Commissioning a long-duration indirect drive planar platform for highly nonlinear ablative Rayleigh-Taylor experiments on NIF

We will present the first results acquired on the National Ignition Facility with a gas-filled room temperature platform driven by 64 beams of the lower half hemisphere. This platform developed under the auspices of the Fundamental Science Program is devoted to the study of the ablative Rayleigh-Taylor Instability (RTI) in transition from weakly nonlinear to highly nonlinear regimes [1]. Simultaneous double axis radiographies (face-on and side-on) are performed on each shot to measure RTI growth and trajectory.. We demonstrate in particular that a 10 ns long radiative temperature plateau at 170 eV has been created which allows to accelerate planar samples over much larger distances and longer time periods than previously achieved. We report on the first face-on measurements for the growth of 2D single-mode modulations and comparison are done with FCI2 postshot simulations. We will discuss the path toward a highly nonlinear bubble merger regime for multimode pattern. \\[4pt] [1] A. Casner et al., Phys. Plasmas 19, 082708 (2012).