Systematic Study of Rayleigh-Taylor Growth in Directly Driven Plastic Targets in a Laser-Intensity Range from ~2 x 10^14 to ~1.5 x 10^15 W/cm^2

Journal Article · Fri Sep 05 04:00:00 EDT 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2967899· OSTI ID:936751

Smalyuk, V A ^[1]; Hu, S X; Goncharov, V N; Meyerhofer, D D; Sangster, T C; Stoeckl, C; Yaakobi, B

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1. Laboratory for Laser Energetics, University of Rochester, Rochester, NY

Direct-drive, Rayleigh–Taylor (RT) growth experiments were performed using planar plastic targets on the OMEGA Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] at laser intensities between ~2 x 10^14 and ~1.5 x 10^15 W/cm^2. The primary purpose of the experiments was to test fundamental physics in hydrocodes at the range of drive intensities relevant to ignition designs. The target acceleration was measured with a streak camera using side-on, x-ray radiography, while RT growth was measured with a framing camera using face-on radiography. In a laser-intensity range from 2 to 5 x 10^14 W/cm^2, the measured RT growth agrees well with two-dimensional simulations, based on a local model of thermal-electron transport. The RT growth at drive intensities above ~1.0 x 10^15 W/cm^2 was strongly stabilized compared to the local model predictions. The experiments demonstrate that standard simulations, based on a local model of electron thermal transport, break down at peak intensities of ignition designs, although they work well at lower intensities. These results also imply that direct-drive ignition targets are significantly more stable than previously calculated using local electron-transport models at peak intensities of ignition designs. The preheating effects by nonlocal electron transport and hot electrons were identified as some of the stabilizing mechanisms.

• Research Organization: Laboratory for Laser Energetics
• Sponsoring Organization: USDOE
• DOE Contract Number: FC52-08NA28302
• OSTI ID: 936751
• Report Number(s): DE/NA/28302-848; 2008-32; 1822
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 15; ISSN 1070-664X
• Country of Publication: United States
• Language: English