An entropy based thermalization scheme for hybrid simulations of Coulomb collisions

L. F. Ricketson, M. S. Rosin, Russel Caflisch, A. M. Dimits

Research output: Contribution to journalArticle

Abstract

We formulate and test a hybrid fluid-Monte Carlo scheme for the treatment of elastic collisions in gases and plasmas. While our primary focus and demonstrations of applicability are for moderately collisional plasmas, as described by the Landau-Fokker-Planck equation, the method is expected to be applicable also to collision processes described by the Boltzmann equation. This scheme is similar to the previously discussed velocity-based scheme (R. Caflisch, et al., (2008) [7]) and the scattering-angle-based scheme (A.M. Dimits, et al., (2010) [14])], but with a firmer theoretical basis and without the inherent limitation to the Landau-Fokker-Planck case. It gives a significant performance improvement (e.g., error for a given computational effort) over the velocity-based scheme. These features are achieved by assigning passive scalars to each simulated particle and tracking their evolution through collisions. The method permits a formal error analysis that agrees with numerical results. The tests performed are for the evolution of an anisotropic Maxwellian and a bump-on-tail distribution.

Original languageEnglish (US)
Pages (from-to)77-99
Number of pages23
JournalJournal of Computational Physics
Volume273
DOIs
StatePublished - Sep 15 2014

Fingerprint

Coulomb collisions
Collisional plasmas
Entropy
entropy
Fokker Planck equation
collisional plasmas
collisions
Boltzmann equation
error analysis
Fokker-Planck equation
Error analysis
elastic scattering
Demonstrations
simulation
Scattering
scalars
Plasmas
Fluids
fluids
Gases

Keywords

  • Coulomb collisions
  • Entropy
  • Hybrid
  • Monte Carlo
  • Particle collisions
  • Plasma

ASJC Scopus subject areas

  • Computer Science Applications
  • Physics and Astronomy (miscellaneous)

Cite this

An entropy based thermalization scheme for hybrid simulations of Coulomb collisions. / Ricketson, L. F.; Rosin, M. S.; Caflisch, Russel; Dimits, A. M.

In: Journal of Computational Physics, Vol. 273, 15.09.2014, p. 77-99.

Research output: Contribution to journalArticle

Ricketson, L. F. ; Rosin, M. S. ; Caflisch, Russel ; Dimits, A. M. / An entropy based thermalization scheme for hybrid simulations of Coulomb collisions. In: Journal of Computational Physics. 2014 ; Vol. 273. pp. 77-99.
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