Shock initiation of CL-20 based explosives

In the present work, shock initiation experiments on CL-20, CL-20/NTO and CL-20/FOX-7 mixed explosives were performed to investigate the shock initiation characteristics of Hexanitrohexaazaisowurtzitane (CL-20) based explosives. An explosive driven flyer device was utilized to initiate the charges with manganin gauges embedded into the target to measure time resolved local pressure histories. The shock initiation of CL-20 based explosives was simulated using the ignition and growth reactive flow model, and the parameters were obtained by fitting the experimental data. Furthermore, the reaction of two compositions in CL-20/NTO and CL-20/FOX-7 was simulated respectively using the two growth terms in the ignition and growth model. The parameters were then applied in the calculation of the initial shock pressure-distance to detonation relationship (Pop plot) and the shock initiation critical thresholds for the three mixed explosives. The results show that the CL-20/NTO explosive has a higher shock initiation critical threshold, while the CL-20/FOX-7 explosive has a longer distance to detonation under the same loading conditions. Besides, this model for the explosive with the two compositions can be applied to predict the shock initiation characteristics of the explosive with new formulations.