WHAT MAKES AN EMP SO DAMAGING?
To fully understand what makes an EMP so lethal to electronics, one needs to understand the science behind an EMP. Although it is termed a “pulse”, which would imply a single wave of energy, much like the pulse from your heart, an EMP is actually combined of three pulses, each of which is damaging to electronics in its own special way. These pulses are termed E1, E2, and E3.
Here’s what they are:
The first part of the tripartite multi pulse that is EMP begins with the E1 component. As gamma radiation from the detonation punches electrons out of atoms high in the atmosphere, these electrons begin to travel downwards towards the Earth at incredible speeds – almost the speed of light. As the electrons travel downwards, they encounter the Earth’s magnetic field, which aligns them at right angles to itself.
It is this combination of fast travel and magnetic alignment that causes the E1 pulse – an extremely large but brief wave of energy. The energy wave occurs just nanoseconds after the blast, and can have a strength of 50,000 volts per meter or 6.6 Megawatts per square meter – exceptionally powerful.
The E1 pulse is best known for its ability to destroy sensitive electronics such as those found within computers and communications equipment. This pulse travels far too fast for surge protectors and other protective devices to be of any good from a protection standpoint.
The E2 burst follows on the heels of the E1 burst, and essentially wreaks more havoc. This phase lasts from approximately 1 microsecond to one second after the E1 pulse. The E2 pulse is akin to a lightning strike and is thus relatively easy to protect against using conventional means. The problem, however, is that most of these protective devices would have been negatively affected or even knocked out by the preceding E1 burst and thus any protection they may have offered would be nullified, allowing the power surge to go past them and cause destruction.
The E3 pulse rolls in after the first two pulses have done their damage and causes yet more. This is a slow pulse, lasting potentially minutes after the first two. The E3 pulse mimics a natural solar storm, and can cause the same sorts of effects on infrastructure. What E3 bursts do is induce huge currents in long conductors – things like pipelines, telephone lines, power lines – anything that is a long conductor.
Taking the whole EMP into account, it’s easy to see why it’s so destructive. Within microseconds, the E1 pulse destroys sensitive electronics. Shortly thereafter, the E2 pulse acts like a one-two punch combo to destroy everything that’s left. Finally, the E3 pulse damages non-sensitive electronics, conductors like power transformers, power lines, telephone lines, and all kinds of other long, conducting devices. To say that an EMP is the perfect storm for technology is an understatement.