Direct-Drive Target Designs for the National Ignition Facility

LLE Review, Volume 79 121 The National Ignition Facility (NIF) is currently under construction at Lawrence Livermore National Laboratory (LLNL). One of the primary missions of the NIF is to achieve fusion ignition by means of inertial confinement fusion (ICF). Two main approaches have been considered for achieving thermonuclear yield in ICF. The first approach, known as indirectdrive ICF,1 encloses a DT-fuel target inside a hohlraum. The laser beams are incident on the hohlraum’s wall where the laser light is converted to x rays. These x rays then implode the target, leading to the ion temperature and ρR product necessary to achieve ignition. The second approach, known as directdrive ICF, dispenses with the hohlraum and directly illuminates the laser light onto the target.