Modeling ablator defects as a source of mix in high-performance implosions on the National Ignition Facility*

Recent megajoule-class inertial confinement fusion experiments at the National Ignition Facility have shown variability in implosion performance due to the quality of the high density carbon (HDC) shells used as ablators.  In particular, these shells can have a number of defects that have been found to correlate with the appearance of ablator mix into the hot spot and degraded nuclear yield.  These defects include pits on the ablator surface, voids in the ablator bulk, and high-Z debris attached to the ablator surface, as well as the inherent granular micro-structure of the HDC ablator itself.  This talk summarizes recent high-resolution simulations to assess the impact of these different mix sources in current implosions and the prospects for design improvements to mitigate them.