Long term instability growth of radiatively driven thin planar shells

The Rayleigh-Taylor instability of radiatively driven thin copper foils is studied under pure ablation, as well as with beryllium buffers to provide a dditional pressure drive, in support of the target design for Inertial Conf inement Fusion. Modeling was done with the RAGE adaptive mesh refinement co de [R. M. Baltrusaitis, M. L. Gittings, R. P. Weaver, R. F. Benjamin, and J . M. Budzinski, Phys. Fluids 8, 2471 (1996)] of experiments done on the OME GA [T. R. Boehly, D. L. Brown, R. S. Craxton , Opt. Commun. 133, 495 (1997) ] laser. The copper foils were typically 11.5 mum thick with 0.45 mum ampli tude and 45 mum wavelength cosine surface perturbations. The beryllium laye r was 5 mum thick. The drive was a "PS26"-like [J. D. Lindl, Phys. Plasmas 2, 3933 (1995)] laser pulse delivering peak 160-185 eV radiation temperatur es. Good agreement between experiment and simulation has been obtained out to 4.5 ns. Mechanisms for late time agreement are discussed. (C) 2001 Ameri can Institute of Physics.