Analysis of the Instability Growth Rate During the Jet - Background Interaction in the Magnetic Field

TL;DR

This paper analyzes how the magnetic field influences the growth rate of the two-stream instability during jet-background plasma interactions, providing insights into turbulence and thermalization processes.

Contribution

It extends the understanding of the two-stream instability by deriving growth rate dependencies on magnetic field orientation and plasma parameters in non-relativistic regimes.

Findings

Growth rate varies with magnetic field magnitude and direction.

Instability peaks near parameters causing strong energy transfer.

Results aid in predicting plasma thermalization conditions.

Abstract

The two-stream instability is a common instability, responsible for many observed phenomena in nature, especially the interaction of jets of various origin with the background plasma (e.g. extragalactic jet interacting with the cosmic background). The dispersion relation not considering magnetic field is described by the well-known Buneman relation. In 2011, Bohata, Bren, and Kulhanek derived the relation for the two-stream instability without the cold limit, with the general orientation of magnetic field, and arbitrary stream directions. The maximum value of the imaginary part of the individual dispersion branches is of interest from the physical point of view. It represents the instability growth rate which is responsible for the turbulence mode onset and subsequent reconnection on the ion radius scale accompanied by a strong plasma thermalization. The paper presented here is focused on the non-relativistic instability growth rate and its dependence on various input parameters, such as magnitude and direction of magnetic field, sound velocity, plasma frequency of the jet and direction of the wave vector during the jet - background interaction. The results are presented in well-arranged plots and can be used for determination of the plasma parameter values close to which the strong energy transfer and thermalization between the jet and the background plasma occur.