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Molecular dynamics calculation of the spectral densities of plasma fluctuations

Published online by Cambridge University Press:  01 June 2018

A. Panarese
Affiliation:
Department of Chemistry, University of Bari, Bari 70126, Italy Institute of Nanotechnology (NANOTEC), CNR, Bari 70126, Italy
D. Bruno*
Affiliation:
Institute of Nanotechnology (NANOTEC), CNR, Bari 70126, Italy
P. Tolias
Affiliation:
Space and Plasma Physics, Royal Institute of Technology (KTH), Stockholm 10044, Sweden Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli, Naples 80126, Italy
S. Ratynskaia
Affiliation:
Space and Plasma Physics, Royal Institute of Technology (KTH), Stockholm 10044, Sweden
S. Longo
Affiliation:
Department of Chemistry, University of Bari, Bari 70126, Italy Institute of Nanotechnology (NANOTEC), CNR, Bari 70126, Italy
U. de Angelis
Affiliation:
Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli, Naples 80126, Italy
*
Email address for correspondence: domenico.bruno@cnr.it

Abstract

Spectral densities of plasma fluctuations are calculated for the thermal case using classical molecular dynamics (MD) assuming Coulomb interactions and a short-range cutoff radius. The aim of the calculation is to verify limits and performances of such calculations in the light of possible generalizations, e.g. collisional or non-ideal plasmas. Results are presented for ideal, collisionless, fully ionized thermal plasmas. Comparison with the analytical theory reveals a generally satisfactory agreement with possibility for improvement when more strict numerical parameters are used albeit with a strong increase in computational cost. The largest deviations have been observed in the vicinity of the weakly damped eigenmodes. The agreement is strong in other parts of the spectrum, where Landau damping is prominent, and overcomes the effects stemming from the excess collisionality and coupling as well as from the exclusion of short-range collisions.

Type
Research Article
Copyright
© Cambridge University Press 2018 

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