Abstract
Direct drive laser fusion ignition experiments rely on detailed understanding and control of irradiation uniformity, the Rayleigh-Taylor instability and target fabrication. The Laboratory for Laser Energetics (LLE) is investigating various theoretical aspects of a direct drive National Ignition Facility (NIF) ignition target based on an `all-DT' design: a spherical target of ∼3.4 mm diameter, with a 1-2 μm CH wall thickness and a DT ice layer of ∼340 μm near the triple point of DT (∼19 K). OMEGA experiments are designed to address the critical issues related to direct drive laser fusion and to provide the necessary data to validate the predictive capability of LLE computer codes. The cryogenic targets to be used on OMEGA are hydrodynamically equivalent to those planned for the NIF. The current experimental studies on OMEGA address the essential components of direct drive laser fusion: irradiation uniformity and laser imprinting, Rayleigh-Taylor growth and saturation, compressed core performance and shell-fuel mixing, laser-plasma interactions and their effect on target performance, and cryogenic target fabrication and handling.