On the background-gyroresonant character of the Bell instability

Abstract

We show that the Bell instability, which is widely considered potentially important for cosmic-ray acceleration, is the low-frequency limit of a gyroresonant interaction between the protons of the interstellar medium and shear-Alfvén waves. At large cosmic-ray current densities, its growth rate is therefore limited by the proton gyrofrequency, and two modes emerge from the cold-beam dispersion relation. A third mode driven by electron gyroresonance is only weakly unstable at low current densities. We discuss implications for magnetic-field amplification and its saturation in the vicinity of supernova remnants.

arXiv commentAnalytic theory spin-off from 1805.11220 (the latter has been abridged for resubmission)

References in corpus (10)

• Simulations of Ion Acceleration at Non-relativistic Shocks. I. Acceleration Efficiency
• A kinetic approach to cosmic ray induced streaming instability at supernova shocks
• Non-linear Study of Bell's Cosmic Ray Current-driven Instability
• Diffusive Shock Acceleration with Magnetic Amplification by Non-resonant Streaming Instability in SNRs
• Production of Magnetic Turbulence by Cosmic Rays Drifting Upstream of Supernova Remnant Shocks
• Cosmic Ray Streaming in Clusters of Galaxies
• Ion acceleration in non-relativistic astrophysical shocks
• Cosmic-ray-induced filamentation instability in collisionless shocks
• Turbulence and particle acceleration in collisionless supernovae remnant shocks: I-Anisotropic spectra solutions
• Environments for Magnetic Field Amplification by Cosmic Rays

Cited by in corpus (9)

• PIC Simulation Methods for Cosmic Radiation and Plasma Instabilities
• On the Growth and Saturation of the Gyroresonant Streaming Instabilities
• dHybridR: a Hybrid--Particle-in-Cell Code Including Relativistic Ion Dynamics
• A new cosmic ray-driven instability
• How it cramps the flow: three regimes for the saturation of parallel ion-beam instabilities
• Lepton-driven Non-resonant Streaming Instability
• Deciphering the physical basis of the intermediate-scale instability
• Revisiting the role of cosmic-ray driven Alfvén waves in pre-existing magnetohydrodynamic turbulence. I. Turbulent damping rates and feedback on background fluctuations
• Magnetic Field Amplification and Particle Acceleration in Weakly Magnetized Trans-relativistic Electron-ion Shocks