J. Phys. IV France
Volume 133, June 2006
Page(s) 247 - 251
Publié en ligne 16 juin 2006
Inertial Fusion Sciences and Applications 2005
J.-C. Gauthier, et al.
J. Phys. IV France 133 (2006) 247-251

DOI: 10.1051/jp4:2006133050

Modeling parametric scattering instabilities in large-scale expanding plasmas

P.E. Masson-Laborde1, 2, S. Hüller1, D. Pesme1, M. Casanova2, P. Loiseau2 and Ch. Labaune3

1  Centre de Physique Théorique, École Polytechnique, CNRS UMR 7644, Palaiseau, France
2  Commisariat à l'Énergie Atomique - DIF/DCSA, Bruyères-le-Châtel, France
3  Laboratoire pour l'Utilisation des Lasers Intenses, École Polytechnique, UMR CNRS 7605, Palaiseau, France

We present results from two-dimensional simulations of long scale-length laser-plasma interaction experiments performed at LULI. With the goal of predictive modeling of such experiments with our code Harmony2D, we take into account realistic plasma density and velocity profiles, the propagation of the laser light beam and the scattered light, as well as the coupling with the ion acoustic waves in order to describe Stimulated Brillouin Scattering (SBS). Laser pulse shaping is taken into account to follow the evolution of the SBS reflectivity as close as possible to the experiment. The light reflectivity is analyzed by distinguishing the backscattered light confined in the solid angle defined by the aperture of the incident light beam and the scattered light outside this cone. As in the experiment, it is observed that the aperture of the scattered light tends to increase with the mean intensity of the RPP-smoothed laser beam. A further common feature between simulations and experiments is the observed localization of the SBS-driven ion acoustic waves (IAW) in the front part of the target (with respect to the incoming laser beam).

© EDP Sciences 2006