Multidimensional Simulations of Next-Generation Inertial Confinement Fusion Targets

The next generation of laser-direct-drive inertial confinement fusion facilities should be capable of reaching burning-plasma conditions in order to facilitate high-yield, robust ignition designs for stockpile stewardship and inertial fusion energy. The knowledge that has been gained at current facilities will be leveraged to propose implosion target designs that can be reasonably expected to achieve robustly burning plasmas at a test implosion facility (OMEGA Next). A class of targets has been proposed that uses moderate laser energy (250 kJ) and ignites in 1D simulations with moderate gains (1 to 20) while maintaining a stability parameter within the bounds of present-day experiments. These target designs assume the use of laser technology with large bandwidths to suppress laser–plasma instabilities and laser focal-spot zooming, which collectively improve laser–plasma energy coupling efficiency with acceptable levels of low- and mid-mode perturbations due to beam geometry. We present 2D radiation-hydrodynamics simulations of OMEGA Next-scale targets using the code DRACO. A laser beam-port geometry is proposed that uses a 108-beam t-design sphere to significantly reduce beam modes when compared to that of the OMEGA and the NIF. Additionally, we find the level of laser imprint required to maintain shell integrity and produce targets gains above 1.