Magnetic field generation and diffusion by a laser-produced blast wave propagating in non-homogenous plasma

Abstract

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.

Anisotropic heating and magnetic field generation due to Raman scattering in laser-plasma interactions

“…The ability to use the interaction of intense lasers with plasmas to reproduce astrophysical scenarios in the laboratory is a powerful tool to explore astrophysical phenomena [1,2], specifically in connection with laser-plasma produced magnetic fields. Several mechanisms for magnetic field generation, such as the Biermann battery and the inverse Faraday effect, have been discussed over the years [3][4][5][6][7][8][9][10][11]. Laser-plasma interactions can generate strong magnetic fields, as shown in experimental and numerical studies of magnetic turbulence [12], laser wakefield acceleration [13], and collisionless shocks [14][15][16].…”

Measurements of parametric instabilities at laser intensities relevant to strong shock generation

“…While particle in cell simulations (of the Vlasov-Fokker-Planck equation) are limited to a few picoseconds due to their computation costs, a series of reduced-hydrodynamic models are being investigated to partially take into account some effects that might influence the nanosecond plasma evolution, such as the nonlocal electron transport, 29 the growth of parametric instability, the generation of fast electrons, 30 and the influence of self-induced magnetic fields. 31 A few experiments carried out at OMEGA 11,12,32,33 and LULI facilities [34][35][36] investigated the laser plasma interaction at SI intensities. The overall energy scattered by SRS/SBS in these experiments is disparate, in a range going from a few percent up to $40%-50% of the incident energy, strongly dependent on the irradiation geometry and on the laser intensity.…”

Extension of a reduced entropic model of electron transport to magnetized nonlocal regimes of high-energy-density plasmas

“…Magnetic fields play an important role in astrophysics (Gregori et al, 2012;Marocchino et al, 2015) and may affect the transport properties of high-energy-density plasmas in laboratory conditions (Clark et al, 2000;Stamper et al, 1971).…”