VOLUME IGNITION TARGETS FOR HEAVY-ION INERTIAL FUSION

Inertial confinement fusion (ICF) targets can be imploded by heavy-ion beams (HIBs) in order to obtain a highly compressed fuel microsphere. The hydrodynamic efficiency of the compression can be optimized by tu ning the ablation process in order to produce the total evaporation of the pusher material by the end of the implosion. Such pusherless comp ressions produce very highly compressed targets for relatively short c onfinement times. However, these times are long enough for a fusion bu rst to take place, and burnup fractions of 30% and higher can be obtai ned if the volume ignition requirements are met. Numerical simulations demonstrate that targets of 1-mg DT driven by a few MJ can yield ener gy gains of over 70. Although direct drive is used in these simulation s, the main conclusions about volume ignition are also applicable to i ndirect drive.