Controlling shock uniformity in nanocrystalline diamond

Suppressing inhomogeneities in the first shock front of nanocrystalline diamond (NCD) ablators is essential for achieving a lower fuel adiabat and higher yield in inertial confinement fusion (ICF) experiments. Non-planar shock fronts act as seeds for hydrodynamic instabilities, which reduce the yield during the ignition of deuterium-tritium fuel. Using quantum-accurate, billion-atom, micron-scale molecular dynamics simulations, we explore the microstructural evolution of shocked NCD under high compressions of up to 20 Mbar. We investigate the effects of grain size, orientation, and texture on the dynamics of shock compression. Our findings reveal a significant dependence of shock planarity on grain orientation and size, attributable to the anisotropic shock response of diamond when shocked along different crystallographic directions. These simulations aim to inform the design of future high-yield ICF experiments.