Hydrodynamic Evolution of Perturbations Seeded by Rear Surface Isolated Defects

The hydrodynamic growth of pre-imposed isolated rear surface defects, 20 µm deep by 20 µm wide grooves, has been measured on the Nike laser. High resolution monochromatic x-ray imagers captured streaked and two-dimensional images of the defect evolution. High resolution FASTRAD3D simulations and analytic theory show excellent agreement with experimental results. Material accelerated into the groove produces an initial jet which is overtaken by multi-mode bubble and spike Rayleigh-Taylor growth. Similarities and differences between front and rear side seeds, as well as the role of the rarefaction wave will be discussed.