Magnetic instability in a dilute circular rarefaction wave

Abstract

The generation of a magnetic field in a circular rarefaction wave is examined in form of a 2D particle-in-cell (PIC) simulation. Electrons with a temperature of 32 keV are uniformly distributed within a cloud with a radius of 14.2 electron skin depths. They expand under their thermal pressure and carry with them the cold protons, which are initially concentrated in a hollow ring at the boundary of the electron cloud. The interior of the ring contains an immobile positive charge background that compensates for the electron charge. The protons expand in form of a circularly symmetric rarefaction wave and they extract energy from the electrons. A thermal anisotropy of the electrons develops and triggers through a Weibel-type instability the growth of TM waves within the plasma cloud, which acts as a wave guide. The changing cross section of this waveguide introduces a coupling between the TM wave and a TE wave and in-plane magnetic fields grow. The relevance of the simulation results to a previous experimental study of a laser-ablated wire is discussed.

Accepted for publication in Physics of Plasmas

References in corpus (5)

• Production of Magnetic Turbulence by Cosmic Rays Drifting Upstream of Supernova Remnant Shocks
• PIC simulations of the Thermal Anisotropy-Driven Weibel Instability: Field growth and phase space evolution upon saturation
• Nonlinear Kinetic Development of the Weibel Instability and the generation of electrostatic coherent structures
• PIC Simulations of the Temperature Anisotropy-Driven Weibel Instability: Analyzing the perpendicular mode
• PIC simulation of a thermal anisotropy-driven Weibel instability in a circular rarefaction wave