Abstract
We have extended a recently developed multispecies, multitemperature Bhatnagar-Gross-Krook model [Haack, J. Stat. Phys. 168, 822 (2017)JSTPBS0022-471510.1007/s10955-017-1824-9], to include multiphysics capabilities that enable modeling of a wider range of physical conditions. In terms of geometry, we have extended from the spatially homogeneous setting to one spatial dimension. In terms of the physics, we have included an atomic ionization model, accurate collision physics across coupling regimes, self-consistent electric fields, and degeneracy in the electronic screening. We apply the model to a warm dense matter scenario in which the ablator-fuel interface of an inertial confinement fusion target is heated, but for larger length and time scales and for much higher temperatures than can be simulated using molecular dynamics. Relative to molecular dynamics, the kinetic model greatly extends the temperature regime and the spatiotemporal scales over which we are able to model. In our numerical results we observe hydrogen from the ablator material jetting into the fuel during the early stages of the implosion and compare the relative size of various diffusion components (Fickean diffusion, electrodiffusion, and barodiffusion) that drive this process. We also examine kinetic effects, such as anisotropic distributions and velocity separation, in order to determine when this problem can be described with a hydrodynamic model.
| Original language | English |
|---|---|
| Article number | 063310 |
| Journal | Physical Review E - Statistical, Nonlinear, and Soft Matter Physics |
| Volume | 96 |
| Issue number | 6 |
| DOIs | |
| State | Published - Dec 21 2017 |
Funding
We thank Jim Glosli and Liam Stanton, both of Lawrence Livermore National Laboratory, for sharing MD results as well as the MD implementation of the mean ionization state for mixtures. This manuscript has been authored, in part, by UT-Battelle, LLC, under Contract No. DE-AC0500OR22725, with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for the United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). The research of C.H. was sponsored by the Office of Advanced Scientific Computing Research and performed at the Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, under Contract No. DE-AC0500OR22725. The research of J.H. and M.S.M. was performed as part of the NAMBE Project under the auspices of the U.S. Department of Energy by Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396. This work has been approved for unlimited public release under Los Alamos Release No. LA-UR-17-25906.
