Rayleigh-Taylor stabilization by material strength at Mbar pressures
Studies of solid-state material dynamics at high pressures ({approx}1 Mbar) and ultrahigh strain rates (>10{sup 6} s{sup -1}) are performed using a unique laser based, quasi-isentropic high-pressure acceleration platform. Vanadium foils with pre-imposed sinusoidal ripples are accelerated in the solid state with this ramped high pressure drive. This causes Rayleigh-Taylor (RT) instability growth at the interface, where the rate of growth is sensitive to the solid-state material properties. The RT growth history is measured by face-on radiography using synchronized laser-driven x-ray backlighters at the Omega Laser. The experimental results are compared with 2D hydrodynamics simulations utilizing constitutive models of high pressure material strength. We find that the vanadium strength increases by a factor of 3.5-4 at peak pressure, compared to its ambient (undriven) strength. Both pressure hardening and strain rate hardening are the suggested cause for this increase in strength. An analysis treating strength as an effective lattice viscosity finds that a viscosity of {approx}400 poise is required to reproduce our RT data.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 977227
- Report Number(s):
- LLNL-JRNL-413702
- Journal Information:
- Physics Review Letters, vol. 104, no. 13, April 2, 2010, pp. 135504, Journal Name: Physics Review Letters, vol. 104, no. 13, April 2, 2010, pp. 135504 Journal Issue: 13 Vol. 104
- Country of Publication:
- United States
- Language:
- English
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