Seeing inside shocked plastic-bonded explosives

Plastic-bonded explosives (PBX) generally consist of microparticles and polymer binders. We want to see inside PBX as powerful shock waves pass through them. Unfortunately PBX strongly scatter light, so it is difficult to see inside them. Here I will focus on two applications. With organic explosives such as HMX, it is important to determine which microstructural features are most likely to generate hot spots, and how hot spots grow (or decay) as a function of their sizes and temperatures. With heterogeneous explosives with metal microparticles, it is important to understand what happens to metal particles and associated oxidizers with the intent of finding ways to make more energetic metal combustion reactions occur as fast as organic explosives, which can react in a few nanoseconds. We have developed a tabletop high-throughput experiment that uses a pulsed laser to generate hypervelocity flyer plates used to shock tiny explosives mass-produced in multielement arrays. Lately we have developed sample geometries that allow us to watch organic and inorganic particles react under strong shock compression with time and space resolution of 2 ns and 2 m. So come to this talk, sit back and watch these things react.