X-ray Thomson Scattering for Partially Ionized Plasmas Including the Effect of Bound Levels

X-ray Thomson Scattering for Partially Ionized Plasmas Including the Effect of Bound Levels PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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X-ray Thomson Scattering for Partially Ionized Plasmas Including the Effect of Bound Levels

X-ray Thomson Scattering for Partially Ionized Plasmas Including the Effect of Bound Levels PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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The Effect of Bound States on X-ray Thomson Scattering for Partially Ionized Plasmas

The Effect of Bound States on X-ray Thomson Scattering for Partially Ionized Plasmas PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

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Using the X-FEL to Understand X-ray Thomson Scattering for Partially Ionized Plasmas

Using the X-FEL to Understand X-ray Thomson Scattering for Partially Ionized Plasmas PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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Using X-ray Thomson Scattering to Measure Plasma Conditions in Warm Dense Matter Experiments on the OMEGA Laser

Using X-ray Thomson Scattering to Measure Plasma Conditions in Warm Dense Matter Experiments on the OMEGA Laser PDF Author: Alison Marie-Anne Saunders
Publisher:
ISBN:
Category :
Languages : en
Pages : 143

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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.

Theory of Thomson Scattering from a Weakly Ionized Plasma

Theory of Thomson Scattering from a Weakly Ionized Plasma PDF Author: Richard G. Seasholtz
Publisher:
ISBN:
Category : Magnetic fields
Languages : en
Pages : 45

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The theory of Thomson scattering from a weakly ionized plasma is extended to include the effects of unequal electron and ion temperatures, a constant magnetic field, and electron drift. The plasma is described by the two fluid continuum equations that are valid if the wavelength of the probing wave is longer than the ion-neutral mean free path. The spectrum and total scattered power are calculated. Collisions and a magnetic field are both shown to influence the scattered power for unequal electron and ion temperatures.

Atoms and Molecules in Strong External Fields

Atoms and Molecules in Strong External Fields PDF Author: P. Schmelcher
Publisher: Springer Science & Business Media
ISBN: 0306470748
Category : Science
Languages : en
Pages : 330

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Book Description
This book contains contributions to the 172. WE-Heraeus-Seminar “Atoms and Molecules in Strong External Fields,” which took place April 7–11 1997 at the Phys- zentrum Bad Honnef (Germany). The designation “strong fields” applies to external static magnetic, and/or electric fields that are sufficiently intense to cause alterations in the atomic or molecular str- ture and dynamics. The specific topics treated are the behavior and properties of atoms in strong static fields, the fundamental aspects and electronic structure of molecules in strong magnetic fields, the dynamics and aspects of chaos in highly excited R- berg atoms in external fields, matter in the atmosphere of astrophysical objects (white dwarfs, neutron stars), and quantum nanostructures in strong magnetic fields. It is obvious that the elaboration of the corresponding properties in these regimes causes the greatest difficulties, and is incomplete even today. Present-day technology has made it possible for many research groups to study the behavior of matter in strong external fields, both experimentally and theore- cally, where the phrase “experimentally” includes the astronomical observations. - derstanding these systems requires the development of modern theories and powerful computational techniques. Interdisciplinary collaborations will be helpful and useful in developing more efficient methods to understand these important systems. Hence the idea was to bring together people from different fields like atomic and molecular physics, theoretical chemistry, astrophysics and all those colleagues interested in aspects of few-body systems in external fields.

X-ray Thomson Scattering from Dense Plasmas

X-ray Thomson Scattering from Dense Plasmas PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Advances in the development of laser-produced x-ray sources have enabled a new class of high-energy density physics experiments. Powerful narrow-bandwidth x rays penetrate through short-lived hot dense states of matter and probe the physical properties with spectrally resolved x-ray scattering. Experiments from isochorically-heated plasmas with electron densities in the range of solid density and above have been demonstrated allowing for the first time exploration of the microscopic properties of dense matter regime close to strongly-coupled and Fermi degenerate conditions. Backscatter measurements have accessed the non-collective Compton scattering regime, which provides accurate diagnostic information on the temperature, density and ionization states. The forward scattering spectrum has been shown to measure the collective plasmon oscillations. Besides extracting the standard plasma parameters, density and temperature, forward scattering yields new observables such as a direct measure of collisions, quantum effects and detailed balance. In this talk, we will discuss new results important for applications of this technique for novel experiments in a wide range of research areas such as inertial confinement fusion, radiation-hydrodynamics, material science, and laboratory astrophysics.

Theoretical Model and Interpretation of Dense Plasma X-Ray Thomson Scattering

Theoretical Model and Interpretation of Dense Plasma X-Ray Thomson Scattering PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The authors present analytical expressions for the dynamic structure factor, or form factor S(k, [omega]), which is the quantity describing the inelastic x-ray cross section from a dense plasma or a simple liquid. The results, based on the random phase approximation (RPA) for the treatment on the charged particle coupling, can be applied to describe scattering from either weakly coupled classical plasmas or degenerate electron liquids. The form factor correctly reproduces the Compton energy downshift and the usual Fermi-Dirac electron velocity distribution for S(k, [omega]) in the case of a cold degenerate plasma. the usual concept of scattering parameter is also reinterpreted for the degenerate case in order to include the effect of the Thomas-Fermi screening. The results shown in this work can be applied to interpreting x-ray scattering in warm dense plasmas occurring in inertial confinement fusion experiments or inside the interior of planets.

Demonstration of Successful X-ray Thomson Scattering Using Picosecond K-[alpha] X-ray Sources for the Characterization of Dense Heated Matter

Demonstration of Successful X-ray Thomson Scattering Using Picosecond K-[alpha] X-ray Sources for the Characterization of Dense Heated Matter PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
We discuss the first successful K-[alpha] x-ray Thomson scattering experiment from solid density plasmas for use as a diagnostic in determining the temperature, density, and ionization state of warm dense matter with picosecond resolution. The development of this source as a diagnostic and stringent requirements for successful K-[alpha] x-ray Thomson scattering are addressed. Data for the experimental techniques described in this paper [1] suggest the capability of single shot characterization of warm dense matter and the ability to use this scattering source at future Free Electron Lasers (FEL) where comparable scattering signal levels are predicted.

Warm, Dense Plasma Characterization by X-ray Thomson Scattering

Warm, Dense Plasma Characterization by X-ray Thomson Scattering PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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Book Description
We describe how the powerful technique of spectrally resolved Thomson scattering can be extended to the x-ray regime, for direct measurements of the ionization state, density, temperature, and the microscopic behavior of dense cool plasmas. Such a direct measurement of microscopic parameters of solid density plasmas could eventually be used to properly interpret laboratory measurements of material properties such as thermal and electrical conductivity, EUS and opacity. In addition, x-ray Thomson scattering will provide new information on the characteristics of rarely and hitherto difficult to diagnose Fermi degenerate and strongly coupled plasmas.