Observation of self-similar behavior of the 3D, nonlinear Rayleigh-Taylor instability

The Rayleigh-Taylor unstable growth of laser-seeded, 3D broadband perturbations was experimentally measured in the laser-accelerated, planar plastic foils. The first experimental observation showing the self-similar behavior of the bubble size and amplitude distributions under ablative conditions is presented. In the nonlinear regime, the modulation σrms grows as ασgt2, where g is the foil acceleration, t is the time, and ασ is constant. The number of bubbles evolves as N(t)( tg+C)-4 and the average size evolves as λ(t) 2gt2, where C is a constant and I=0.83±0.1 is the measured scaled bubble-merging rate.