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Title: An equation of state for partially ionized plasmas: The Coulomb contribution to the free energy

Abstract

We have previously developed an equation of state (EOS) model called ChemEOS (Hakel and Kilcrease, Atomic Processes in Plasmas, Eds., J. Cohen et al., AIP, 2004) for a plasma of interacting ions, atoms and electrons. It is based on a chemical picture of the plasma and is derived from an expression for the Helmholtz free energy of the interacting species. All other equilibrium thermodynamic quantities are then obtained by minimizing this free energy subject to constraints, thus leading to a thermodynamically consistent EOS. The contribution to this free energy from the Coulomb interactions among the particles is treated using the method of Chabrier and Potekhin (Phys. Rev. E 58, 4941 (1998)) which we have adapted for partially ionized plasmas. This treatment is further examined and is found to give rise to unphysical behavior for various elements at certain values of the density and temperature where the Coulomb coupling begins to become significant and the atoms are partially ionized. We examine the source of this unphysical behavior and suggest corrections that produce acceptable results. The sensitivity of the thermodynamic properties and frequency-dependent opacity of iron is examined with and without these corrections. Lastly, the corrected EOS is used to determine themore » fractional ion populations and level populations for a new generation of OPLIB low-Z opacity tables currently being prepared at Los Alamos National Laboratory with the ATOMIC code.« less

Authors:
 [1];  [1];  [1];  [1];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1236712
Alternate Identifier(s):
OSTI ID: 1422866
Report Number(s):
LA-UR-15-23071
Journal ID: ISSN 1574-1818; PII: S1574181815000531
Grant/Contract Number:  
AC52-06NA25396; DEAC52-06NA25396
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
High Energy Density Physics
Additional Journal Information:
Journal Volume: 16; Journal Issue: C; Journal ID: ISSN 1574-1818
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; opacity, equation of state

Citation Formats

Kilcrease, D. P., Colgan, J., Hakel, P., Fontes, C. J., and Sherrill, M. E. An equation of state for partially ionized plasmas: The Coulomb contribution to the free energy. United States: N. p., 2015. Web. doi:10.1016/j.hedp.2015.05.005.
Kilcrease, D. P., Colgan, J., Hakel, P., Fontes, C. J., & Sherrill, M. E. An equation of state for partially ionized plasmas: The Coulomb contribution to the free energy. United States. https://doi.org/10.1016/j.hedp.2015.05.005
Kilcrease, D. P., Colgan, J., Hakel, P., Fontes, C. J., and Sherrill, M. E. 2015. "An equation of state for partially ionized plasmas: The Coulomb contribution to the free energy". United States. https://doi.org/10.1016/j.hedp.2015.05.005. https://www.osti.gov/servlets/purl/1236712.
@article{osti_1236712,
title = {An equation of state for partially ionized plasmas: The Coulomb contribution to the free energy},
author = {Kilcrease, D. P. and Colgan, J. and Hakel, P. and Fontes, C. J. and Sherrill, M. E.},
abstractNote = {We have previously developed an equation of state (EOS) model called ChemEOS (Hakel and Kilcrease, Atomic Processes in Plasmas, Eds., J. Cohen et al., AIP, 2004) for a plasma of interacting ions, atoms and electrons. It is based on a chemical picture of the plasma and is derived from an expression for the Helmholtz free energy of the interacting species. All other equilibrium thermodynamic quantities are then obtained by minimizing this free energy subject to constraints, thus leading to a thermodynamically consistent EOS. The contribution to this free energy from the Coulomb interactions among the particles is treated using the method of Chabrier and Potekhin (Phys. Rev. E 58, 4941 (1998)) which we have adapted for partially ionized plasmas. This treatment is further examined and is found to give rise to unphysical behavior for various elements at certain values of the density and temperature where the Coulomb coupling begins to become significant and the atoms are partially ionized. We examine the source of this unphysical behavior and suggest corrections that produce acceptable results. The sensitivity of the thermodynamic properties and frequency-dependent opacity of iron is examined with and without these corrections. Lastly, the corrected EOS is used to determine the fractional ion populations and level populations for a new generation of OPLIB low-Z opacity tables currently being prepared at Los Alamos National Laboratory with the ATOMIC code.},
doi = {10.1016/j.hedp.2015.05.005},
url = {https://www.osti.gov/biblio/1236712}, journal = {High Energy Density Physics},
issn = {1574-1818},
number = C,
volume = 16,
place = {United States},
year = {Sat Jun 20 00:00:00 EDT 2015},
month = {Sat Jun 20 00:00:00 EDT 2015}
}

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Cited by: 18 works
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Works referenced in this record:

The new Los Alamos opacity code ATOMIC
journal, May 2006


Equation of state of fully ionized electron-ion plasmas
journal, October 1998


Equation of state of classical Coulomb plasma mixtures
journal, January 2009


Equilibrium Properties of a Partially Ionized Plasma
journal, September 1960


Light element opacities of astrophysical interest from ATOMIC
journal, March 2015


Galaxy formation and clustering in an N-body experiment
journal, September 1988


Plasma non-ideality effects on the photon–electron scattering contribution to radiative opacities
journal, October 2001


An Equation of State for Low-Mass Stars and Giant Planets
journal, July 1995


A higher-than-predicted measurement of iron opacity at solar interior temperatures
journal, December 2014


Works referencing / citing this record:

Charge State Distributions in Dense Plasmas
preprint, January 2020