Non-nuclear electromagnetic pulse
(NNEMP) is an electromagnetic pulse generated without use of nuclear weapons. There are a number of devices that can achieve this objective, ranging from a large low-inductance capacitor bank discharged into a single-loop antenna or a microwave generator to an explosively pumped flux compression generator. To achieve the frequency characteristics of the pulse needed for optimal coupling into the target, wave-shaping circuits and/or microwave generators are added between the pulse source and the antenna. A vacuum tube particularly suitable for microwave conversion of high energy pulses is the vircator.
NNEMP generators can be carried as a payload of bombs and cruise missiles, allowing construction of electromagnetic bombs with diminished mechanical, thermal and ionizing radiation effects and without the political consequences of deploying nuclear weapons.
The range of
NNEMP weapons
(non-nuclear electromagnetic bombs) is severely limited compared to nuclear
EMP. This is because nearly all
NNEMP devices used as weapons require chemical explosives as their initial energy source, but nuclear explosives have an energy yield on the order of one million times that of chemical explosives of similar weight. In addition to the large difference in the energy density of the initial energy source, the electromagnetic pulse from
NNEMP weapons must come from within the weapon itself, while nuclear weapons generate
EMP as a secondary effect, often at great distances from the detonation. These facts severely limit the range of
NNEMP weapons as compared to their nuclear counterparts, but allow for more surgical target discrimination. The effect of small e-bombs has proven to be sufficient for certain terrorist or military operations. Examples of such operations include the destruction of certain fragile electronic control systems of the type critical to the operation of many ground vehicles and aircraft.
NNEMP generators also include large structures built to generate
EMP for testing of electronics to determine how well it survives
EMP. In addition, the use of ultra-wideband radars can generate
EMP in areas immediately adjacent to the radar; this phenomenon is only partly understood.
Information about the
EMP simulators used by the United States during the latter part of the Cold War, along with more general information about electromagnetic pulse, are now in papers under the care of the
SUMMA Foundation, which is now hosted at the University of New Mexico.
The
SUMMA Foundation web site includes documentation about the huge wooden Trestle simulator in New Mexico, which was the world's largest EMP simulator. Nearly all of these large
EMP simulators used a specialized version of a Marx generator. The
SUMMA Foundation now has a 44-minute documentary movie on its web site called
"TRESTLE: Landmark of the Cold War".
Many large
EMP simulators were also built in the Soviet Union, as well as in the United Kingdom, France, Germany, The Netherlands, Switzerland and Italy.
Post-Cold War nuclear EMP attack scenarios
Typical modern scenarios seen in large numbers of news accounts and opinion articles speculate about the use of nuclear weapons by rogue states or terrorists in an
EMP attack. Details of such scenarios are always controversial. It is impossible to know what kind of capabilities such terrorists might acquire, especially if they are aided by state sponsors with access to advanced technology.
Some rogue states have developed an ability to deliver a light missile payload to the necessary altitude for an EMP attack. Nuclear weapons in general have a much heavier missile payload, however advanced weapons design enables larger weapon yields with lighter weight. It is difficult to know if any particular rogue state has the necessary combination of advanced missile technology and nuclear weapons technology to perform an effective nuclear
EMP attack over an industrialized country.
A common scenario is the detonation of a device over the middle of the U.S. using long-range missiles that have historically been available only to major military powers. An offshore detonation at high altitude, by contrast, would present less technical difficulty and would disrupt both an entire coast and regions hundreds of miles inland
(e.g. 120 mile altitude, 1,000 mile EMP radius).
The United States military services have developed, and in some cases have published, hypothetical
EMP attack scenarios that are likely to be much more technically accurate than those that appear in the popular press.
http://www.missilethreat.com/archives/id.11/detail.asp
http://www.iec.ch/cgi-bin/procgi.pl/www/iecwww.p?wwwlang=E&wwwprog=cat-det.p&wartnum=020728
http://www.todaysengineer.org/2007/Sep/HEMP.asp