Systematic study of Rayleigh-Taylor growth in directly driven plastic targets in a laser-intensity range from {approx}2x10{sup 14} to {approx}1.5x10{sup 15} W/cm{sup 2}
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)
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 {approx}2x10{sup 14} and {approx}1.5x10{sup 15} W/cm{sup 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 5x10{sup 14} W/cm{sup 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 {approx}1.0x10{sup 15} W/cm{sup 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.
- OSTI ID:
- 21120524
- Journal Information:
- Physics of Plasmas, Vol. 15, Issue 8; Other Information: DOI: 10.1063/1.2967899; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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