A high-power electromagnetic source for disabling improvised explosive devices

Ultra-wideband (UWB) microwave sources driven by specialised pulsed power generators have experienced a considerable development in the last decade due to their wide domain of new applications such as defence or counter-terrorism activity. The authors present the main findings of a research dedicated to the development of a pulsed power-driven electromagnetic field source for disabling improvised explosive devices (IED). The pulsed power generator driving the source is a 13-stage compact Marx producing voltage pulses reaching an amplitude of 0.5 MV, with a pulse repetition frequency (PRF) of up to 100 Hz. The generator is coupled to a bipolar pulse forming line, providing bipolar pulses with a dV/dt of around 1.6 MV/ns. This pulsed power system feeds an array composed of 16 Koshelev-type UWB antennas through an impedance matching transformer. The resulting electromagnetic source is capable to produce pulsed electric fields (PEFs) having a figure-of-merit (FOM) of 1 MV. First, practical experiments were carried out to study the effects of the PEFs on targets. The targets used in the present study are M2B type flashbulbs, known to have the same susceptibility as the US army M6 detonator. Different configurations of wires (shielded, twisted, etc) with different lengths were used in connecting items inside these targets. The tests were performed by placing the flashbulbs at different distances to determine the essential parameters (i.e., amplitude, duration, and frequency range) of the PEFs required to trigger them. An overview of the experimental campaign and the main findings are also presented followed by conclusions.