Detonation of Low-Density Explosives

Abstract

Electromagnetic measurements of the particle velocity are performed in a situation when the detonation wave reaches the interface between a powdered high explosive (HE) and a window made of an inert material (Plexiglas). PETN, RDX, and HMX with densities close to the natural bulk density are studied. In order to measure not only the averaged velocity profile, but also possible fluctuations at scales of the order of the HE grain size, small sensors with the working arm length approximately 1 mm are used. In most experiments, profiles with clear chemical spikes are obtained; in some of the measured results, however, the chemical spike cannot be detected on the background of strong signal oscillations, which may be considered as manifestation of the nonclassical mechanism of wave propagation (explosive burning suggested by Apin). Along withour previous study, the present results suggest parallel operation of the shock and convective mechanisms with domination of each mechanism at different segments of the wave front.