Real time diagnostics of detonation products from lead azide using coherent anti-Stokes Raman scattering

We report on the first example that applies coherent anti-Stokes Raman scattering (CARS) to real time diagnostics of detonation products from a solid explosive. The supersonically expanding gaseous products, from the detonation of either lead azide pellets or powders, are studied, using broadband CARS. The density, and the rotational and vibrational temperatures of ground electronic state N₂ molecules, N₂(X), are monitored as a function of time at a fixed distance, 3.3 cm, from the azide surface. The rotational temperature is low, around 200-300 K, while the vibrational temperature is around 2000 K for delays of 8-12 μs, following the initiation of detonation. The density of N₂(X), during this time interval, increases from ∼1×10¹⁷ to 1×10¹⁸ cm^-3.