Numerical Investigation of the Effect of Two-Plasmon-Decay Electron Preheat in Planar Rayleigh--Taylor Experiments

Planar Rayleigh--Taylor (RT) experiments carried out at laser intensities near 10$^{15}$~W/cm$^{2}$ showed RT growth suppression for the 20-\textit{$\mu $}m-wavelength mode but not for longer wavelength modes.\footnote{V. A. Smalyuk \textit{et al.}, Phys. Rev. Lett. \textbf{101}, 025002 (2008).} This RT growth stabilization was attributed mainly to the nonlocal transport of coronal electrons with only minor estimated preheat from two-plasmon-decay (TPD) electrons. Simulations have been performed with the 2-D hydrodynamics code \textit{DRACO} in which the TPD electrons' preheat is modeled with a straight-line transport package. The effect of the TPD electron preheat on the RT amplitudes for 20-, 30- and 60-\textit{$\mu $}m wavelengths are presented for intensities 5 $\times $ 10$^{14}$ and 10$^{15}$ W/cm$^{2}$. Comparisons with experiments will elucidate the role of TPD electron preheat to the RT-stabilization mechanism. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.