Speaker
Longqing Yi
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/O2.J201.pdf
Relativistic magnetic reconnection driven by a laser
interacting with a micro-scale plasma slab
Longqing Yi1, Baifei Shen2, Alexander Pukhov3, and Tünde Fülöp1
1: Department of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
2: Department of Physics, Shanghai Normal University, Shanghai, 200234, China
3: Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, 40225, Germany
Magnetic reconnection is a fundamental plasma process associated with conversion of
embedded magnetic field energy into kinetic and thermal plasma energy, via bulk
acceleration and Ohmic dissipation. In many high-energy astrophysical events, magnetic
reconnection operating in the relativistic regime, i.e. with magnetic energy per particle
exceeds the rest mass energy, is usually invoked to explain the non-thermal signatures.
However, due to the difficulty in making direct measurements in remote high-energy
astrophysical systems and/or achieving the extreme energy density conditions that are
necessary to observe relativistic reconnection in laboratory environments, the process
by which field energy is transferred to the plasma to power the observed emission are
still not properly understood. In this work 1, we propose a novel scenario where the
relativistic reconnection is accessed via the interaction of a readily available (TW-mJ-
class) laser with micro-scale plasma slab. By means of fully-kinetic 3D particle-in-cell
simulations, we show that when the electron beams excited on both sides of the slab
approaches the end of the plasma structure, ultra-fast relativistic reconnection occurs in
a magnetically-dominated (low-β) plasma. As the field topology changes, the explosive
release of magnetic energy results in the emission of relativistic electron jets with cut-off
energy ~ 12 MeV. In the meantime, various signatures of magnetic reconnection are
observed, including a hard power-law electron energy distribution (with index p ~ 1.8),
out-of-plane quadrupole fields pattern, and quantified agyrotropy peaks in the
reconnection site. The proposed scenario can be straightforwardly implemented in
experiments, and the significant field dissipation process (0.1-TW-class) makes it a
promising platform to study the non-thermal signatures and energy conversion in the
relativistic regime of reconnection.
[1] L. Q. Yi, B. F. Shen, A. Pukhov, and T. Fülöp, Relativistic magnetic reconnection
driven by a laser interacting with a micro-scale plasma slab, under consideration in Nat.
Commun. (2017) https://arxiv.org/abs/1708.07676
