A view on the functioning mechanism of EBW detonators -part 2: bridgewire output

This is the second paper of three papers describing the studies to identify the initiating mechanisms in Exploding Bridgewire (EBW) detonators. In this paper the results of experiments to quantify the effect of the bridgewire explosion are described. Experiments have been performed to characterise the output from the bridgewire in terms of the stimulus it would apply to the surrounding explosive in an EBW detonator. The expansion speed of the bridgewire at burst as a function of input energy has been measured using Photonic Doppler Velocimety (PDV). To complement the bridgewire expansion velocity determinations aquarium experiments were carried out in which the shock wave velocity in water was measured, as a function of energy, by high speed photography. The shock pressures were calculated and compared to initiation criteria for PETN.