J. Phys. IV France
Volume 133, June 2006
Page(s) 123 - 127
Publié en ligne 16 juin 2006
Inertial Fusion Sciences and Applications 2005
J.-C. Gauthier, et al.
J. Phys. IV France 133 (2006) 123-127

DOI: 10.1051/jp4:2006133024

Ablative Richtmyer-$\!$-Meshkov instability: Theory and experimental results

V.N. Goncharov1, O.V. Gotchev1, R.L. McCrory1, P.W. McKenty1, D.D. Meyerhofer1, T.C. Sangster1, S. Skupsky1 and C. Cherfils-Clerouin2

1  Laboratory for Laser Energetics, University of Rochester, 250 E. River Rd., Rochester, NY 14623, USA
2  CEA-DIF, BP. 12, 91680 Bruyères-le-Châtel, France

Rayleigh-Taylor instability, the main source of symmetry degradation in ICF experiments, is seeded at the early stage of an implosion, during the shock transit through the shell. The ablation-front nonuniformities at such a time can be amplified by an instability, which is similar to the Richtmyer-Meshkov instability. In the presence of ablation, however, the dynamic overpressure (rocket effect) significantly reduces the perturbation growth. The modes localized inside the conduction zone between the laser-absorption region and the ablation front are totally stabilized. An analytical model is presented to describe the perturbation evolution at the ablation front during the shock propagation time. The model is compared against the results of both the multidimensional simulations and a series of experiments performed on the OMEGA Laser System.

© EDP Sciences 2006