Laurent Catoire

In a former work, the effect of a volumetric nanosecond discharge at decreasing the detonation cell size was demonstrated experimentally. The experiments were performed under non-optimal conditions for plasma homogeneity. The present work is a paremetric study that aims at optimizing these experimental conditions. An electrode system was installed in a tube to produce a double-pulse discharge with high deposited energy ahead of the detonation front. The amplitude of the high-voltage pulses, the gas mixture and pressure were optimized so that the plasma filled the entire interelectrode space. The analysis of the detonation cell size with and without plasma generation was performed via the sooted-plate technique. Production of atoms and radicals in the discharge triggered combustion chemistry and decreased the ignition delay time. At these optimal conditions, the detonation cell size was thus reduced by a factor of 2, while passing through the region of the discharge.

The development of nanothermites and the understanding of their behaviors need several improvements in many domains including thermochemistry and chemical kinetics. In this paper a brief state of the art is presented in these fields and possible approaches are presented.

2,4,6-trinitrotoluene (TNT) is widely used in conventional and insensitive munitions as a fusible binder, commonly melt-cast with other explosives such as 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) or 3-nitro-1,2,4-triazol-one (NTO). In this paper, we study the shock-to-detonation transition phenomenon in two melt-cast high explosives (HE). We have performed plate impact tests on wedge samples to measure run-distance and time-to-detonation in order to establish the Pop-plot relation for several melt-cast HE. Highlighting the existence of the single curve buildup, we propose a two phase model based on a Zeldovich, Von-Neumann, Döring (ZND) approach where the deflagration fronts grow from the explosive grain boundaries. Knowing the grain size distribution, we calculate the deflagration velocities of the explosive charges as a function of shock pressure and explore the possible grain fragmentation.