Feedthrough and dynamic stabilization in convergent geometry

A sharp boundary model describing the linear evolution of the R-T instability in accelerated planar foils and imploding spherical shells is derived for ablation fronts with large Froude numbers. The model consists of two coupled equations for the ablation front and the inner surface that can be solved for arbitrary time-dependent accelerations and ablation velocities. Applications of the model to study the ablation-front distortion and perturbation feedthrough of imploding cryogenic capsules have revealed that a properly selected modulation of the laser intensity could significantly reduce the growth of the R-T instability