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We present results of 2D and 3D PIC simulations of magnetic turbulence production by isotropic cosmic-ray ions drifting upstream of SNR shocks. The studies aim at testing recent predictions of a strong amplification of short wavelength…

Astrophysics · Physics 2009-11-13 Jacek Niemiec , Martin Pohl , Thomas Stroman , and Ken-Ichi Nishikawa

We present preliminary results of Particle-In-Cell simulations of magnetic turbulence production by isotropic cosmic-ray ions streaming upstream of supernova remnant shocks. The studies aim at testing the MHD predictions by Bell (2004,…

Astrophysics · Physics 2008-11-26 Jacek Niemiec , Martin Pohl

Weakly collisional space plasmas are rarely in local thermal equilibrium and often exhibit non-Maxwellian electron and ion velocity distributions that lead to the growth of microinstabilities, that is, enhanced electric and magnetic fields…

Electromagnetic turbulence and ion kinetics in counter-streaming plasmas hold great significance in laboratory astrophysics, such as turbulence field amplification and particle energization. Here, we quantitatively demonstrate for the first…

Plasma Physics · Physics 2024-03-13 P. Liu , D. Wu , T. X. Hu , D. W. Yuan , G. Zhao , Z. M. Sheng , X. T. He , J. Zhang

A nonresonant cosmic-ray-current-driven instability may operate in the shock precursors of young supernova remnants and be responsible for magnetic-field amplification, plasma heating and turbulence. Earlier simulations demonstrated…

High Energy Astrophysical Phenomena · Physics 2018-01-08 Oleh Kobzar , Jacek Niemiec , Martin Pohl , Artem Bohdan

When a moderately intense, few-picoseconds long laser pulse ionizes gas to produce an underdense plasma column, a linear relativistic plasma wave or wake can be excited by the self-modulation instability that may prove useful for…

We present the results of a 2-D, two fluid (ions and neutrals) simulation of the ambipolar filamentation process, in which a magnetized, weakly ionized plasma is stirred by turbulence in the ambipolar frequency range. The higher turbulent…

Astrophysics · Physics 2007-05-23 M. Franqueira , M. Tagger , A. I. Gomez de Castro

We study the long term evolution of magnetic fields generated by an initially unmagnetized collisionless relativistic $e^+e^-$ shock. Our 2D particle-in-cell numerical simulations show that downstream of such a Weibel-mediated shock,…

Astrophysics · Physics 2009-06-23 Philip Chang , Anatoly Spitkovsky , Jonathan Arons

We use large hybrid simulations to study ion acceleration and generation of magnetic turbulence due to the streaming of particles that are self-consistently accelerated at non-relativistic shocks. When acceleration is efficient, we find…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Damiano Caprioli , Anatoly Spitkovsky

Turbulence is often invoked to explain the origin of nonthermal particles in space and astrophysical plasmas. By means of 3D fully kinetic particle-in-cell simulations, we demonstrate that turbulence in low-$\beta$ plasmas ($\beta$ is the…

High Energy Astrophysical Phenomena · Physics 2022-09-16 Luca Comisso , Lorenzo Sironi

Mildly relativistic shocks in magnetized electron-ion plasmas are investigated with 2D kinetic particle-in-cell simulations of unprecedentedly high resolution and large scale for conditions that may be found at internal shocks in blazar…

The maximum magnetic field strength generated by Weibel-type plasma instabilities is estimated for typical conditions in the interstellar medium. The relevant kinetic dispersion relations are evaluated by conducting a parameter study both…

High Energy Astrophysical Phenomena · Physics 2015-06-16 R. C. Tautz , J. Triptow

Turbulence is a predominant process for energizing electrons and ions in collisionless astrophysical plasmas, and thus is responsible for shaping their radiative signatures (luminosity, spectra, and variability). To better understand the…

High Energy Astrophysical Phenomena · Physics 2021-02-24 Vladimir Zhdankin , Dmitri A. Uzdensky , Matthew W. Kunz

It is pointed out that the unmagnetized inhomogeneous plasmas can support a low frequency electromagnetic ion wave as a normal mode like Alfven wave of magnetized plasmas. But this is a coupled mode produced by the mixing of longitudinal…

Plasma Physics · Physics 2011-02-18 Hamid Saleem

We explore streaming instabilities of the electron-ion plasma with relativistic and ultra-relativistic cosmic rays in the background magnetic field in the multi-fluid approach. Cosmic rays can be both electrons and ions. The drift speed of…

High Energy Astrophysical Phenomena · Physics 2015-06-11 A. K. Nekrasov

Particle transport, acceleration and energisation are phenomena of major importance for both space and laboratory plasmas. Despite years of study, an accurate theoretical description of these effects is still lacking. Validating models with…

We study the long term evolution of magnetic fields generated by a collisionless relativistic $e^+e^-$ shock which is initially unmagnetized. Our 2D particle-in-cell numerical simulations show that downstream of such a Weibel-mediated…

Astrophysics · Physics 2009-11-13 P. Chang , A. Spitkovsky , J. Arons

We study collective processes for an electron beam propagating through a background plasma using simulations and analytical theory. A new regime where the instability of a Langmuir wave packet can grow locally much faster than ion frequency…

Plasma Physics · Physics 2022-10-05 Haomin Sun , Jian Chen , Igor D. Kaganovich , Alexander Khrabrov , Dmytro Sydorenko

The relationship between a decaying strong turbulence and kinetic instabilities in a slowly expanding plasma is investigated using two-dimensional (2-D) hybrid expanding box simulations. We impose an initial ambient magnetic field…

It is argued and demonstrated by particle-in-cell simulations that the synchrotron maser instability could develop at the front of a relativistic, magnetized shock. The instability generates strong low-frequency electromagnetic waves…

Astrophysics · Physics 2008-11-26 Yuri Lyubarsky
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