Relativistic electron beam driven longitudinal wake-wave breaking in a cold plasma

TL;DR

This paper investigates the evolution and breaking of relativistic electron beam driven wakefields in a cold plasma using 1D-fluid simulations, revealing phase mixing as the cause of wave steepening and establishing scaling laws for breaking time.

Contribution

It demonstrates that the wakefield is an Akhiezer-Polovin mode and explains wave breaking through phase mixing caused by relativistic mass effects.

Findings

Wakefield is an Akhiezer-Polovin mode.

Wave breaking is due to phase mixing.

Breaking time follows known scaling laws.

Abstract

Space-time evolution of relativistic electron beam driven wake-field in a cold, homogeneous plasma, is studied using 1D-fluid simulation techniques. It is observed that the wake wave gradu- ally evolves and eventually breaks, exhibiting sharp spikes in the density profile and sawtooth like features in the electric field profile [1]. It is shown here that the excited wakefield is a longitudi- nal Akhiezer-Polovin mode [2] and its steepening (breaking) can be understood in terms of phase mixing of this mode, which arises because of relativistic mass variation effects. Further the phase mixing time (breaking time) is studied as a function of beam density and beam velocity and is found to follow the well known scaling presented in ref.[3].