Thermal Transport Modeling in ICF Direct-Drive Experiments

Thermal transport plays an important role in inertial confinement fusion. A new nonlocal heat transport model\footnote{V. N. Goncharov \textit{et al}., Phys. Plasmas \textbf{13}, 012702 (2006). } has been implemented in the 1-D hydrocode \textit{LILAC}. The model is based on a solution of a simplified Boltzmann equation with a Krook-type collisional operator. The simulation results show enhanced laser absorption during the first 100 to 200 ps of the laser drive due to the resonance absorption. The hot electrons generated by the resonance field are treated using existing models.\footnote{ E. J. Valeo and W. L. Kruer, Phys. Rev. Lett. \textbf{33}, 750 (1974); V. B. Rozanov and S. A. Shumskii, Sov. J. Quantum Electronics \textbf{16}, 1010 (1986).} Simulations indicate that these electrons do not significantly modify the shell adiabat for directly driven, ignition-scaled targets. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-92SF19460.