Strong stabilization of the Rayleigh-Taylor instability by material strength at megabar pressures

Journal Article · Sat May 15 04:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3363170· OSTI ID:21371300

Park, Hye-Sook; Remington, B A; Becker, R C; Bernier, J V; Cavallo, R M; Lorenz, K T; Pollaine, S M; Prisbrey, S T; Rudd, R E; Barton, N R ^[1]

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1. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

Experimental results showing significant reductions from classical in the Rayleigh-Taylor (RT) instability growth rate due to high pressure effective lattice viscosity in metal foils are presented. Stabilization of RT instability (RTI) by ablation and density gradients has been studied for decades. The regime of stabilized RTI due to material strength at high pressure is new. On the Omega Laser in the Laboratory for Laser Energetics, University of Rochester, target samples of polycrystalline vanadium are compressed and accelerated quasi-isentropically at approx1 Mbar pressures, while maintaining the samples in the solid-state. Provided strong shocks are avoided, the higher the applied peak pressure, the higher the predicted foil strength, and hence, the higher the degree of strength stabilization of RTI. Several experiments were conducted where the amount of RT growth is measured by face-on radiography. The vanadium samples are probed by a laser driven He-alpha x-ray backlighter which produced 5.2 keV radiation. Comparison of the results with constitutive models for solid state strength under these conditions show that the measured RT growth is substantially lower than predictions using existing models that work well at low pressures and long time scales. High pressure, high strain rate data can be explained by the enhanced strength due to a phonon drag mechanism, creating a high effective lattice viscosity.

• OSTI ID: 21371300
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABLATION
COMPRESSION STRENGTH
CRYSTALS
ELEMENTS
FOILS
INSTABILITY
INSTABILITY GROWTH RATES
LASERS
MECHANICAL PROPERTIES
METALS
PHONONS
PLASMA DIAGNOSTICS
POLYCRYSTALS
QUASI PARTICLES
RAYLEIGH-TAYLOR INSTABILITY
SHOCK WAVES
STABILIZATION
STRAIN RATE
TRANSITION ELEMENTS
VANADIUM