Strongly Enhanced Stimulated Brillouin Backscattering in an Electron-Positron Plasma

Matthew R. Edwards, Nathaniel J. Fisch, and Julia M. Mikhailova

Phys. Rev. Lett. 116, 015004 – Published 8 January 2016

Abstract

Stimulated Brillouin backscattering of light is shown to be drastically enhanced in electron-positron plasmas, in contrast to the suppression of stimulated Raman scattering. A generalized theory of three-wave coupling between electromagnetic and plasma waves in two-species plasmas with arbitrary mass ratios, confirmed with a comprehensive set of particle-in-cell simulations, reveals violations of commonly held assumptions about the behavior of electron-positron plasmas. Specifically, in the electron-positron limit three-wave parametric interaction between light and the plasma acoustic wave can occur, and the acoustic wave phase velocity differs from its usually assumed value.

Received 13 September 2015

DOI:https://doi.org/10.1103/PhysRevLett.116.015004

Physics Subject Headings (PhySH)

Electromagnetic waves & oscillations Stimulated Brillouin & Raman scattering in plasmas

Electron-positron plasmas

Particle-in-cell methods

Plasma Physics

Authors & Affiliations

Matthew R. Edwards^1,*, Nathaniel J. Fisch², and Julia M. Mikhailova^1,3,†

¹Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA
²Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
³Prokhorov General Physics Institute, Russian Academy of Sciences, 119991 Moscow, Russia