Fast Ignition Target Compression Campaign

Abstract

We propose an experimental campaign on the NIF to validate key elements of the fast ignition target design. Experimental measurements will provide feedback for refinement of the target design. In lieu of the cryogenic DT target, which requires ongoing target fabrication R&D, the initial experiments will use a surrogate target design consisting of a cryogenic H/He gas-filled hohlraum with CH capsule. In the first year we will validate hohlraum energetics, symmetry tuning, and measure peak ρR with spherical capsule implosions, for each of our two candidate pulse shapes, with the aim of down selecting to a preferred drive pulse. In the second year we will progress to cone-in-shell implosions, using x-ray radiography and Streaked Optical Pyrometry (SOP) inside the cone to measure and optimize the ρR and shape of the compressed core and the timing between optimum fuel compression and shock breakout in the cone. Our goal is to establish an indirect drive fast ignition compression platform that will demonstrate the validity of the implosion scheme, and provide a basis for future core heating experiments using the 10 kJ, 10 ps Advanced Radiographic Capability (ARC) short-pulse NIF beam line.