X-ray Investigations of Combustion Phenomena Occurring in Confined Pyrotechnic Charges

Investigation of the combustion processes occurring in end-burning, multi-segment, delay elements of hand-grenade firing-explosive trains using Real-Time X-ray Radioscopy (RTR) are presented. RTR detection, operating at 30 frames per second, registered the development of the combustion process, visualized as the border between the burnt and unburnt parts of the pyrotechnic column, travelling from the ignition (input) end to the output end. This border had a variable shape, ranging from planar to very non-regular. At the end of the combustion process, i.e. during burning of the final-output pyrotechnic segment, the formation of a longitudinal cavity beginning from the output end of the delay element and reaching a depth of nearly 40% of the total length of the pyrotechnic column, was detected. Such strong erosion of the output part of the pyrotechnic column indicates that in the creation of the output combustion products (firing output impulse) of the tested delay element, a relatively significant mass of the pyrotechnic charge was involved.