THE MINI-CHAMBER, AN ADVANCED PROTECTION CONCEPT FOR NIF

Inertial confinement fusion (ICF) target debris and ablated near-targe t materials pose the primary threat to the National Ignition Facility (NIF) final optics debris shields, as well as a major challenge in fut ure inertial fusion energy (IFE) power plants. This work discusses a N IF ''mini-chamber,'' designed to mitigate the debris threat. Although the NIF base-line design protects against debris using a frost-protect ed target positioner and refractory first-wall coatings, the mini-cham ber provides important flexibility in three areas: debris-shield prote ction from beyond-design basis shots (i.e. heavy hohlraums, special di agnostics, shields); fielding of large experiments with significant su rface ablation; and studying key ablation and gas-dynamics issues for liquid-wall IFE power plants. followed by discussion of equipment requ irements for fielding a NIF mini-chamber.