Several fictional portrayals have drawn attention to the possibility of an electromagnetic pulse (EMP) being used as a weapon, capable of disabling or destroying electronic equipment over a wide area. Such pulses can be created by detonating nuclear weapons at high altitude, though doing so in a war would provoke international outrage. To get around that, the United States and possibly others have developed non-nuclear EMP generators:
One such weapon uses a small charge of explosive to ram an armature down the axis of a current-carrying coil, squeezing its magnetic field so violently in the process that it emits a powerful burst of electromagnetic energy over distances of several hundred metres. Another type employs a Marx generator (a machine used for simulating lightning strikes) to dump a large electrical charge stored in a bank of capacitors into a specially shaped antenna.
American defence forces have converted a number of cruise missiles to function as non-nuclear EMP generators. Apparently, cars parked up to 300 metres away have had their alternators, ignition coils and engine controls disabled this way. Such e-weapons are said to have been used in Kosovo, the Persian Gulf and Afghanistan.
Intriguingly, a pair of such devices has recently broken cover. The Counter-Electronics High-Power Microwave Advanced Missile Project (CHAMP) is an unmanned aircraft fitted with a microwave pulse generatorâ€”presumably for disrupting enemy communications. The Pentagon has also announced that it is deploying an electromagnetic weapon, believed to be called Max Power, for detonating roadside bombs and disabling enemy vehicles. Both CHAMP and Max Power mimic the electromagnetic pulse of a nuclear explosionâ€”albeit over a narrowly focused area and without the geomagnetic effect.
Such weapons could be useful for reducing civilian casualties in war, particularly in situations where military targets are located in civilian areas. For example, if a state put an air defence RADAR station in a residential area, an EMP weapon could disable it at lesser risk to the civilian population, compared with conventional munitions.
Apparently, electromagnetic pulses can also be used to punch holes through steel for industrial purposes.