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Title: Accessing ultrahigh-pressure, quasi-isentropic states of matter

Abstract

A new approach to the study of material strength of metals at extreme pressures has been developed on the Omega laser, using a ramped plasma piston drive. The laser drives a shock through a solid plastic reservoir that unloads at the rear free surface, expands across a vacuum gap, and stagnates on the metal sample under study. This produces a gently increasing ram pressure, compressing the sample nearly isentropically. The peak pressure on the sample, inferred from interferometric measurements of velocity, can be varied by adjusting the laser energy and pulse length, gap size, and reservoir density, and obeys a simple scaling relation [J. Edwards et al., Phys. Rev. Lett. 92, 075002 (2004)]. In an important application, using in-flight x-ray radiography, the material strength of solid-state samples at high pressure can be inferred by measuring the reductions in the growth rates (stabilization) of Rayleigh-Taylor unstable interfaces. This paper reports the first attempt to use this new laser-driven, quasi-isentropic technique for determining material strength in high-pressure solids. Modulated foils of Al-6061-T6 were accelerated and compressed to peak pressures of {approx}200 kbar. Modulation growth was recorded at a series of times after peak acceleration and well into the release phase. Fits tomore » the growth data, using a Steinberg-Guinan constitutive strength model, give yield strengths 38% greater than those given by the nominal parameters for Al-6061-T6. Calculations indicate that the dynamic enhancement to the yield strength at {approx}200 kbar is a factor of {approx}3.6x over the ambient yield strength of 2.9 kbar. Experimental designs based on this drive developed for the National Ignition Facility laser [W. Hogan, E. Moses, B. Warner, M. Sorem, and J. Soures, Nuclear Fusion 41, 567 (2001)] predict that solid-state samples can be quasi-isentropically driven to pressures an order of magnitude higher than on Omega, accessing new regimes of dense, high-pressure matter.« less

Authors:
; ; ; ; ; ;  [1]
  1. Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States)
Publication Date:
OSTI Identifier:
20736601
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 12; Journal Issue: 5; Other Information: DOI: 10.1063/1.1873812; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALUMINIUM; FOILS; LASERS; PLASMA PRESSURE; RAYLEIGH-TAYLOR INSTABILITY; YIELD STRENGTH

Citation Formats

Lorenz, K T, Edwards, M J, Glendinning, S G, Jankowski, A F, McNaney, J, Pollaine, S M, and Remington, B A. Accessing ultrahigh-pressure, quasi-isentropic states of matter. United States: N. p., 2005. Web. doi:10.1063/1.1873812.
Lorenz, K T, Edwards, M J, Glendinning, S G, Jankowski, A F, McNaney, J, Pollaine, S M, & Remington, B A. Accessing ultrahigh-pressure, quasi-isentropic states of matter. United States. https://doi.org/10.1063/1.1873812
Lorenz, K T, Edwards, M J, Glendinning, S G, Jankowski, A F, McNaney, J, Pollaine, S M, and Remington, B A. Sun . "Accessing ultrahigh-pressure, quasi-isentropic states of matter". United States. https://doi.org/10.1063/1.1873812.
@article{osti_20736601,
title = {Accessing ultrahigh-pressure, quasi-isentropic states of matter},
author = {Lorenz, K T and Edwards, M J and Glendinning, S G and Jankowski, A F and McNaney, J and Pollaine, S M and Remington, B A},
abstractNote = {A new approach to the study of material strength of metals at extreme pressures has been developed on the Omega laser, using a ramped plasma piston drive. The laser drives a shock through a solid plastic reservoir that unloads at the rear free surface, expands across a vacuum gap, and stagnates on the metal sample under study. This produces a gently increasing ram pressure, compressing the sample nearly isentropically. The peak pressure on the sample, inferred from interferometric measurements of velocity, can be varied by adjusting the laser energy and pulse length, gap size, and reservoir density, and obeys a simple scaling relation [J. Edwards et al., Phys. Rev. Lett. 92, 075002 (2004)]. In an important application, using in-flight x-ray radiography, the material strength of solid-state samples at high pressure can be inferred by measuring the reductions in the growth rates (stabilization) of Rayleigh-Taylor unstable interfaces. This paper reports the first attempt to use this new laser-driven, quasi-isentropic technique for determining material strength in high-pressure solids. Modulated foils of Al-6061-T6 were accelerated and compressed to peak pressures of {approx}200 kbar. Modulation growth was recorded at a series of times after peak acceleration and well into the release phase. Fits to the growth data, using a Steinberg-Guinan constitutive strength model, give yield strengths 38% greater than those given by the nominal parameters for Al-6061-T6. Calculations indicate that the dynamic enhancement to the yield strength at {approx}200 kbar is a factor of {approx}3.6x over the ambient yield strength of 2.9 kbar. Experimental designs based on this drive developed for the National Ignition Facility laser [W. Hogan, E. Moses, B. Warner, M. Sorem, and J. Soures, Nuclear Fusion 41, 567 (2001)] predict that solid-state samples can be quasi-isentropically driven to pressures an order of magnitude higher than on Omega, accessing new regimes of dense, high-pressure matter.},
doi = {10.1063/1.1873812},
url = {https://www.osti.gov/biblio/20736601}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 5,
volume = 12,
place = {United States},
year = {2005},
month = {5}
}