Overview of recent ICF and HEDP related experiments on the Z-machine

There continues to be dramatic progress in applying pulsed-power to research in High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF). The Z facility at Sandia National Laboratories delivers 20-MA currents to create high magnetic fields (> 1000 T) and pressures (Mbar to Gbar). The large magnetic pressures directly-drive material dynamics and EOS studies at pressures up to 10 Mbar in Al. In a z-pinch configuration, the magnetic pressure supersonically implodes plasma created from a cylindrical wire-array. At stagnation, these plasmas have energy densities of 10 MJ/cm3 at densities up to 0.1% of solid, and produce x-ray energies of 1-2 MJ at powers up to 230 TW. Applications of wire-array radiation sources include two different z-pinch driven ICF concepts: the dynamic-hohlraum and the double-ended z-pinch hohlraum (DEH). Progress in many of these areas was recently reviewed [1]. After a brief overview of the pulsed-power HEDP/ICF program, this talk will focus on progress in achieving radiation symmetry of 2-4% for indirectly driven ICF capsule implosions with the DEH. In this concept, wire-array implosions heat two separate primary hohlraums located at each end of a central co-axial secondary hohlraum containing the ICF capsule. The DEH is the first pulsed-power concept to demonstrate ICF-relevant radiation symmetry. Capsule convergence of up to 14-21 have been shown with x-ray back lighting. We will summarize the development of the capabilities that now permit studies of low-mode radiation symmetry control at capsule diam. of 2.2 to 4.7 mm. Scaling of this concept to high fusion yields relevant for Inertial Fusion Energy will require x-ray powers of order .1 PW. Recent experiments have measured the mass distribution of wire arrays with monochromatic x-ray back lighting. We also summarize this and other progress in the understanding of the dynamics of single and nested wire-array z-pinches at currents of >13 MA, the impact on the scaling of the array power with drive current and mass, and the development of z-pinch designs that permit radiation pulse shaping appropriate for low entropy ICF capsule compression. This research is performed in collaboration with many other groups from around the world. (Author)