Thermally cooled shock initiation of PBX 9502

Temperature affects the shock initiation of high explosives (HEs). It is hypothesized that when HEs are held at higher temperatures, the material expands, thereby increasing the number of voids (i.e. hot spots). This increase in voids then results in increased sensitivity of the HE. When HEs are cooled, the material contracts, reducing the number of voids, and, therefore, decreasing the sensitivity of the HE. For this work, we studied a specific lot of PBX 9502, which has not previously undergone thermally cooled shock initiation experiments. We performed single- and two-stage gas gun planar impact experiments with embedded electromagnetic gauges. These gauges provide in situ reactive growth and detonation profiles. The reactive growth profiles help to inform the reactants equation of state, and the transition from reactive profiles to detonation profiles, in time and distance, provide the shock-to-detonation transition of the HE based on input stress.

LA-UR-25-20886