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Moldabekov Z, Dornheim T, Böhme M, Vorberger J, Cangi A. The relevance of electronic perturbations in the warm dense electron gas. J Chem Phys 2021; 155:124116. [PMID: 34598570 DOI: 10.1063/5.0062325] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Warm dense matter (WDM) has emerged as one of the frontiers of both experimental physics and theoretical physics and is a challenging traditional concept of plasma, atomic, and condensed-matter physics. While it has become common practice to model correlated electrons in WDM within the framework of Kohn-Sham density functional theory, quantitative benchmarks of exchange-correlation (XC) functionals under WDM conditions are yet incomplete. Here, we present the first assessment of common XC functionals against exact path-integral Monte Carlo calculations of the harmonically perturbed thermal electron gas. This system is directly related to the numerical modeling of x-ray scattering experiments on warm dense samples. Our assessment yields the parameter space where common XC functionals are applicable. More importantly, we pinpoint where the tested XC functionals fail when perturbations on the electronic structure are imposed. We indicate the lack of XC functionals that take into account the needs of WDM physics in terms of perturbed electronic structures.
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Affiliation(s)
- Zhandos Moldabekov
- Center for Advanced Systems Understanding (CASUS), D-02826 Görlitz, Germany
| | - Tobias Dornheim
- Center for Advanced Systems Understanding (CASUS), D-02826 Görlitz, Germany
| | - Maximilian Böhme
- Center for Advanced Systems Understanding (CASUS), D-02826 Görlitz, Germany
| | - Jan Vorberger
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), D-01328 Dresden, Germany
| | - Attila Cangi
- Center for Advanced Systems Understanding (CASUS), D-02826 Görlitz, Germany
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2
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Zaporozhets Y, Mintsev V, Fortov V, Reinholz H, Röpke G, Rosmej S, Omarbakiyeva YA. Polarized angular-dependent reflectivity and density-dependent profiles of shock-compressed xenon plasmas. Phys Rev E 2019; 99:043202. [PMID: 31108619 DOI: 10.1103/physreve.99.043202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Indexed: 11/07/2022]
Abstract
New data for the reflectivity of shock-compressed xenon plasmas at pressures of 10-12 GPa at large incident angles are presented. In addition, measurements have been performed at different densities. These data allow to analyze the free-electron density profile across the shock wave front. Assuming a Fermi-like density profile, the width of the front layer is inferred. The reflectivity coefficients for the s- and p-polarized waves are calculated. The influence of atoms, which was taken into account on the level of the collision frequency, proves to be essential for the understanding of the reflection process. Subsequently, a unique density profile is sufficient to obtain good agreement with the experimental data at different incident angles and at all investigated optical laser frequencies. Reflectivity measurements for different densities allow to determine the dependence of shock-front density profiles on the plasma parameters. As a result, it was found that the width of the front layer increases with decreasing density.
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Affiliation(s)
- Y Zaporozhets
- Institute of Problems of Chemical Physics, Chernogolovka, Moscow Reg., 142432 Russia
| | - V Mintsev
- Institute of Problems of Chemical Physics, Chernogolovka, Moscow Reg., 142432 Russia
| | - V Fortov
- Institute of Problems of Chemical Physics, Chernogolovka, Moscow Reg., 142432 Russia
| | - H Reinholz
- University of Western Australia, School of Physics, 35 Stirling Highway, Crawley, Western Australia 6009, Australia and University of Rostock, Institute of Physics, Universitätsplatz 1, D-18051 Rostock, Germany
| | - G Röpke
- University of Rostock, Institute of Physics, Universitätsplatz 1, D-18051 Rostock, Germany
| | - S Rosmej
- Carl von Ossietzky University of Oldenburg, Institute of Physics, D-26111 Oldenburg, Germany
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3
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Zaghoo M. Dynamic conductivity and partial ionization in dense fluid hydrogen. Phys Rev E 2018; 97:043205. [PMID: 29758665 DOI: 10.1103/physreve.97.043205] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Indexed: 11/07/2022]
Abstract
A theoretical description for optical conduction experiments in dense fluid hydrogen is presented. Different quantum statistical approaches are used to describe the mechanism of electronic transport in hydrogen's high-temperature dense phase. We show that at the onset of the metallic transition, optical conduction could be described by a strong rise in atomic polarizability, due to increased ionization, whereas in the highly degenerate limit, the Ziman weak scattering model better accounts for the observed saturation of reflectance. The inclusion of effects of partial ionization in the highly degenerate region provides great agreement with experimental results. Hydrogen's fluid metallic state is revealed to be a partially ionized free-electron plasma. Our results provide some of the first theoretical transport models that are experimentally benchmarked, as well as an important guide for future studies.
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Affiliation(s)
- Mohamed Zaghoo
- Laboratory for Laser Energetics, University of Rochester, New York 14620, USA and Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02143, USA
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4
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Conductivity and dissociation in liquid metallic hydrogen and implications for planetary interiors. Proc Natl Acad Sci U S A 2017; 114:11873-11877. [PMID: 29078318 DOI: 10.1073/pnas.1707918114] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Liquid metallic hydrogen (LMH) is the most abundant form of condensed matter in our solar planetary structure. The electronic and thermal transport properties of this metallic fluid are of fundamental interest to understanding hydrogen's mechanism of conduction, atomic or pairing structure, as well as the key input for the magnetic dynamo action and thermal models of gas giants. Here, we report spectrally resolved measurements of the optical reflectance of LMH in the pressure region of 1.4-1.7 Mbar. We analyze the data, as well as previously reported measurements, using the free-electron model. Fitting the energy dependence of the reflectance data yields a dissociation fraction of 65 ± 15%, supporting theoretical models that LMH is an atomic metallic liquid. We determine the optical conductivity of LMH and find metallic hydrogen's static electrical conductivity to be 11,000-15,000 S/cm, substantially higher than the only earlier reported experimental values. The higher electrical conductivity implies that the Jovian and Saturnian dynamo are likely to operate out to shallower depths than previously assumed, while the inferred thermal conductivity should provide a crucial experimental constraint to heat transport models.
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5
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Norman G, Saitov I. Brewster angle and reflectivity of optically nonuniform dense plasmas. Phys Rev E 2016; 94:043202. [PMID: 27841633 DOI: 10.1103/physreve.94.043202] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Indexed: 11/07/2022]
Abstract
We provide theoretical analysis of the reflectance of shock-compressed plasmas and warm dense matter for normal incidence of laser radiation as well as for the dependence of s- and p-polarized reflectivity on the incidence angle. The self-consistent approach for the calculation of the optical and electronic properties of warm dense matter and nonideal plasmas developed in our previous works is extended for the description of normal and polarized reflectivity from the broadened optically nonuniform medium. Two methods are applied for the calculation of the reflectivity from spatially broadened optically nonuniform medium. The first one is based on the solution of the Helmholtz equation for the amplitudes of the electromagnetic field. Another one is based on Drude theory of reflection. It allows us to calculate the ratio of the s- and p-polarized reflectivity if dependence of the dielectric function on distance is known. For the case of the polarized reflectivity, the particular attention is concentrated on the Brewster angle. The calculation results for the dielectric function, obtained within the framework of the density-functional theory with the longitudinal expression for the dielectric tensor, are applied for the calculation of the reflectivity. Comparison with the experimental data for shock-compressed xenon is performed.
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Affiliation(s)
- G Norman
- Joint Institute for High Temperatures of RAS, Izhorskaya st. 13, Bld. 2, Moscow 125412, Russia
| | - I Saitov
- Joint Institute for High Temperatures of RAS, Izhorskaya st. 13, Bld. 2, Moscow 125412, Russia
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6
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Veysman M, Röpke G, Winkel M, Reinholz H. Optical conductivity of warm dense matter within a wide frequency range using quantum statistical and kinetic approaches. Phys Rev E 2016; 94:013203. [PMID: 27575226 DOI: 10.1103/physreve.94.013203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 06/06/2023]
Abstract
Fundamental properties of warm dense matter are described by the dielectric function, which gives access to the frequency-dependent electrical conductivity; absorption, emission, and scattering of radiation; charged particles stopping; and further macroscopic properties. Different approaches to the dielectric function and the related dynamical collision frequency are compared in a wide frequency range. The high-frequency limit describing inverse bremsstrahlung and the low-frequency limit of the dc conductivity are considered. Sum rules and Kramers-Kronig relation are checked for the generalized linear response theory and the standard approach following kinetic theory. The results are discussed in application to aluminum, xenon, and argon plasmas.
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Affiliation(s)
- M Veysman
- Joint Institute for High Temperatures (JIHT) RAS, Izhorskaya 13/19, Moscow 125412, Russia
| | - G Röpke
- Universität Rostock, Institut für Physik, 18051 Rostock, Germany
- National Research Nuclear University (MEPhI), 115409 Moscow, Russia
| | - M Winkel
- Institute for Advanced Simulation, Juelich Supercomputing Centre, Forschungszentrum, Juelich GmbH, 52425 Juelich, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany
| | - H Reinholz
- Universität Rostock, Institut für Physik, 18051 Rostock, Germany
- The University of Western Australia, School of Physics, Crawley, Western Australia 6009, Australia
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8
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McWilliams RS, Dalton DA, Konôpková Z, Mahmood MF, Goncharov AF. Opacity and conductivity measurements in noble gases at conditions of planetary and stellar interiors. Proc Natl Acad Sci U S A 2015; 112:7925-30. [PMID: 26080401 PMCID: PMC4491786 DOI: 10.1073/pnas.1421801112] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The noble gases are elements of broad importance across science and technology and are primary constituents of planetary and stellar atmospheres, where they segregate into droplets or layers that affect the thermal, chemical, and structural evolution of their host body. We have measured the optical properties of noble gases at relevant high pressures and temperatures in the laser-heated diamond anvil cell, observing insulator-to-conductor transformations in dense helium, neon, argon, and xenon at 4,000-15,000 K and pressures of 15-52 GPa. The thermal activation and frequency dependence of conduction reveal an optical character dominated by electrons of low mobility, as in an amorphous semiconductor or poor metal, rather than free electrons as is often assumed for such wide band gap insulators at high temperatures. White dwarf stars having helium outer atmospheres cool slower and may have different color than if atmospheric opacity were controlled by free electrons. Helium rain in Jupiter and Saturn becomes conducting at conditions well correlated with its increased solubility in metallic hydrogen, whereas a deep layer of insulating neon may inhibit core erosion in Saturn.
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Affiliation(s)
- R Stewart McWilliams
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015; School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom; Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom; Departamento de Geociencias, Universidad de Los Andes, Bogotá DC, Colombia; Department of Mathematics, Howard University, Washington, DC 20059;
| | - D Allen Dalton
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015
| | - Zuzana Konôpková
- Deutsches Elektronen-Synchrotron Photon Science, 22607 Hamburg, Germany
| | - Mohammad F Mahmood
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015; Department of Mathematics, Howard University, Washington, DC 20059
| | - Alexander F Goncharov
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015; Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
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Norman G, Saitov I, Stegailov V, Zhilyaev P. Ab initio calculation of shocked xenon reflectivity. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:023105. [PMID: 25768616 DOI: 10.1103/physreve.91.023105] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Indexed: 06/04/2023]
Abstract
Reflectivity of shocked compressed xenon plasma is calculated within the framework of the density functional theory approach. Dependencies on the frequency of incident radiation and on the plasma density are analyzed. The Fresnel formula for the reflectivity is used. The longitudinal expression in the long-wavelength limit is applied for the calculation of the imaginary part of the dielectric function. The real part of the dielectric function is calculated by means of the Kramers-Kronig transformation. The results are compared with experimental data. The approach for the calculation of plasma frequency is developed.
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Affiliation(s)
- G Norman
- Joint Institute for High Temperatures of RAS, Izhorskaya st. 13 Bld. 2, Moscow 125412, Russia
- Moscow Institute of Physics and Technology (State University), Institutskiy per. 9, Dolgoprudny, Moscow Region 141700, Russia
| | - I Saitov
- Joint Institute for High Temperatures of RAS, Izhorskaya st. 13 Bld. 2, Moscow 125412, Russia
| | - V Stegailov
- Joint Institute for High Temperatures of RAS, Izhorskaya st. 13 Bld. 2, Moscow 125412, Russia
- Moscow Institute of Physics and Technology (State University), Institutskiy per. 9, Dolgoprudny, Moscow Region 141700, Russia
- National Research University Higher School of Economics, Myasnitskaya st. 20, Moscow 101000, Russia
| | - P Zhilyaev
- Joint Institute for High Temperatures of RAS, Izhorskaya st. 13 Bld. 2, Moscow 125412, Russia
- Moscow Institute of Physics and Technology (State University), Institutskiy per. 9, Dolgoprudny, Moscow Region 141700, Russia
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10
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Zheng J, Chen QF, Gu YJ, Chen ZY, Li CJ. Thermodynamics, compressibility, and phase diagram: Shock compression of supercritical fluid xenon. J Chem Phys 2014; 141:124201. [DOI: 10.1063/1.4896071] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- J. Zheng
- Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan, People's Republic of China
| | - Q. F. Chen
- Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan, People's Republic of China
| | - Y. J. Gu
- Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan, People's Republic of China
| | - Z. Y. Chen
- Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan, People's Republic of China
| | - C. J. Li
- Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan, People's Republic of China
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11
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Fortov VE, Mintsev VB. Extreme states of matter on the Earth and in the cosmos: is there any chemistry beyond the megabar? RUSSIAN CHEMICAL REVIEWS 2013. [DOI: 10.1070/rc2013v082n07abeh004394] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Zheng J, Chen QF, Gu YJ, Chen ZY. Hugoniot measurements of double-shocked precompressed dense xenon plasmas. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:066406. [PMID: 23368058 DOI: 10.1103/physreve.86.066406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Indexed: 06/01/2023]
Abstract
The current partially ionized plasmas models for xenon show substantial differences since the description of pressure and thermal ionization region becomes a formidable task, prompting the need for an improved understanding of dense xenon plasmas behavior at above 100 GPa. We performed double-shock compression experiments on dense xenon to determine accurately the Hugoniot up to 172 GPa using a time-resolved optical radiation method. The planar strong shock wave was produced using a flyer plate impactor accelerated up to ∼6 km/s with a two-stage light-gas gun. The time-resolved optical radiation histories were acquired by using a multiwavelength channel optical transience radiance pyrometer. Shock velocity was measured and mass velocity was determined by the impedance-matching methods. The experimental equation of state of dense xenon plasmas are compared with the self-consistent fluid variational calculations of dense xenon in the region of partial ionization over a wide range of pressures and temperatures.
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Affiliation(s)
- J Zheng
- National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, P. O. Box 919-102, Mianyang, Sichuan, P. R. China
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Bobrov VB, Mendeleyev VY, Skovorod'ko SN, Trigger SA. Second sum rule for the hot plasma permittivity. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:026402. [PMID: 21405913 DOI: 10.1103/physreve.83.026402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Indexed: 05/30/2023]
Abstract
Based on linear response theory, Kramers-Kronig relations, and diagram techniques of perturbation theory, it is shown that the second sum rule is satisfied for hot plasma permittivity. An explicit analytical expression for the second sum rule in the limit of weak nonideality is derived.
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Affiliation(s)
- V B Bobrov
- Joint Institute for High Temperatures, Russian Academy of Sciences, 13/19, Izhorskaia Street, Moscow 125412, Russia.
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Zaporoghets Y, Mintsev V, Gryaznov V, Fortov V, Reinholz H, Raitza T, Röpke G. Reflectivity of nonideal plasmas. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/0305-4470/39/17/s03] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Raitza T, Reinholz H, Röpke G, Mintsev V, Wierling A. Reflectivity in shock wave fronts of xenon. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/0305-4470/39/17/s13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Morozov I, Reinholz H, Röpke G, Wierling A, Zwicknagel G. Molecular dynamics simulations of optical conductivity of dense plasmas. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:066408. [PMID: 16089881 DOI: 10.1103/physreve.71.066408] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2005] [Revised: 04/06/2005] [Indexed: 05/03/2023]
Abstract
The optical conductivity sigma (omega) for dense Coulomb systems is investigated using molecular dynamics simulations on the basis of pseudopotentials to mimic quantum effects. Starting from linear response theory, the response in the long-wavelength limit k=0 can be expressed by different types of autocorrelation functions (ACF's) such as the current ACF, the force ACF, or the charge density ACF. Consistent simulation data for transverse as well as longitudinal ACF's are shown which are based on calculations with high numerical accuracy. Results are compared with perturbation expansions which are restricted to small values of the plasma parameter. The relevance with respect to a quantum Coulomb plasma is discussed. Finally, results are presented showing a consistent description of these model plasmas in comparison to quantum statistical approaches and to experimental data.
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Affiliation(s)
- I Morozov
- Institute for High Energy Densities of RAS, IHED-IVTAN, Izhorskaya, 13/19, Moscow 127412, Russia
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Reinholz H, Morozov I, Röpke G, Millat T. Internal versus external conductivity of a dense plasma: many-particle theory and simulations. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:066412. [PMID: 15244750 DOI: 10.1103/physreve.69.066412] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2003] [Revised: 03/01/2004] [Indexed: 05/24/2023]
Abstract
In the long-wavelength limit k=0, the response function has been investigated with respect to the external and internal fields which is expressed by the external and internal conductivity, respectively. Molecular dynamics simulations are performed to obtain the current-current correlation function and the dynamical collision frequency which are compared with analytical expressions. Special attention is given to the dynamical collision frequency and the description of plasma oscillations in the case of k=0. The relation between the external and internal conductivity and the current-current correlation function is analyzed.
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Affiliation(s)
- H Reinholz
- University of Western Australia, School of Physics, 35 Stirling Highway, Crawley, WA 6009, Australia.
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