English
Related papers

Related papers: DC magnetic field generation in unmagnetized shear…

200 papers

Collisionless plasma instabilities are fundamental in magnetic field generation in astrophysical scenarios, but their role has been addressed in scenarios where velocity shear is absent. In this work we show that velocity shears must be…

High Energy Astrophysical Phenomena · Physics 2015-05-30 E. P. Alves , T. Grismayer , S. F. Martins , F. Fiúza , R. A. Fonseca , L. O. Silva

We have investigated generation of magnetic fields associated with velocity shear between an unmagnetized relativistic jet and an unmagnetized sheath plasma. We have examined the strong magnetic fields generated by kinetic shear…

High Energy Astrophysical Phenomena · Physics 2013-09-10 K. -I. Nishikawa , P. Hardee , B. Zhang , I. Dutan , M. Medvedev , E. J. Choi , K. W. Min , J. Niemiec , Y. Mizuno , A. Nordlund , J. T. Frederiksen , H. Sol , M. Pohl , D. H. Hartmann

We have investigated magnetic field generation in velocity shears via the kinetic Kelvin-Helmholtz instability (kKHI) using a relativistic plasma jet core and stationary plasma sheath. Our three-dimensional particle-in-cell simulations…

High Energy Astrophysical Phenomena · Physics 2014-09-08 K. -I. Nishikawa , P. E. Hardee , I. Dutan , J. Niemiec , M. Medvedev , Y. Mizuno , A. Meli , H. Sol , B. Zhang , M. Pohl , D. H. Hartmann

Strong shear flow regions found in astrophysical jets are shown to be important dissipation regions, where the shear flow kinetic energy is converted into electric and magnetic field energy via shear instabilities. The emergence of these…

High Energy Astrophysical Phenomena · Physics 2014-04-03 E. P. Alves , T. Grismayer , R. A. Fonseca , L. O. Silva

Very large DC and AC electric fields cannot be sustained between conducting electrodes because of volume gas breakdown and/or surface field emission. However, very large potential fields are now routinely generated in plasma structures such…

Plasma Physics · Physics 2023-07-26 Jean-Marcel Rax , Renaud Gueroult , Nathaniel J. Fisch

A rigorous theory for the generation of a large-scale magnetic field by random non-helically forced motions of a conducting fluid combined with a linear shear is presented in the analytically tractable limit of low Rm and weak shear. The…

Astrophysics · Physics 2011-12-15 T. Heinemann , J. C. McWilliams , A. A. Schekochihin

We propose a new mechanism for turbulent mean-field dynamo in which the magnetic fluctuations resulting from a small-scale dynamo drive the generation of large-scale magnetic fields. This is in stark contrast to the common idea that…

Solar and Stellar Astrophysics · Physics 2015-11-23 Jonathan Squire , Amitava Bhattacharjee

A review of recent studies on a new mechanism of generation of large-scale magnetic field in a sheared turbulent plasma is presented. This mechanism is associated with the shear-current effect which is related to the W x J-term in the mean…

Astrophysics · Physics 2009-11-13 N. Kleeorin , I. Rogachevskii

The nonlinear evolution of the Kelvin Helmholtz instability in a magnetized plasma with a perpendicular flow close to, or in, the supermagnetosonic regime can produce a significant parallel-to-perpendicular pressure anisotropy. This…

Space Physics · Physics 2016-02-17 S. De Camillis , S. S. Cerri , F. Califano , F. Pegoraro

The mechanisms that generate "seed" magnetic fields in our Universe and that amplify them throughout cosmic time remain poorly understood. By means of fully-kinetic particle-in-cell simulations of turbulent, initially unmagnetized plasmas,…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 L. Sironi , L. Comisso , R. Golant

The Kelvin-Helmholtz instability in an ionized plasma is considered with a focus on the generation of magnetic field via the Biermann battery mechanisms. The problem is studied through direct numerical simulations of two counter-directed…

Plasma Physics · Physics 2014-08-11 Mikhail Modestov , Vitaly Bychkov , Gert Brodin , Mattias Marklund , Axel Brandenburg

We present numerical simulations of the growth and saturation of the Kelvin-Helmholtz instability in a compressible fluid layer with and without a weak magnetic field. In the absence of a magnetic field, the instability generates a single…

Astrophysics · Physics 2009-11-13 M. L. Palotti , F. Heitsch , E. G. Zweibel , Y. -M. Huang

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

Electron-scale Kelvin-Helmholtz instabilities (ESKHI) are found in several astrophysical scenarios. Naturally ESKHI is subject to a background magnetic field, but an analytical dispersion relation and an accurate growth rate of ESKHI under…

Plasma Physics · Physics 2025-02-25 Yao Guo , Dong Wu , Jie Zhang

The feasibility of a mean-field dynamo in nonhelical turbulence with superimposed linear shear is studied numerically in elongated shearing boxes. Exponential growth of magnetic field at scales much larger than the outer scale of the…

Using 2.5-dimensional Particle-in-Cell simulations, we study the kinetic physics of relativistic shear flow boundary in collisionless electron-positron (e+e-) plasmas. We find efficient magnetic field generation and particle energization at…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Edison Liang , Markus Boettcher , Ian Smith

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 use particle-in-cell, fully electromagnetic, plasma kinetic simulation to study the effect of external magnetic field on electron scale Kelvin-Helmholtz instability (ESKHI). The results are applicable to collisionless plasmas when e.g.…

Plasma Physics · Physics 2024-09-19 D. Tsiklauri

The onset and evolution of magnetic fields in laboratory and astrophysical plasmas is determined by several mechanisms, including instabilities, dynamo effects and ultra-high energy particle flows through gas, plasma and interstellar-media.…

Plasma Physics · Physics 2015-05-20 A. Flacco , J. Vieira , A. Lifschitz , F. Sylla , S. Kahaly , M. Veltcheva , L. O. Silva , V. Malka

Electron-scale surface waves are shown to be unstable in the transverse plane of a shear flow in an initially unmagnetized plasma, unlike in the (magneto)hydrodynamics case. It is found that these unstable modes have a higher growth rate…

Plasma Physics · Physics 2015-08-26 E. P. Alves , T. Grismayer , R. A. Fonseca , L. O. Silva
‹ Prev 1 2 3 10 Next ›