Benchtop energetics: Detection of hyperthermal species

We present a novel scheme for monitoring the transition between deflagration and "detonation-like" behavior of small-scale explosive samples subjected to shock stimuli. The intended geometry for this setup incorporates a laser-driven-flyer impact technique to generate a pure mechanical input. However, we report results here using a simplified geometry for purposes of evaluating the time-of-flight mass spectrometric (TOFMS) diagnostics using direct laser ablation of solid aluminum and of an aluminum mirror coated with a small amount (~1 μg) of PETN. This manuscript presents the TOFMS detection of fast aluminum atoms (>10 km/s) resulting from laser ablation, confirming our ability to detect hyperthermal species. Preliminary results from pentaerythritol tetranitrate (PETN) experiments reveal a transition from species consistent with deflagration (primarily NO2) at low laser fluence, to those consistent with detonation-like events (N2, CO, CO2) at higher laser fluence. At this time, due to several unknown par...