Quantum molecular dynamics simulations of transport properties in liquid and dense-plasma plutonium

Journal Article · Tue Feb 15 00:00:00 EST 2011 · Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)

DOI:https://doi.org/10.1103/PHYSREVE.83.026404· OSTI ID:21560033

Kress, J D; Cohen, James S; Kilcrease, D P; Horner, D A; Collins, L A ^[1]

---

1. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

We have calculated the viscosity and self-diffusion coefficients of plutonium in the liquid phase using quantum molecular dynamics (QMD) and in the dense-plasma phase using orbital-free molecular dynamics (OFMD), as well as in the intermediate warm dense matter regime with both methods. Our liquid metal results for viscosity are about 40% lower than measured experimentally, whereas a previous calculation using an empirical interatomic potential (modified embedded-atom method) obtained results 3-4 times larger than the experiment. The QMD and OFMD results agree well at the intermediate temperatures. The calculations in the dense-plasma regime for temperatures from 50 to 5000 eV and densities about 1-5 times ambient are compared with the one-component plasma (OCP) model, using effective charges given by the average-atom code inferno. The inferno-OCP model results agree with the OFMD to within about a factor of 2, except for the viscosity at temperatures less than about 100 eV, where the disagreement is greater. A Stokes-Einstein relationship of the viscosities and diffusion coefficients is found to hold fairly well separately in both the liquid and dense-plasma regimes.

• OSTI ID: 21560033
• Journal Information: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print), Vol. 83, Issue 2; Other Information: DOI: 10.1103/PhysRevE.83.026404; (c) 2011 American Institute of Physics; ISSN 1539-3755
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ATOMS
EFFECTIVE CHARGE
EV RANGE
LIQUID METALS
MOLECULAR DYNAMICS METHOD
PLASMA DENSITY
PLUTONIUM
POTENTIALS
SELF-DIFFUSION
SIMULATION
TRANSPORT THEORY
VISCOSITY
ACTINIDES
CALCULATION METHODS
DIFFUSION
ELEMENTS
ENERGY RANGE
FLUIDS
LIQUIDS
METALS
TRANSURANIUM ELEMENTS