Numerical Simulation of the Explosion Dynamics and Energy Release from High-Gain ICF Targets

Results from numerical simulations are presented describing the explosion energetics of a high-gain indirect-drive ICF target. The light ion fusion LIBRA-SP target, which consists of an x-ray driven capsule embedded in a spherical foam-filled hohlraum, is imploded using 12 prepulse and 12 full power Li beams containing a total energy of 8 MJ. Here, we report on the dynamics of the target energy release, focussing in particular on the partitioning of energy between x rays, neutrons, and target debris kinetic energy. Our results indicate that 72% and 22% of the 552 MJ yield is emitted by the target in the form of neutrons and x-rays, respectively. Calculated emergent spectra for the target neutrons and x rays are also presented.