HR: 0830h
AN: U51B-0018    [PDF]
TI: NEAR MBAR-LEVEL DYNAMIC LOADING OF MATERIALS BY DIRECT LASER-IRRADIATION
AU: * Tierney, T E
EM: tierney@lanl.gov
AF: P-24 Plasma Physics Group, Los Alamos National Laboratory, PO Box 1663 Mailstop E526, Los Alamos, NM 87545 United States
AU: Swift, D C
EM: dswift@lanl.gov
AF: P-24 Plasma Physics Group, Los Alamos National Laboratory, PO Box 1663 Mailstop E526, Los Alamos, NM 87545 United States
AU: Gammel, J T
EM: jtg@lanl.gov
AF: T-1 Equation of State and Mechanics of Materials Group, Los Alamos National Labora-tory, PO Box 1663 Mailstop B221, Los Alamos, NM 87545 United States
AU: Luo, S
EM: sluo@lanl.gov
AF: P-24 Plasma Physics Group, Los Alamos National Laboratory, PO Box 1663 Mailstop E526, Los Alamos, NM 87545 United States
AU: Johnson, R P
EM: rpjohnson@lanl.gov
AF: P-24 Plasma Physics Group, Los Alamos National Laboratory, PO Box 1663 Mailstop E526, Los Alamos, NM 87545 United States
AB: We are developing techniques to perform direct-laser-illumination-driven, dynamic materials experiments at up to Mbar pressures with use of the Trident Laser Laboratory at Los Alamos. By temporally controlling the laser-irradiance, we are able to shape our loading for studies of fast-rise shocks, precursors, or isentropic compression. Laser-driven shock experiments are advantageous when considering the efficiency (fast turnaround), relative ease of sample recovery, taylorable dynamic loading, and in-situ structure diagnostics. Frequently, these experiments last 1-5 nanoseconds, and thus, permit investigation of rate-dependent processes and high strain rate environments. Laser-driven dynamic experiments are an important complement to traditional dynamic (e.g., light-gas gun) and static (e.g., diamond-anvil cell) experiments with certain advantages in studying equation of state, phase transitions and mechanical-chemical properties of Earth and planetary materials. Understanding high-pressure behavior in this regime is critical to phase boundaries for planetary interiors and dynamic properties of impact processes. Although we have studied silicates, oxides, metals, alloys and organic materials, this paper will focus on shocked and isentropically-compressed results obtained for iron in the range of 10-70 GPa (0.1-0.7 Mbar). Free surface velocities are measured using a Velocity Interferometer System for Any Reflector (VISAR). Nanosecond-scale laser experiments were interpreted with careful attention to exaggerated elastic-plastic effects and using accurate new equations of state for the phases of iron. This poster will present our technique, experimental results, and interpretation. *Work performed under the auspices of the US DOE under contract No. W-7405-ENG-36.
DE: 3919 Equations of state
DE: 3924 High-pressure behavior
DE: 3944 Shock wave experiments
DE: 3994 Instruments and techniques
SC: U
MN: 2003 Fall Meeting