Equation of State of Dense Plasma Mixtures: Application to the Sun Center

Pain, Jean‐Christophe; Dejonghe, G.; Błeński, T.

doi:10.1002/ctpp.201100069

Cited by 6 publications

(5 citation statements)

References 21 publications

(41 reference statements)

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“…The wide-used implementation of these methods is, for instance, Quantum Molecular Dynamics (QMD) [11]. In the case of Average Atom Models (AAM) the plasma is divided into a mixture of non-overlapping neutral spherical cell of Wigner-Seitz radius [15][16][17]. The cell contains the nucleus and the electrons to ensure the electroneutrality.…”

Section: Introductionmentioning

confidence: 99%

The Thermophysical Properties of Iron Plasma

Apfelbaum

2016

Contrib. Plasma Phys.

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The pressure, internal energy, conductivity, thermal conductivity and thermal power of Iron plasma have been calculated at temperatures 10 -100 kK and densities less than 2 g/cm 3 . The plasma composition has been obtained by means of corresponding system of coupled mass action laws. We have considered the atom ionization up to +6. The transport coefficients have been obtained within the relaxation time approximation. The comparison of our results with available measurement and calculation data has shown very good agreement for the pressure and less good agreement for the conductivity.

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Section: Introductionmentioning

confidence: 99%

The Thermophysical Properties of Iron Plasma

Apfelbaum

2016

Contrib. Plasma Phys.

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“…Screening was taken into account through the neutrality of the WS sphere, the free electrons being described with the Thomas-Fermi approach [69]. A few years later, we developed a new model of plasma, providing a consistent modelling of plasma mixtures [70,71], implemented the quantum-mechanical description of continuum states, with the proper depiction of shape resonances in the density of free states [72,73], and added the capability to compute the equation of state [74,75]. In order to refine the spectra, we developed the SCO-RCG code combining statistical (UTA, SOSA, STA) methods and fine-structure calculations, using subroutines from Cowan's code.…”

Section: Discussionmentioning

confidence: 99%

Super Transition Arrays: A Tool for Studying Spectral Properties of Hot Plasmas

Pain

2021

Plasma

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For the theoretical study of X and extreme-UV spectra of ions in plasmas, quantum mechanics brings more detailed results than statistical physics. However, it is impossible to handle individually the billions of levels that must be taken into account in order to properly describe hot plasmas. Such levels can be gathered into electronic configurations or superconfigurations (groups of configurations) and the corresponding calculations rely on appropriate statistical methods, for local or non-local thermodynamic equilibrium plasmas. In this article we present the basic principles of the Super-Transition-Array approach as well as its practical implementation. During the last decades, calculations performed with the SCO code (Superconfiguration Code for Opacity) have been compared to opacity measurements. The code includes static screening of ions by plasma and is well suited for studying plasma density effects (for example pressure ionization) on opacity and equation of state. The recently developed SCO-RCG code (Superconfiguration Code for Opacity combined with Robert Cowan’s “G” subroutine) combines statistical methods from SCO and fine-structure (detailed-level-accounting) calculations using subroutine RCG from Cowan’s code. SCO-RCG enables us to obtain very detailed spectra and to significantly improve the interpretation of experimental spectra. The Super-Transition-Array formalism is still the cornerstone of several opacity codes, and new ideas are emerging, such as the Configurationally Resolved-Super-Transition-Array approach or the extension of the Partially Resolved-Transition-Array concept to the superconfiguration method.

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“…(We note that in reality, one would expect p c (t) to be larger than this, since the density of the Sun increases towards the centre rather than being uniform, as in our model. For example, in [25] the central pressure of the Sun is found to be ∼ 10 16 Pa, which is ∼ 100 times greater than the value for a uniform density.) to the Sun, modelled as a uniform-density object residing in a concordance ΛCDM universe, at the present cosmological epoch t = t0, and the future times t = 1.2t0 and t = 5t0.…”

Section: Application To the Sunmentioning

confidence: 91%

“…Consequently, we may identify the differential operator L t in (25) as the derivative with respect to the proper time of a comoving observer, since L t =ṫ∂ t +ṙ∂ r = d/dτ (it is also straightforward to show that L r coincides with the derivative with respect to the radial proper distance of a comoving observer).…”

Section: A Tetrad-based Solution For Spherical Systemsmentioning

confidence: 99%

Dynamics of a spherical object of uniform density in an expanding universe

Nandra¹,

Lasenby²,

Hobson³

2013

Phys. Rev. D

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We present Newtonian and fully general-relativistic solutions for the evolution of a spherical region of uniform interior density ρi(t), embedded in a background of uniform exterior density ρe(t). In both regions, the fluid is assumed to support pressure. In general, the expansion rates of the two regions, expressed in terms of interior and exterior Hubble parameters Hi(t) and He(t), respectively, are independent. We consider in detail two special cases: an object with a static boundary, Hi(t) = 0; and an object whose internal Hubble parameter matches that of the background, Hi(t) = He(t).In the latter case, we also obtain fully general-relativistic expressions for the force required to keep a test particle at rest inside the object, and that required to keep a test particle on the moving boundary. We also derive a generalised form of the Oppenheimer-Volkov equation, valid for general time-dependent spherically-symmetric systems, which may be of interest in its own right.

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Equation of State of Dense Plasma Mixtures: Application to the Sun Center

Cited by 6 publications

References 21 publications

The Thermophysical Properties of Iron Plasma

The Thermophysical Properties of Iron Plasma

Super Transition Arrays: A Tool for Studying Spectral Properties of Hot Plasmas

Dynamics of a spherical object of uniform density in an expanding universe

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