Design of a full-scale High AdiabaT CH ablator implosion (HATCH) for the National Ignition Facility

A series of experiments are scheduled beginning in November 2024 to investigate the potential for improved indirect-drive implosion efficiency in a NIF ignition platform using a CH ablator. We present the design for a cryogenic fuel layered implosion that uses a 1.6 MJ laser pulse to achieve the same peak fuel velocity and total remaining mass at peak velocity as the current 2.1 MJ HDC ablator ignition platform in the same hohlraum. An important difference between this design and previous CH ablator implosions on NIF is a shorter pulse shape for better symmetry control in the low gas-fill hohlraum. This change increases the fuel entropy relative to previous implosions but also improves the predicted stability, including resistance to the tent perturbation. The amorphous nature of the CH is expected to reduce variability relative to HDC implosions due to reproducible dopant levels and a lack of microstructure and voids. Results from integrated and high-resolution capsule simulations will be presented that predict performance and estimate robustness to asymmetry and mix. This work was performed under the auspices of the U.S. DOE by LLNL under contract DE-AC52-07NA27344.