Dissipation of weakly nonlinear wakefields due to ion motion

TL;DR

This paper investigates how ion motion limits the lifetime of weakly nonlinear plasma wakefields, introduces a new way to measure this lifetime in simulations, and discusses implications for terahertz radiation generation.

Contribution

It presents a novel method for quantifying wakefield lifetime in simulations and analyzes how ion mass influences this lifetime.

Findings

Wakefield lifetime scales with ion mass.

Radial component perturbation destroys plasma wave.

Implications for terahertz radiation methods.

Abstract

In an initially uniform plasma, the lifetime of a weakly nonlinear plasma wave excited by a short driver is limited by the ion dynamics. The wakefield contains a slowly varying radial component, which results in a perturbation of the ion density profile and consequent destruction of the plasma wave. We suggest a novel method of characterizing the wave lifetime in numerical simulations quantitatively and study how the lifetime scales with the ion mass. We also discuss the implications of the limited lifetime on a recently proposed method of generating high-power terahertz radiation with counterpropagating wakefields driven by colliding laser pulses.