Hot Spot Dynamics in Ice-Layered Inertial Confinement Fusion Implosions *

The mainline approach to achieving inertial confinement fusion (ICF) ignition in the laboratory involves the use of ice-layered implosions, where a hot spot is formed during the implosion from ablation of the inner layer of DT ice. The dynamics of the formation and evolution of the hot spot are complex and a recent study by the authors indicates the potential value of reexamining a few of the physics assumptions commonly made by the community. This paper will describe recent work on this problem, one which is central to understanding ICF capsule performance on the National Ignition Facility and to the prospects of achieving ignition.