Stimulated scattering instability in a relativistic plasma

TL;DR

This paper investigates how intense electromagnetic waves interact with relativistic plasmas containing degenerate electrons, revealing that relativistic and degeneracy effects significantly alter stimulated scattering and modulational instabilities.

Contribution

It derives coupled nonlinear equations and dispersion relations for plasma oscillations in relativistic degenerate plasmas, highlighting the impact of relativistic and degeneracy pressures on instabilities.

Findings

Relativistic and degeneracy pressures modify scattering instability characteristics.

Derived nonlinear dispersion relations for plasma oscillations.

Identified significant effects on SRS, SBS, and modulational instabilities.

Abstract

We study the stimulated scattering instabilities of an intense linearly polarized electromagnetic wave (EMW) in a relativistic plasma with degenerate electrons. Starting from a relativistic hydrodynamic model and the Maxwell's equations, we derive coupled nonlinear equations for low-frequency electron and ion plasma oscillations that are driven by the EMW's ponderomotive force. The nonlinear dispersion relations are then obtained from the coupled nonlinear equations which reveal stimulated Raman scattering (SRS), stimulated Brillouin scattering (SBS), and modulational instabilities (MIs) of EMWs. It is shown that the thermal pressure of ions and the relativistic degenerate pressure of electrons significantly modify the characteristics of SRS, SBS, and MIs.