Elastic precursor decay in S-200F beryllium

We have performed a series of plate impact experiments on vacuum hot-pressed (VHP) S-200F Be at peak shock stresses between 2.1 and 23.0 GPa to gain insight into the dynamic strength (Hugoniot elastic limit (HEL)), equation-of-state, and damage behavior of this technologically important material. In this paper we focus on our VISAR observations of the evolution of elastic precursor amplitude with Be target thickness in a series of plate impact experiments conducted in both transmission and reverse geometry. We observe monotonic decay in precursor amplitude with run distance for sample thicknesses between 4 and 8 mm and present the HEL values obtained from these experiments. We will discuss the observed precursor decay with respect to the relative roles of twinning and dislocation-mediated slip in the overall dynamic material mechanical response.