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Related papers: Relativistic Collisionless Shocks in Unmagnetized …

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We report here on a fast current-driven instability at relativistic collisionless shocks, triggered by the perpendicular current carried by the supra-thermal particles as they gyrate around the background magnetic field in the shock…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Martin Lemoine , Guy Pelletier , Laurent Gremillet , Illya Plotnikov

We investigate the formation of collisionless magnetized shocks triggered by the interaction between magnetized plasma flows and miniature-sized (order of plasma kinetic-scales) magnetic obstacles resorting to massively parallel, full…

Plasma Physics · Physics 2017-03-08 F. Cruz , E. P. Alves , R. A. Bamford , R. Bingham , R. A. Fonseca , L. O. Silva

This work describes the scientific basis and associated simulation results for the magnetization of an unmagnetized plasma via beat wave current drive. Two-dimensional electromagnetic particle-in-cell simulations have been performed for a…

Plasma Physics · Physics 2012-11-29 D. R. Welch , T. C. Genoni , C. Thoma , N. Bruner , D. V. Rose , S. C. Hsu

Observations of afterglows of gamma-ray bursts suggest (GRBs) that post-shock magnetic fields are strongly amplified to about 100 times the shock-compressed value. The Weibel instability appears to play an important role in generating of…

High Energy Astrophysical Phenomena · Physics 2016-07-13 Sara Tomita , Yutaka Ohira

Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are…

Astrophysics · Physics 2009-11-07 K. -I. Nishikawa , P. Hardee , G. Richardson , R. Preece , H. Sol , G. J. Fishman

We study with particle-in-cell (PIC) simulations the stability of fast magnetosonic shocks. They expand across a collisionless plasma and an orthogonal magnetic field that is aligned with one of the directions resolved by the 2D…

Plasma Physics · Physics 2023-07-17 M E Dieckmann , C Huete , F Cobos , A Bret , D Folini , B Eliasson , R Walder

For parameters that are applicable to the conditions at young supernova remnants, we present results of 2D3V particle-in-cell simulations of a non-relativistic plasma shock with a large-scale perpendicular magnetic field inclined at 45-deg…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Volkmar Wieland , Martin Pohl , Jacek Niemiec , Iman Rafighi , Ken-Ichi Nishikawa

We model relativistically colliding plasma by PIC simulations in one and two spatial dimensions, taking an ion-to-electron mass ratio of 400. Energy dissipation by a wave precursor of mixed polarity and different densities of the colliding…

Astrophysics · Physics 2009-11-13 M. E. Dieckmann , P. K. Shukla , L. O. C. Drury

Previous studies of phase mixing of ion cyclotron (IC), Alfv\'enic, waves in the collisionless regime have established the generation of parallel electric field and hence acceleration of electrons in the regions of transverse density…

Astrophysics · Physics 2008-12-23 D. Tsiklauri , T. Haruki

Collisionless shocks are ubiquitous structures throughout the universe. Shock waves in space and astrophysical plasmas convert the energy of a fast-flowing plasma to other forms of energy, including thermal and magnetic energies. Plasma…

Plasma Physics · Physics 2024-04-11 Hadi Madanian , Imogen Gingell , Li-Jen Chen , Eli Monyek

Recent studies about collisionless shocks in partially ionized plasmas showed that some of neutral particles leak into the shock upstream region from the downstream region. In this paper, we perform a linear analysis and show that acoustic…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Yutaka Ohira

Relativistic sources, e.g. gamma-ray bursts, pulsar wind nebulae and powerful active galactic nuclei produce relativistic outflows that lead to the formation of collisionless shock waves, where particle acceleration is thought to take…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Martin Lemoine , Guy Pelletier

An ablative plasma shock can emanate from the interface between a cold/dense plasma and a hot/dilute ambient plasma, where the plasma mean-free-path is much longer than the temperature gradient length. The shock is driven by thermal flux…

Plasma Physics · Physics 2025-05-06 Yanzeng Zhang , Xian-Zhu Tang

A new concept for spinning unmagnetized plasma is demonstrated experimentally. Plasma is confined by an axisymmetric multi-cusp magnetic field and biased cathodes are used to drive currents and impart a torque in the magnetized edge.…

Plasma Physics · Physics 2012-05-31 C. Collins , N. Katz , J. Wallace , J. Jara-Almonte , I. Reese , E. Zweibel , C. B. Forest

While the front of a fluid shock is a few mean-free-paths thick, the front of a collisionless shock can be orders of magnitude thinner. By bridging between a collisional and a collisionless formalism, we assess the transition between these…

Plasma Physics · Physics 2021-07-01 Antoine Bret , Asaf Pe'er

Ablating a target with an ultraintense laser pulse can create a cloud of collisionless plasma. A density ramp forms, in which the plasma density decreases and the ion's mean speed increases with distance from the plasma source. Its width…

Plasma Physics · Physics 2024-02-07 M E Dieckmann , L Palodhi , C Fegan , M Borghesi

The nonlinear evolution of unstable C-type shocks in weakly ionized plasmas is studied by means of time-dependent magnetohydrodynamical simulations. This study is limited to shocks in magnetically dominated plasmas (in which the Alfven…

Astrophysics · Physics 2009-10-30 James M. Stone

Collisionless shocks are pervasive in astrophysics and they are critical to understand cosmic ray acceleration. Laboratory experiments with intense lasers are now opening the way to explore and characterise the underlying microphysics,…

Plasma Physics · Physics 2014-01-14 A. Stockem , F. Fiuza , A. Bret , R. A. Fonseca , L. O. Silva

We study electrical excitation of nonlinear plasma waves in heterostructures with two-dimensional electron channels and with split gates, and the propagation of these waves using hydrodynamic equations for electron transport coupled with…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 E. Vostrikova , A. Ivanov , I. Semenikhin , V. Ryzhii

Collisionless plasma shock theory, which applies for example to the afterglow of gamma ray bursts, still contains key issues that are poorly understood. In this paper we study charged particle dynamics in a highly relativistic collisionless…

Astrophysics · Physics 2009-11-10 C. B. Hededal , T. Haugboelle , J. Trier Frederiksen , Å. Nordlund