SHOCK-WAVES IN MOLECULAR-SOLIDS - ULTRAFAST VIBRATIONAL SPECTROSCOPY OF THE FIRST NANOSECOND

A novel technique which uses a microfabricated shock target array asse mbly is described, where the passage of a shock front through a thin ( 0.5 mu m) polycrystalline layer and the subsequent unloading process i s monitored in real time with ultrafast coherent Raman spectroscopy. U sing a high repetition rate laser shock generation technique, high res olution, coherent Raman spectra are obtained in shocked anthracene and in a high explosive material, NTO, with time resolution of similar to 50 ps, Spectroscopic measurements are presented which yield the shock pressure (up to 5 GPa), the shock velocity (similar to 4 km/s), the s hock front rise-time (t(r) < 25 ps), and the temperature (similar to 4 00 degrees C). A brief discussion is presented, how this new technique can be used to determine the Hugoniot, the equation of state, the ent ropy increase across the shock front, and monitor shock induced chemic al reactions in real time.