Effects of microstructure on shock initiation of insensitive explosives

Understanding the effects of microstructure on shock initiation requires testing methods that can distinguish between energetic materials that have the same composition and the same overall chemistry, but differ only in microstructure. TATB (2,4,6 trinitro 1,3,5 triamino benzene) is an insensitive energetic material with many unique properties. Slight variations in the synthetic procedure can lead to a diverse library of microstructures. We studied 10 different TATB microstructures fabricated in the form of arrays of hundreds of small cylindrical plastic-bonded explosive (PBX) charges. Each charge is shocked by a high-velocity impact with a thin laser-launched flyer plate that produces a short-duration shock so we can time resolve the spectral radiance with a high dynamic range to produce a unique fingerprint and temperature profile for each microstructure, which reveals how the microstructure interacts with a shock to ignite critical hot spots which can grow and interact to produce widespread combustion.