The inadequacy of a magnetohydrodynamic approach to the Biermann battery. (7th December 2020)

• Record Type: Journal Article
• Authors: Ridgers, C. P.; Arran, C.; Bissell, J. J.; Kingham, R. J.
• Is Part Of: Philosophical transactions. Volume 379:Number 2189(2021)
• Publication Date: 2020-12-07
• Subjects: plasma -- magnetic field -- high intensity laser -- inertial confinement fusion; Physical sciences -- Periodicals; Engineering -- Periodicals; Mathematics -- Periodicals; 500
• DOI: 10.1098/rsta.2020.0017
• Languages: English
• ISSNs: 1364-503X

Abstract

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. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.