Collisionless Weibel shocks: full formation mechanism and timing

Abstract

Collisionless shocks in plasmas play an important role in space physics (Earth's bow shock) and astrophysics (supernova remnants, relativistic jets, gamma-ray bursts, high energy cosmic rays). While the formation of a fluid shock through the steepening of a large amplitude sound wave has been understood for long, there is currently no detailed picture of the mechanism responsible for the formation of a collisionless shock. We unravel the physical mechanism at work and show that an electromagnetic Weibel shock always forms when two relativistic collisionless, initially unmagnetized, plasma shells encounter. The predicted shock formation time is in good agreement with 2D and 3D particle-in-cell simulations of counterstreaming pair plasmas. By predicting the shock formation time, experimental setups aiming at producing such shocks can be optimised to favourable conditions.

To appear in Physics of Plasmas

References in corpus (4)

• Particle acceleration in relativistic collisionless shocks: Fermi process at last?
• Long Term Evolution of Magnetic Turbulence in Relativistic Collisionless Shocks: Electron-Positron Plasmas
• Exact relativistic kinetic theory of an electron beam-plasma system: hierarchy of the competing modes in the system parameter space
• Relativistic Collisionless Shocks in Unmagnetized Electron-Positron Plasmas

Cited by in corpus (12)

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• Nonlinear dynamics of the ion Weibel-filamentation instability: an analytical model for the evolution of the plasma and spectral properties
• Laser-driven hole boring and gamma-ray emission in high-density plasmas
• Long-term Evolution of Relativistic Unmagnetized Collisionless Shocks
• Shock formation in electron-ion plasmas: mechanism and timing
• Microphysics of Relativistic Collisionless Electron-ion-positron Shocks
• Spatial-temporal evolution of the current filamentation instability
• Astrophysical Plasma Instabilities induced by Long-Range Interacting Dark Matter
• Density jump as a function of magnetic field for collisionless shocks in pair plasmas: the perpendicular case
• Hierarchy of instabilities for two counter-streaming magnetized pair beams: influence of field obliquity
• Particles trajectories in Weibel magnetic filaments with a flow-aligned magnetic field
• A pressure tensor description for the time-resonant Weibel instability