Multi-scale magnetic field structures in an expanding elongated plasma cloud with hot electrons subject to an external magnetic field

Abstract

We carry out 3D and 2D PIC-simulations of the expansion of a magnetized plasma that initially uniformly fills a half-space and contains a semi-cylindrical region of heated electrons elongated along the surface of the plasma boundary. This geometry is related, for instance, to the ablation of a plane target by a femtosecond laser beam under quasi-cylindrical focusing. We find that the decay of the inhomogeneous plasma--vacuum discontinuity is strongly affected by an external magnetic field parallel to its boundary. We observe various transient phenomena, including the anisotropic scattering of electrons and the accompanying Weibel instability, and reveal various spatial structures of the arising magnetic field and current, including multiple flying apart filaments of a z-pinch type and slowly evolving current sheets with different orientations. The magnitude of the self-generated magnetic field can be of the order of or significantly exceed that of the external one. Such phenomena are expected in the laser and cosmic plasmas, including the explosive processes in the planetary magnetospheres and stellar coronal arches.

arXiv comment13 pages, 6 figures, submitted to JPP

References in corpus (20)

• Generation of Magnetic Fields in the Relativistic Shock of Gamma-Ray-Burst Sources
• Particle acceleration in relativistic collisionless shocks: Fermi process at last?
• The Maximum Energy of Accelerated Particles in Relativistic Collisionless Shocks
• Observation of magnetic field generation via the Weibel instability in interpenetrating plasma flows
• Particle Acceleration in Relativistic Magnetized Collisionless Pair Shocks: Dependence of Shock Acceleration on Magnetic Obliquity
• Long Term Evolution of Magnetic Turbulence in Relativistic Collisionless Shocks: Electron-Positron Plasmas
• Weibel, Two-Stream, Filamentation, Oblique, Bell, Buneman... which one grows faster ?
• GRB Phenomenology, Shock Dynamo, and the First Magnetic Fields
• Are GRB shocks mediated by the Weibel instability?
• Relativistic electron streaming instabilities modulate proton beams accelerated in laser-plasma interactions
• Non-Equilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind \textit{(Invited Review)}
• Kinetic simulation of magnetic field generation and collisionless shock formation in expanding laboratory plasmas
• On the observations of rapid forced reconnection in the solar corona
• Weibel instability-mediated collisionless shocks in laser-irradiated dense plasmas:Prevailing role of the electrons in the turbulence generation
• The filamentation instability driven by warm electron beams: Statistics and electric field generation
• Physical problems (microphysics) in relativistic plasma flows
• Impact of continuous particle injection on generation and decay of the magnetic field in collisionless shocks
• Expansion of a radially symmetric blast shell into a uniformly magnetized plasma
• General kinetic solution for the Biermann battery with an associated pressure anisotropy generation
• A 3D Magnetohydrodynamic simulation for the propagation of plasma plume transverse to applied magnetic field