Understanding Streaming Instabilities in the Limit of High Cosmic Ray Current Density

Fuente: arXiv
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Main Authors: Lichko, Emily, Caprioli, Damiano, Schroer, Benedikt, Gupta, Siddhartha
Format: Preprint
Published: 2024
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_version_ 1866929705236561920
author Lichko, Emily
Caprioli, Damiano
Schroer, Benedikt
Gupta, Siddhartha
author_facet Lichko, Emily
Caprioli, Damiano
Schroer, Benedikt
Gupta, Siddhartha
contents A critical component of particle acceleration in astrophysical shocks is the non-resonant (Bell) instability, where the streaming of cosmic rays (CRs) leads to the amplification of magnetic fields necessary to scatter particles. In this work we use kinetic particle-in-cells simulations to investigate the high-CR current regime, where the typical assumptions underlying the Bell instability break down. Despite being more strongly driven, significantly less magnetic field amplification is observed compared to low-current cases, an effect due to the anisotropic heating that occurs in this regime. We also find that electron-scale modes, despite being fastest growing, mostly lead to moderate electron heating and do not affect the late evolution or saturation of the instability.
format Preprint
id arxiv_https___arxiv_org_abs_2411_05704
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Understanding Streaming Instabilities in the Limit of High Cosmic Ray Current Density
Lichko, Emily
Caprioli, Damiano
Schroer, Benedikt
Gupta, Siddhartha
High Energy Astrophysical Phenomena
Plasma Physics
A critical component of particle acceleration in astrophysical shocks is the non-resonant (Bell) instability, where the streaming of cosmic rays (CRs) leads to the amplification of magnetic fields necessary to scatter particles. In this work we use kinetic particle-in-cells simulations to investigate the high-CR current regime, where the typical assumptions underlying the Bell instability break down. Despite being more strongly driven, significantly less magnetic field amplification is observed compared to low-current cases, an effect due to the anisotropic heating that occurs in this regime. We also find that electron-scale modes, despite being fastest growing, mostly lead to moderate electron heating and do not affect the late evolution or saturation of the instability.
title Understanding Streaming Instabilities in the Limit of High Cosmic Ray Current Density
topic High Energy Astrophysical Phenomena
Plasma Physics
url https://arxiv.org/abs/2411.05704