Designing a High-Throughput Drop-Weight-Impact Instrument for Real-Time Reaction Imaging of Energetic Materials*

Characterizing the handling safety and sensitivity of explosives has been a challenging area of study for over 60 years. Historically one of the most accessible and widely utilized experiments has been the drop-weight impact test, which involves dropping a weight on a small sample sandwiched between two anvils. Because this experiment generally only utilizes sound thresholds to determine whether or not a sample reacted, the physical parameters governing sensitivity remain convolved. Better understanding of chemical and material characteristics is needed to give the chemistry and engineering communities a predictive tool to determine the handling sensitivity of explosives prior to pursuing expensive and potentially hazardous synthesis and formulation operations. We are developing a high-throughput drop tower instrument capable of imaging energetic material deformation during impact and the resulting thermal ignition and propagation events. Herein, we present key design features including a drop tower module and diagnostic impact chamber enabling high-speed visible and thermal imaging of explosive initiation by sub-shock impacts. Combined with thermal testing results, this instrument will provide data needed to untangle the physical parameters that govern explosive sensitivity.