-
Author(s):
H. Shimazu, S. Machida and M. Tanaka
-
Title:
Macro-Particle Simulation of Collisionless Parallel Shocks
Date of publication:
Oct. 1995
-
Key words:
beam-plasma instability, electron kinetic effects, shock collapse and re-formation, implicit-particle simulation
-
Abstract:
An implicit-particle simulation of the collisionless parallel shock created at the interface between an injected beam and a stationary plasma is performed in one dimensional geometry with kinetic electrons inclusive. Electromagnetic waves with the right-hand circular polarization propagating upstream (R^- waves) are generated at the interface of the two plasmas. The R^- waves decelerate the injected beam to form a shock. The shock transition region is not monotonic but consists of two distinct regions, a pedestal and a shock ramp. The length of the transition region which contains the plasma interface is a few thousand electron skin depths. The parallel shock is non-stationary and repeats collapse and re-formation periodically in time. The right-hand circularly polarized electromagnetic waves propagating downstream (R^+waves) are repeatedly excited at the shock ramp. Nonlinear wave-particle interaction between the beam and the R^+ waves causes wave condensation and density modulation. The R^+ waves are considered to sweep away the downstream plasma to suppress its thermal diffusion across the shock.
-
|
