Shock-Ignition Studies in Planar Geometry on OMEGA

In the shock-ignition concept,\footnote{R. Betti \textit{et al.}, Phys. Rev. Lett. \textbf{98}, 155001 (2007).} the gain in an inertial confinement fusion (ICF) experiment is enhanced compared to conventional hot-spot ignition through the separation of the fuel assembly and ignition stages. A strong, spherically converging shock of several hundred megabar is launched into the cold fuel assembly of an ICF target by a high-intensity laser spike of $\sim $10$^{16}$ W/cm$^{2}$ at the end of the assembly pulse, igniting the fuel. We present results from recent OMEGA experiments in planar geometry studying the shock-ignition concept and strong shock generation in the presence of a pre-plasma. These experiments provide important data on backscattering, hot-electron generation, and shock strength at shock-ignition relevant intensities of up to $\sim $5 $\times $ 10$^{15}$ W/cm$^{2}$. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.