English
Related papers

Related papers: Constraints on dynamo action in plasmas

200 papers

Decay in time of undriven weakly collisional kinetic plasma turbulence in systems large compared to the ion kinetic scales is investigated using fully electromagnetic particle-in-cell simulations initiated with transverse flow and magnetic…

Plasma Physics · Physics 2015-06-16 P. Wu , M. Wan , W. H. Matthaeus , M. A. Shay , M. Swisdak

The dissipative mechanism in weakly collisional plasma is a topic that pervades decades of studies without a consensus solution. We compare several energy dissipation estimates based on energy transfer processes in plasma turbulence and…

Plasma densification through magnetic compression has been suggested for time-resolved control of the wave properties in plasma-based accelerators. Using particle in cell simulations with real mass ratio, the practicality of large magnetic…

Plasma Physics · Physics 2016-04-20 Renaud Gueroult , Nathaniel J. Fisch

We propose that pressure anisotropy causes weakly collisional turbulent plasmas to self-organize so as to resist changes in magnetic-field strength. We term this effect "magneto-immutability" by analogy with incompressibility (resistance to…

High Energy Astrophysical Phenomena · Physics 2019-02-27 Jonathan Squire , Alexander A. Schekochihin , Eliot Quataert , Matthew W. Kunz

Internal shocks between propagating plasma shells, originally ejected at different times with different velocities are believed to play a major role in dissipating the kinetic energy, thereby explaining the observed lightcurve and spectra…

High Energy Astrophysical Phenomena · Physics 2017-09-06 Asaf Pe'er , Killian Long , Piergiorgio Casella

Hot plasma is highly conductive in the direction parallel to a magnetic field. This often means that the electrical potential will be nearly constant along any given field line. When this is the case, the cross-field voltage drops in…

Plasma Physics · Physics 2024-05-29 E. J. Kolmes , I. E. Ochs , J. -M. Rax , N. J. Fisch

In Sun and sun-like stars, it is believed that the cycles of the large-scale magnetic field are produced due to the existence of differential rotation and helicity in the plasma flows in their convection zones (CZs). Hence, it is expected…

Solar and Stellar Astrophysics · Physics 2021-12-08 Vindya Vashishth , Bidya Binay Karak , Leonid Kitchatinov

This work concentrates on the effect of an irrotational forcing on a magnetized flow in the presence of rotation, baroclinicity, shear, or a combination of them. By including magnetic field in the model we can evaluate the occurrence of…

Astrophysics of Galaxies · Physics 2023-09-08 Albert Elias-López , Fabio Del Sordo , Daniele Viganò

When particle speeds are large the motion of a collisionless plasma is modeled by the relativistic Vlasov Maxwell system. Large time behavior of solutions which depend on one position variable and two momentum variables is considered. In…

Analysis of PDEs · Mathematics 2010-01-02 Robert Glassey , Stephen Pankavich , Jack Schaeffer

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

Upper bounds on the growth of free energy in gyrokinetics are derived. These bounds apply to all local gyrokinetic instabilities in the geometry of a flux tube, i.e. a slender volume of plasma aligned with the magnetic field, regardless of…

Plasma Physics · Physics 2022-05-04 P. Helander , G. G. Plunk

Violation of the axial synnetry of a magnetic field essentially modifies the physics of the plasma outflow in the magnetosphere of rotating objects. In comparison to the axisymmetric outflow, two new affects appear: more efficient…

Astrophysics · Physics 2009-10-31 S. V. Bogovalov

Driven particles in presence of crowded environment, obstacles or kinetic constraints often exhibit negative differential mobility (NDM) due to their decreased dynamical activity. We propose a new mechanism for complex many-particle systems…

Statistical Mechanics · Physics 2018-06-06 Amit Kumar Chatterjee , Urna Basu , P. K. Mohanty

A three-dimensional numerical computation of magnetohydrodynamic dynamo behavior is described. The dynamo is mechanically forced with a driving term of the Taylor-Green type. The magnetic field development is followed from negligibly small…

Astrophysics · Physics 2007-05-23 P. D. Mininni , Y. Ponty , D. C. Montgomery , J. -F. Pinton , H. Politano , A. Pouquet

Based on the generic acceleration model, which suggests different types of electromagnetic interactions between the cosmic charged particles and the different configurations of the electromagnetic (plasma) fields, the ultra high energy…

High Energy Astrophysical Phenomena · Physics 2014-03-21 A. Tawfik , A. Saleh , M. T. Ghoneim , A. Hady

We obtain exact upper and lower bounds on the steady state drift velocity, and kinetic energy of electrons, driven by an external field in a weakly ionized plasma (swarm approximation). The scattering is assumed to be elastic with…

Plasma Physics · Physics 2009-10-31 A. Rokhlenko , J. L. Lebowitz

According to the kinematic theory of nonhelical dynamo action the magnetic energy spectrum increases with wavenumber and peaks at the resistive cutoff wavenumber. It has previously been argued that even in the dynamical case the magnetic…

Astrophysics · Physics 2009-11-10 Nils Erland L. Haugen , Axel Brandenburg , Wolfgang Dobler

We present a self-consistent mean field theory of the dynamo in 3D and turbulent diffusion in 2D in weakly ionized gas. We find that in 3D, the backreaction does not alter the beta effect while it suppresses the alpha effect when the…

Astrophysics · Physics 2011-02-11 Nicolas Leprovost , Eun-Jin Kim

Several recent advances in turbulent dynamo theory are reviewed. High resolution simulations of small-scale and large-scale dynamo action in periodic domains are compared with each other and contrasted with similar results at low magnetic…

Solar and Stellar Astrophysics · Physics 2012-07-10 Axel Brandenburg , Dmitry Sokoloff , Kandaswamy Subramanian

The efficient production of electricity from nuclear fusion in magnetically confined plasmas relies on a good confinement of the thermal energy. For more than thirty years, the observation that such confinement depends on the mass of the…

Plasma Physics · Physics 2016-06-07 J. Garcia , T. Goerler , F. Jenko
‹ Prev 1 8 9 10 Next ›