Effect of Decomposition of CuO Film on Ignition of Organic Explosives by a Laser Pulse

This work presents experimental results of the PETN ignition in a three-layer system: glass - copper oxide (CuO) - explosive materials (EM) and results of numerical simulations of the ignition of PETN, RDX, HMX, and TATB with a CuO film heated by a YLS-150 fiber laser with a pulse duration of 20ms. In the numerical simulations, the endothermic reaction of decomposition of the CuO film and decomposition reaction of EM were taken into account. It has been established that the endothermic effect of the CuO decomposition reaction increases the dynamic ignition delay time of EM. The expression for an estimation of width of a reaction layer in EM at heating by a constant heat stream is obtained. Calculations have shown that the dynamic threshold of ignition of organic explosives by laser pulse in a three-layer system (glass - CuO - EM) has a minimum for the thickness of the copper oxide film of 5 mu m. The density of the critical ignition energy of an explosive laser pulse increases in the sequence of PETN, RDX, HMX, and TATB. The calculated dependence of the PETN dynamic ignition delay time on the thickness of the CuO film is consistent with the experimental data.