Timeline - 2007 - Laboratory for Laser Energetics

LLE Infers 200 mg/cm² Fuel Areal Density
On April 17, 2007, LLE scientists completed a National Ignition Campaign (NIC) Level-2 milestone when a neutron-burn-averaged areal density of 202±7 mg/cm² was measured for the first time from a direct-drive cryogenic D₂ implosion on OMEGA. This demonstrated that hydrogen could be compressed to ignition-relevant densities using laser-driven capsules.

LLE Validates Polar-Direct-Drive for Ignition on the NIF
LLE completed a study using the National Ignition Facility (NIF) in the x-ray-drive configuration for direct-drive–ignition experiments. The study focused on implementing the standard polar-direct-drive illumination scheme, which uses judicious repointing of the NIF beams to minimize illumination perturbations that arise from the absence of equatorial beams in the x-ray-drive laser configuration. The conclusion of the study validated the polar-direct-drive concept using numerical simulations and experiments on OMEGA for ignition on the NIF.

Black-and-white microscope image of a spherical capsule or droplet centered inside a circular holder.

Optical shadowgraph showing a 2.4-μm rms inner-ice-surface roughness of a cryogenic D2 capsule

Diagram of a target cross-section with labeled layers—CH, DT, and CH(DT)—shown next to a simulated fluid-flow contour map in blue, yellow, and green.

Isodensity contours (color) and iontemperature contours (white lines) of the implosion of a NIF wetted-foam, polardrive– ignition target

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