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P. Loubeyre - One of the best experts on this subject based on the ideXlab platform.
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Sound Velocity and refractive index of pure N2 fluid and of equimolar N2 –CO2 fluid mixture up to 15 GPa
Journal of Chemical Physics, 2020Co-Authors: S. Ninet, G. Weck, A. Dewaele, Frédéric Datchi, V. Giordano, P. LoubeyreAbstract:The Sound Velocity and refractive index of pure N2 and of the equimolar N2–CO2 mixture are measured up to 15 GPa and 700 K in a resistive heating diamond anvil cell. The refractive index vs pressure is obtained by an interferometric method. The adiabatic Sound Velocity is then determined from the measurement of the Brillouin frequency shift in the backscattering geometry and the refractive index data. No phase separation of the N2–CO2 fluid mixture is observed. The fluid mixture properties are discussed in terms of ideal mixing.
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pressure evolution of the high frequency Sound Velocity in liquid water
Physical Review Letters, 2002Co-Authors: M Krisch, P. Loubeyre, G Ruocco, F Sette, A Cunsolo, M Dastuto, R Letoullec, M Lorenzen, A Mermet, G MonacoAbstract:Despite the importance of water in natural science andits unique role in defining biological activity, the structuraland dynamical properties of liquid water are far from beingcompletely understood. Numerous experimental and theo-retical studies [1,2] have already been devoted to under-standing the distinctive properties of water and, inparticular, the role of the intermolecular hydrogen bonds.There is a common agreement that the unique physico-chemical behavior of water arises from the hydrogen-bondorganization of water molecules, which is characterized byan open three-dimensional hydrogen-bond network with analmost perfect tetrahedral arrangement of nearest neigh-bors. Three models are currently proposed to explain theproperties and anomalies of water: (i) the existence of aliquid-liquid transition line between two liquid phases ofdifferent densities [3,4], (ii) a singularity-free scenario inwhich the thermodynamic anomalies are related to thepresence of low-density and low-entropy structural hetero-geneities [5], and (iii) a description within the frameworkof mode-coupling theory, initially developed to describethe properties of glass-forming liquids [6]. It remains,however, a challenge to find discriminating experimentaltests. Most of the work on water has been focused on thechanges of its properties with temperature, but to a lesserextent on its properties under pressure. Early pressurestudies dealt with the evolution of thermodynamic andtransport properties such as density, heat capacity, com-pressibility, longitudinal relaxation time, diffusion coeffi-cient, and zero-frequency Sound Velocity [2,7–9]. Morerecent pressure work focused on the microscopic structuralchanges of the liquid water structure: neutron and x-rayscattering experiments were performed to pressures of 1.6[10–12] and 0.8 GPa [13], respectively.Previous inelastic x-ray and neutron scattering (IXS andINS) work focused to a large extent on the temperatureevolution of the high-frequency dynamics at ambient pres-sure [14–18]. These experiments revealed a particularlylarge dispersion effect in the Sound Velocity as a function offrequency, which—at variance with many other liquids[19]—takes place at very high frequencies, i.e., in theterahertz region. Specifically, at
C A Mccoy - One of the best experts on this subject based on the ideXlab platform.
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measurement of the Sound Velocity and gruneisen parameter of polystyrene at inertial confinement fusion conditions
Physical Review B, 2020Co-Authors: C A Mccoy, M C Marshall, D N Polsin, D E Fratanduono, P M Celliers, T R Boehly, Y H Ding, D D MeyerhoferAbstract:The principal Hugoniot, Sound Velocity, and Gr\"uneisen parameter of polystyrene were measured at conditions relevant to shocks in inertial confinement fusion implosions, from 100 to 1000 GPa. The Sound Velocity is in good agreement with quantum molecular dynamics calculations and all tabular equation of state models at pressures below 200 GPa. Above 200 GPa, the experimental results agree with two of the examined tables, but do not agree with the most recent table developed for design of inertial confinement fusion (ICF) experiments. The Gr\"uneisen parameter increases with density below $\ensuremath{\sim}3.1\phantom{\rule{0.16em}{0ex}}\mathrm{g}/{\mathrm{cm}}^{3}$ and approaches the asymptotic value for an ideal gas after complete dissociation. This behavior is in good agreement with quantum molecular dynamics results and previous work but is not represented by any of the tabular models. The discrepancy between tabular models and experimental measurement of the Sound Velocity and Gr\"uneisen parameter is sufficient to impact simulations of ICF experiments.
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Sound Velocity shear modulus and shock melting of beryllium along the hugoniot
Physical Review B, 2019Co-Authors: C A Mccoy, M D Knudson, M P DesjarlaisAbstract:Magnetically launched flyer plates were used to investigate the shock response of beryllium between 90 and 300 GPa. Solid aluminum flyer plates drove steady shocks into polycrystalline beryllium to constrain the Hugoniot from 90 to 190 GPa. Multilayered copper/aluminum flyer plates generated a shock followed by an overtaking rarefaction which was used to determine the Sound Velocity in both solid and liquid beryllium between 130 and 300 GPa. Disappearance of the longitudinal wave was used to identify the onset of melt along the Hugoniot and measurements were compared to density functional theory calculations to explore the proposed hcp-bcc transition at high pressure. The onset of melt along the Hugoniot was identified at $\ensuremath{\sim}205\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$, which is in good agreement with theoretical predictions. These results show no clear indication of an hcp-bcc transition prior to melt along the beryllium Hugoniot. Rather, the shear stress, determined from the release wave profiles, was found to gradually decrease with stress and eventually vanish at the onset of melt.
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hugoniot Sound Velocity and shock temperature of mgo to 2300 gpa
Physical Review B, 2019Co-Authors: C A Mccoy, M C Marshall, D N Polsin, D E Fratanduono, P M Celliers, D D Meyerhofer, T R BoehlyAbstract:MgO is a major constituent of the ${\text{MgO-FeO-SiO}}_{2}$ system that comprises the Earth's mantle and that of super-Earth exoplanets. Knowledge of its high-pressure behavior is important for modeling the more complex compounds. This paper presents measurements of the principal Hugoniot, Sound Velocity, and temperature of MgO, shocked to pressures of 710 to 2300 GPa using laser-driven compression. The Hugoniot and temperature measurements compare favorably to previous results constraining the shock response of MgO at extreme conditions. The Gr\"uneisen parameter was calculated from the Hugoniot and Sound Velocity data and was found to be underpredicted by tabular models. The Sound Velocity of liquid MgO is overpredicted by models implying that the quantity of partial melt required to match decreased wave speeds in ultralow Velocity zones in the lower mantle may be less than previously assumed and experiments at lower-mantle pressures are needed.
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absolute measurement of the hugoniot and Sound Velocity of liquid copper at multimegabar pressures
Physical Review B, 2017Co-Authors: C A Mccoy, Marcus D Knudson, Seth RootAbstract:Measurement of the Hugoniot and Sound Velocity provides information on the bulk modulus and Gr\"uneisen parameter of a material at extreme conditions. The capability to launch multilayered (copper/aluminum) flyer plates at velocities in excess of 20 km/s with the Sandia Z accelerator has enabled high-precision Sound-Velocity measurements at previously inaccessible pressures. For these experiments, the Sound Velocity of the copper flyer must be accurately known in the multi-Mbar regime. Here we describe the development of copper as an absolutely calibrated Sound-Velocity standard for high-precision measurements at pressures in excess of 400 GPa. Using multilayered flyer plates, we performed absolute measurements of the Hugoniot and Sound Velocity of copper for pressures from 500 to 1200 GPa. These measurements enabled the determination of the Gr\"uneisen parameter for dense liquid copper, clearly showing a density dependence above the melt transition. Combined with earlier data at lower pressures, these results constrain the Sound Velocity as a function of pressure, enabling the use of copper as a Hugoniot and Sound-Velocity standard for pressures up to 1200 GPa.
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measurements of the Sound Velocity of shock compressed liquid silica to 1100 gpa
Journal of Applied Physics, 2016Co-Authors: C A Mccoy, D N Polsin, D E Fratanduono, P M Celliers, T R Boehly, M C Gregor, D D MeyerhoferAbstract:The Sound Velocity in a shocked material provides information about its off-Hugoniot behavior of a material at high pressures. This information can be used to extend the knowledge gained in Hugoniot experiments and to model the re-shock and release behavior. Silica is one of the most important materials for equation of state studies because of its prevalence in the earth's interior and the well-defined properties of α-quartz. This article presents the Sound Velocity measurements of amorphous fused silica over the range 200 to 1100 GPa using laser-driven shocks and an α-quartz standard. These measurements demonstrate the technique proposed by Fratanduono et al. [J. Appl. Phys. 116, 033517 (2014)] to determine the Sound Velocity from the arrival of acoustic perturbations. The results compare favorably to the SESAME 7386 equation-of-state table. The Gruneisen parameter was calculated from the Sound Velocity data and found to be Γ=0.66±0.05 at densities above 6 g/cm3, an increase in precision by a factor of t...
Neil C. Holmes - One of the best experts on this subject based on the ideXlab platform.
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tantalum Sound Velocity under shock compression
Journal of Applied Physics, 2019Co-Authors: Minta Akin, Jeffrey H. Nguyen, Ricky Chau, Paul D. Asimow, Martha A Beckwith, Patrick W Ambrose, O V Fatyanov, Neil C. HolmesAbstract:We used several variations of the shock compression method to measure the longitudinal Sound Velocity of shocked tantalum over the pressure range 37–363 GPa with a typical uncertainty of 1.0 %. These data are consistent with Ta remaining in the bcc phase along the principal Hugoniot from ambient pressure to ≈300 GPa, at which pressure melting occurs. These data also do not support the putative melting phenomena reported below 100 GPa in some static compression experiments.We used several variations of the shock compression method to measure the longitudinal Sound Velocity of shocked tantalum over the pressure range 37–363 GPa with a typical uncertainty of 1.0 %. These data are consistent with Ta remaining in the bcc phase along the principal Hugoniot from ambient pressure to ≈300 GPa, at which pressure melting occurs. These data also do not support the putative melting phenomena reported below 100 GPa in some static compression experiments.
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Molybdenum Sound Velocity and shear modulus softening under shock compression
Physical Review B, 2014Co-Authors: Jeffrey H. Nguyen, Minta Akin, Ricky Chau, Dayne Fratanduono, W. Patrick Ambrose, O. V. Fat'yanov, Paul D. Asimow, Neil C. HolmesAbstract:We measured the longitudinal Sound Velocity in Mo shock compressed up to 4.4 Mbars on the Hugoniot. Its Sound speed increases linearly with pressure up to 2.6 Mbars; the slope then decreases up to the melting pressure of ∼3.8 Mbars. This suggests a decrease of shear modulus before the melt. A linear extrapolation of our data to 1 bar agrees with the ambient Sound speed. The results suggest that Mo remains in the bcc phase on the Hugoniot up to the melting pressure. There is no statistically significant evidence for a previously reported bcc→hcp phase transition on the Hugoniot.
Frederick J. Ryerson - One of the best experts on this subject based on the ideXlab platform.
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Composition of the Earth's inner core from high-pressure Sound Velocity measurements in Fe-Ni-Si alloys
Earth and Planetary Science Letters, 2010Co-Authors: Daniele Antonangeli, Julien Siebert, James Badro, Daniel L. Farber, Guillaume Fiquet, Guillaume Morard, Frederick J. RyersonAbstract:We performed room-temperature Sound Velocity and density measurements on a polycrystalline alloy, Fe0.89Ni0.04Si0.07, in the hexagonal close-packed (hcp) phase up to 108 GPa. Over the investigated pressure range the aggregate compressional Sound Velocity is ∼9% higher than in pure iron at the same density. The measured aggregate compressional (VP) and shear (VS) Sound velocities, extrapolated to core densities and corrected for anharmonic temperature effects, are compared with seismic profiles. Our results provide constraints on the silicon abundance in the core, suggesting a model that simultaneously matches the primary seismic observables, density, P-wave and S-wave velocities, for an inner core containing 4 to 5 wt.% of Ni and 1 to 2 wt.% of Si.
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Composition of the Earth's inner core from high-pressure Sound Velocity measurements in Fe–Ni–Si alloys
Earth and Planetary Science Letters, 2010Co-Authors: Daniele Antonangeli, Julien Siebert, James Badro, Daniel L. Farber, Guillaume Fiquet, Guillaume Morard, Frederick J. RyersonAbstract:We performed room-temperature Sound Velocity and density measurements on a polycrystalline alloy, Fe0.89Ni0.04Si0.07, in the hexagonal close-packed (hcp) phase up to 108 GPa. Over the investigated pressure range the aggregate compressional Sound Velocity is not, vert, similar 9% higher than in pure iron at the same density. The measured aggregate compressional (VP) and shear (VS) Sound velocities, extrapolated to core densities and corrected for anharmonic temperature effects, are compared with seismic profiles. Our results provide constraints on the silicon abundance in the core, suggesting a model that simultaneously matches the primary seismic observables, density, P-wave and S-wave velocities, for an inner core containing 4 to 5 wt.% of Ni and 1 to 2 wt.% of Si.
D D Meyerhofer - One of the best experts on this subject based on the ideXlab platform.
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measurement of the Sound Velocity and gruneisen parameter of polystyrene at inertial confinement fusion conditions
Physical Review B, 2020Co-Authors: C A Mccoy, M C Marshall, D N Polsin, D E Fratanduono, P M Celliers, T R Boehly, Y H Ding, D D MeyerhoferAbstract:The principal Hugoniot, Sound Velocity, and Gr\"uneisen parameter of polystyrene were measured at conditions relevant to shocks in inertial confinement fusion implosions, from 100 to 1000 GPa. The Sound Velocity is in good agreement with quantum molecular dynamics calculations and all tabular equation of state models at pressures below 200 GPa. Above 200 GPa, the experimental results agree with two of the examined tables, but do not agree with the most recent table developed for design of inertial confinement fusion (ICF) experiments. The Gr\"uneisen parameter increases with density below $\ensuremath{\sim}3.1\phantom{\rule{0.16em}{0ex}}\mathrm{g}/{\mathrm{cm}}^{3}$ and approaches the asymptotic value for an ideal gas after complete dissociation. This behavior is in good agreement with quantum molecular dynamics results and previous work but is not represented by any of the tabular models. The discrepancy between tabular models and experimental measurement of the Sound Velocity and Gr\"uneisen parameter is sufficient to impact simulations of ICF experiments.
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hugoniot Sound Velocity and shock temperature of mgo to 2300 gpa
Physical Review B, 2019Co-Authors: C A Mccoy, M C Marshall, D N Polsin, D E Fratanduono, P M Celliers, D D Meyerhofer, T R BoehlyAbstract:MgO is a major constituent of the ${\text{MgO-FeO-SiO}}_{2}$ system that comprises the Earth's mantle and that of super-Earth exoplanets. Knowledge of its high-pressure behavior is important for modeling the more complex compounds. This paper presents measurements of the principal Hugoniot, Sound Velocity, and temperature of MgO, shocked to pressures of 710 to 2300 GPa using laser-driven compression. The Hugoniot and temperature measurements compare favorably to previous results constraining the shock response of MgO at extreme conditions. The Gr\"uneisen parameter was calculated from the Hugoniot and Sound Velocity data and was found to be underpredicted by tabular models. The Sound Velocity of liquid MgO is overpredicted by models implying that the quantity of partial melt required to match decreased wave speeds in ultralow Velocity zones in the lower mantle may be less than previously assumed and experiments at lower-mantle pressures are needed.
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measurements of the Sound Velocity of shock compressed liquid silica to 1100 gpa
Journal of Applied Physics, 2016Co-Authors: C A Mccoy, D N Polsin, D E Fratanduono, P M Celliers, T R Boehly, M C Gregor, D D MeyerhoferAbstract:The Sound Velocity in a shocked material provides information about its off-Hugoniot behavior of a material at high pressures. This information can be used to extend the knowledge gained in Hugoniot experiments and to model the re-shock and release behavior. Silica is one of the most important materials for equation of state studies because of its prevalence in the earth's interior and the well-defined properties of α-quartz. This article presents the Sound Velocity measurements of amorphous fused silica over the range 200 to 1100 GPa using laser-driven shocks and an α-quartz standard. These measurements demonstrate the technique proposed by Fratanduono et al. [J. Appl. Phys. 116, 033517 (2014)] to determine the Sound Velocity from the arrival of acoustic perturbations. The results compare favorably to the SESAME 7386 equation-of-state table. The Gruneisen parameter was calculated from the Sound Velocity data and found to be Γ=0.66±0.05 at densities above 6 g/cm3, an increase in precision by a factor of t...