X-ray Thomson scattering in warm dense matter at low frequencies

Journal Article · Mon Mar 15 00:00:00 EDT 2010 · Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)

DOI:https://doi.org/10.1103/PHYSREVE.81.036403· OSTI ID:21347432

Murillo, Michael S ^[1]

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1. Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

The low-frequency portion of the x-ray Thomson scattering spectrum is determined by electrons that follow the slow ion motion. This ion motion is characterized by the ion-ion dynamic structure factor, which contains a wealth of information about the ions, including structure and collective modes. The frequency-integrated (diffraction) contribution is considered first. An effective dressed-particle description of warm dense matter is derived from the quantum Ornstein-Zernike equations, and this is used to identify a Yukawa model for warm dense matter. The efficacy of this approach is validated by comparing a predicted structure with data from the extreme case of a liquid metal; good agreement is found. A Thomas-Fermi model is then introduced to allow the separation of bound and free states at finite temperatures, and issues with the definition of the ionization state in warm dense matter are discussed. For applications, analytic structure factors are given on either side of the Kirkwood line. Finally, several models are constructed for describing the slow dynamics of warm dense matter. Two classes of models are introduced that both satisfy the basic sum rules. One class of models is the 'plasmon-pole'-like class, which yields the dispersion of ion-acoustic waves. Damping is then included via generalized hydrodynamics models that incorporate viscous contributions.

• OSTI ID: 21347432
• Journal Information: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print), Journal Name: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print) Journal Issue: 3 Vol. 81; ISSN 1539-3755
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOMIC MODELS
CHARGED PARTICLES
COHERENT SCATTERING
DIFFRACTION
DIMENSIONLESS NUMBERS
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
EQUATIONS
FERMIONS
FLUID MECHANICS
FLUIDS
HYDRODYNAMICS
INELASTIC SCATTERING
ION ACOUSTIC WAVES
ION WAVES
IONIZATION
IONIZING RADIATIONS
IONS
LEPTONS
LIQUID METALS
LIQUIDS
MATHEMATICAL MODELS
MATTER
MECHANICS
METALS
PLASMA WAVES
RADIATIONS
SCATTERING
STRUCTURE FACTORS
SUM RULES
THOMAS-FERMI MODEL
THOMSON SCATTERING
X RADIATION