Propellants Explosives Pyrotechnics, Vol.45, No.3, 396-405, 2020
Ultra-High Fidelity Laser-Induced Air Shock from Energetic Materials
Recent interest in the implementation of the Laser-induced Air Shock from Energetic Materials (LASEM) technique prompted an investigation using ultra-high-speed imaging diagnostics to provide early-time (sub-mu s) shock-wave-radius-versus-time data necessary to accurately determine the characteristic laser-induced-shock velocity (y-intercept) for high explosives (HE) of interest. Ultra-high-speed focused-shadowgraphy images were collected from nanosecond-pulsed laser-ablated samples of HE similar to those in the published literature. Shadowgraphy images were collected using interframe times ranging from 50-750 ns, with exposure times of 5 ns. Acquired shock-wave-radius-versus-time data permitted a high-fidelity assessment of the shock wave velocity produced at the characteristic radius of the generated laser-plasma pulse. The resulting data from eight different HE indicated that early-time energy contributions and the resulting laser-induced shock velocity profiles produced from ablation of the HE material were indistinguishable amongst the explosives tested for the majority of the time domain characterized (0-12 mu s).
Keywords:detonation performance;energetic-material characterization;shock physics laser-induced plasma;laser-induced shock wave