Optimization with \textit{Telios} of the Polar-Drive Point Design for the National Ignition Facility

Polar drive\footnote{S. Skupsky\textit{ et al.}, Phys. Plasmas \textbf{11}, 2763 (2004).} (PD) will make it possible to conduct direct-drive--ignition experiments at the National Ignition Facility\footnote{ G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. \textbf{43}, 2841 (2004).} while the facility is configured for x-ray drive. A PD-ignition design has been developed\footnote{T. J. B. Collins\textit{ et al.}, Phys. Plasmas \textbf{19}, 056308 (2012).} achieving high gain in simulations including single- and multiple-beam nonuniformities, and ice and outer-surface roughness. This design has been further optimized to reduce the in-flight aspect ratio and implosion speed, increasing target stability while maintaining moderately high thermonuclear gains. The dependence of target properties on implosion speed has been examined using the optimization shell \textit{Telios}. \textit{Telios} has the capability to drive complex radiation--hydrodynamic simulations and optimized results over an arbitrarily large parameter space, including ring pointing angles, spot-shape parameters, target dimensions, pulse timing, and relative pulse energies. \textit{Telios} is capable of extracting output from a variety of sources and combining them to form arbitrarily complex, user-specified metrics. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.