The United States is drawn to EMP technology because it is potentially non-lethal, but is still highly destructive. An E-bomb attack would leave buildings standing and spare lives, but it could destroy a sizeable military.
There is a range of possible attack scenarios. Low-level electromagnetic pulses would temporarily jam electronics systems, more intense pulses would corrupt important computer data and very powerful bursts would completely fry electric and electronic equipment.
In modern warfare, the various levels of attack could accomplish a number of important combat missions without racking up many casualties. For example, an e-bomb could effectively neutralize:
vehicle control systems
targeting systems, on the ground and on missiles and bombs
long and short-range sensor systems.
“We needed to protect our ballistic missiles, B1 bombers, and communications systems for command and control. A decade later I laid out design of how you made an even stronger enhanced EMP weapon. That was almost 50 years ago.”
Coupling of the three EMP components to ground systems
An EMP affects electrical systems by “coupling” to them: in effect, electrical devices, and their attachments (e.g. power cables), simply act like antennas which pick-up the EMP signal. The different types of EMP—E1, E2, and E3—couple in different ways to the various types of electrical systems.[11,12]
The prompt E1 couples well to local antennas, short (1–10 m) cable runs, equipment in buildings (through apertures), and can disrupt or damage integrated circuit (IC)-based control systems, sensors, communication systems, protective systems, computers, and similar devices. The most common protection against the effects of E1 is the use of electromagnetic shielding, filters, and surge arresters .
E2 couples well to longer conductive lines, vertical antenna towers, and aircraft with trailing wire antennas. It is similar to lightning in its time-dependence, but would, of course, be more geographically widespread, while being lower in intensity, especially for a low-yield weapon. As the EMP commission acknowledges, the E2 pulse would not, in general, be an issue for critical infrastructure systems since they already have protective measures for defense against occasional lightning strikes.
The E3 pulse couples well to power and long communications lines including undersea and underground cables. The low frequencies (sub-Hertz) of E3 make shielding and isolation difficult. Experience from both geomagnetic storms and 1960s-era Russian and American nuclear testing indicates that there is a great likelihood of commercial power and landline disruption from E3 pulses of powerful (>100 kt) nuclear devices. Small isolated systems will however, typically, be unaffected by E3. The E3 environment is so slowly varying that quasi-DC analysis models are appropriate for estimating the behavior of the induced power system responses.
Dr. Radsaky and Mr. Kappenman have summarized the effects of E1 and E3 from a large nuclear device in their statement before the House Homeland Security Subcommittee on Emerging Threats, Cybersecurity, and Science and Technology:
For the operation of the electric power grid, the… E1 and E3 pulses are the most important. Research performed for the EMP Commission clearly indicates the following concerns:
1) Malfunctions and damage to solid-state relays in electric substations (E1)
2) Malfunctions and damage to computer controls in power generation facilities, substations, and control centers (E1)
3) Malfunctions and damage to power system communications (E1)
4) Flashover and damage to distribution class insulators (E1)
5) Voltage collapse of the power grid due to transformer saturation (E3)
6) Damage to [High Voltage] HV and [Extremely High Voltage] EHV transformers due to internal heating (E3)