Ultrafast Dynamics of Shock Waves and Shocked Energetic Materials

Abstract

AbstractExperimental measurements of material effects induced by the passage of sharp shock fronts require techniques which provide high temporal resolution and high spatial resolution. Since typical shock velocities are a few microns per nanosecond, sub-nanosecond probing requires sub-micron spatial resolution. In our experiments, the required temporal resolution is furnished using picosecond laser generated shock waves and picosecond spectroscopy. The spatial resolution is furnished by engineering nanometer scale structures into our shock target arrays. In one technique, absorption transients in the spectrum of a thin layer of molecules, termed an optical nanogauge, are investigated. Shock-induced molecular energy transfer processes are observed in condensed matter for the first time. In a second technique, sub-micron particles of an energetic material are shocked and probed using ps coherent Raman spectroscopy. This probing technique permits the instantaneous measurement of the temperature, pressure and composition of an energetic material under dynamic shock loading.