Stiff Response of Aluminum under Ultrafast Shockless Compression to 110GPA

A laser-produced x-ray drive was used to shocklessly compress solid aluminum to a peak longitudinal stress of 110 GPa within 10 ns. Interface velocities versus time for multiple sample thicknesses were measured and converted to stress density (P_x-ρ) using an iterative Lagrangian analysis. These are the fastest shockless compression P_x(ρ) results reported to date, and are stiffer than models that have been benchmarked against both static and shock-wave experiments. The present results suggest that at these short time scales there is a higher stress-dependent strength and a stiffer time-dependent inelastic response than had been expected.