skip to main content

Title: Instabilities in a simplified Fermi-like model with Krook-type collisions, intrinsic damping, and a source

Plasma micro-instabilities have been investigated numerically using a simplified Fermi-like model extended to include also a Krook-type collision operator containing a source plus collisions and a phenomenologically introduced intrinsic damping. In this simplified Fermi-like model, the wave is modeled as a single potential well. The resonant wave-particle interaction occurs due to bounces of the particles trapped between the well barriers, the height of which depends on the energy exchange between the particles and the wave. A fast numerical algorithm is used for solving the simplified Fermi-like model with the source and the relaxation processes and is briefly described and the obtained numerical results are presented and discussed. The main observation is that the presence of the source and the Krook-type collisions tends to suppress the process of filamentation in phase space and to restore the initial distribution function with free energy. In the Fermi like model including source and collisions, the steady state of the wave amplitude is achieved only due to the presence of the damping in the system. This is different from the collisionless case, when the steady state is achieved due to phase mixing. Some remarks in the end of the paper compare the results of themore » Fermi-like model with those of the analytical Berk-Breizman model, which inspired the extension of the Fermi-like model to include a source, collisions, and damping.« less
Authors:
 [1]
  1. West Pomeranian University of Technology, Institute of Physics, 70-310 Szczecin (Poland)
Publication Date:
OSTI Identifier:
22227868
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 8; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOLTZMANN-VLASOV EQUATION; COMPARATIVE EVALUATIONS; DAMPING; DISTRIBUTION FUNCTIONS; FREE ENERGY; MAXWELL EQUATIONS; NUMERICAL ANALYSIS; PHASE SPACE; PLASMA; PLASMA INSTABILITY; PLASMA WAVES; STEADY-STATE CONDITIONS; TRAPPING; WALL EFFECTS