The growth of the longitudinal beam-plasma instability in the presence of an inhomogeneous background - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue J.Plasma Phys. Année : 2020

The growth of the longitudinal beam-plasma instability in the presence of an inhomogeneous background

Mohamad Shalaby
Avery E. Broderick
  • Fonction : Auteur
Philip Chang
  • Fonction : Auteur
Christoph Pfrommer
Ewald Puchwein

Résumé

We study the longitudinal stability of beam-plasma systems in the presence of a density inhomogeneity in the background plasma. Previous works have focused on the non-relativistic regime where hydrodynamical models are used to evolve pre-existing Langmuir waves within inhomogeneous background plasmas. Here, for the first time we study the problem with kinetic equations in a fully-relativistic way. We do not assume the existence of Langmuir waves, and we focus on the rate and the mechanism by which waves are excited in such systems from an initial perturbation. We derive the structure of the unstable modes and compute an analytical approximation for their growth rates. Our computation is limited to dilute and cold beams, and shows an excellent agreement with particle-in-cell simulations performed using the SHARP code. We show that, due to such an inhomogeneity, the virulent beam-plasma instabilities in the intergalactic medium are not suppressed but their counterparts in the solar wind can be suppressed as evidenced by propagating type-III solar radio bursts.

Dates et versions

hal-02518088 , version 1 (24-03-2020)

Identifiants

Citer

Mohamad Shalaby, Avery E. Broderick, Philip Chang, Christoph Pfrommer, Ewald Puchwein, et al.. The growth of the longitudinal beam-plasma instability in the presence of an inhomogeneous background. J.Plasma Phys., 2020, 86 (2), pp.535860201. ⟨10.1017/S0022377820000215⟩. ⟨hal-02518088⟩
86 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More