Speaker
Oldrich Renner
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.2008.pdf
Temporal characteristics of hot electron generation
inside kJ-laser irradiated Cu foils
O. Renner1,2, M. Šmíd1, T. Schlegel3, A. Colaitis4, V.T. Tikhonchuk5, F.B. Rosmej6,7
1
Institute of Physics & ELI-Beamlines, Czech Academy of Sciences, Prague, Czech Republic
2
Institute of Plasma Physics & PALS Facility, Prague, Czech Republic
3
GSI Helmholtzzentrum f. Schwerionenforschung GmbH, Darmstadt, Germany
4
University of Rochester, Laboratory for Laser Energetics, Rochester, USA
5
Centre Lasers Intense et Applications, University of Bordeaux-CNRS-CEA, France
6
Sorbonne Université, Faculté des Sciences et Ingénierie, Paris, France
7
LULI, École Polytechnique, CEA, CNRS, Palaiseau, France
Hot electron (HE) production driven by instabilities accompanying the laser plasma interaction
[1] is of paramount interest for the inertial confinement fusion science and high energy density
physics. Their accurate characterization is crucial for interpretation of high-intensity laser
matter experiments. Here we report studies of non-thermal atomic states in kJ-laser produced
plasmas allowing to characterize HE generation with respect to their fraction and temporal
evolution. The action of HE was visualized via high-resolution x-ray spectra emitted from the
laser-deflected part of the 1.5-µm-thick Cu foil. Hot electrons are penetrating the accelerated
foil and produce the K-shell emission in rather cold dense matter that otherwise would not emit
x-rays. A quantitative analysis of the measured spectra based on 2D hydrosimulations [2] and
non-Maxwellian kinetics [3] indicates that hot electrons are produced significantly after the
laser maximum. Good agreement between experimental observations and simulations indicates
that a combination of advanced high-resolution x-ray spectroscopy and non-thermal atomic
physics spectral modelling offers a novel method to characterize hot electrons inside the laser
accelerated solid density matter. In the same time, fine spectral features identified in x-ray
emission originating from several Cu charge states represent a set of precise spectroscopic data
capable to benchmark the state-of-the-art multiscale nonlinear hydrodynamic modelling of the
laser-plasma interaction.
The authors acknowledge the support of Eurofusion Project No. AWP17-ENR-IFE-CEA-01.
[1] G. Cristoforetti et al, Phys. Plasmas 25 (2018) 012702.
[2] A. Colaitis et al, Phys. Rev. E 92 (2015) 041101.
[3] F.B. Rosmej, X-ray emission spectroscopy and diagnostics of non-equilibrium fusion and laser produced
plasmas. Taylor & Francis (2012).
