Download or read book Influence of Ambient Gas on Laser Induced Breakdown Spectroscopy of Uranium Metal written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Laser-induced breakdown spectroscopy (LIBS) is regarded as a suitable method for the remote analysis of materials in any phase, even in an environment with high radiation levels. In the present work we used the third harmonic pulse of a Nd:YAG laser for ablation of uranium metal and measured the plasma emission with a fiber-optic spectrometer. The LIBS spectra of uranium metal and their features in different ambient gases (i.e., argon, neon, oxygen, and nitrogen) at atmospheric pressure were studied. Strong continuum spectrum and several hundreds of emission lines from UI and UII were observed. It is found that the continuum spectrum observed in uranium not only comes from bremsstrahlung emission but is also due to the complex spectrum of uranium. The influence of ambient gas and the gas flow rate for ablation of uranium metal was investigated. The experimental results indicate that the intensity of the uranium lines was enhanced in argon and nitrogen. However, the intensity of uranium lines was decreased in oxygen due to the generation of UO and other oxides. The results also showed that the highest intensity of uranium lines were obtained in argon gas with a gas flow rate above 2.5 L/min. The enhanced mechanism in ambient gas and the influence of the gas flow rate were analyzed in this work.

Download or read book Handbook of Laser Induced Breakdown Spectroscopy written by David A. Cremers and published by John Wiley & Sons. This book was released on 2013-03-15 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Laser Induced Breakdown Spectroscopy written by Reinhard Noll and published by Springer Science & Business Media. This book was released on 2012-01-14 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book A Fundamental Study of Laser induced Breakdown Spectroscopy Using Fiber Optics for Remote Measurements of Trace Metals 1998 Annual Progress Report written by and published by . This book was released on 1998 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Improved technologies are required by DOE for characterization and monitoring for site clean-up and waste processing applications. Especially needed are field deployable methods and devices of real-time monitoring to reduce dependency on laboratory analyses which are costly and time consuming. Improved sensors are needed for on-site analyses to provide real-time analytical capabilities for screening level and/or decision-quality data. Matrices of interest to the DOE are soils (or other solids), slurries, and aqueous and non-aqueous solutions. Laser-induced breakdown spectroscopy (LIBS) is a useful method for determining the elemental composition of solids. This method has been recently reviewed and a number of different applications have been described. In the LIBS technique, a high-power pulsed laser is used to generate a plasma from the sample of interest. This phenomenon was first demonstrated in 1963 using a pulsed ruby laser. The elemental composition of the sample is accomplished by measuring the atomic emission from the atoms and ions in the plasma. There are many reports of the use of LIBS for measuring metals in solid substrates. There have also been LIBS investigations of aerosols, single particles, metals in solution including uranium, and even chlorinated species in solution. More recently, LIBS has been used for measuring Ba and Cr in soil using a fiber-optic cable. LIBS shows great potential for measuring metal contaminants in soils and on particles (e.g., stack emissions) based on their atomic emission in a laser-induced plasma. Another important application for this technique is the remote analysis of highly radioactive materials, such as the glasses produced by the Defense Waste Processing Facility. The use of fiber optics for both collection of the atomic emission and delivery of the laser to the sampling area could eliminate the need for sampling. In this work the authors study the time-evolution of the LIBS emission for different matrices to better understand how to optimize the signal. Also, they investigate the use of fiber optics for laser delivery and signal collection, and the influence of the geometry of the fiber optic launch and collection probes to determine the effect on the signal-to-noise ratio (SNR). Finally, they study the LIBS signal for different sample matrices as a function of excitation wavelength across a broad spectrum. A result of this study should be a determination of the optimal excitation and collection conditions and sampling times for metal contaminants in different matrices, and an understanding of the strengths and limitations of using fiber optics for LIBS sampling.

Download or read book Laser Induced Breakdown Spectroscopy written by Jagdish P. Singh and published by Elsevier. This book was released on 2020-06-02 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-Induced Breakdown Spectroscopy, Second Edition, covers the basic principles and latest developments in instrumentation and applications of Laser Induced Breakdown Spectroscopy (LIBS). Written by active experts in the field, it serves as a useful resource for analytical chemists and spectroscopists, as well as graduate students and researchers engaged in the fields of combustion, environmental science, and planetary and space exploration. This fully revised second edition includes several new chapters on new LIBS techniques as well as several new applications, including flame and off-gas measurement, pharmaceutical samples, defense applications, carbon sequestration and site monitoring, handheld instruments, and more. LIBS has rapidly developed into a major analytical technology with the capability of detecting all chemical elements in a sample, of real- time response, and of close-contact or stand-off analysis of targets. It does not require any sample preparation, unlike conventional spectroscopic analytical techniques. Samples in the form of solids, liquids, gels, gases, plasmas, and biological materials (like teeth, leaves, or blood) can be studied with almost equal ease. This comprehensive reference introduces the topic to readers in a simple, direct, and accessible manner for easy comprehension and maximum utility. Covers even more applications of LIBS beyond the first edition, including combustion, soil physics, environment, and life sciences Includes new chapters on LIBS techniques that have emerged in the last several years, including Femtosecond LIBS and Molecular LIBS Provides inspiration for future developments in this rapidly growing field in the concluding chapter

Download or read book Laser Induced Breakdown Spectroscopy written by Sergio Musazzi and published by Springer. This book was released on 2014-07-08 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the Laser-Induced Breakdown Spectroscopy (LIBS) a widely used atomic emission spectroscopy technique for elemental analysis of materials. It is based on the use of a high-power, short pulse laser excitation. The book is divided into two main sections: the first one concerning theoretical aspects of the technique, the second one describing the state of the art in applications of the technique in different scientific/technological areas. Numerous examples of state of the art applications provide the readers an almost complete scenario of the LIBS technique. The LIBS theoretical aspects are reviewed. The book helps the readers who are less familiar with the technique to understand the basic principles. Numerous examples of state of the art applications give an almost complete scenario of the LIBS technique potentiality. These examples of applications may have a strong impact on future industrial utilization. The authors made important contributions to the development of this field.

Download or read book Laser Induced Breakdown Spectroscopy with Improved Detection Sensitivity and Isotopic Discrimination written by Kyle Hartig and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-induced breakdown spectroscopy (LIBS) could be used to perform rapid, real-time, elemental, and isotopic analysis of materials relevant to nuclear forensics, safeguards, and counterproliferation. The detection sensitivity of LIBS is element dependent and the limits of detection (LODs) are higher than competing techniques used in nuclear forensics like secondary ionization mass-spectroscopy or gamma spectroscopy. LIBS non-invasiveness, small sample size requirements, and a need for minimal or no sample preparation, are the main attributes and moderately responsible for the challenges encountered when identifying and quantifying elements with this technique. Secondly, interference of the individual spectral lines in the plasma emission spectrum limit the LIBS detection selectivity and reliability. Finally, the matrix effects also limit the performance of LIBS since the emission intensity from the target element depends on not only the concentration, but also the chemical and physical properties of the matrix.In this dissertation, optimization of the characteristics of the laser pulse have been pursued and new analysis techniques were introduced to improve LIBS detection sensitivity and isotope selectivity. Optimization of the laser pulse shape through simple and more complex pulse shaping techniques was shown to influence the overall LIBS emission intensity, signal-to-background, and the ionization state of the plasma. Similarly, 2.05 m femtosecond (fs) laser pulses were observed to produce a plasma of lower temperature and density compared to 800 nm fs laser pulses, resulting in an increased signal-to-background ratio (SBR). Ab initio mod- eling was applied to show that the reduced plasma temperature and density for longer wavelength laser pulses leads to the increased SBR.As an extension of LIBS, laser ablation molecular isotopic spectrometry (LAMIS) was adapted for use with fs-laser pulses. Expansion of the LAMIS technique to isotopic analysis of uranium using fs-laser pulses and the capability to per- form this analysis at remote distances through the combination of fs-filamentation LAMIS (F2LAMIS) was demonstrated. The molecular isotope shift for the UO emission band at 593.57 nm was measured to be ~0.05 0.007 nm, which is twice as large as the largest known atomic/ionic isotope shift of 0.025 nm for the 424.43 nm U II emission line. Spatio-temporally resolved spectral and shad- owgraphic measurements showed that the UO species expanded at a slower rate compared to the uranium atomic species.The bulk matrix composition of the sample was observed to affect the measured LIBS and LAMIS signal, and resulted in a reduced analytic capability of the technique for both elemental and isotopic measurement. In specific examples, the measured LIBS emission intensity for an analyte of interest was observed to increase with the presence of a second element of greater concentration, which is the inverse of what is expected for many other analytical techniques. The increase in the analyte emission intensity was studied via temporally resolved plasma and emission diagnostics and through the use of ab initio modeling.The results of this work provide new insights that will aid the development of LIBS/LAMIS as a technique capable of not just elemental analysis, but also isotopic analysis at standoff distances in real time, which is important to remote sensing applications in nuclear forensics, safeguards, and counterproliferation.

Download or read book Laser induced Breakdown Spectrometry written by Yong-Ill Lee and published by Nova Publishers. This book was released on 2000 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: When the output from a pulsed laser is forced onto a small spot of a sample, optically induced plasma, called laser-induced plasma (LIP) is formed at the surface. The plasma is formed when the laser power density exceeds the breakdown threshold value of the surface. The plasma can be used in sampling but is proposed as a source for atomic emission spectrometry (AES). In this case the technique is referred to as laser induced breakdown (emission) spectrometry (LIBS). The spectrally and temporally resolved detection and subsequent determination of the specific atomic emission reveals analytical information about the elemental composition of the sample, including solids, liquids and gases. This book is devoted to the analytical technique of laser-induced breakdown spectrometry. An introduction covering some basic principles of atomic emission spectrometry, analytical performance characteristics, and a comparison to more conventional techniques provides background information for the reader. The book is then conveniently divided into three parts: the first part described the instrumentation required and options available, the second part on fundamental studies of the laser plasma, and the third part on applications. Finally the future development of LIBS is presented.

Download or read book Laser Induced Breakdown Spectroscopy for Detection of Organic Residues written by Christopher G. Brown and published by . This book was released on 2011 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser Induced Breakdown Spectroscopy (LIBS) is showing great potential as an atomic analytical technique. With its ability to rapidly analyze all forms of matter, with little-to-no sample preparation, LIBS has many advantages over conventional atomic emission spectroscopy techniques. With the maturation of the technologies that make LIBS possible, there has been a growing movement to implement LIBS in portable analyzers for field applications. In particular, LIBS has long been considered the front-runner in the drive for stand-off detection of trace deposits of explosives. Thus there is a need for a better understanding of the relevant processes that are responsible for the LIBS signature and their relationships to the different system parameters that are helping to improve LIBS as a sensing technology. This study explores the use of LIBS as a method to detect random trace amounts of specific organic materials deposited on organic or non-metallic surfaces. This requirement forces the limitation of single-shot signal analysis. This study is both experimental and theoretical, with a sizeable component addressing data analysis using principal components analysis to reduce the dimensionality of the data, and quadratic discriminant analysis to classify the data. In addition, the alternative approach of 'target factor analysis' was employed to improve detection of organic residues on organic substrates. Finally, a new method of characterizing the laser-induced plasma of organics, which should lead to improved data collection and analysis, is introduced. The comparison between modeled and experimental measurements of plasma temperatures and electronic density is discussed in order to improve the present models of low-temperature laser induced plasmas.

Download or read book Portable Laser induced Breakdown Spectroscopy for Nuclear Forensics Applications written by Michael Bernard Shattan and published by . This book was released on 2018 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work demonstrates the capability of a readily available, and portable Laser Induced Breakdown Spectroscopy (LIBS) systems to conduct field screening of samples with nuclear forensics interest. A hand-held device for laser-induced breakdown spectroscopy has been investigated for the determination of uranyl fluoride surface contamination. This research demonstrates the ability to successfully detect uranium on surfaces when using a low resolving power ([lambda]/[Delta][lambda]= 4000) [lambda/ delta lambda] spectrograph, with a 5mJ [milijoule] energy per 1 ns [nanosecond] pulsed laser radiation, available as a commercially packaged hand-held system. Sand/uranyl fluoride mixtures are prepared to simulate residue likely encountered during decontamination efforts at facilities that handle uranium hexafluoride. Detection limits are described for four uranium lines with one revealing the capability to detect uranium at a level of 250 parts-per-million. Advantages of the studied compact device include that location specific information can be obtained on-site to augment contamination identification. This work also demonstrates the capability of a readily potentially portable Laser Induced Breakdown Spectroscopy (LIBS) system to conduct macroscopic chemical mapping of uranium and iron in surrogate nuclear debris for sample interior and exterior surfaces, for the first time. Techniques focus on the mitigation of chemical and physical matrix effects of four uranium atomic emission lines, relatively free of interferences and of good analytical value. The acceptable data spatial resolution is 0.5 mm [millimeter]. A material fractionation pattern occurs and is discussed in terms of constituent melting temperatures and thermal gradients experienced during the cooling process is proposed. Finally, Areas of further research to advance portable LIBS capabilities for nuclear forensics are discussed.

Download or read book Measurement of Rare Earth and Uranium Elements Using Laser induced Breakdown Spectroscopy LIBS in an Aerosol System for Nuclear Safeguards Applications written by Ammon Ned Williams and published by . This book was released on 2016 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this research is to develop an applied technology and provide an assessment for remotely measuring and analyzing the real time or near real time concentrations of used nuclear fuel (UNF) elements in electrorefiners (ER). Here, Laser-Induced Breakdown Spectroscopy (LIBS) in UNF pyroprocessing facilities was investigated. LIBS is an elemental analysis method, which is based on the emission from plasma generated by focusing a laser beam into the medium. This technology has been reported to be applicable in solids, liquids (includes molten metals), and gases for detecting elements of special nuclear materials. The advantages of applying the technology for pyroprocessing facilities are: (i) Rapid real-time elemental analysis; (ii) Direct detection of elements and impurities in the system with low limits of detection (LOD); and (iii) Little to no sample preparation is required. One important challenge to overcome is achieving reproducible spectral data over time while being able to accurately quantify fission products, rare earth elements, and actinides in the molten salt. Another important challenge is related to the accessibility of molten salt, which is heated in a heavily insulated, remotely operated furnace in a high radiation environment within an argon gas atmosphere. This dissertation aims to address these challenges and approaches in the following phases with their highlighted outcomes: 1. Aerosol-LIBS system design and aqueous testing: An aerosol-LIBS system was designed around a Collison nebulizer and tested using deionized water with Ce, Gd, and Nd concentrations from 100 ppm to 10,000 ppm. The average %RSD values between the sample repetitions were 4.4% and 3.8% for the Ce and Gd lines, respectively. The univariate calibration curve for Ce using the peak intensities of the Ce 418.660 nm line was recommended and had an R2 value, LOD, and RM. S. ECV of 0.994, 189 ppm, and 390 ppm, respectively. The recommended Gd calibration curve was generated using the peak areas of the Gd 409.861 nm line and had an R2, LOD, and RMSECV of 0.992, 316 ppm, and 421 ppm, respectively. The partial least squares (PLS) calibration curves yielded similar results with RMSECV of 406 ppm and 417 ppm for the Ce and Gd curves, respectively. 2. High temperature aerosol-LIBS system design and CeCl3 testing: The aerosol-LIBS system was transitioned to a high temperature and used to measure Ce in molten LiCl-KCl salt within a glovebox environment. The concentration range studied was from 0.1 wt% to 5 wt% Ce. Normalization was necessary due to signal degradation over time; however, with the normalization the %RSD values averaged 5% for the mid and upper concentrations studied. The best univariate calibration curve was generated using the peak areas of the Ce 418.660 nm line. The LOD for this line was 148 ppm with the RMSECV of 647 ppm. The PLS calibration curve was made using 7 latent variables (LV) and resulting in the RMSECV of 622 ppm. The LOD value was below the expected rare earth concentration within the ER. 3. Aerosol-LIBS testing using UCl3: Samples containing UCl3 with concentrations ranging from 0.3 wt% to 5 wt% were measured. The spectral response in this range was linear. The best univariate calibration curves were generated using the peak areas of the U 367.01 nm line and had an R2 value of 0.9917. Here, the LOD was 647 ppm and the RMSECV was 2,290 ppm. The PLS model was substantially better with a RMSECV of 1,110 ppm. The LOD found here is below the expected U concentrations in the ER. The successful completion of this study has demonstrated the feasibility of using an aerosol-LIBS analytical technique to measure rare earth elements and actinides in the pyroprocessing salt.

Download or read book Laser induced Breakdown Spectroscopy written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-induced breakdown spectroscopy has been applied to the continuous determination of uranium in solutions. The technique is rapid, non-invasive, and unaffected by radioactivity. Powerful laser pulses are focused through an optical access onto the solution surface to produce a hot spark plasma. In experiments on static solutions, uranium concentrations between 0.1 and 300 g/L were determined, using a pulsed Md:YAG laser and a time-gated photodiode array. A concentration of 4.2 g/L was measured with 1.0% precision in 3 minutes. Substances that absorb at the laser wavelength, suspended materials, and variations in the acidity of the solution have little or no effect on the results. Experiments are in progress on flowing streams contained in a test loop that simulates plant operating conditions. 1 ref., 3 figs., 3 tabs.

Download or read book Laser induced Breakdown Spectroscopy LIBS written by Andrzej W. Miziolek and published by . This book was released on 2014-05-14 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Dual pulse Laser Induced Breakdown Spectroscopy in the Vacuum Ultraviolet with Ambient Gas written by Jiang, Xi and published by . This book was released on 2012 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Temperature and Aerosol Content on Laser induced Breakdown Spectroscopy Detection Limits written by Kyle F. Kratzsch and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Fundamental Study of Laser Induced Breakdown Spectroscopy Using Fiber Optics for Remote Measurements of Trace Metals written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Develop a fiber-optic imaging probe for microanalysis of solid samples. Design a time-resolved plasma imaging system to measure the development of the LIBS signal. Setup a laboratory system capable of timing two lasers independently, for optimizing and characterizing dual-pulse LIBS. Compare the development of laser-induced plasmas generated with a single laser pulse to the development of laser induced plasmas generated with a pre-ablation spark prior to sample ablation. Examine the effect of sample matrix on the LIBS signals of elements in different sample matrices. Investigate the effect of excitation wavelength of the ablation beam in pre-ablation spark dual-pulse LIBS experiments. Determine the effect of the physical properties of the sample on the mass of materials ablated.

Download or read book Laser Spectroscopy and its Applications written by Richard W. Solarz and published by Routledge. This book was released on 2017-11-22 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bringing together scattered literature from a range of sources, Laser Spectroscopy and ItsApplications clearly elucidates the tools and concepts of this dynamic area, and providesextensive bibliographies for further study.Distinguished experts in their respective fields discuss resonance photoionization, laser absorption,laser-induced breakdown, photodissociation, Raman scattering, remote sensing,and laser-induced fluorescence. The book also incorporates an overview of the semiclassicaltheory of atomic and molecular spectra.Combining background at an intermediate level with an in-depth discussion of specifictechniques, Laser Spectroscopy and Its Applications is essential reading for laser and opticalscientists and engineers; analytical chemists; health physicists; researchers in optical,chemical, pharmaceutical, and metallurgical industries. It will also prove useful for upperlevelundergraduate and graduate students of laser spectroscopy and its applications, andin-house seminars and short courses offered by firms and professional societies.