Experiments and Simulations of Shocked and Ramp-Compressed Metals to 5 Mbars

In this report, we present a series of shocked and ramp compressed data on various metals including tantalum, iron and tin. These samples were shocked and ramp-compressed to pressures as high as 5 Mbars with graded density impactors (GDI). To analyze these data, we utilize both backward (characteristics) and forward analyses. The former method does not require a priori knowledge of a pressure drive, and often fails in the presence of strength or phase transition. By employing simulations in analysis of these experiments, we can improve experimental uncertainty as well as gain better understanding of phase transition and strength during ramp compression. In particular, we will examine the alpha-epsilon and solid-liquid transitions in iron. We will also report on recent efforts to characterize GDI in situ impedance profile.
This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344