Ultrafast Dynamics of Shock Waves and Shocked Energetic Materials

摘要

Experimental measurements of material effects induced by the passage of sharpshock fronts required 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 pico second 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, submicron particles of an energetic material are shocked and probed using Ps coherent Ramen spectroscopy. This probing technique permits the instantaneous measurement of the temperature, pressure and composition of an energetic material under dynamic shock loading.