Phase-mixing of large amplitude electron oscillations in a cold inhomogeneous plasma

Abstract

Phase-mixing of large amplitude non-relativistic electron oscillations around an inhomogeneous background of massive ions has been studied in a cold plasma. For our purpose, a space periodic but time independent ion density profile along with a perturbation in the electron density is considered. An exact space-time dependent solution is presented in the parametric form by using Lagrangian coordinates. An inhomogeneity in the ion density causes the characteristic plasma frequency to acquire spatial dependency, leading to phase-mixing and thus breaking of excited oscillations at arbitrary amplitudes. The effects of finite amplitude electron density perturbation on the process of phase-mixing have also been discussed.