Drive and Symmetry Experiments in Ignition-Scale Hohlraums

The goal of the symmetry capsule (``symcap'') experimental campaign on the National Ignition Facility (NIF) is to achieve a symmetric implosion at a radiation temperature suitable for ignition. In this talk, we describe the design of the symcap experiments, including performance predictions from the radiation-hydrodynamics code H\textsc{ydra}. Performance predictions are based on levels of Raman backscatter (SRS) and cross-beam transfer extrapolated from 2009 ignition-scale hohlraum experimental results. Simulated diagnostic results include x-ray drive (radiant intensity) and spectrum, laser-entrance-hole (LEH) x-ray images, imploded core self-emission brightness and emission time, imploded core shape and size, and D-D neutron yield. Recent experimental results are compared to predictions and to 2009 ignition-scale hohlraum data.