Neutralization of explosives by plasma jet impingement: Feasibility study

Preliminary results of an experimental study to determine the feasibility o f neutralizing explosives by impingement of a high-temperature, high-veloci ty pulsed plasma jet are presented. The pulsed plasma jet was created by an electrothermal gun, a device that relies upon vaporization of solid metal to produce a metal vapor plasma. The tests were conducted using an aluminum plasma with a pulse duration of I ms and peak energy of 100 kJ on 1-g spec imens of PETN explosive. The specimens were placed inside a chamber at stan doff distances of 15-30 cm from the 6.65-mm diameter muzzle of the electrot hermal gun. The effectiveness of the plasma impingement was determined by c omparing postdetonation experiments on the exposed and unexposed explosive specimens. High-speed imaging of the plasma jet impinging on the explosive and postmortem examination of the explosive specimens suggests that three d istinct interactions occur. These interactions are: slow thermal decomposit ion (burning); rapid thermal decomposition (deflagration); and change in ch emistry with negligible or no thermal decomposition. Initial results sugges t that these three distinct interactions are a function of the mass flow ra te and energy of the plasma.