Open AccessMagnetic field generation and diffusion by a laser-produced blast wave propagating in non-homogenous plasma
Author(s) -
A. Marocchino,
S. Atzeni,
A. Schiavi
Publication year - 2015
Publication title -
new journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.584
H-Index - 190
ISSN - 1367-2630
DOI - 10.1088/1367-2630/17/4/043052
Subject(s) - physics , wavenumber , magnetic field , amplitude , magnetic diffusivity , thermal diffusivity , dimensionless quantity , computational physics , magnetohydrodynamics , blast wave , perturbation (astronomy) , shock wave , mechanics , condensed matter physics , quantum electrodynamics , classical mechanics , optics , quantum mechanics
In this paper we discuss the magnetic field self generation, via the so-called Biermann battery effect, and its diffusion for a blast wave (BW) expanding in a perturbed background medium. A series of simulations verify the bi-linear behavior of the Biermann battery source term both in amplitude and in wavenumber. Such a behavior is valid in the limit of no diffusivity. When diffusivity is also considered, we observe an inverse proportionality with the wavenumber: for large wavenumber perturbation magnetic diffusivity plays a key role. Writing the induction equation in a dimensionless form we discuss how, in terms of magnetic properties, the BW can be subdivided into three main regions: the remnant where the frozen-in-flow approximation holds, the thin shell where the magnetic field is in fact generated but at the same time begins to diffuse, and the shock front where the magnetic field diffuses away. A possible experimental scenario that could induce magnetic fields of about 100 gauss is finally investigated. Simulations have been performed with the code DUED