Integrated performance of large HDC-capsule implosions on the National Ignition Facility

We report on eight, indirect-drive, deuterium-tritium-layered, inertial-confinement-fusion experiments at the National Ignition Facility to determine the largest capsule that can be driven symmetrically without relying on cross-beam energy transfer or advanced Hohlraum designs. Targets with inner radii of up to 1050 mu m exhibited controllable P-2 symmetry, while larger capsules suffered from diminished equatorial drive. Reducing the Hohlraum gas-fill-density from 0.45mg/cm(3) to 0.3mg/cm(3) did not result in a favorable shift of P-2 amplitude as observed in preceding tuning experiments. Reducing the laser-entrance-hole diameter from 4mm to 3.64mm decreased polar radiation losses as expected, resulting in an oblate symmetry. The experiments exhibited the expected performance benefit from increased experimental scale, with yields at a fixed implosion velocity roughly following the predicted 1D dependence. With an inner radius of 1050 mu m and a case-to-capsule-ratio of 3.0, experiment N181104 is the lowest implosion-velocity experiment to exceed a total neutron yield of 10(16).