Contributions to Plasma Physics [SJR: 0.717] [H-I: 31] [4 followers] Follow Hybrid journal (It can contain Open Access articles) ISSN (Print) 0863-1042 - ISSN (Online) 1521-3986 Published by John Wiley and Sons [1608 journals] |
- Ionization Potential Depression in Hot Dense Plasmas Through a Pure
Classical Model- Authors: A. Calisti; S. Ferri, B. Talin
Abstract: The ionization potential of an ion embedded in a plasma, lowered due to the whole of the charged particles (ions and electrons) interacting with this ion, is the so‐called plasma effect. A numerical plasma model based on classical molecular dynamics has been developed recently. It is capable to describe a neutral plasma at equilibrium involving ions of various charge states of the same atom together with electrons. This code is used here to investigate the ionization potential depression (IPD). The study of the IPD is illustrated and discussed for aluminum plasmas at mid and solid density and electron temperatures varying from 50eV to 190eV. The method relies on a sampling of the total potential energy of the electron located at an ion being ionized. The potential energy of such electron results from all of the interacting charged particles interacting with it. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T07:10:19.380767-05:
DOI: 10.1002/ctpp.201400087
- Authors: A. Calisti; S. Ferri, B. Talin
- Linear Fluid Theory for Weakly Inhomogeneous Plasmas with Strong
Correlations- Authors: H. Kählert; G. J. Kalman, M. Bonitz
Abstract: Linearized fluid equations for the collective modes of weakly inhomogeneous plasmas including strong coupling effects are derived from a recent kinetic theory based on an extended Singwi‐Tosi‐Land‐Sjölander (STLS) ansatz [H. Kählert, G. J. Kalman, and M. Bonitz, Phys. Rev. E 90, 011101(R) (2014)]. The equations are analogous to the equations of linearized elasticity theory with space dependent elastic moduli that correspond to those of a bulk system with the local fluid density. The identification of the latter as infinite‐frequency elastic moduli shows that the present version of the extended STLS theory accounts for the elastic properties of the fluid but does not capture the viscous behavior. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:47.164641-05:
DOI: 10.1002/ctpp.201400085
- Authors: H. Kählert; G. J. Kalman, M. Bonitz
- Influence of Gap Spacing between Dielectric Barriers in Atmospheric
Pressure Discharges- Authors: M.M. Iqbal; M.M. Turner
Abstract: The breakdown activity in helium atmospheric pressure dielectric barrier discharge (DBD) plasma is strongly modified by introducing small impurities (nitrogen (N2) and air in ppm), although its precise implications for the behavior of discharge plasma is not evident under several constraints. In this simulation study, we investigate the influence of gap spacing between the dielectric barriers to explore the dynamic modification in the structure of discharge plasma in distinct phases of the discharge current pulse using a two‐dimensional fluid model in He‐air gas mixture. Specifically, the impact of nitrogen and air impurities is contrasted by exploring the spatial distributions of electrons in the breakdown phase under similar operating conditions. The filamentary mode of DBD plasma in He‐N2 is transformed into uniform glow discharge in He‐air gas mixture by the dominant effect of Penning ionization. Finally, the outcomes of two‐dimensional fluid model are validated by comparing with three‐dimensional fluid model to provide the reliability of numerical simulations. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:45.088714-05:
DOI: 10.1002/ctpp.201400035
- Authors: M.M. Iqbal; M.M. Turner
- PIC/MCC Simulation of Electron and Ion Currents to Spherical Langmuir
Probe- Authors: D. Trunec; Z. Bonaventura, P. Zikán, J. Jánský
Abstract: The Particle In Cell/Monte Carlo Collisions (PIC/MCC) simulation was used for the calculation of electron and ion currents to a spherical Langmuir (electrostatic) probe. This simulation took into account the collisions of collected charged particles with neutral gas particles around the probe and it can calculate the probe currents at higher neutral gas pressures. The improvements of usual simulation techniques enabled to speed up the simulation and to calculate the probe current even for neutral gas pressures above 1 kPa. The simulations were carried out for two cases: i) probe with radius of 0.5 mm in non‐thermal plasma with high electron temperature, ii) probe with radius of 10 µm in afterglow plasma with low electron temperature. The influence of probe radius on electron probe current was also studied. The simulations showed that thick sheath limit of OML theory provides incorrect values of probe current for probes with radii larger than 200 µm at plasma parameters considered even at very low neutral gas pressures. The probe characteristics were calculated for probe with 0.5 mm radius for pressures up to 500 Pa and for probe with 10 µm radius for pressures up to 3 kPa. The influence of collisions on electron and ion probe current was demonstrated and the procedure for determination of electron and ion densities from the probe measurement at higher pressures was developed. The results from PIC/MCC simulations were compared with results from continuum theory. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:44.094155-05:
DOI: 10.1002/ctpp.201400046
- Authors: D. Trunec; Z. Bonaventura, P. Zikán, J. Jánský
- Second Harmonic Generation of Self Focused Cosh‐Gaussian Laser Beam
in Collisionless Plasma- Authors: A. Singh; N. Gupta
Abstract: This paper presents an investigation of self‐focusing of a Cosh‐Gaussian (ChG) laser beam and its effect on second harmonic generation in collisionless plasma. In the presence of ChG laser beam the carriers get redistributed from high field region to low field region on account of ponderomotive force as a result of which a transverse density gradient is produced in the plasma which in turn generates an electron‐plasma wave at pump frequency. Generated plasma wave interacts with the incident laser beam and hence generates its second harmonics. Moment theory has been used to derive differential equation governing the evolution of spot size of ChG laser beam propagating through collisionless plasma. The differential equation so obtained has been solved numerically. The effect of decentered parameter, intensity of ChG laser beam and density of plasma on self‐focusing of the laser beam and second harmonic yield has been investigated. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:42.298535-05:
DOI: 10.1002/ctpp.201400071
- Authors: A. Singh; N. Gupta
- Gas Chromatography Analysis of Discharge Products in N2‐CH4 Gas
Mixture at Atmospheric Pressure: Study of Mimic Titan's Atmosphere- Authors: L. Torokova; J. Watson, F. Krcma, V. Mazankova, N. J. Mason, G. Horvath, S. Matejcik
Abstract: In this paper, we report presence of various organic products formed in a flowing atmospheric glow discharge fed by gas mixture containing 1‐5 % of methane in nitrogen, which mimics the Titan's atmosphere. Gaseous products from the discharge exhaust were analysed by Gas Chromatography with Mass Spectrometry (GC‐MS). The experimental results revealed C2H2, HCN, and CH3CN as the major products. Various hydrocarbons and nitriles were the other determined gaseous products. Whilst many of these compounds have been predicted and/or observed in the Titan atmosphere, the present plasma experiments provide evidence of both the chemical complexity of Titan atmospheric processes and the mechanisms by which larger species grow prior to form the dust that should cover much of the Titan's surface. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:41.407385-05:
DOI: 10.1002/ctpp.201400052
- Authors: L. Torokova; J. Watson, F. Krcma, V. Mazankova, N. J. Mason, G. Horvath, S. Matejcik
- Molecular Dynamics Simulations of Warm Dense Carbon
- Authors: H. D. Whitley; D. M. Sanchez, S. Hamel, A. A. Correa, L. X. Benedict
Abstract: We present classical and DFT‐based molecular dynamics (MD) simulations of carbon in the warm dense matter regime (ρ = 3.7 g/cc, 0. 86 eV < T < 8.62 eV [T < 100 eV for classical MD]). Two different classical interatomic potentials are used: 1. LCBOP, designed to simulate condensed (e.g. solid) phases of C, and 2. linearly screened Coulomb (Yukawa) potentials. It is shown that LCBOP over‐predicts minima and maxima in the pair correlation functions of liquid‐C in this regime when compared to the DFT‐MD results. The screened Coulomb model, while under‐correlating at low‐T, seems to produce the correct qualitative features in the static ionic pair distributions at the highest‐T. However, both approaches predict the decay in the ionic contribution of the specific heat as T → ∞ to be much slower than that predicted by a model based on DFT‐MD. These differences in the MD‐derived equations of state in warm dense regimes could have important consequences when using classical inter‐ionic forces such as these in large‐scale MD simulations aimed at studying, for instance, processes of relevance to inertial confinement fusion when C is used as an ablator material. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:39.547734-05:
DOI: 10.1002/ctpp.201400101
- Authors: H. D. Whitley; D. M. Sanchez, S. Hamel, A. A. Correa, L. X. Benedict
- A Calculation of the Electron Temperature of Complex Plasma of Noble Gases
Mixture in CCRF Discharge- Authors: S. A. Orazbayev; Y. A. Ussenov, T. S. Ramazanov, M. K. Dosbolayev, A. U. Utegenov
Abstract: In this paper the results of studying of the electron temperature of buffer and complex plasmas in mixtures of noble gases (helium + argon) in capacitively coupled radiofrequency (CCRF) discharge are presented. The optical properties of dusty plasma in argon, helium and their mixtures have been studied using optical diagnostic methods. Based on spectral lines of plasma forming gases, the dependence of the electron temperature on gas pressure and discharge power has been determined. The axial distribution of electron temperature in the interelectrode gap has been measured. Measurements have been made using an RF compensated electric probe. The comparison of the experimental results shows that admixture of a small amount of argon to helium leads to a decrease in the electron temperature of buffer plasma. The presence of dust particles in the plasma causes an increase in the electron temperature. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:36.980462-05:
DOI: 10.1002/ctpp.201400089
- Authors: S. A. Orazbayev; Y. A. Ussenov, T. S. Ramazanov, M. K. Dosbolayev, A. U. Utegenov
- A Method of Separation of Polydisperse Particles in the Plasma of
Radio‐Frequency Discharge- Authors: D. G. Batryshev; T. S. Ramazanov, M. K. Dosbolayev, M. T. Gabdullin
Abstract: A method of separation of polydisperse dust particles in the plasma of radio‐frequency (RF) capacitive discharge is considered. Investigations of plasma equipotential field enabled us to determine conditions for separation of polydisperse dust particles. The simplicity of the technology made it possible to obtain small dispersed particles of different materials. Samples of small dispersed microparticles of silica and alumina were obtained. The size and chemical composition of samples were examined using a Quanta 3D 200i scanning electron microscope (SEM, FEI, USA). The average size of separated silica nanoparticles was 600 nm, that of silica and alumina microparticles was 5 μm. Two separation methods were developed: the first one used a special trap and shape of the bottom electrode of RF discharge (for separation of microparticles) and the second used an electrical trap (for separation of nanoparticles). The graphs of particle size distribution were constructed using graphical and mathematical calculations. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:35.282823-05:
DOI: 10.1002/ctpp.201400091
- Authors: D. G. Batryshev; T. S. Ramazanov, M. K. Dosbolayev, M. T. Gabdullin
- Dynamic Collision Frequency in Kelbg‐Pseudopotential‐Modelled
Plasmas and the Method of Moments with Local Constraints- Authors: Yu.V. Arkhipov; A. Askaruly, D.Yu. Dubovtsev, L.T. Erimbetova, I.M. Tkachenko
Abstract: The dense plasma dynamic collision frequency is modeled by the first two terms of its asymptotic expansion at high frequencies and its values at a few interpolation points on the real axis. This makes the dynamic collision frequency a non‐rational function whose extension onto the upper half‐plane of the complex frequency is holomorphic with a non‐negative imaginary part and with a continuous extension to the real axis. The validity of the suggested analytic form of the latter is tested against the simulation data, where the Kelbg effective potential was used. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:34.580657-05:
DOI: 10.1002/ctpp.201400100
- Authors: Yu.V. Arkhipov; A. Askaruly, D.Yu. Dubovtsev, L.T. Erimbetova, I.M. Tkachenko
- Localization and Screening Enhancement in Asymmetric Binary Ionic Mixtures
- Authors: H. D. Whitley; W. E. Alley, W. H. Cabot, J. I. Castor, J. Nilsen, H. E. DeWitt
Abstract: The equation of state of binary ionic mixtures of similar ions, such as nitrogen, oxygen and carbon, has been extensively studied. The study of dense asymmetric mixtures, where Z 2 >> Z 1, has primarily focused on mixtures of hydrogen and iron at solar conditions. Using molecular dynamics simulations, we examine the behavior of highly asymmetric binary ionic mixtures, where the coupling of the high‐Z species may be orders of magnitude higher than the coupling of the low‐Z species. For the conditions we have studied, we find that strong correlations and signatures of solidification occur in the high‐Z species, while the low‐Z species exists as a freely flowing fluid within the high‐Z solid matrix. Solidification of the low‐Z species is correlated with the coupling between the two components. Using the Widom expansion method, we compute the plasma screening enhancement of the nuclear reaction rates for Z = 1 in a high‐Z matrix. We also provide some estimates of the coefficient of binary diffusion in the mixture. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:32.39171-05:0
DOI: 10.1002/ctpp.201400106
- Authors: H. D. Whitley; W. E. Alley, W. H. Cabot, J. I. Castor, J. Nilsen, H. E. DeWitt
- Note on Mechanism for Formation of Bulbs (Structures) in Complex Plasmas
with Grains of Different Size- Authors: V. Tsytovich; R. Suetterlin, H. Thomas, A. Ivlev
Abstract: In this note the phenomena of formation of grain bulbs (compact grain structure) in presence of grains with different size is discussed from point of view of grain force balance. The requirement is found showing where in the equilibrium conditions the larger size grains are expelled from the regions of smaller size grains forming dust bulbs containing only the smallest size grains. The experiments where this phenomenon was observed are discussed. It is possible to conclude that these experiments can serve as direct evidence for existence of the non‐linear screening of individual grains and for excitation of collective large scale electric fields that balances the drag forces in domain of structures. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:31.608886-05:
DOI: 10.1002/ctpp.201500012
- Authors: V. Tsytovich; R. Suetterlin, H. Thomas, A. Ivlev
- Filamentation Instability in a Current‐Carrying Plasma in the
Presence of Quantum Effects- Authors: S.M. Khorashadizadeh; M.R. Taghadosi, A.R. Niknam
Abstract: The filamentation instability of a current‐carrying plasma under the diffusion condition is investigated taking into account the Bohm potential and the Fermi electron pressure. Using quantum hydrodynamic equations, the dispersion relation and growth rate of the instability is obtained. It is found that the filamentation instability, in the presence of quantum effects, depends on various characteristic parameters such as: electron Fermi velocity, plasma number density, ion thermal velocity and electron drift velocity. Moreover, the wavelength region in which the instability occurs is more restricted and the minimum size of filaments is larger, in comparison with the classical case. It is also found that the growth rate of the instability is smaller in the presence of quantum effects. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-04-01T06:10:30.153267-05:
DOI: 10.1002/ctpp.201400075
- Authors: S.M. Khorashadizadeh; M.R. Taghadosi, A.R. Niknam
- Effect of Mass and Charge of Ionic Species on Spatio‐Temporal
Evolution of Transient Electric Field in CCP Discharges- Authors: S. Sharma; S. K. Mishra, P. K. Kaw, M. M. Turner, S. K. Karkari
Abstract: The formation of capacitive sheath and existence of the transition electric field between sheath edge and bulk plasma in RF‐CCP discharge is predicted (PRL 89, 265006 2002); such structures are sensitive to the plasma composition. On the basis of semi‐infinite particle‐in‐cell (PIC) simulation the effect of charge and mass of ionic species on the spatio‐temporal evolution of the transient electric field and phase mixing phenomena in linear and weakly nonlinear regime has been explored. As an important feature, the simulation results predict that the maximum amplitude of the transient electric field decreases with increasing ionic mass and charge; further the sheath width increases with increasing ionic mass while follow opposite trend with increasing ionic charge. The excitation of wave like structures in the transition region and efficient energy transport to the bulk region of CCP discharges in a nonlinear regime has also been predicted. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:23.763261-05:
DOI: 10.1002/ctpp.201400077
- Authors: S. Sharma; S. K. Mishra, P. K. Kaw, M. M. Turner, S. K. Karkari
- A Spectrally Resolved Motional Stark Effect Diagnostic for the TJ‐II
Stellarator- Authors: K. J. McCarthy; N. Panadero, A. López‐Fraguas, J. Hernández, B. van Milligen
Abstract: A spectrally resolved motional stark effect (MSE) diagnostic has been implemented for the TJ‐II stellarator to quantify the magnitude and pitch of components of the magnetic field created in this magnetic confinement device. The system includes a compact diagnostic neutral beam injector (DNBI) that provides a short pulse of accelerated neutral hydrogen atoms with an e–1 beam radius of 2.1 cm to stimulate the Doppler‐displaced Balmer Hα emissions, which are the basis for this diagnostic. Measurement of the wavelength separation of the Stark splitting of the Hα spectrum, as well as of the relative line intensities of its components, allow the local magnitude and direction of the internal magnetic field components to be measured at 10 positions across the plasma. The use of a DNBI extends such measurements to the electron cyclotron resonance (ECR) heated phases of plasmas while also overcoming the need for the complicated inversion techniques that are required when such measurements are performed with a heating neutral beam injector (NBI). Moreover, the use of the shot‐to‐shot technique with reproducible discharges further simplifies fits to the MSE spectra as nearby impurity spectral emission lines can be eliminated or significantly reduced. After outlining the principles of this technique and the diagnostic set‐up, magnetic field measurements made during ECR or NBI heating phases are reported for a range of magnetic configurations and are compared with vacuum magnetic field estimates in order to evaluate the capabilities and limitations of this diagnostic for the TJ‐II. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:20.505008-05:
DOI: 10.1002/ctpp.201400067
- Authors: K. J. McCarthy; N. Panadero, A. López‐Fraguas, J. Hernández, B. van Milligen
- Characterisation of a Simple Non‐Thermal Atmospheric Pressure Plasma
Source for Biomedical Research Applications- Authors: J. Gruenwald; J. Reynvaan, T. Eisenberg, P. Geistlinger
Abstract: The recent progress in plasma medicine as well as biomedical aspects of plasma physics over the last years have enhanced the need for experimental plasma devices which are capable of producing non‐thermal atmospheric pressure plasmas. These plasma sources are used for studying the effect of non‐thermal plasmas on biological samples of different nature. In this paper we present such an easy to build low cost apparatus that can be used for scientific as well as for educational purposes. Directions for the construction of the device are given and the basic plasma parameters are investigated. The characterisation of the experiment was done by electrical diagnostics for the measurements of the plasma potential in combination with optical emission spectroscopy. The latter is used for the determination of the excitation temperature of the plasma and the electron density. Furthermore the influence of the produced plasma on yeast cells is demonstrated. The produced plasma is characterised in different ways and it was found that the feeding gas has also a considerable impact on the radio frequency wave form of the source. It is also demonstrated that the constructed plasma source is capable of producing non‐thermal plasma that hinder cell growth of yeast colonies on a agar substrate. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:19.05767-05:0
DOI: 10.1002/ctpp.201400059
- Authors: J. Gruenwald; J. Reynvaan, T. Eisenberg, P. Geistlinger
- The Dynamical Structure Function of the One‐Component Plasma
Revisited- Authors: I. Korolov; G. J. Kalman, L. Silvestri, Z. Donkó
Abstract: We present high precision Molecular Dynamics simulations for the dynamical structure function, S (k, ω), of the classical Coulomb One Component Plasma (OCP), for a wide range of the coupling parameter Π (from 0.05 to 10 000). We follow the positive‐to‐negative transition of the slope of the ω (k) dispersion curve at small wave numbers caused by the onset of correlations with increasing coupling. The high signal‐to‐noise ratio of the data over several orders of magnitude allows examination of a wide dynamical range of S (k, ω), including extreme values of ω and k, and the identification of waves at higher harmonics of the plasma frequency. Sum rules are found to be accurately satisfied. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:15.821681-05:
DOI: 10.1002/ctpp.201400098
- Authors: I. Korolov; G. J. Kalman, L. Silvestri, Z. Donkó
- Cover Picture: Contrib. Plasma Phys. 2–3/2015
- Pages: 78 - 78
Abstract: zzz
PubDate: 2015-02-26T12:08:54.526395-05:
DOI: 10.1002/ctpp.201590002
- Pages: 78 - 78
- Issue Information: Contrib. Plasma Phys. 2–3/2015
- Pages: 78 - 79
PubDate: 2015-02-26T12:08:54.458937-05:
DOI: 10.1002/ctpp.201590003
- Pages: 78 - 79
- Contents: Contrib. Plasma Phys. 2–3/2015
- Pages: 79 - 81
PubDate: 2015-02-26T12:08:51.894769-05:
DOI: 10.1002/ctpp.201510002
- Pages: 79 - 81
- Preface: Contrib. Plasma Phys. 2–3/2015
- Pages: 82 - 84
PubDate: 2015-02-26T12:08:51.815954-05:
DOI: 10.1002/ctpp.201510003
- Pages: 82 - 84
- A Review of Studies on Strongly‐Coupled Coulomb Systems Since the
Rise of DFT and SCCS‐1977- Authors: M. W. C. Dharmawardana
First page: 85
Abstract: The conferences on “Strongly Coupled Coulomb Systems” (SCCS) arose from the “Strongly Coupled Plas‐mas” meetings, inaugurated in 1977. The progress in SCCS theory is reviewed in an ‘author‐centered’ frame to limit its scope. Our efforts, i.e., with François Perrot, sought to apply density functional theory (DFT) to SCCS calculations. DFT was then poised to become the major computational scheme for condensed matter physics. The ion‐sphere models of Salpeter and others evolved into useful average‐atom models for finite‐T Coulomb systems, as in Lieberman's Inferno code. We replaced these by correlation‐sphere models that exploit the description of matter via density functionals linked to pair‐distributions. These methods provided practical computational means for studying strongly interacting electron‐ion Coulomb systems like warm‐dense matter (WDM). The staples of SCCS are wide‐ranged, viz., equation of state, plasma spectroscopy, opacity (absorption, emission), scattering, level shifts, transport properties, e.g., electrical and heat conductivity, laser‐ and shock‐created plasmas, their energy relaxation and transient properties etc. These calculations need pseudopotentials and exchange‐correlation functionals applicable to finite‐T Coulomb systems that may be used in ab initio codes, molecular dynamics, etc. The search for simpler computational schemes has proceeded via proposals for orbital‐free DFT, statistical potentials, classical maps of quantum systems using classical schemes like HNC to include strong coupling effects (CHNC). Laughlin's classical plasma map for the fractional quantum Hall effect (FQHE) is a seminal example where we report new results for graphene. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:22.268184-05:
DOI: 10.1002/ctpp.201400073
- Authors: M. W. C. Dharmawardana
- Inhomogeneous Models of Jupiter and Saturn
- Authors: N. Nettelmann
First page: 116
Abstract: The H‐He rich giant planets Jupiter and Saturn serve to test predictions on the high‐pressure behavior of hydrogen and helium. Incorporating the process of H/He phase separation and He rain, or of core erosion, into planet structure and evolution models leads naturally to the assumption of inhomogeneous planetary interiors. In this article we review and discuss recent developments in that regard. It is found that Saturn's luminosity is consistent with a semi‐convective thick shell where the heavy element abundance changes continuously, and that Jupiter's luminosity can as well be explained by a balance between additional gravitational energy and reduced cooling through a He‐rain zone. We present the first Jupiter structure models that include a superadiabatic shell. Using the SCvHi EOS, Jupiter emerges as a mostly homogeneous body apart from a He‐rain zone at a few Megabars. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:26.898093-05:
DOI: 10.1002/ctpp.201400093
- Authors: N. Nettelmann
- Pressure‐Driven Enthalpic and Lifshitz Transition in
122‐Pnictides- Authors: K.F. Quader; M. Widom
Pages: 128 - 135
Abstract: Iron‐arsenic pnictides are a class of compounds in which strong Coulomb interactions manifest in novel prop¬erties. We discuss basic ideas behind a Lifshitz transition and review salient properties of 122‐pnictides (AFe2As2; A = Ca, Sr, Ba, Ra). Using T = 0 first principles total energy calculations, as a function of hydro¬static pressure, we show that several pressure‐driven anomalies, and the tetragonal (T) to collapsed tetragonal (cT) phase transition in the 122‐pnictides family, can be understood as consequences of Lifshitz transitions arising from nontrivial changes in Fermi surface topology. We also show that several features found in our calculations, namely, enthalpic, magnetic and T‐cT transitions, are universal to the 122‐pnictides. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-02-26T12:08:52.986065-05:
DOI: 10.1002/ctpp.201400104
- Authors: K.F. Quader; M. Widom
- Two‐Temperature Pair Potentials and Phonon Spectra for Simple Metals
in the Warm Dense Matter Regime- Authors: L. Harbour; M. W. C. Dharma‐wardana, D. D. Klug, L. J. Lewis
Pages: 144 - 151
Abstract: We develop ion‐ion pair potentials for Al, Na and K for densities and temperatures relevant to the warm‐densematter (WDM) regime. Furthermore, we emphasize non‐equilibrium states where the ion temperature Ti differs from the electron temperature Te. This work focuses mainly on ultra‐fast laser‐metal interactions where the energy of the laser is almost exclusively transferred to the electron sub‐system over femtosecond time scales. This results in a two‐temperature system with Te > Ti and with the ions still at the initial room temperature Ti = Tr. First‐principles calculations, such as density functional theory (DFT) or quantum Monte Carlo, are as yet not fully feasible for WDM conditions due to lack of finite‐T features, e.g. pseudopotentials, and extensive CPU time requirements. Simpler methods are needed to study these highly complex systems. We propose to use two‐temperature pair potentials Uii(r, Ti, Te) constructed from linear‐response theory using the non‐linear electron density n (r) obtained from finite‐T DFT with a single ion immersed in the appropriate electron fluid. We compute equilibrium phonon spectra at Tr which are found to be in very good agreement with experiments. This gives credibility to our non‐equilibrium phonon dispersion relations which are important in determining thermophysical properties, stability, energy‐relaxation mechanisms and transport coefficients. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-02-26T12:08:52.502473-05:
DOI: 10.1002/ctpp.201400092
- Authors: L. Harbour; M. W. C. Dharma‐wardana, D. D. Klug, L. J. Lewis
- Pressure in electronically excited warm dense metals
- Authors: V. Stegailov; P. Zhilyaev
First page: 164
Abstract: Non‐equilibrium two‐temperature warm dense metals consist of the ion subsystem that is subjected to structural transitions and involved in the mass transfer, and the electron subsystem that in various pulsed experiments absorbs energy and then evolves together with ions to equilibrium. Definition of pressure in such non‐equilibrium systems causes certain controversy. In this work we make an attempt to clarify this definition that is vital for proper description of the whole relaxation process. Using the density functional theory we analyze on examples of Al and Au electronic pressure components in warm dense metals. Appealing to the Fermi gas model we elucidate a way to find a number of free delocalized electrons in warm dense metals. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:13.277617-05:
DOI: 10.1002/ctpp.201400103
- Authors: V. Stegailov; P. Zhilyaev
- Low‐Density Crystals in Charged Colloids: Comparison with Yukawa
Theory- Authors: I. Rios de Anda; A. Statt, F. Turci, C.P. Royall
First page: 172
Abstract: Charged colloids can behave as Yukawa systems, with similar phase behaviour. Using particle‐resolved studies, we consider a system with an unusually long Debye screening length which forms crystals at low colloid volume fraction φ ≈ 0.01. We quantitatively compare this system with the Yukawa model and find that its freezing point is compatible with the theoretical prediction but that the crystal polymorph is not always that expected. In particular we find body‐centred cubic crystals where face‐centred cubic crystals are expected. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:14.533684-05:
DOI: 10.1002/ctpp.201400099
- Authors: I. Rios de Anda; A. Statt, F. Turci, C.P. Royall
- Polarization and Finite Size Effects in Correlation Functions of Dusty
Plasmas- Authors: A. E. Davletov; L. T. Yerimbetova, Ye. S. Mukhametkarimov, A. K. Ospanova
First page: 180
Abstract: An approach is presented to derive a pseudopotential model of interaction between dust particles that simultaneously takes into account the polarization, finite size and screening effects. The consideration starts from the assumption that the dust particles are hard balls made of a conductive material such that their mutual interaction and interaction with the electrons and ions of the buffer plasma can analytically be interpreted within the method of image charges. Then, the renormalization theory of plasma particles interaction, leading to the so‐called generalized Poisson‐Boltzmann equation, is applied to obtain the interaction potential of two isolated dust grains immersed into the buffer plasma of electrons and ions. After that the Ornstein‐Zernike relation in the hyper‐netted chain approximation (HNC) is numerically solved to study the radial distribution function and the static structure factor of the dust grains. In doing so the system of hard balls is actually replaced by a system of point‐like charges with properly adjusted number density in the form of van der Waals correction. A straightforward comparison is made with the Monte‐Carlo simulation to find a fairly good agreement for the radial distribution function at relatively high dust couplings. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:25.706339-05:
DOI: 10.1002/ctpp.201400086
- Authors: A. E. Davletov; L. T. Yerimbetova, Ye. S. Mukhametkarimov, A. K. Ospanova
- Dynamical Screening and Wake Effects in Classical, Quantum, and
Ultrarelativistic Plasmas- Authors: Zh. A. Moldabekov; P. Ludwig, J.‐P. Joost, M. Bonitz, T. S. Ramazanov
First page: 186
Abstract: Wakefields are of omnipresent nature in non‐equilibrium situations, but their appearance and parametrical scaling is very diverse. Therefore, in this work the topological structure and characteristics of the dynamically screened potential is outlined for three representative systems in completely different physical regimes: (i) a classical complex (dusty) plasma, (ii) a degenerate electron‐ion plasma at high densities, and (iii) an ultrarelativistic quark‐gluon plasma. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:12.139897-05:
DOI: 10.1002/ctpp.201400105
- Authors: Zh. A. Moldabekov; P. Ludwig, J.‐P. Joost, M. Bonitz, T. S. Ramazanov
- Thermodynamics of the Quark‐Gluon Plasma at Finite Chemical
Potential: Color Path Integral Monte Carlo Results- Authors: V.S. Filinov; M. Bonitz, Y.B. Ivanov, E.‐M. Ilgenfritz, V.E. Fortov
First page: 203
Abstract: Based on the constituent quasiparticle model of the quark‐gluon plasma (QGP), color quantum path‐integral Monte‐Carlo (PIMC) calculations of the thermodynamic properties of the QGP are performed. We extend our previous zero chemical potential simulations to the QGP at finite baryon chemical potential. The results indicate that color PIMC can be applied not only above the QCD critical temperature Tc but also below Tc. Besides reproducing the lattice equation of state our approach yields also valuable additional insight into the internal structure of the QGP, via the pair distribution functions of the various quasiparticles. In particular, the pair distribution function of gluons reflects the existence of gluon‐gluon bound states at low temperatures and μ = 175 MeV, i.e. glueballs, while meson‐like bound states are not found. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:30:18.098209-05:
DOI: 10.1002/ctpp.201400056
- Authors: V.S. Filinov; M. Bonitz, Y.B. Ivanov, E.‐M. Ilgenfritz, V.E. Fortov
- Classical‐Map Hypernetted Chain Calculations for Dense Plasmas
- Authors: R. Bredow; Th. Bornath, W.‐D. Kraeft, M.W.C. Dharma‐wardana, R. Redmer
Pages: 222 - 229
Abstract: Warm dense matter is of interest for modeling the interiors of planets and Brown Dwarfs. Corresponding pump‐probe experiments are performed at free electron laser facilities such as FLASH, LCLS or the future XFEL in Hamburg. X‐ray Thomson scattering is of special interest to extract the plasma parameters. In order to explain or predict the X‐ray Thomson scattering spectra, simulations on the structural properties of plasmas are performed. While ab initio simulations are computationally expensive, semi‐classical approaches can deliver results fast for pair distribution functions and static structure factors, even for dense systems. We solve the Ornstein‐Zernike equation within the hypernetted chain approximation for dense multi‐component plasmas using the classical‐map method. This approach proposes to treat the quantum features of the electrons using an adapted temperature for the electron system while the ions are treated classically. Results for pair distribution functions and static structure factors are presented for dense hydrogen, beryllium, carbon and CH plasmas. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-02-26T12:08:57.11171-05:0
DOI: 10.1002/ctpp.201400080
- Authors: R. Bredow; Th. Bornath, W.‐D. Kraeft, M.W.C. Dharma‐wardana, R. Redmer
- Phase Shifts and Scattering Cross Sections of the Particles of
Non‐ideal Semiclassical Plasmas Based on the Dynamic Interaction
Potential- Authors: K. N. Dzhumagulova; E. O. Shalenov, T. S. Ramazanov, G. L. Gabdullina
First page: 230
Abstract: The elastic scattering processes of the charged particles in the dense nonideal plasma on the basis of the dynamic interaction potential were investigated. It is shown that dynamic charge screening increases the phase shifts and the scattering cross sections in comparison with static screening. The problem was solved on the basis of the Calogero equation for finding the phase shifts. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:24.783193-05:
DOI: 10.1002/ctpp.201400078
- Authors: K. N. Dzhumagulova; E. O. Shalenov, T. S. Ramazanov, G. L. Gabdullina
- Waves in a Lennard‐Jones Dusty Plasma Liquid
- Authors: M. Rosenberg; G. J. Kalman, V. Grewal
First page: 264
Abstract: Recently it has been proposed to alter the interaction between dust grains in a plasma by applying ac electric fields to distort the Debye spheres surrounding the grains, which may lead to interaction potentials with a Lennard‐Jones form under certain conditions (e.g., Kompaneets et al., Phys. Plasmas 16, 043705 (2009)). Motivated by this, we consider the dispersion relations of longitudinal and transverse waves in a dusty plasma liquid where the grains interact via a Lennard‐Jones potential. We use the Quasi‐Localized Charge approximation combined with an analytic expression for the pair distribution function for Lennard‐Jones fluids (Matteoli and Mansoori, J. Chem. Phys. 103, 4672 (1995)). Possible dusty plasma experimental parameters are considered. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:30:19.443459-05:
DOI: 10.1002/ctpp.201400057
- Authors: M. Rosenberg; G. J. Kalman, V. Grewal
- Investigation of Coulomb Logarithm and Relaxation Processes in Dense
Plasma on the Basis of Effective Potentials- Authors: S. K. Kodanova; T. S. Ramazanov, M. K. Issanova, G. N. Nigmetova, Zh. A. Moldabekov
First page: 271
Abstract: In this paper the relaxation properties of non‐isothermal dense plasmas were studied. Based on the effective interaction potentials between particles, the Coulomb logarithm for two‐temperature non‐isothermal dense plasmas was obtained. These potentials take into consideration long‐range multi‐particle screening effects and short‐range quantum‐mechanical effects in two‐temperature plasmas. The relaxation processes in such plasmas were studied using the Coulomb logarithm. The obtained results were compared with theoretical works of other authors and with the results of molecular dynamics simulation. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2015-01-23T07:40:16.908767-05:
DOI: 10.1002/ctpp.201400094
- Authors: S. K. Kodanova; T. S. Ramazanov, M. K. Issanova, G. N. Nigmetova, Zh. A. Moldabekov
- Lenard‐Balescu Calculations and Classical Molecular Dynamics
Simulations of Electrical and Thermal Conductivities of Hydrogen Plasmas- Authors: H. D. Whitley; Ch. R. Scullard, L. X. Benedict, J. I. Castor, A. Randles, J. N. Glosli, D. F. Richards, M. P. Desjarlais, F. R. Graziani
Abstract: We present a discussion of kinetic theory treatments of linear electrical and thermal transport in hydrogen plasmas, for a regime of interest to inertial confinement fusion applications. In order to assess the accuracy of one of the more involved of these approaches, classical Lenard‐Balescu theory, we perform classical molecular dynamics simulations of hydrogen plasmas using 2‐body quantum statistical potentials and compute both electrical and thermal conductivity from our particle trajectories using the Kubo approach. Our classical Lenard‐Balescu results employing the identical statistical potentials agree well with the simulations. Comparison between quantum Lenard‐Balescu and classical Lenard‐Balescu for conductivities then allows us to both validate and critique the use of various statistical potentials for the prediction of plasma transport properties. These findings complement our earlier MD/kinetic theory work on temperature equilibration [1], and reach similar conclusions as to which forms of statistical potentials best reproduce true quantum behavior. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-12-04T06:13:28.962083-05:
DOI: 10.1002/ctpp.201400066
- Authors: H. D. Whitley; Ch. R. Scullard, L. X. Benedict, J. I. Castor, A. Randles, J. N. Glosli, D. F. Richards, M. P. Desjarlais, F. R. Graziani
- Towards ab Initio Thermodynamics of the Electron Gas at Strong Degeneracy
- Authors: T. Schoof; S. Groth, M. Bonitz
Abstract: Recently a number of theoretical studies of the uniform electron gas (UEG) at finite temperature have appeared that are of relevance for dense plasmas, warm dense matter and laser excited solids and thermodynamic density functional theory simulations. In particular, restricted path integral Monte Carlo (RPIMC) results became available which, however, due to the Fermion sign problem, are confined to moderate quantum degeneracy, i.e. low to moderate densities. We have recently developed an alternative approach–configuration PIMC [T. Schoof et al., Contrib. Plasma Phys. 51, 687 (2011)] that allows one to study the so far not accessible high degeneracy regime. Here we present the first step towards UEG simulations using CPIMC by studying implementation and performance of the method for the model case of N = 4 particles. We also provide benchmark data for the total energy. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-12-04T06:13:27.447548-05:
DOI: 10.1002/ctpp.201400072
- Authors: T. Schoof; S. Groth, M. Bonitz
- Hierarchy of Fluctuation‐Dissipation Theorems for the Classical
One‐Component Plasma- Authors: K. I. Golden; J. T. Heath
Abstract: We have derived tractable cubic (p = 3) and quartic (p = 4) fluctuation‐dissipation theorems (FDTs) for the classical one‐component plasma in a form that links a single (p + 1)‐point dynamical structure function to a linear combination of p th‐order density response functions amenable to calculation from model plasma kinetic equations. For p ≥ 3, we note the emergence of “remainder” contributions comprised of clusters of lower‐order dynamical structure functions which can be ultimately traded for response functions vis‐á‐vis the linear and quadratic FDTs. Our analysis provides insight into the structure of the FDT hierarchy. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-12-04T06:13:26.060248-05:
DOI: 10.1002/ctpp.201400082
- Authors: K. I. Golden; J. T. Heath
- A tribute to pioneers of strongly coupled plasmas: Hugh E. DeWitt, Bernard
Jancovici, and Forrest J. Rogers- Authors: H. D. Whitley; A. Alastuey, J.A. Gaffney, R. Cauble, W.D. Kraeft, M. Bonitz
Abstract: The field of strongly coupled Coulomb systems that stretches from dense plasma, to astrophysics, condensed matter and high energy physics has seen a dramatic development over the last four decades. At the beginning of this process were a few physicists whose work has had a high impact on many exciting developments of the recent years. Among them are Hugh E. DeWitt, Bernard Jancovici and Forrest J. Rogers who passed away in 2013–2014. Their important contributions to the field of strongly coupled Coulomb systems are summarized in this article. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-12-04T06:13:24.52535-05:0
DOI: 10.1002/ctpp.201400083
- Authors: H. D. Whitley; A. Alastuey, J.A. Gaffney, R. Cauble, W.D. Kraeft, M. Bonitz
- Plasma‐Plasma and Liquid‐Liquid First‐Order Phase
Transitions- Authors: G. E. Norman; I. M. Saitov, V. V. Stegailov
Abstract: Ab initio quantum modeling is applied to check the ideas that motivated studies of both plasma phase transition (PPT) and Brazhkin semiconductor‐to‐metal phase transition, and to analyze both similarity and difference between them as well as with the Wigner metallization. Electron density of states and the characteristic gap in it are investigated to verify the semiconductor‐to‐metal nature of the transition. The change of plasma frequency is suggested to be used instead of the “degree of ionization” to characterize the difference between two plasma phases at PPT. Electron density of states, pair distribution function, and conductivity are calculated as well. It is shown that Norman‐Starostin ideas about (a) PPT and (b) phase diagram for fluids are not anymore a hypothesis. They are confirmed by the experimental data. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-12-04T06:13:22.758472-05:
DOI: 10.1002/ctpp.201400088
- Authors: G. E. Norman; I. M. Saitov, V. V. Stegailov
- Diagnostics of Tin Plasma Produced by Visible and IR Nanosecond Laser
Ablation- Authors: M. Hanif; M. Salik
Abstract: We present the optical emission spectroscopic studies of the Tin (Sn) plasma, produced by the fundamental (1064 nm) and second (532 nm) harmonics of a Q switched Nd: YAG pulsed laser having pulse duration of 5 ns and 10 Hz repetition rate which is capable of delivering 400 mJ at 1064 nm, and 200 mJ at 532 nm using Laser Induced Breakdown Spectroscopy (LIBS). The laser beam was focused on target material by placing it in air at atmospheric pressure. The experimentally observed line profiles of four neutral tin (Sn I) lines at 231.72, 248.34, 257.15 and 266.12 nm were used to extract the electron temperature (Te) using the Boltzmann plot method and determined its value 6360 and 5970 K respectively for fundamental and second harmonics of the laser. Whereas, the electron number density (Ne) has been determined from the Stark broadening profile of neutral tin (Sn I) line at 286.33 nm and determined its value 5.85 x 1016 and 6.80 x 1016cm–3 for fundamental and second harmonics of the laser respectively. Both plasma parameters (Te and Ne) have also been calculated by varying distance from the target surface along the line of propagation of plasma plume and also by varying the laser irradiance. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-12-04T05:42:39.353283-05:
DOI: 10.1002/ctpp.201400055
- Authors: M. Hanif; M. Salik
- Effects of Direct Double Auger Decay on the Population Dynamics of Neon
Irradiated by Ultraintense x‐ray Pulses- Authors: C. Gao; J. Zeng, J. Yuan
Abstract: The population and charge state distribution of neon interacting with ultraintense x‐ray pulses are investigated by solving a time‐dependent rate equation in the detailed level‐accounting (DLA) approximation. Due to the detailed description of neon atom and ions, our DLA result improves the agreement between predictions and experimental measurements for odd neon charge states. In the framework of the DLA formalism, we further studied the effects of direct double Auger decay (DDAD) on charge state distribution. After the 1s photoionization of neon atom, the DDAD processes give accessible decay channels from the K‐shell hole state of Ne+ to levels of Ne3+, resulting in an increase of the population fraction of Ne3+ and a decrease of that of Ne2+. Compared with the results without considering the DDAD effects, better agreement is obtained between theory and experiment. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-12-04T05:42:38.075782-05:
DOI: 10.1002/ctpp.201400061
- Authors: C. Gao; J. Zeng, J. Yuan
- Effects of the System Temperature on Dust Cluster Formation in Plasma
- Authors: Y. L. Song; F. Huang, Z. Y. Chen, Y. H. Liu, M. Y. Yu, K. F. Chen, L. Wang
Abstract: Effects of the system temperature on dust aggregation in plasmas are investigated using two‐dimensional molecular dynamics simulations. It is shown that as the system temperature increases, the boundary of the clusters becomes gradually irregular (i.e., deviating from sphere‐like), and the cluster system gradually changes from solid to liquid and finally to gas state. The mean square displacement, mean nearest‐neighbor distance in the clusters, cluster size and coupling parameter of the system are obtained and the properties of the system structure and dynamics are investigated. The time τ needed for reaching equilibrium for different temperatures is obtained. It is shown that τ firstly decreases and then increases with the temperature, indicating that there is an optimum temperature allowing a dust aggregation to reach an equilibrium state most rapidly. The simulation results agree qualitatively with the experimental observations. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-11-27T07:20:10.41795-05:0
DOI: 10.1002/ctpp.201400028
- Authors: Y. L. Song; F. Huang, Z. Y. Chen, Y. H. Liu, M. Y. Yu, K. F. Chen, L. Wang
- First‐Principle Results for the Radial Pair Distribution Function in
Strongly Coupled One‐Component Plasmas- Authors: T. Ott; M. Bonitz
Abstract: The radial pair distribution function (RPDF) is the most simple way to characterize the structure of a system. In this work, we provide a comprehensive overview of the dependence of the RPDF on the coupling parameter and screening length in Coulomb and Yukawa One‐Component plasmas. These data allows for a precise assessment of the coupling strength of experiments and simulations via a structural measurement and give a benchmark for analytical models. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-11-27T07:20:09.298594-05:
DOI: 10.1002/ctpp.201400063
- Authors: T. Ott; M. Bonitz
- Self‐Organization in Dense Plasmas: The Gamma‐Plateau
- Authors: J. Clérouin; Ph. Arnault, G. Robert, C. Ticknor, J. D. Kress, L. A. Collins
Abstract: When heated at constant volume (isochoric heating) a hot and dense plasma (10‐5000 eV, 1‐50 g/cm3) exhibits the same persistent microscopic structure over a wide range of temperatures as intuited long time ago by Laughlin [1]. In this steady‐state regime, which depends on the chosen density and on the atomic number, the static structure is essentially independent of the temperature and results in the subtle balance between ionization and temperature leading to a constant coupling between ions. This behavior, suggested by simulations, is confirmed by an analysis in the framework of the Thomas‐Fermi scaling laws and is driven by the ionization dynamics which regulates the coupling between ions and electrons. A simple fit is derived allowing for predicting the occurrence of this self‐organized regime: the Γ‐plateau. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-11-27T07:20:08.217253-05:
DOI: 10.1002/ctpp.201400064
- Authors: J. Clérouin; Ph. Arnault, G. Robert, C. Ticknor, J. D. Kress, L. A. Collins
- Toward a Nonequilibrium Green Functions Approach to Diffusion in Strongly
Coupled Finite Quantum Systems- Authors: M. Bonitz; N. Schlünzen, S. Hermanns
Abstract: Transport properties of strongly correlated quantum systems are of central interest in condensed matter, ultracold atoms and in dense plasmas. There, the proper treatment of strong correlations poses a great challenge to theory. Here, we apply a Nonequilibrium Green Functions approach using a lattice model as a basic system. This allow us to treat a finite spatially inhomogeneous system with an arbitrary nonequilibrium initial state. Placing all particles initially to one side of the system allows for a nonequilibrium study of diffusion. Strong correlation effects are incorporated via T‐matrix selfenergies. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-11-27T07:20:06.885232-05:
DOI: 10.1002/ctpp.201400065
- Authors: M. Bonitz; N. Schlünzen, S. Hermanns
- Effective Potential Theory: A Practical Way to Extend Plasma Transport
Theory to Strong Coupling- Authors: S.D. Baalrud; K. Ø. Rasmussen, J. Daligault
Abstract: The effective potential theory is a physically motivated method for extending traditional plasma transport theories to stronger coupling. It is practical in the sense that it is easily incorporated within the framework of the Chapman‐Enskog or Grad methods that are commonly applied in plasma physics and it is computationally efficient to evaluate. The extension is to treat binary scatterers as interacting through the potential of mean force, rather than the bare Coulomb or Debye‐screened Coulomb potential. This allows for aspects of many‐body correlations to be included in the transport coefficients. Recent work has shown that this method accurately extends plasma theory to orders of magnitude stronger coupling when applied to the classical one‐component plasma model. The present work shows that similar accuracy is realized for the Yukawa one‐component plasma model and it provides a comparison with other approaches. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-11-27T07:20:05.501046-05:
DOI: 10.1002/ctpp.201400084
- Authors: S.D. Baalrud; K. Ø. Rasmussen, J. Daligault
- Nonlinear Transport Processes in Non‐Ideal Media
- Authors: G. A. Pavlov; Yu. V. Troshchiev
First page: 254
Abstract: The theory of non‐linear transport is elaborated to determine the Burnett transport properties of non‐ideal multielement plasma and neutral systems. The procedure of the comparison of the phenomenological conservation equations of a continuous dense medium and the microscopic equations for dynamical variables operators in the form of the generalized nonlinear Langevin equations is used for the definition of these properties. In consequence, the microscopic expressions of transport coefficients corresponding to second order thermal disturbances (temperature, mass velocity, etc.) have been found in the long‐wavelength and low frequency limits of correlations functions. Situations are considered when the use of nonlinear transport characteristics (in the Burnett approximation) significantly affects the results of modeling of hydrodynamic processes in dense charged and neutral media. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PubDate: 2014-12-16T10:40:04.382293-05:
DOI: 10.1002/ctpp.201400050
- Authors: G. A. Pavlov; Yu. V. Troshchiev