Effects of finite ion inertia on phase-mixing of Langmuir oscillations in cold electron-positron-ion plasmas

Abstract

We study the influences of finite ion mass on the phase-mixing process of Langmuir oscillations (LOs) in cold electron-positron-ion (EPI) plasmas. We solve the three fluid-Maxwell's equations in a perturbative way to provide an analytical estimate of phase-mixing time of LOs in such multispecies plasmas. The phase-mixing time is shown to depend on the perturbation amplitude, on the equilibrium ion-to-electron density ratio, and on the electron-to-ion mass ratio. The analytical dependence of phase-mixing time on these parameters is also discussed in various plasma limits.