Numerical study of the wave-break in the vacuum-plasma interface during the interaction of an intense laser pulse

Amir Chakhmachi,Elnaz Khalilzadeh,Jamalaldin Yazdanpanah,Masoud Pishdast

doi:10.1063/1.4986017

Amir Chakhmachi, Elnaz Khalilzadeh + Show 2 more

Open Access

https://doi.org/10.1063/1.4986017

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Abstract

In this paper, the wave break in the plasma-vacuum interface during the intense laser interaction is investigated. Since the nonlinear wave breaking is a non-adiabatic process, the fully kinetic 1D-3V Particle-In-Cell (PIC) simulation experiments are performed to identify whether that the origin of this mechanism is electromagnetic or electrostatic. Our simulation results show that the nonlinear wave breaking on the vacuum-plasma interface has electrostatic origin. In addition, it is found that for pulse lengths exceeding the plasma wavelength this electrostatic phenomenon comes in conjunction with some active electromagnetic effects having the same impact on the electron acceleration. In these regards, we conduct sophisticated simulations isolating these electromagnetic effects and study the effects of the pulse parameters such as the pulse rise time, pulse length, and pulse shape on the boundary nonlinear wave breaking. The study of the pulse rise-time variation effects shows that as the rise time of the laser pulse decreases, the number of the electrons involved in the nonlinear wave breaking, maximum energy of the trapped electrons and the path length of the accelerated electrons in the phase space are increased. Also, the study of phase space and field patterns in our simulation indicates that the reduction of the pulse flat top duration time causes that the smaller part of the electrons and the smaller portion of the wake wave involve in the nonlinear wave breaking.

Highlights

The interaction of an ultra-short intense laser pulse with the under-dense plasma is one of the most motivating subjects in the plasma physics
Based on what was mentioned in the previous section, it is evident that the boundary nonlinear wave breaking can be highly sensitive to the initial laser pulse parameters
This paper focuses on the origin of the nonlinear wave breaking due to the inhomogeneity of the plasma density

Summary

INTRODUCTION

The interaction of an ultra-short intense laser pulse with the under-dense plasma is one of the most motivating subjects in the plasma physics In this context, a vast number of wave-particle phenomena become interesting when the high power laser causes the electron quiver velocity to become highly relativistic. For pulse lengths exceeding the plasma wavelength the nonlinear wave breaking effect comes in conjunction with some active electromagnetic effects having the same impact on the electron acceleration This issue is not considered in the previous literature. In these regards, we conduct sophisticated simulations isolating the electromagnetic effects and study the effects of the pulse parameters such as the pulse rise time, pulse length, and pulse shape on the boundary nonlinear wave breaking.

SIMULATION RESULTS AND DISCUSSION

PARAMETRIC ANALYSES

CONCLUSION