Investigation of plasma flow and interface dynamics in Au-foam lined hohlraums at OMEGA

In indirect drive inertial confinement fusion (ICF) experiments, laser interactions with the hohlraum wall generate dense, high-Z blowoff. The blowoff can contribute to asymmetric capsule drive by shifting laser absorption areas, preventing beams from reaching the inner hohlraum wall, and stagnating too quickly on the hohlraum axis. The most effective attempts to tamp this high-Z blowoff include the use of a gas fill and exploration of non-cylindrical hohlraum geometries, but even these configurations have drawbacks. Within the last few years, another promising alternative has been demonstrated through simulations and experiment at Lawrence Livermore National Laboratory: using inner-wall, high-Z foam linings to tamp the wall blowoff. We are further studying Au-foam-lined hohlraum dynamics through experiments at OMEGA. Proton and x-ray radiography will be used to reconstruct the self-generated electric and magnetic fields in hohlraums lined with ~200 um thick, ~30-40 mg/cc Au-doped CH foam. These measurements will reveal the associated plasma flow and interface dynamics during the hohlraum drive and contribute to the physics understanding and optimization of high-Z foam linings in hohlraums.