Mass Transport Properties of LiD-U Mixtures from Orbital Free Molecular Dynamics Simulations and a Pressure-Matching Mixing Rule

doi:https://doi.org/10.2172/1042987

Title: Mass Transport Properties of LiD-U Mixtures from Orbital Free Molecular Dynamics Simulations and a Pressure-Matching Mixing Rule

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Abstract

Mass transport properties for LiD-U mixtures were calculated using a pressure matching mixture rule for the mixing of LiD and of U properties simulated with Orbital Free Molecular Dynamics (OFMD). The mixing rule was checked against benchmark OFMD simulations for the fully interacting three-component (Li, D, U) system. To obtain transport coefficients for LiD-U mixtures of different (LiD){sub x}U{sub (1-x)} compositions as functions of temperature and mixture density is a tedious task. Quantum molecular dynamics (MD) simulations can be employed, as in the case LiD or U. However, due to the presence of the heavy constituent U, such simulations proceed so slowly that only a limited number of numerical data points in the (x, {rho}, T) phase space can be obtained. To finesse this difficulty, transport coefficients for a mixture can be obtained using a pressure-matching mixing rule discussed. For both LiD and U, the corresponding transport coefficients were obtained earlier from quantum molecular dynamics simulations. In these simulations, the quantum behavior of the electrons was represented using an orbital free (OF) version of density functional theory, and ions were advanced in time using classical molecular dynamics. The total pressure of the system, P = nk{sub B}T/V + P{sub e},more »« less

Authors:

Burakovsky, Leonid ^[1]; Kress, Joel D. ^[1]; Collins, Lee A. ^[1]

Los Alamos National Laboratory

Publication Date:: 2012-05-31

Research Org.:: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:: DOE/LANL

OSTI Identifier:: 1042987

Report Number(s):: LA-UR-12-21806
TRN: US1203068

DOE Contract Number:: AC52-06NA25396

Resource Type:: Technical Report

Country of Publication:: United States

Language:: English

Subject:: Plasma Physics & Fusion Technology(70); BENCHMARKS; DIFFUSION; ELECTRONS; FUNCTIONALS; MIXTURES; PHASE SPACE; SELF-DIFFUSION; SHEAR; TRANSPORT; VISCOSITY

Citation Formats


                    Burakovsky, Leonid, Kress, Joel D., and Collins, Lee A. Mass Transport Properties of LiD-U Mixtures from Orbital Free Molecular Dynamics Simulations and a Pressure-Matching Mixing Rule.  United States: N. p., 2012. 
        Web.  doi:10.2172/1042987.

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                    Burakovsky, Leonid, Kress, Joel D., & Collins, Lee A. Mass Transport Properties of LiD-U Mixtures from Orbital Free Molecular Dynamics Simulations and a Pressure-Matching Mixing Rule.  United States.  https://doi.org/10.2172/1042987

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                    Burakovsky, Leonid, Kress, Joel D., and Collins, Lee A. Thu .  
        "Mass Transport Properties of LiD-U Mixtures from Orbital Free Molecular Dynamics Simulations and a Pressure-Matching Mixing Rule".  United States.  https://doi.org/10.2172/1042987.  https://www.osti.gov/servlets/purl/1042987.

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@article{osti_1042987,

  title        = {Mass Transport Properties of LiD-U Mixtures from Orbital Free Molecular Dynamics Simulations and a Pressure-Matching Mixing Rule},

  author       = {Burakovsky, Leonid and Kress, Joel D. and Collins, Lee A.},

  abstractNote = {Mass transport properties for LiD-U mixtures were calculated using a pressure matching mixture rule for the mixing of LiD and of U properties simulated with Orbital Free Molecular Dynamics (OFMD). The mixing rule was checked against benchmark OFMD simulations for the fully interacting three-component (Li, D, U) system. To obtain transport coefficients for LiD-U mixtures of different (LiD){sub x}U{sub (1-x)} compositions as functions of temperature and mixture density is a tedious task. Quantum molecular dynamics (MD) simulations can be employed, as in the case LiD or U. However, due to the presence of the heavy constituent U, such simulations proceed so slowly that only a limited number of numerical data points in the (x, {rho}, T) phase space can be obtained. To finesse this difficulty, transport coefficients for a mixture can be obtained using a pressure-matching mixing rule discussed. For both LiD and U, the corresponding transport coefficients were obtained earlier from quantum molecular dynamics simulations. In these simulations, the quantum behavior of the electrons was represented using an orbital free (OF) version of density functional theory, and ions were advanced in time using classical molecular dynamics. The total pressure of the system, P = nk{sub B}T/V + P{sub e}, is the sum of the ideal gas pressure of the ions plus the electron pressure. The mass self-diffusion coefficient for species {alpha}, D{sub {alpha}}, the mutual diffusion coefficient for species {alpha} and {beta}, D{alpha}{beta}, and the shear viscosity, {eta}, are computed from the appropriate autocorrelation function. The details of similar QMD calculations on LiH are described in Ref. [1] for 0.5 eV < T < 3 eV, and in Ref. [2] for 2 eV < T < 6 eV.},

  doi          = {10.2172/1042987},

  url          = {https://www.osti.gov/biblio/1042987},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {2012},

  month        = {5}

}

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