PIC Simulation of Current‐Driven Buneman Instability in Presence of Collisional and Thermal Effects

Abstract

Key words Current-driven plasma, Buneman instability, particle in cell simulation.Collisional and thermal effects on the nonlinear evolution of Buneman instability in an unmagnetized currentdriven plasma are investigated by particle in cell simulations. These simulations show that, as the time passes, the electron distribution function profiles deviate from initial shifted Maxwellian distribution and the electron phase-space holes can be formed. The electron distribution function profiles also indicate the counter-streaming and plateau formation. Moreover, the contour of the electric field and profiles of the growth rate display the resonance condition for this instability. Finally, the time evolution of the electric field energy density and ion kinetic energy in the presence of collisional and thermal effects are presented. These evolutions illustrate that in the presence of collisions, the growth rate of the Buneman instability is smaller than the collisionless case.

Investigation of plasma density gratings in current carrying plasmas by particle in cell method

“…In this case the electric field gives its energy to electrons, positrons and ions and the system becomes stable. It is important to note that after the saturation time, the energy can be exchanged between the electric field and ions but this energy exchange can not cause instability, thus the system remains stable [8]. Assuming delta distribution function, the normalized electron density as a function of ω x u / pe e0 has been depicted in figure 5 for various times.…”

“…Some of these processes are nonlinear effects and instabilities [5][6][7]. The nonlinear effects in plasmas including multiple beams are the counter-streaming, plateau structure of electron distribution function, generation of electron holes in phase space, rising of the electron and ion densities, etc [8][9][10]. These nonlinear effects have been studied theoretically, experimentally, and computationally.…”