Equation of state, occupation probabilities and conductivities in the average atom Purgatorio code

Sterne, P. A.; Hansen, Ole; Wilson, B. G.; Isaacs, W. A.

doi:10.1016/j.hedp.2007.02.037

Cited by 131 publications

(100 citation statements)

References 25 publications

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“…3 contain similar features to the valence densities calculated using self-consistent field IS methods 31 . However, our calculation goes beyond such average-atom approaches in that it is a true multi-centred treatment of the plasma environment with no requirement of spherical symmetry, which can compute a fully three-dimensional (3D) electron structure, and from it, the full DOS.…”

Section: Discussionmentioning

confidence: 54%

Density functional theory calculations of continuum lowering in strongly coupled plasmas

2014

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An accurate description of the ionization potential depression of ions in plasmas due to their interaction with the environment is a fundamental problem in plasma physics, playing a key role in determining the ionization balance, charge state distribution, opacity and plasma equation of state. Here we present a method to study the structure and position of the continuum of highly ionized dense plasmas using finite-temperature density functional theory in combination with excited-state projector augmented-wave potentials. The method is applied to aluminium plasmas created by intense X-ray irradiation, and shows excellent agreement with recently obtained experimental results. We find that the continuum lowering for ions in dense plasmas at intermediate temperatures is larger than predicted by standard plasma models and explain this effect through the electronic structure of the valence states in these strong-coupling conditions.

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Section: Discussionmentioning

confidence: 54%

Density functional theory calculations of continuum lowering in strongly coupled plasmas

2014

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“…Such a comparison is also problematic due to the lack of an unequivocal value for the mean ionizationZ in IS-AA models [45]. We list several differences with the NPA which particularly affect conductivity calculations:…”

Section: Details Of the Npa Model Andzmentioning

confidence: 99%

Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime

et al. 2017

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We study the conductivities σ of (i) the equilibrium isochoric state (σis), (ii) the equilibrium isobaric state (σ ib ), and also the (iii) non-equilibrium ultrafast matter (UFM) state (σ uf ) with the ion temperature Ti less than the the electron temperature Te. Aluminum, lithium and carbon are considered, being increasingly complex warm dense matter (WDM) systems, with carbon having transient covalent bonds. First-principles calculations, i.e., neutral-pseudoatom (NPA) calculations and density-functional theory (DFT) with molecular-dynamics (MD) simulations, are compared where possible with experimental data to characterize σic, σ ib and σ uf . The NPA σ ib are closest to the available experimental data when compared to results from DFT+MD, where simulations of about 64-125 atoms are typically used. The published conductivities for Li are reviewed and the value at a temperature of 4.5 eV is examined using supporting X-ray Thomson scattering calculations. A physical picture of the variations of σ with temperature and density applicable to these materials is given. The insensitivity of σ to Te below 10 eV for carbon, compared to Al and Li, is clarified.

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“…The bulk of the simulations described above are 2D simulations using ALE hydrodynamics [68], multi-group radiation transport in the diffusion approximation [69], tabular equation of state [70][71][72] and opacity data [73], and Monte Carlo transport of fusion products. These characteristics raise the necessity of demonstrating convergence of the simulations with respect to the computational mesh used to resolve the hydrodynamic motion, the number of radiation groups used to transport x-ray radiation, and the number of Monte Carlo particles used to model the slowing down of fusion products.…”

Section: Discussionmentioning

confidence: 99%

Capsule modeling of high foot implosion experiments on the National Ignition Facility

Clark

Kritcher

Milovich

et al. 2017

Plasma Phys. Control. Fusion

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This paper summarizes the results of detailed, capsule-only simulations of a set of high foot implosion experiments conducted on the National Ignition Facility (NIF). These experiments span a range of ablator thicknesses, laser powers, and laser energies, and modeling these experiments as a set is important to assess whether the simulation model can reproduce the trends seen experimentally as the implosion parameters were varied. Two-dimensional (2D) simulations have been run including a number of effects-both nominal and off-nominal-such as hohlraum radiation asymmetries, surface roughness, the capsule support tent, and hot electron pre-heat. Selected three-dimensional simulations have also been run to assess the validity of the 2D axisymmetric approximation. As a composite, these simulations represent the current state of understanding of NIF high foot implosion performance using the best and most detailed computational model available. While the most detailed simulations show approximate agreement with the experimental data, it is evident that the model remains incomplete and further refinements are needed. Nevertheless, avenues for improved performance are clearly indicated.

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Equation of state, occupation probabilities and conductivities in the average atom Purgatorio code

Cited by 131 publications

References 25 publications

Density functional theory calculations of continuum lowering in strongly coupled plasmas

Density functional theory calculations of continuum lowering in strongly coupled plasmas

Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime

Capsule modeling of high foot implosion experiments on the National Ignition Facility

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