Counter-Streaming Beams in Collisionless Pair Plasma Instability Systems I: Evolution and Parameterization of the Weibel Instability

TL;DR

This paper investigates the evolution of the Weibel instability in collisionless pair plasmas through particle-in-cell simulations, highlighting parameter effects, secondary instabilities, and filament mergers relevant to astrophysical phenomena.

Contribution

It provides a detailed analysis of how initial beam parameters influence the Weibel instability's evolution and identifies secondary instabilities and filament merger processes.

Findings

Secondary electromagnetic instabilities are generated.

Filament mergers occur during the decay phase.

Parameter variations affect the instability timeline.

Abstract

Energetic astrophysical phenomena, such as $\gamma$-ray bursts and supernova explosion-driven shocks in collisionless plasmas, involve various plasma kinetic instabilities, such as the Weibel instability. In this paper, we explore the evolution of the Weibel instability using the spectral analysis and physical field evolution of particle-in-cell simulations. Effects of varying parameters of the initial counter-streaming beams are detailed in reference to the total evolutionary timeline of the instability. Generation of a secondary instability and excitation of electromagnetic waves primary decay have been observed. We also discuss the filament mergers during the instability decay.