A5030583683- High-pressure geophysics and materials
- Astro and Planetary Science
- Advanced Chemical Physics Studies
- Atomic and Molecular Physics
- Stellar, planetary, and galactic studies
- Geomagnetism and Paleomagnetism Studies
- Phase Equilibria and Thermodynamics
- Spectroscopy and Quantum Chemical Studies
- Quantum, superfluid, helium dynamics
- Planetary Science and Exploration
- Diamond and Carbon-based Materials Research
- Dust and Plasma Wave Phenomena
- Solar and Space Plasma Dynamics
- Laser-induced spectroscopy and plasma
- Energetic Materials and Combustion
- Earthquake Detection and Analysis
- Crystal Structures and Properties
- Hydrocarbon exploration and reservoir analysis
- Gas Dynamics and Kinetic Theory
- Advanced Thermodynamics and Statistical Mechanics
- Astrophysics and Star Formation Studies
- nanoparticles nucleation surface interactions
- Boron and Carbon Nanomaterials Research
- Metallurgy and Cultural Artifacts
- Metal Alloys Wear and Properties
CEA DAM Île-de-France
2012-2025
Université Paris-Saclay
2021-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2012-2024
CEA Paris-Saclay
2021-2024
Sandia National Laboratories
2024
Laboratoire de Géologie de Lyon : Terre, Planètes et Environnement
2019-2022
École Normale Supérieure de Lyon
2012-2022
Centre National de la Recherche Scientifique
2012-2021
University of California, Berkeley
2014-2021
Planetary Science Institute
2014-2021
We report the results of second charged-particle transport coefficient code comparison workshop, which was held in Livermore, California on 24–27 July 2023. This workshop gathered theoretical, computational, and experimental scientists to assess state computational techniques for understanding coefficients relevant high-energy-density plasma science. Data electronic ionic coefficients, namely, direct current electrical conductivity, electron thermal ion shear viscosity, conductivity were...
We present a new equation of state (EOS) for dense hydrogen/helium mixtures which covers range densities from $10^{-8}$ to $10^6$ g.cm$^{-3}$, pressures $10^{-9}$ $10^{13}$ GPa and temperatures $10^{2}$ $10^{8}$ K. The calculations combine the EOS Saumon, Chabrier & vanHorn (1995) in low density, temperature molecular/atomic domain, Potekhin (1998) high-density, high-temperature fully ionized limits differ H He, ab initio quantum molecular dynamics (QMD) intermediate density regime,...
This article provides an overview of how models giant planet interiors are constructed. We review measurements from past space missions that provide constraints for the interior structure Jupiter. discuss typical three-layer consist a dense central core and inner metallic outer molecular hydrogen-helium layer. These rely heavily on experiments, analytical theory, first-principle computer simulations hydrogen helium to understand their behavior up extreme pressures ~10 Mbar temperatures...
We put together a first-principles equation of state (FPEOS) database for matter at extreme conditions by combining results from path integral Monte Carlo and density functional molecular dynamics simulations the elements H, He, B, C, N, O, Ne, Na, Mg, Al, Si as well compounds $\mathrm{LiF}, {\mathrm{B}}_{4}\mathrm{C}, \mathrm{BN}, {\mathrm{CH}}_{4}, {\mathrm{CH}}_{2}, {\mathrm{C}}_{2}{\mathrm{H}}_{3}, \mathrm{CH}, {\mathrm{C}}_{2}\mathrm{H}, \mathrm{MgO}, \mathrm{and} {\mathrm{MgSiO}}_{3}$....
We present results from ab initio simulations of liquid water–hydrogen mixtures in the range 2 to 70 GPa and 1000 6000 K, covering conditions interiors ice giant planets parts outer envelope gas planets. In addition computing pressure internal energy, we derive Gibbs free energy by performing a thermodynamic integration. For all under consideration, our predict hydrogen water mix proportions. The behavior mixture can be well described with an ideal mixing approximation. suggest that...
Abstract Super-Earths are extremely common among the numerous exoplanets that have been discovered. The high pressures and temperatures in their interiors likely to lead long-lived magma oceans. If electrical conductivity is sufficiently high, mantles of Super-Earth would generate own magnetic fields. With ab initio simulations, we show upon melting, behavior typical mantle silicates changes from semi-conducting semi-metallic. increases optical properties substantially modified. Melting...
We perform first-principles path integral Monte Carlo (PIMC) and density functional theory molecular dynamics (DFT-MD) calculations to explore warm dense matter states of aluminum. Our equation state (EOS) simulations cover a wide density-temperature range 0.1-32.4gcm^{-3} 10^{4}-10^{8} K. Since PIMC DFT-MD accurately treat effects the atomic shell structure, we find two compression maxima along principal Hugoniot curve attributed K-shell L-shell ionization. The results provide benchmark for...
We computed the equation of state iron using extended first-principles molecular dynamics simulations, ranging from 7.874g/cm3 and 5500 K up to 47.2g/cm3 109K. compared principal Hugoniot curve with semiempirical models, average atom-based model predictions, shock experiment results. derived Helmholtz free energy entropy via thermodynamic integration along isochores. explore ionization processes at play by analyzing evolution electronic densities states in gigabar regime. locked icon Physics...
We perform all-electron path integral Monte Carlo (PIMC) and density functional theory molecular dynamics (DFT-MD) calculations to explore warm dense matter states of oxygen. Our simulations cover a wide density-temperature range 1–100 g cm−3 104–109 K. By combining results from PIMC DFT-MD, we are able compute pressures internal energies first-principles at all temperatures provide coherent equation state. compare our with analytic equations state, which tend agree for above 8 × 106...
We use path integral Monte Carlo and density functional molecular dynamics to construct a coherent set of equations state (EOS) for series hydrocarbon materials with various C:H ratios (2:1, 1:1, 2:3, 1:2, 1:4) over the range 0.07-22.4gcm^{-3} 6.7×10^{3}-1.29×10^{8}K. The shock Hugoniot curve derived each material displays single compression maximum corresponding K-shell ionization. For = occurs at 4.7-fold initial we show radiation effects significantly increase ratio above 2 Gbar,...
The core accretion model for giant planet formation suggests a two layer picture the initial structure of Jovian planets, with heavy elements in dense and thick H-He envelope. Late planetesimal erosion could potentially enrich envelope elements, which is supported by three-fold solar metallicity that was measured Jupiter's atmosphere Galileo entry probe. In order to reproduce observed gravitational moments Jupiter Saturn, models their interiors include $Z$, various proportions. However,...
With density functional molecular dynamics simulations, we computed the phase diagram of MgO from 50 to 2000 GPa up 20 000 K. Via thermodynamic integration (TDI), derive Gibbs free energies B1, B2, and liquid phases determine their boundaries. TDI a pseudo-quasi-harmonic approach, show that anharmonic effects are important stabilize B1 in particular. As result, B1-B2 transition boundary pressure-temperature plane exhibits steep slope. We predict B1-B2-liquid triple point occur at...
Carbon-hydrogen plasmas and hydrocarbon materials are of broad interest to laser shock experimentalists, high energy density physicists, astrophysicists. Accurate equations state (EOSs) hydrocarbons valuable for various studies from inertial confinement fusion planetary science. By combining path integral Monte Carlo (PIMC) results at temperatures functional theory molecular dynamics lower temperatures, we compute the EOSs simulations performed 1473 separate (ρ, T)-points distributed over a...
In order to provide a comprehensive theoretical description of ${\mathrm{MgSiO}}_{3}$ at extreme conditions, we combine results from path integral Monte Carlo and density functional molecular dynamics simulations generate consistent equation state for this material. We consider wide range temperature conditions ${10}^{4}$ ${10}^{8}\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ 0.321 64.2 $\mathrm{g}\phantom{\rule{0.16em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$ (0.1- 20-fold the ambient density)....
The dynamics of an inertial confinement fusion capsule, or a stellar planet interior, obey very similar set equations: magneto-radiative-hydrodynamic equations. solutions these equations, however, depend entirely on the transport properties associated with different materials at play. To properly model systems, it is necessary to determine high accuracy coefficients several over large range thermodynamic conditions. Experimental capabilities in this respect are still limited due nature...
Abstract We investigate the material properties of a mixture hydrogen, helium, and oxygen representative Saturn’s interior at pressure–temperature conditions recent Saturn model (see Mankovich & Fortney) with molecular dynamics simulations based on density functional theory. Their considers demixing hydrogen helium predicts He-rich layer above diluted core. calculate thermodynamic transport discuss impact evolution structure. find significant specific heat capacity, speed sound,...
Recent observations of Jupiter and Saturn provided by spacecraft missions, such as Juno Cassini, compel us to revise improve our models giant planet interiors. Even though hydrogen helium are far the dominant species in these planets, heavy elements can play a significant role structure evolution planet. For instance, giant-planet cores may be eroded their surrounding fluid, which would result significantly increased concentration hydrogen-helium envelope. Furthermore, could inhibit...
As one of the simple alkali metals, sodium has been fundamental interest for shock physics experiments, but knowledge its equation state (EOS) in hot, dense regimes is not well known. By combining path integral Monte Carlo (PIMC) results partially ionized states [B. Militzer and K. P. Driver, Phys. Rev. Lett. 115, 176403 (2015)] at high temperatures density functional theory molecular dynamics (DFT-MD) lower temperatures, we have constructed a coherent over wide density-temperature range...
Abstract Understanding materials behaviour under extreme thermodynamic conditions is fundamental in many branches of science, including High-Energy-Density physics, fusion research, material and planetary science. Silica (SiO 2 ) primary importance as a key component rocky planets’ mantles. Dynamic compression the most promising approach to explore molten silicates conditions. Although experimental studies are restricted Hugoniot curve, wider range must be reached distill temperature...
By performing direct simulations of demixing for an equimolar mixture hydrogen and helium, we find that reflectivity measurements performed during dynamic experiments could be used to identify this liquid-liquid phase transition under conditions encountered in giant planet interiors. These first principles show the exhibits a distinctive signature at wavelengths currently available using VISAR (velocity interferometer system any reflector) measurements. We further make estimation timescale...
We revisit the reflectivity measurements of Celliers et al. [P. M. Celliers, P. Loubeyre, J. H. Eggert, S. Brygoo, R. McWilliams, D. G. Hicks, T. Boehly, Jeanloz, and W. Collins, Phys. Rev. Lett. 104, 184503 (2010)] for He at high density by taking into account a temperature dependence, based on existing ab initio calculations, in functional form gap energy inferred from these data. show that, when accounting such predicted behavior differs significantly one suggested that is to become...
Determining the depth of atmospheric winds in outer planets Solar System is a key topic planetary science. We provide constraints on these depths Uranus and Neptune via total induced Ohmic dissipation, due to interaction zonal flows magnetic fields. An upper bound can be placed dissipation energy entropy flux throughout interior. The directly linked electrical conductivity profile materials involved flow. present method for calculating profiles ionically conducting hydrogen-helium-water...
Average atom (AA) models allow one to efficiently compute electronic and optical properties of materials over a wide range conditions are often employed interpret experimental data. However, at high pressure, predictions from AA have been shown disagree with results ab initio computer simulations. Here we reconcile these deviations by developing an innovative type model, AVION, that computes the eigenstates novel boundary within ion sphere. Bound free states derived consistently. We drop...