometric and the model-dependent spectral measurements of plasma density. Predictions by new non-stationary L-shell models currently being developed are also presented. 14 refs., 10 figs.
