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

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Applying Gibb's geometrical methods to the thermodynamics of H-plasmas we explore the landscape of the free energy as a function of the degrees of ionization and dissociation. Several approximations for the free energy are discussed. We…

Astrophysics · Physics 2009-11-07 Werner Ebeling , Hendrik Hache , Michael Spahn

We report data of the O2- ion mobility in neon gas over broad density and temperature ranges along with its theoretical description in terms of the thermodynamic, free volume model that has successfully been adopted for the interpretation…

Chemical Physics · Physics 2019-09-24 A. F. Borghesani , F. Aitken

The temperature of the intergalactic medium (IGM) is set by the competition between photoheating and adiabatic cooling, which are usually assumed to define a tight equation of state in which the temperature increases monotonically with…

Astrophysics · Physics 2009-11-13 Steven Furlanetto , S. Peng Oh

We show that, at high densities, fully variational solutions of solid-like type can be obtained from a density functional formalism originally designed for liquid 4He. Motivated by this finding, we propose an extension of the method that…

Other Condensed Matter · Physics 2009-11-11 F. Ancilotto , M. Barranco , F. Caupin , R. Mayol , M. Pi

We build a predictive theory for the evolution of mixture of helium and supercooled helium at low temperature. The absolute temperature and the volume fraction of helium, which is dominant at temperature larger than the phase change…

Analysis of PDEs · Mathematics 2012-11-14 Bonetti Elena , Fremond Michel

The ionization state of the gas in the dynamic solar chromosphere can depart strongly from the instantaneous statistical equilibrium commonly assumed in numerical modeling. We improve on earlier simulations of the solar atmosphere that only…

Solar and Stellar Astrophysics · Physics 2016-02-03 Thomas Peter Golding , Jorrit Leenaarts , Mats Carlsson

A statistical-type model is developed to describe the ion production and electron emission in collisions of (molecular) ions with atoms. The model is based on the Boltzmann population of the bound electronic energy levels of the quasi…

Atomic Physics · Physics 2016-08-19 Zoltán Juhász

Recent observations have found the ratio of H-alpha to free-free radio continuum to be surprisingly high in the diffuse ionized ISM (the so-called WIM), corresponding to an electron temperature of only ~3000K. Such low temperatures were…

Astrophysics of Galaxies · Physics 2015-05-19 Ruobing Dong , B. T. Draine

The properties of hydrogen-helium mixtures at Mbar pressures and intermediate temperatures (4000 to 10000 K) are calculated with first-principles molecular dynamics simulations. We determine the equation of state as a function of density,…

Materials Science · Physics 2009-03-06 M. A. Morales , E. Schwegler , D. M. Ceperley , C. Pierleoni , S. Hamel , K. Caspersen

Polymer microgels exhibit intriguing macroscopic flow properties arising from their unique microscopic structure. Microgel colloids usually comprise a crosslinked polymer network with a radially decaying density profile, resulting in a…

Soft Condensed Matter · Physics 2025-02-10 Maxime Bergman , Yixuan Xu , José Muñéton Díaz , Zhang Chi , Thomas G. Mason , Frank Scheffold

We study the thermal structure of the neutral atomic (H {\small I}) interstellar medium across a wide range of metallicities, from supersolar down to vanishing metallicity, and for varying UV intensities and cosmic-ray ionization rates. We…

Astrophysics of Galaxies · Physics 2019-09-04 Shmuel Bialy , Amiel Sternberg

We use a two-fluid model combining the quantum Green's function technique for the electrons and a classical HNC description for the ions to calculate the high-density equation of state of hydrogen. This approach allows us to describe fully…

Plasma Physics · Physics 2011-08-25 J. Vorberger , D. O. Gericke , W. -D. Kraeft

The basic continuum model for polar fluids is deceptively simple. The free energy integral consists of four terms: The coupling of polarization to an external field, the electrostatic energy of the induced electric field interacting with…

Soft Condensed Matter · Physics 2021-12-22 Michiel Sprik

Using concepts from classical density functional theory (DFT) we investigate the freezing of a two-dimensional (2D) system of ultra-soft particles in a one-dimensional (1D) external potential; a phenomenon often called laser-induced…

Soft Condensed Matter · Physics 2020-02-05 Alexander Kraft , Sabine H. L. Klapp

The properties of helium-filled nanopores in amorphous silicon are elucidated by combining theoretical knowledge of helium electronic structure with the results of Scanning Transmission electron microscopy/electron energy loss spectroscopy…

Mesoscale and Nanoscale Physics · Physics 2024-07-08 Bertrand Lacroix , Asunción Fernández , N. C. Pyper , Alex J. W. Thom , Colm T. Whelan

We examine the influence of the main approximations employed in density-functional theory descriptions of the solid phase of molecular hydrogen near dissociation. We consider the importance of nuclear quantum effects on equilibrium…

Materials Science · Physics 2015-06-15 M. A. Morales , J. M. McMahon , C. Pierleoni , D. M. Ceperley

We calculate ground-state energies and densities of a helium atom confined in an impenetrable spherical box within density functional theory. These calculations are performed by variationally solving Kohn-Sham equation with the ground-state…

Atomic Physics · Physics 2010-06-24 Subhajit Waugh , Avijit Chowdhury , Arup Banerjee

The location of the hydrogen-helium (H/He) immiscibility boundary controls whether and where helium rain occurs in giant planets, yet it remains uncertain because high-pressure experiments are challenging and ab initio simulations are…

Earth and Planetary Astrophysics · Physics 2026-04-01 Xiaoyu Wang , Sebastien Hamel , Bingqing Cheng

We develop analytic approximations of thermodynamic functions of fully ionized nonideal electron-ion plasma mixtures. In the regime of strong Coulomb coupling, we use our previously developed analytic approximations for the free energy of…

Plasma Physics · Physics 2009-02-12 A. Y. Potekhin , G. Chabrier , F. J. Rogers

Thermodynamic quantities of Coulomb plasmas consisting of point-like ions immersed in a compressible, polarizable electron background are calculated for ion charges Z=1 to 26 and for a wide domain of plasma parameters ranging from the…

Plasma Physics · Physics 2016-09-08 G. Chabrier , A. Y. Potekhin