Equivalence between pressure- and structure-defined ionization in hot dense carbon.

The determination of the ionization of a system in the hot dense regime is a long standing issue. Recent studies have shown inconsistencies between standard predictions using average atom models and evaluations deduced from electronic transport properties computed with quantum molecular dynamics simulations [Bethkenhagen et al., Phys.

Carbon ionization from a quantum average-atom model up to gigabar pressures.

We use a nonrelativistic average-atom model to calculate carbon ionization at megabar and gigabar pressures. The pressure is calculated using the stress-tensor method. The electronic electrical conductivity is also considered using the Kubo-Greenwood approach.

Electrical resistivity calculations in dense plasmas.

We present calculations of electrical resistivity in dense plasmas using the average-atom model. The Born approximation is proposed to improve the computations especially in the hot domain of the density and temperature plane. Both the nonrelativistic and relativistic regimes are considered.

Pressure in warm and hot dense matter using the average-atom model.

Expressions of pressure in warm and hot dense matter using the average-atom model are presented. They are based on the stress-tensor approach. Nonrelativistic and relativistic cases are considered.

Density effects on electronic configurations in dense plasmas.

We present a quantum mechanical model to describe the density effects on electronic configurations inside a plasma environment. Two different approaches are given by starting from a quantum average-atom model. Illustrations are shown for an aluminum plasma in local thermodynamic equilibrium at solid density and at a temperature of 100 eV and in the thermodynamic conditions of a recent experiment designed to characterize the effects of the ionization potential depression treatment.

Degeneracy and relativistic microreversibility relations for collisional-radiative equilibrium models.

We present the relativistic expressions of standard nonrelativistic microreversibility relations that can be used in collisional-radiative equilibrium models to calculate the transition rates including the free electron degeneracy for collisional excitation and deexcitation, collisional ionization and three-body recombination, dielectronic capture and autoionization, photoexcitation and photodeexcitation, and radiative recombination and photoionization. Semiempirical expressions or more refined calculations can be used for the cross sections of interest as long as they are calculated by taking into account either nonrelativistic, relativistic, or ultrarelativistic effects for both the bound and free electrons. The bound and the free electrons should be treated on the same footing.

Multidimensional Chebyshev interpolation for warm and hot dense matter.

We propose a scheme based on a multidimensional Chebyshev interpolation to approximate smooth functions that depend on more than one variable. The present method generalizes the one dimensional Chebyshev approximation. The multidimensional approach can be used for generating databases like equation of state in the warm and hot dense matter.

Temperature relaxation in dense plasma mixtures.

We present a model to calculate temperature-relaxation rates in dense plasma mixtures. The electron-ion relaxation rates are calculated using an average-atom model and the ion-ion relaxation rates by the Landau-Spitzer approach. This method allows the study of the temperature relaxation in many-temperature electron-ion and ion-ion systems such as those encountered in inertial confinement fusion simulations.

Temperature relaxation in dense plasmas.

We present a model to calculate temperature-relaxation rates in dense plasmas. The electron-ion interaction potential and the thermodynamic data of interest are provided by an average-atom model. This approach allows the study of the temperature relaxation in a two-temperature electron-ion system.

Out-of-equilibrium conditions in x-ray Thomson scattering experiments.

We study out-of-equilibrium conditions in recent x-ray Thomson scattering experiments performed in warm dense matter. We use an effective one-component plasma model to characterize the states in which electron and ion temperatures are different. An estimation of the ion temperature is obtained.

Refractive index in warm and hot dense matter.

A method to estimate the index of refraction in warm and hot dense matter is proposed. This method combines the Kubo-Greenwood approach, Maxwell equations, and existing codes that calculate photoabsorption and photoemission coefficients in warm and hot dense plasmas. An effective electrical conductivity is calculated from existing opacity codes from which the index of refraction is derived.

Resistivity saturation in warm dense matter.

Electrical resistivity is shown to saturate in solid-density aluminum in the warm dense matter regime. Calculations are done using the average-atom model SCAALP and the finite-temperature Ziman-Evans formula for electrical resistivity. The mean free path is estimated using the Drude law.

Pressure and electrical resistivity measurements on hot expanded nickel: comparisons with quantum molecular dynamics simulations and average atom approaches.

We present experimental results on pressure and resistivity on expanded nickel at a density of 0.1 g/cm3 and temperature of a few eV. These data, corresponding to the warm dense matter regime, are used to benchmark different theoretical approaches.