Dynamo in Weakly Collisional Nonmagnetized Plasmas Impeded by Landau Damping of Magnetic Fields
Journal article, 2020

We perform fully kinetic simulations of flows known to produce dynamo in magnetohydrodynamics (MHD), considering scenarios with low Reynolds number and high magnetic Prandtl number, relevant for galaxy cluster scale fluctuation dynamos. We find that Landau damping on the electrons leads to a rapid decay of magnetic perturbations, impeding the dynamo. This collisionless damping process operates on spatial scales where electrons are nonmagnetized, reducing the range of scales where the magnetic field grows in high magnetic Prandtl number fluctuation dynamos. When electrons are not magnetized down to the resistive scale, the magnetic energy spectrum is expected to be limited by the scale corresponding to magnetic Landau damping or, if smaller, the electron gyroradius scale, instead of the resistive scale. In simulations we thus observe decaying magnetic fields where resistive MHD would predict a dynamo.


Istvan Pusztai

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

J. Juno

University of Maryland

A. Brandenburg

Royal Institute of Technology (KTH)

J. M. TenBarge

Princeton University

A. Hakim

Princeton University

Manaure Francisquez

Massachusetts Institute of Technology (MIT)

Andréas Sundström

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 124 25 255102

Subject Categories

Astronomy, Astrophysics and Cosmology

Other Physics Topics

Fusion, Plasma and Space Physics





Related datasets

Dynamo in weakly collisional non-magnetized plasmas impeded by Landau damping of magnetic fields [dataset]

DOI: 10.5281/zenodo.3886561

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