title: Molecular dynamics simulations and generalized Lenard-Balescu calculations of electron-ion temperature equilibration in plasmas.
abstract: We study the problem of electron-ion temperature equilibration in plasmas. We consider pure H at various densities and temperatures and Ar-doped H at temperatures high enough so that the Ar is fully ionized. Two theoretical approaches are used: classical molecular dynamics (MD) with statistical two-body potentials and a generalized Lenard-Balescu (GLB) theory capable of treating multicomponent weakly coupled plasmas. The GLB is used in two modes: (1) with the quantum dielectric response in the random-phase approximation (RPA) together with the pure Coulomb interaction and (2) with the classical (ℏ→0) dielectric response (both with and without local-field corrections) together with the statistical potentials. We find that the MD results are described very well by classical GLB including the statistical potentials and without local-field corrections (RPA only); worse agreement is found when static local-field effects are included, in contradiction to the classical pure-Coulomb case with like charges. The results of the various approaches are all in excellent agreement with pure-Coulomb quantum GLB when the temperature is high enough. In addition, we show that classical calculations with statistical potentials derived from the exact quantum two-body density matrix produce results in far better agreement with pure-Coulomb quantum GLB than classical calculations performed with older existing statistical potentials.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: Lorin X
authors.initials: LX
authors.lastname: Benedict
authors.forename: Michael P
authors.initials: MP
authors.lastname: Surh
authors.forename: John I
authors.initials: JI
authors.lastname: Castor
authors.forename: Saad A
authors.initials: SA
authors.lastname: Khairallah
authors.forename: Heather D
authors.initials: HD
authors.lastname: Whitley
authors.forename: David F
authors.initials: DF
authors.lastname: Richards
authors.forename: James N
authors.initials: JN
authors.lastname: Glosli
authors.forename: Michael S
authors.initials: MS
authors.lastname: Murillo
authors.forename: Christian R
authors.initials: CR
authors.lastname: Scullard
authors.forename: Paul E
authors.initials: PE
authors.lastname: Grabowski
authors.forename: David
authors.initials: D
authors.lastname: Michta
authors.forename: Frank R
authors.initials: FR
authors.lastname: Graziani