MR13C-2724
Shock Melting of Forsterite by In-Situ X-Ray Diffraction
Monday, 14 December 2015
Poster Hall (Moscone South)
Matthew Newman1, Richard G Kraus2, June K Wicks3, Federica Coppari4, Raymond Smith4 and Thomas S Duffy5, (1)California Institute of Technology, Pasadena, CA, United States, (2)Lawrence Livermore National Lab, Reno, NV, United States, (3)Princeton University, Princeton, NJ, United States, (4)Lawrence Livermore National Laboratory, Livermore, CA, United States, (5)Princeton University, Department of Geosciences, Princeton, NJ, United States
Abstract:
The equation of state of magnesium silicates at pressures and temperatures
near the solid-liquid coexistence curve is important for understanding the
thermal evolution and interior structure of rocky planets. Here, we
present a series of laser driven shock-melt experiments on single crystal
Mg_2SiO_4 forsterite, conducted at the Omega EP laser facility. Particle
velocities in the Mg_2SiO_4 samples were measured using a line VISAR and
used to infer the thermodynamic state of the shocked samples. In situ
X-ray diffraction measurements are used to probe the melting transition
and investigate the potential decomposition of Mg_2SiO_4 in to MgO and
MgSiO_3 upon melt. This work examines potential kinetic effects of
decomposition due to the short time scale of laser-shock experiments. In
addition, the thermodynamic data collected in these experiments adds to a
limited body of information regarding the equation of state of Mg_2SiO_4,
which is the dominant end member composition in Earth’s upper mantle.
This work was performed under the auspices of the U.S. Department of
Energy by Lawrence Livermore National Laboratory under Contract
DE-AC52-07NA27344.
