Hydrodynamic instabilities at ablation front: Numerical investigation on stabilization by adiabat shaping

Abstract
This study deals with the hydrodynamic stability of a planar target in the context of direct drive ICF. Recently, different schemes have been proposed in order to reduce ablative Rayleigh-Taylor growth. They are based on the target adiabat shaping in the ablation zone. In this work, we consider an adiabat shaping scheme by relaxation: a prepulse is followed by a relaxation period where the laser is turned off. A numerical study is performed with a perturbation code dedicated to the linear stability analysis. The simulations show stabilizing effects of the relaxation scheme on the linear Rayleigh-Taylor growth rate. Influence of the picket parameters is also discussed.