Review of indirect-drive ignition design options for the National IgnitionFacility

Several inertial confinement fusion (ICF) capsule designs have been propose d as possible candidates for achieving ignition by indirect drive on the Na tional Ignition Facility (NIF) laser [Paisner et al., Laser Focus World 30, 75 (1994)]. This article reviews these designs, their predicted performanc e using one-, two-, and three- dimensional numerical simulations, and their fabricability. Recent design work at a peak x-ray drive temperature of 250 eV with either 900 or 1300 kJ total laser energy confirms earlier capsule performance estimates [Lindl, Phys. Plasmas 2, 3933 (1995)] that were based on hydrodynamic stability arguments. These simulations at 250 eV and other s at the nominal 300 eV drive show that capsules having either copper doped beryllium (Be+Cu) or polyimide (C22H10N2O4) ablators have favorable implos ion stability and material fabrication properties. Prototypes of capsules u sing these ablator materials are being constructed using several techniques : brazing together machined hemishells (Be+Cu), sputter deposition (Be+Cu), and monomer deposition followed by thermal processing (polyimide). [S1070- 664X(99)95305-3].