One-dimensional particle simulation of the filamentation instability: Electrostatic field driven by the magnetic pressure gradient force

M.E. Dieckmann, Ioannis Kourakis, Marco Borghesi, G. Rowlands

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15 Citations (Scopus)


Two counterpropagating cool and equally dense electron beams are modeled with particle-in-cell simulations. The electron beam filamentation instability is examined in one spatial dimension, which is an approximation for a quasiplanar filament boundary. It is confirmed that the force on the electrons imposed by the electrostatic field, which develops during the nonlinear stage of the instability, oscillates around a mean value that equals the magnetic pressure gradient force. The forces acting on the electrons due to the electrostatic and the magnetic field have a similar strength. The electrostatic field reduces the confining force close to the stable equilibrium of each filament and increases it farther away, limiting the peak density. The confining time-averaged total potential permits an overlap of current filaments with an opposite flow direction.
Original languageEnglish
Article number074502
Pages (from-to)074502-074502-4
Number of pages74499
JournalPhysics of Plasmas
Issue number7
Publication statusPublished - Jul 2009

ASJC Scopus subject areas

  • Condensed Matter Physics

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