Download or read book X ray Probing of Warm Dense Matter written by G. Shabbir Naz and published by LAP Lambert Academic Publishing. This book was released on 2010-09 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the major challenges of contemporary physics is to understand the behavior of matter at extreme conditions of temperature, pressure, density and electromagnetic fields. It is relevant to many branches of physics like astrophysics, nuclear physics and quantum physics due to wide occurrence of such states of matter in the universe. Warm dense matter (WDM) defined by a temperature of few electron volts and densities comparable and greater than the solid density, occurs during the implosion phase of thermonuclear fusion and is a non-trivial problem to create and probe it. This book introduces the subject, briefly describe the available options to probe WDM and use spectrally resolved inelastic X-ray scattering method to demonstrate its potential use as a standard diagnostic technique. Three state of the art methods to create WDM are used to demonstrate its applications. The book would be beneficial for the students and researchers working in simulation codes to understand the complex systems occur in strongly correlated dense plasmas relevant to the planetary science, cold star physics and to the indirect driven inertial confinement fusion research.
Download or read book X ray Spectroscopies of Warm Dense Matter written by Oliver Hoidn and published by . This book was released on 2017 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation provides a perspective on the role of x-ray spectroscopy and diffraction diagnostics in experimental studies of warm dense matter (WDM). The primary focus of the work I discuss is the development of techniques to measure the structure and state variables of laboratory-generated WDM with a view towards both phenomenlogy and placing contraints on theoretical models. I present techniques adapted to two experimental venues for WDM studies: large-scale laser plasma facilities and x-ray free electron lasers. My focus is on the latter, in the context of which I have studied a dose enhancement technique that exploits nonlocal heat transport in nanostructured targets and considered several aspects of optimizing x-ray diffraction measurements. This work came into play in beam runs at the Linac Coherent Light Source (LCLS) in which my group performed x-ray diffraction studies of several materials heated to eV-scale temperatures. The results from these experiments include confirmation of the persistence of long-range crystalline order upon heating of metal oxides to tens of eV temperarures on the 40 fs timescale. One material, MgO, additionally manifested a surprising anomalous early onset in delocalization of valence charge density, contradicting predictions of all models based on either ground state electronic structure or (high-energy density) plasma physics. This particular result outlines a future path for studies of ordered insulators heated to temperatures on the order of the band gap. Such experiments will offer strong tests of electronic strucure theory, implementing a scientific approach that sees measurement of real-space charge density via x-ray diffraction (XRD) as a particularly effectve means to constrain density functional theory (DFT)-based modeling of the solid state/plasma transitional regime.
Download or read book Ultrafast X Ray Absorption Spectroscopy of Isochorically Heated Warm Dense Matter written by Kyle Craig Engelhorn and published by . This book was released on 2015 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation will present a series of new tools, together with new techniques, focused on the understanding of warm and dense matter. We report on the development of a high time resolution and high detection efficiency x-ray camera. The camera is integrated with a short pulse laser and an x-ray beamline at the Advanced Light Source synchrotron. This provides an instrument for single shot, broadband x-ray absorption spectroscopy of warm and dense matter with 2 picosecond time resolution. Warm and dense matter is created by isochorically heating samples of known density with an ultrafast optical laser pulse, and X-ray absorption spectroscopy probes the unoccupied electronic density of states before the onset of hydrodynamic expansion and electron-ion equilibrium is reached. Measured spectra from a variety of materials are compared with first principle molecular dynamics and density functional theory calculations. In heated silicon dioxide spectra, two novel pre-edge features are observed, a peak below the band gap and absorption within the band gap, while a reduction was observed in the features above the edge. From consideration of the calculated spectra, the peak below the gap is attributed to valence electrons that have been promoted to the conduction band, the absorption within the gap is attributed to broken Si-O bonds, and the reduction above the edge is attributed to an elevated ionic temperature. In heated copper spectra, a time-dependent shift and broadening of the absorption edge are observed, consistent with and elevated electron temperature. The temporal evolution of the electronic temperature is accurately determined by fitting the measured spectra with calculated spectra. The electron-ion equilibration is studied with a two-temperature model. In heated nickel spectra, a shift of the absorption edge is observed. This shift is found to be inconsistent with calculated spectra and independent of incident laser fluence. A shift of the chemical potential is applied to the calculated spectra to obtain satisfactory agreement with measured spectra.
Download or read book Isochoric Heating Into the Warm Dense Matter Regime by Laser solid Produced K alpha X rays written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of matter at near solid density and at temperatures of 1-10 eV is a great challenge to both experimentalists and theorists, because such matter exhibits internal energy density which is very high but insufficient to overpower the inter-atomic potentials. This form of matter, intermediate to condensed matter and plasmas, exists in many astrophysical systems. In this paper, we describe an experimental program to study solid-density matter heated to temperatures near 1 eV per atom with ultrafast pulses of x-rays. An intense, ultra-short laser pulse incident upon a thin foil produces a burst of K-[alpha] x-rays, which are used to flash heat an adjacent bulk sample. Optical interferometric probing of the sample with sub-ps time resolution allows us to measure its expansion into vacuum upon heating. K-[alpha] source target properties are optimized for irradiation of the adjacent sample. Initial results on K-[alpha] yields and heating of Al foils will be discussed.
Download or read book Isochoric Heating Into the Warm Dense Matter Regime by Laser solid Produced K alpha X rays written by R. W. Lee and published by . This book was released on 2003 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of matter at near solid density and at temperatures of 1-10 eV is a great challenge to both experimentalists and theorists, because such matter exhibits internal energy density which is very high but insufficient to overpower the inter-atomic potentials. This form of matter, intermediate to condensed matter and plasmas, exists in many astrophysical systems. In this paper, we describe an experimental program to study solid-density matter heated to temperatures near 1 eV per atom with ultrafast pulses of x-rays. An intense, ultra-short laser pulse incident upon a thin foil produces a burst of K-{alpha} x-rays, which are used to flash heat an adjacent bulk sample. Optical interferometric probing of the sample with sub-ps time resolution allows us to measure its expansion into vacuum upon heating. K-{alpha} source target properties are optimized for irradiation of the adjacent sample. Initial results on K-{alpha} yields and heating of Al foils will be discussed.
Download or read book Frontiers and Challenges in Warm Dense Matter written by Frank Graziani and published by Springer Science & Business. This book was released on 2014-04-28 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm Dense Matter (WDM) occupies a loosely defined region of phase space intermediate between solid, liquid, gas, and plasma, and typically shares characteristics of two or more of these phases. WDM is generally associated with the combination of strongly coupled ions and moderately degenerate electrons, and careful attention to quantum physics and electronic structure is essential. The lack of a small perturbation parameter greatly limits approximate attempts at its accurate description. Since WDM resides at the intersection of solid state and high energy density physics, many high energy density physics (HEDP) experiments pass through this difficult region of phase space. Thus, understanding and modeling WDM is key to the success of experiments on diverse facilities. These include the National Ignition Campaign centered on the National Ignition Facility (NIF), pulsed-power driven experiments on the Z machine, ion-beam-driven WDM experiments on the NDCX-II, and fundamental WDM research at the Linear Coherent Light Source (LCLS). Warm Dense Matter is also ubiquitous in planetary science and astrophysics, particularly with respect to unresolved questions concerning the structure and age of the gas giants, the nature of exosolar planets, and the cosmochronology of white dwarf stars. In this book we explore established and promising approaches to the modeling of WDM, foundational issues concerning the correct theoretical description of WDM, and the challenging practical issues of numerically modeling strongly coupled systems with many degrees of freedom.
Download or read book High Intensity X rays Interaction with Matter written by Stefan P. Hau-Riege and published by John Wiley & Sons. This book was released on 2012-09-19 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling the need for a book bridging the effect of matter on X-ray radiation and the interaction of x-rays with plasmas, this monograph provides comprehensive coverage of the topic. As such, it presents and explains such powerful new X-ray sources as X-ray free-electron lasers, as well as short pulse interactions with solids, clusters, molecules, and plasmas, and X-ray matter interactions as a diagnostic tool. Equally useful for researchers and practitioners working in the field.
Download or read book X ray Scattering from Warm Dense Matter written by María Elena García Saiz and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by John von Neumann-Institut für Computing and published by Forschungszentrum Jülich. This book was released on 2012 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Scattering of Electromagnetic Radiation written by John Sheffield and published by Academic Press. This book was released on 2010-11-25 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents one of the most powerful methods of plasma diagnosis in exquisite detail, to guide researchers in the theory and measurement techniques of light scattering in plasmas. Light scattering in plasmas is essential in the research and development of fusion energy, environmental solutions, and electronics.Referred to as the "Bible" by researchers, the work encompasses fusion and industrial applications essential in plasma research. It is the only comprehensive resource specific to the plasma scattering technique. It provides a wide-range of experimental examples and discussion of their principles with worked examples to assist researchers in applying the theory. - Computing techniques for solving basic equations helps researchers compare data to the actual experiment - New material on advances on the experimental side, such as the application of high density plasmas of inertial fusion - Worked out examples of the scattering technique for easier comprehension of theory
Download or read book X ray Scattering from Warm Dense Matter written by Steven Jonathan White and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Collective X ray Thomson Scattering to Measure Temperature and Density of Warm Dense Matter written by and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collective x-ray Thomson scattering allows measuring plasmons, i.e electron plasma oscillations (Langmuir waves). This is manifest in the appearance of spectrally up- and down-shifted spectral features in addition to the Rayleigh signal. The ratio of the up- and down-shifted signals is directly related to detailed balance, allowing to determine the plasma temperature from first principles. The spectral shift of the plasmon signals is sensitive to temperature and electron density. We discuss the experimental considerations that have to be fulfilled to observe plasmon signals with x-ray Thomson scattering. As an example, we describe an experiment that used the Cl Ly-[alpha] x-ray line at 2.96 keV to measure collective Thomson scattering from solid beryllium, isochorically heated to 18 eV. Since temperature measurement based on detailed balance is based on first principles, this method is important to validate models that, for example, calculate the static ion-ion structure factor S{sub ii}(k).
Download or read book Using X ray Thomson Scattering to Measure Plasma Conditions in Warm Dense Matter Experiments on the OMEGA Laser written by Alison Marie-Anne Saunders and published by . This book was released on 2018 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: High energy density physics (HEDP) is an emerging field that seeks to investigate the properties of matter at extreme conditions. High energy density conditions occur in materials with pressures exceeding 1 Mbar, or pressures that exceed Earth’s atmospheric pressure by a factor of more than a million. A regime of HEDP of particular interest is warm dense matter (WDM) physics, which describes the behavior of materials at near solid densities and 10’s of eV temperatures. WDM occurs in astrophysical objects, such as giant planets and brown dwarfs, and is also generated in inertial confinement fusion (ICF) experiments. X-ray Thomson scattering (XRTS) offers a powerful tool to probe the equation of state of WDM. XRTS spectra consist of two components: elastically scattered photons with the frequency of the original x-ray source and inelastically scattered photons that are down- shifted in frequency. The Compton-shifted profile of inelastically scattered x-rays can be analyzed to return the sample’s electron density and electron temperature. The ratio of elastically to inelastically scattered x-rays relates to the number of tightly bound versus free electrons, and thus reflects the ionization state. This thesis discusses the results of XRTS experiments on WDM performed at the OMEGA Laser facility. The first experiment presents and discusses XRTS results from 1 mm diamond spheres. The scattering spectra show evidence of higher ionization than predicted by several commonly-applied ionization models. A second experiment analyzed the contributions to elastic scattering from a small argon impurity in imploding beryllium capsules. The exper- iment found that less than 1 at.% of argon significantly affects the elastic scattering signal strength, and concluded that impurities in a sample should be considered before drawing conclusions from elastic scattering signals. The final experiment uses XRTS to measure the electron temperature and ionization state in isochorically heated materials used in ion stopping power experiments. The results from these experiments demonstrate the power of XRTS to measure ionization in WDM to benchmark theoretical modeling.
Download or read book Inelastic X ray Scattering Measurements of Ionization in Warm Dense Matter written by Paul Davis and published by . This book was released on 2012 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we demonstrate spectrally resolved x-ray scattering from electron-plasma waves in shock-compressed deuterium and proton-heated matter. Because the spectral signature of inelastic x-ray scattering is strongly dependent on the free electron density of the system, it is used to infer ionization in dynamically heated samples. Using 2-6 ns, 500 J laser pulses from LLNL's Janus laser, we shocked liquid deuterium to pressures approaching 50 GPa, reaching compressions of 4 times liquid density. A second laser produced intense 2 keV x-rays. By collecting and spectrally dispersing forward scattered photons at 45 degrees, the onset of ionization was detected at compressions of about 3 times in the form of plasmon oscillations. Backscattered x-rays bolstered this observation by measuring the free electron distribution through Compton scattering. Comparison with simulations shows very close agreement between the pressure dependence of ionization and molecular dissociation in dynamically compressed deuterium. In a second set of experiments, a 10 ps, 200 J Titan laser pulse was split into two beams. One created a stream of MeV protons to heat samples of boron and boron-nitride and the other pumped 4.5 keV K-alpha radiation in a titanium foil to probe the hot target. We observed scattered x-rays 300 ps after heating, noting a strong difference in average ionization between the two target materials at temperatures of 16 eV and very similar mass densities. Comparison with electron structure calculations suggests that this difference is due to a persistence of long-range ion structure in BN resulting in high-temperature band structure. These results underscore the importance of understanding the complex electron structure of materials even at electron-volt temperatures and gigapascal pressures. Our results provide new data to guide the theoretical modeling of warm, dense matter important to understanding giant planets and inertial fusion targets.
Download or read book Probing the Dynamic Response of Dense Matter with X ray Thomson Scattering written by David Alan Chapman and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulations of X ray Thomson Scattering from Warm Dense Matter written by Ghulam Shabbir Naz and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Materials Under Extreme Conditions written by A. K. Tyagi and published by Elsevier. This book was released on 2017-01-13 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials Under Extreme Conditions: Recent Trends and Future Prospects analyzes the chemical transformation and decomposition of materials exposed to extreme conditions, such as high temperature, high pressure, hostile chemical environments, high radiation fields, high vacuum, high magnetic and electric fields, wear and abrasion related to chemical bonding, special crystallographic features, and microstructures. The materials covered in this work encompass oxides, non-oxides, alloys and intermetallics, glasses, and carbon-based materials. The book is written for researchers in academia and industry, and technologists in chemical engineering, materials chemistry, chemistry, and condensed matter physics. - Describes and analyzes the chemical transformation and decomposition of a wide range of materials exposed to extreme conditions - Brings together information currently scattered across the Internet or incoherently dispersed amongst journals and proceedings - Presents chapters on phenomena, materials synthesis, and processing, characterization and properties, and applications - Written by established researchers in the field
