Radiation driven capsules for fast ignition fusion

The energy required to ignite compressed deuterium–tritium fuel decreases strongly with fuel density. Thermal radiation is an effective way of driving inertial fusion capsules to high density. The achievable fuel density increases with peak radiation temperature, since the ablation pressure depends strongly on the radiation temperature. Through a series of detailed numerical simulations, peak fuel densities have been calculated as a function of the peak radiation drive temperature. In these calculations, the time dependence of the radiation temperature has been optimized to obtain maximum density for each scaling point. These results are then used with the fast ignition scaling of Atzeni [S. Atzeni, Phys. Plasmas 6, 3316 (1999)] to obtain ignition energy as peak drive temperature.