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Related papers: Free-energy model for fluid helium at high density

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We investigate the ionization and the opacity of warm, dense helium under conditions found in the atmospheres of cool white dwarf stars. Our particular interest is in densities up to $\rm 3 g/cm^{3}$ and temperatures from 1000K to 10000K.…

Materials Science · Physics 2009-11-11 P. M. Kowalski , S. Mazevet , D. Saumon

The hydrogen plasma is studied at temperatures T ~ 10^4 - 10^6 K using the free energy minimization method. A simple analytic free energy model is proposed which is accurate at densities up to 1 g/cc and yields convergent internal partition…

plasm-ph · Physics 2009-10-30 A. Y. Potekhin

A systematic study of pressure ionization is carried out in the chemical picture by the example of fluid helium. By comparing the variants of the chemical model, it is demonstrated that the behavior of pressure ionization depends on the…

Plasma Physics · Physics 2016-12-13 Qiong Li , Hai-Feng Liu , Gong-Mu Zhang , Yan-Hong Zhao , Guo Lu , Ming-Feng Tian , Hai-Feng Song

By performing an ensemble of molecular dynamics simulations, the model-dependent ionisation state is computed for strongly interacting systems self-consistently. This is accomplished through a free energy minimisation framework based on the…

We investigate the dissociation and ionization equilibria of deuterium fluid over a wide range of temperatures and densities. The partition functions for molecular and atomic species are evaluated, in a statistical-mechanically consistent…

Plasma Physics · Physics 2015-11-19 Mofreh R. Zaghloul

Equilibrium properties of hydrogen-helium mixtures under thermodynamic conditions found in the interior of giant gas planets are studied by means of density functional theory molecular dynamics simulations. Special emphasis is placed on the…

Materials Science · Physics 2009-09-29 Jan Vorberger , Isaac Tamblyn , Stanimir A. Bonev , Burkhard Militzer

A two-dimensional fluid model is used to investigate the electron heating dynamics and the production of neutral species in a capacitively coupled radio-frequency micro atmospheric pressure helium plasma jet -- specifically the COST jet --…

Equilibrium properties of hydrogen-helium mixtures under conditions similar to the interior of giant gas planets are studied by means of first principle density functional molecular dynamics simulations. We investigate the molecular and…

Other Condensed Matter · Physics 2009-07-09 Jan Vorberger , I. Tamblyn , B. Militzer , S. A. Bonev

Thermophysical properties of hydrogen, helium, and hydrogen-helium mixtures have been investigated in the warm dense matter regime at electron number densities ranging from $6.02\times10^{29}\sim2.41\times10^{30}$/m$^{3}$ and temperatures…

Materials Science · Physics 2015-06-16 Cong Wang , Xian-Tu He , Ping Zhang

We report new accurate mesasurements of the mobility of excess electrons in high density Helium gas in extended ranges of temperature $[(26\leq T\leq 77) K ]$ and density $[ (0.05\leq N\leq 12.0) {atoms} \cdot {nm}^{-3}]$ to ascertain the…

Plasma Physics · Physics 2016-09-08 A. F. Borghesani , M. Santini

We report experimental data of the mobility of O\(_2^-\) ions in argon gas as a function of the density in the temperature range between \(180\,\mbox{K}\le T\le 300\,\mbox{K}\). At the intermediate, though fairly large, densities of the…

Chemical Physics · Physics 2022-02-10 Armando Francesco Borghesani , Frédéric Aitken

We present results of molecular dynamics simulations of the electron system on the surface of liquid helium. The simulations are done for 1600 electrons with periodic boundary conditions. Electron scattering by capillary waves and phonons…

Mesoscale and Nanoscale Physics · Physics 2018-09-03 K. Moskovtsev amd M. I. Dykman

The investigation of the mobility \(\mu\) of quasi-free electrons in dense, cold helium gas as a function of its density \(N\) is made difficult by the fact that a significant fraction of electrons is localized in low mobility bubbles. The…

Chemical Physics · Physics 2022-02-10 A. F. Borghesani

We study the thermophysical properties of dense helium plasmas by using quantum molecular dynamics and orbital-free molecular dynamics simulations, where densities are considered from 400 to 800 g/cm$^{3}$ and temperatures up to 800 eV.…

Materials Science · Physics 2011-06-27 Cong Wang , Xian-Tu He , Ping Zhang

We study a partially ionized hydrogen plasma by means of quantum molecular dynamics, which is based on wave packets. We introduce a new model which distinguishes between free and bound electrons. The free electrons are modelled as Gaussian…

Plasma Physics · Physics 2009-10-30 W. Ebeling , B. Militzer

An equation of state for the domain extending from hot gases to cool-dense fluids is formulated for a hydrogen-helium mixture. The physical processes take account of temperature ionization and dissociation, electron degeneracy, Coulomb…

Astrophysics · Physics 2009-10-30 G. Q. Luo

In a dense plasma environment, the energy levels of an ion shift relative to the isolated ion values. This shift is reflected in the optical spectrum of the plasma and can be measured in, for example, emission experiments. In this work, we…

Plasma Physics · Physics 2024-09-11 T. Q. Thelen , D. A. Rehn , C. J. Fontes , C. E. Starrett

We study the thermodynamic properties of a partially ionized hydrogen plasma in strong magnetic fields, B ~ 10^{12}-10^{13} G, typical of neutron stars. The properties of the plasma depend significantly on the quantum-mechanical sizes and…

Astrophysics · Physics 2007-05-23 A. Y. Potekhin , G. Chabrier , Yu. A. Shibanov

Using the Deep Potential methodology, we construct a model that reproduces accurately the potential energy surface of the SCAN approximation of density functional theory for water, from low temperature and pressure to about 2400 K and 50…

Chemical Physics · Physics 2021-06-16 Linfeng Zhang , Han Wang , Roberto Car , Weinan E

The properties of hot dense helium at megabar pressures were studied with two first-principles computer simulation techniques, path integral Monte Carlo and density functional molecular dynamics. The simulations predicted that the…

Materials Science · Physics 2009-11-11 B. Militzer
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