Shock Initiation of XTX-8003 and Pressed PETN

Abstract

Explosively driven, plane shock waves were used to study initiation characteristics of wedge- and pellet-shaped samples of PETN (pentaerythritoltetranitrate) pressed to densities of 1.60 and 1.72 g/cc, and the extrudable explosive XTX-8003, a mixture of PETN and an inert material. In each shot experiment the free-surface motion of the final attenuator element and the buildup to detonation of the reactive shock front through the explosive wedge were observed with a streak camera. Initial shock states of the explosives were determined by using the mirror-image approximation and the impedance-matching technique. Quantitative results include the Hugoniots of the unreacted explosives and curves relating the distance to detonation to the input shock pressure. Buildup to detonation in the lower density PETN samples appears to be controlled by a reaction occurring at or near the shock front, as is usually observed in shock initiation studies of heterogeneous explosives. However, buildup to detonation in the higher density PETN appears to be dominated by a reactive pressure pulse that forms well behind the leading shock, and which accelerates until it overtakes the leading shock, after which detonation occurs. Such an initiation behavior is more characteristic of homogeneous explosives.