Cryogenic Deuterium and Deuterium-Tritium Direct–Drive Implosions on Omega

Abstract

The success of ignition target designs in inertial confinement fusion (ICF) experiments critically depends on the ability to maintain the main fuel entropy at a low level while accelerating the shell to ignition-relevant velocities of V imp > 3 × 10 7 cm/s. The University of Rochester's Laboratory for Laser Energetics has been imploding cryogenic deuterium and deuterium-tritium targets on the Omega Laser System for over a decade. Fuel entropy is inferred in these experiment by measuring fuel areal density near peak compression. Measured areal densities up to ρR n ∼300 mg/cm 2 (larger than 85 % of predicted values) are demonstrated in the cryogenic implosion with V imp approaching 3 × 10 7 cm/s and peak laser intensities of 8 × 10 14 W/cm 2. Scaled to the laser energies available at the National Ignition Facility, implosions, hydrodynamically equivalent to these Omega designs, are predicted to achieve ρR n > 1.2 g/cm 2 , sufficient for ignition demonstration in direct-drive ICF experiments.