SRS-SBS competition and nonlinear laser energy absorption in a high temperature plasma

TL;DR

This paper analyzes the competition between stimulated Raman and Brillouin scattering in high-temperature plasma, demonstrating control over laser energy absorption and scattering through plasma parameters via kinetic simulations.

Contribution

It provides a detailed analysis of the competition between Raman and Brillouin scattering and shows how to control laser absorption in plasma by adjusting specific plasma parameters.

Findings

Control of Brillouin backscattering through plasma parameters.

Ability to modulate nonlinear laser absorption.

Insights into laser-plasma interaction mechanisms.

Abstract

Stimulated Raman and Brillouin scattering of laser radiation in a plasma corona are outstanding issues for the inertial confinement fusion. Stimulated Raman scattering may produce absorption of a significant fraction of laser energy near the plasma quarter critical density associated with plasma cavitation and generation of hot electrons. By contrast, stimulated Brillouin scattering operates in a lower density plasma and prevents the laser light access to the absorption region. In the present paper, we report the results of analysis of competition of these two parametric instabilities with a series of one-dimensional kinetic simulations of laser-plasma interactions. By controlling the Brillouin backscattering through variation such plasma parameters as ion acoustic wave damping, divergence of the plasma expansion velocity or the laser bandwidth, we demonstrate the possibility of controlling the level of nonlinear laser absorption and scattering in a hot, weakly collisional plasma.