Speaker
Simon Bolaños
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.4002.pdf
Investigating guide field reconnection in HED plasmas
Simon Bolaños1,3, R. Smets3, R. Riquier4, A. Grisollet4, J. Fuchs1,2
1) LULI - CNRS, École Polytechnique, CEA: Université Paris-Saclay; UPMC Univ Paris 06:
Sorbonne Universités - F-91128 Palaiseau cedex, France
E-mail: simon.bolanos@polytechnique.edu
2) Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod, Russia
3) LPP, University P. & M. Curie, CNRS, Ecole Polytechnique, F-91128 Palaiseau, France
4) CEA, DIF, Bruyères-le-Chatel, France
Magnetic reconnection (MR) is a process which occurs in many astrophysical plasmas, e.g. in solar
flares, in coronal mass ejecta, or at the outer boundary of the Earth magnetosphere. However, as of now,
the fundamental microphysics implied in this process is far from being well understood. Most of the
investigations on this long standing issue come from numerical studies and space observations. Laboratory
modelling of plasmas, including those that can be generated by high-power lasers, offer now new
perspectives to investigate MR and the processes governing it.
We will present recent experiments, performed using the LULI2000 facility, aimed at investigating
the dynamic of magnetic reconnection in a non-coplanar configuration between two magnetic toroids
induced by two near-by laser spots irradiating solids targets. Despite being distinct from the astrophysical
plasmas where the beta parameter is low ( ̴10^-3 in solar corona and ̴ 1 in solar winds), such HEDP
reconnection experiments are of interest to investigate fundamental issues in MR such as the influence of
a guide field on the dynamic of the MR. A non-coplanar configuration between the two laser-irradiated
targets, as was investigated in our experiments, allows to initialize a guide field. The reconnection rate in
the experiments has been diagnosed with proton radiography which provides a unique way to measure
and map directly the distribution of the strong magnetic fields and their evolution. We observe that the
guide field slow down the MR, depending on the setup between the two laser-irradiated targets, and hence
between the two magnetic toroids that are made to interact. The measurements are compared to
simulations performed by a hybrid simulation code, the 3D HECKLE code. This simulations have been
initialized, with respect to the initial magnetic toroid, by calculations using a hydro-radiative code (FCI2)
and experimental measurements.
