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arXiv · 2009.01562

The inadequacy of a magnetohydrodynamic approach to the Biermann Battery

C. P. Ridgers·C. Arran·J. J. Bissell·R. J. Kingham
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Abstract

Magnetic fields can be generated in plasmas by the Biermann battery when the electric field produced by the electron pressure gradient has a curl. The commonly employed magnetohydrodynamic (MHD) model of the Biermann battery breaks down when the electron distribution function is distorted away from Maxwellian. Using both MHD and kinetic simulations of a laser-plasma interaction relevant to inertial confinement fusion we have shown that this distortion can reduce the Biermann-producing electric field by around 50\%. More importantly, the use of a flux limiter in an MHD treatment to deal with the effect of the non-Maxwellian electron distribution on electron thermal transport leads to a completely unphysical prediction of the Biermann-producing electric field and so results in erroneous predictions for the generated magnetic field.

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C. P. Ridgers, C. Arran, J. J. Bissell, R. J. Kingham. 2020-09-03. The inadequacy of a magnetohydrodynamic approach to the Biermann Battery. https://doi.org/10.1098/rsta.2020.0017

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