Hot spot mass ablation and enthalpy in ice-layered inertial fusion implosions

In layered implosions, most of the fuel in the central hot spot comes from mass ablation from the inner layer of DT ice. This ablation is associated with an enthalpy contribution to the hot spot energy that plays a key role in setting the conditions for thermonuclear ignition. A recent study of this problem indicates that prior studies of hot spot ignition have underestimated by a factor of 2-4 the rate of mass ablation, leading to a corresponding, systematic underestimate of the energy needed to ignite a hot spot [1]. In this presentation, an improved model of mass ablation will be shown that is in excellent agreement with radiation hydrodynamics simulations. Implications of the use of this improved model on setting the conditions for ignition will be discussed.



[1] W. Daughton et al., “Influence of mass ablation on ignition and burn propagation in layered fusion capsules,” https://arxiv.org/abs/2207.00093 (submitted).