Hydrodynamics studies of direct-drive cone-in-shell, fast-ignitor targets on OMEGA

Experiments have been performed on the OMEGA Laser Facility [T. R. Boehly et al. , Opt. Commun. 133, 495 (1997)] to study the hydrodynamics of directly driven cone-in-shell, fast-ignitor targets. A 35° or 70° opening-angle gold cone was inserted into spherical plastic shells of ∼ 24 - μ m thickness and ∼ 870 - μ m diameter, which were imploded with up to 21 kJ of 351-nm laser light. A backlighter was used on some experiments to compare the fuel assembly of targets with or without a high-pressure fill gas. The shock breakthrough to the inside of the cone, where the ultrafast laser propagates in integrated fast-ignitor experiments, was studied using a streaked optical pyrometer. No plasma was seen inside the cone before the assembled core reached peak compression.