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Non-Equilibrium Processes in Dense Plasmas at the Level of Electrons and Ions

 

Dense plasma systems occur in stellar interiors, giant planets and inertial confined fusion (ICF). Because of the extreme conditions of the plasmas and their remoteness (for the astrophysical examples) or their short lifetime (in ICF), there is still much that is poorly understood about their behavior. Traditional theoretical approaches rely on weak-coupling approximations, and often end up with poorly defined cutoffs for the singular Coulomb interactions. Direct simulation of the motion of the electrons and ions in the plasmas is now becoming possible with massively parallel supercomputers. Plasma simulation capabilities have been added to the particle simulation code ddcMD that allow efficient simulation of dense plasmas on supercomputers. We have used these new capabilities to study electron-ion relaxation, stopping power, and fusion processes in dense plasmas.

  • Fusion fuel heating by charged particle scattering is important for ICF, but has been treated empirically.
  • As part of the Cimarron project an MD technique is being developed to calculate multi-component heating due to energy deposition from fast ions in dense plasmas.
  • Also, MD burning plasma simulations.
  • A novel treatment of long-range Coulomb forces enables massively parallel simulations (2009 Gordon Bell Finalist)
  • People: Glosli, Richards, Surh, Graziani,Benedict, Castor, Futterman, Hau-Riege, Hazi, Langden, London, Scullard, Sheppard, Stanton, Whitley; Murillo, Grabowski (LANL); Markmann (Yale), Weisheit (Pitt); Peters (Harvard), et al.

References:

F. R. Graziani et al., "Large-scale molecular dynamics simulations of dense plasmas: The Cimarron Project," High Energy Density Phys. 8, 105 (2012). (http://dx.doi.org/10.1016/j.hedp.2011.06.010)

D.F. Richards, J.N. Glosli, B. Chan, M.R. Dorr, E.W. Draeger, J.-L. Fattebert, W.D. Krauss, T. Spelce, F.H. Streitz, M.P. Surh, J.A. Gunnels, "Beyond homogeneous decomposition: scaling long-range forces on massively parallel systems," in Proc. Supercomputing 2009 (SC09), ACM, New York, NY, USA (2009), pp. 60:1–60:12.

J.N. Glosli, et al., Molecular dynamics simulations of temperature equilibration in dense hydrogen, Physical Review E 78 (2008) 025401(R).

L.X. Benedict, et al., Molecular dynamics simulations of electron-ion temperature equilibration in an SF6 plasma, Physical Review Letters 102 (2009) 205004.

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