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Title: Viscosity and mutual diffusion of deuterium-tritium mixtures in the warm-dense-matter regime

Abstract

We have calculated viscosity and mutual diffusion of deuterium-tritium (DT) in the warm, dense matter regime for densities from 5 to 20 g/cm{sup 3} and temperatures from 2 to 10 eV, using both finite-temperature Kohn-Sham density-functional theory molecular dynamics (QMD) and orbital-free molecular dynamics (OFMD). The OFMD simulations are in generally good agreement with the benchmark QMD results, and we conclude that the simpler OFMD method can be used with confidence in this regime. For low temperatures (3 eV and below), one-component plasma (OCP) model simulations for diffusion agree with the QMD and OFMD calculations, but deviate by 30% at 10 eV. In comparison with the QMD and OFMD results, the OCP viscosities are not as good as for diffusion, especially for 5 g/cm{sup 3} where the temperature dependence is significantly different. The QMD and OFMD reduced diffusion and viscosity coefficients are found to depend largely, though not completely, only on the Coulomb coupling parameter {Gamma}, with a minimum in the reduced viscosity at {Gamma}{approx_equal}25, approximately the same position found in the OCP simulations. The QMD and OFMD equations of state (pressure) are also compared with the hydrogen two-component plasma model.

Authors:
; ; ;  [1];  [2]
  1. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  2. CEA, DAM, DIF, F-91297 Arpajon (France)
Publication Date:
OSTI Identifier:
21464502
Resource Type:
Journal Article
Journal Name:
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)
Additional Journal Information:
Journal Volume: 82; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevE.82.036404; (c) 2010 The American Physical Society; Journal ID: ISSN 1539-3755
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BENCHMARKS; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; COUPLING; DENSITY FUNCTIONAL METHOD; DEUTERIUM; DIFFUSION; EQUATIONS OF STATE; EV RANGE; HYDROGEN; MIXTURES; MOLECULAR DYNAMICS METHOD; PLASMA; PLASMA SIMULATION; TEMPERATURE DEPENDENCE; TRITIUM; VISCOSITY; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CALCULATION METHODS; DISPERSIONS; ELEMENTS; ENERGY RANGE; EQUATIONS; EVALUATION; HYDROGEN ISOTOPES; ISOTOPES; LIGHT NUCLEI; NONMETALS; NUCLEI; ODD-EVEN NUCLEI; ODD-ODD NUCLEI; RADIOISOTOPES; SIMULATION; STABLE ISOTOPES; VARIATIONAL METHODS; YEARS LIVING RADIOISOTOPES

Citation Formats

Kress, J D, Cohen, James S, Horner, D A, Collins, L A, and Lambert, F. Viscosity and mutual diffusion of deuterium-tritium mixtures in the warm-dense-matter regime. United States: N. p., 2010. Web. doi:10.1103/PHYSREVE.82.036404.
Kress, J D, Cohen, James S, Horner, D A, Collins, L A, & Lambert, F. Viscosity and mutual diffusion of deuterium-tritium mixtures in the warm-dense-matter regime. United States. doi:10.1103/PHYSREVE.82.036404.
Kress, J D, Cohen, James S, Horner, D A, Collins, L A, and Lambert, F. Wed . "Viscosity and mutual diffusion of deuterium-tritium mixtures in the warm-dense-matter regime". United States. doi:10.1103/PHYSREVE.82.036404.
@article{osti_21464502,
title = {Viscosity and mutual diffusion of deuterium-tritium mixtures in the warm-dense-matter regime},
author = {Kress, J D and Cohen, James S and Horner, D A and Collins, L A and Lambert, F},
abstractNote = {We have calculated viscosity and mutual diffusion of deuterium-tritium (DT) in the warm, dense matter regime for densities from 5 to 20 g/cm{sup 3} and temperatures from 2 to 10 eV, using both finite-temperature Kohn-Sham density-functional theory molecular dynamics (QMD) and orbital-free molecular dynamics (OFMD). The OFMD simulations are in generally good agreement with the benchmark QMD results, and we conclude that the simpler OFMD method can be used with confidence in this regime. For low temperatures (3 eV and below), one-component plasma (OCP) model simulations for diffusion agree with the QMD and OFMD calculations, but deviate by 30% at 10 eV. In comparison with the QMD and OFMD results, the OCP viscosities are not as good as for diffusion, especially for 5 g/cm{sup 3} where the temperature dependence is significantly different. The QMD and OFMD reduced diffusion and viscosity coefficients are found to depend largely, though not completely, only on the Coulomb coupling parameter {Gamma}, with a minimum in the reduced viscosity at {Gamma}{approx_equal}25, approximately the same position found in the OCP simulations. The QMD and OFMD equations of state (pressure) are also compared with the hydrogen two-component plasma model.},
doi = {10.1103/PHYSREVE.82.036404},
journal = {Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)},
issn = {1539-3755},
number = 3,
volume = 82,
place = {United States},
year = {2010},
month = {9}
}