Shock Initiation of Solid State Explosions

摘要

In this collaborative effort on shock initiation in solids, advances were made in fundamental concepts and methods of investigation. A new theory was developed for shock-induced vibrational excitation, based on translation to vibration energy conversion. The key novelty of this work is the treatment of multiple correlated impulsive forces acting coherently on the internal degrees of the molecule as the shock wave passes. This theory is in excellent agreement with explicit simulations. The experimental effort has focused on the development of tools for initiation and monitoring of shock-induced microscopic dynamics. In the published work, two specific studies are notable. In the molecular solid of chlorine, we have demonstrated the mechanism of positive feedback in exciton-phonon transfer, leading to the formation of catastrophic hot spots in the solid. In superfluid He, under strong-field excitation, we have demonstrated the clear mechanism of cascade driven electronic-phonon energy transfer leading to bubble formation and breakdown. More generally, we have advanced four-wave mixing spectroscopies as both initiator and interrogator of shocks in condensed media. The results of these studies, in the gas solid and liquid phases, are now being published.