Evolution of Unstable Ion Acoustic Solitons

Abstract

The evolution of a localized potential perturbation in a plasma of cold, kinetic ions and Boltzmann electrons is investigated computationally. We find that small perturbations evolve into a train of stable ion acoustic solitons, as predicted by the Korteweg-de Vries theory. Large perturbations, however, are found to evolve into solitons that exceed the soliton speed limit. Such solitons are unstable and decay by emitting reflected ions bursts and ion acoustic waves.