Impact of asymmetries and mix on burn-up fraction for IFE relevant implosions

Inertial confinement fusion (ICF) implosions for power production need to be robust. Degradations from sources such as asymmetries or high-Z mix need to be understood and considered for an economical power plant. In this presentation, the impact of asymmetries and mix on burn-up fraction are studied for inertial fusion energy (IFE) scale implosions. A high gain indirectly driven capsule design is degraded with drive asymmetries. The resulting yield remains stable with increasing amounts of asymmetry until reaching a cliff where the yield quickly drops. This robustness is due to the quality of the degraded implosion’s hotspot. Drive asymmetries launch jets of DT ice into the central hotspot. If the hotspot is performant enough, the jet ablates away, and the implosion overcomes the asymmetry. The robustness is linked to the Generalized Lawson Parameter, χ. The burn-on yield cliff corresponds to when the burn-off χ is close to one. From this, a simple piston model is used to predict where the robustness cliff is for any design. Results from mix degraded implosions are also discussed. Work is ongoing to apply this understanding of asymmetries to current NIF target gain experiments.