Sunday, April 19, 2009


Dreams die hard and a recent article from the journal IEEE Spectrum is a showcase for scientists trying to keep their electromagnetic pulse bomb projects alive for the Dept. of Defense.

A week or two ago DD revisited the phenomenon of US electromagnetic pulse crazies in two posts. The second of the two -- here -- dealt with the social crowd plagued with an Ahab-like obsession for deployable electromagnetic pulse bombs (not dependent on a multi-megaton fusion blast) and hand-held rayguns.

They regularly pop up in the news announcing fantastic weapons are about to arrive, or have arrived and been secretly used, or about to be tested. This has been a regular occurrence in the news, if not obvious to everyone, since around 1994 when the EMP lobby boffins began giving it the hard sell.

Readers will note the top listing from the Google link is a reprint of a cover story published in Popular Mechanics in 2001, an article predicting electromagnetic pulse bombs were about to show, possibly capable of throwing civilization back hundreds of years. If they found their way into terrorist hands. One also notes the piece is accompanied with a harsh critique from various punters.

"Electromagnetic pulse weapons capable of frying the electronics in civil airliners can be built using information and components available on the net, warn counterterrorism analysts," read a very recent piece of EMP crazy emission at the New Scientist a couple weeks ago.

"Kabammy! A huge electronic wave comes along and sends out a few thousand volts! [Like] like man-made lightning bolts!" read a couple newspaper articles just before the second war with Iraq.

In every such article, a blizzard of jargon and promises.

For example, from Popular Mechanics: "An FCG is an astoundingly simple weapon. It consists of an explosives-packed tube placed inside a slightly larger copper coil, as shown below. The instant before the chemical explosive is detonated, the coil is energized by a bank of capacitors, creating a magnetic field. The explosive charge detonates from the rear forward. As the tube flares outward it touches the edge of the coil, thereby creating a moving short circuit."

And the article from IEEE Spectrum is not much different. While e-bomb capabilities have been radically scaled back -- there is no mention of American civilization being returned to the time of The Man Who Shot Liberty Valance or rayguns cobbled together by terrorists for the shooting down of airplanes -- they are still alleged to be relatively cheap and simple.

"This week at an arsenal in Huntsville, Ala., defense researchers are testing a new high-power microwave (HPM) bomb—one that creates an electromagnetic pulse capable of disabling electronics, vehicles, guided missiles, and communications while leaving people and structures unharmed," reads the website of the IEEE, dated April 15. "The tests mark the first time such a device has been shrunk to dimensions that could make it portable enough to fit in a missile or carried in a Humvee or unmanned aerial vehicle."

DD is going to go out on a limb here and suggest that if the weapon was tested last week, it was less than overwhelming, as usual. It has not been immediately obvious that the world was changed by an American revolution in weapons design.

The fundamental problem associated with non-nuclear electromagnetic pulse weapons is simple to describe.

And it's never addressed, except through elliptical statements about limits of their "portability" and the ability to predictably "couple" the weapon's electromagnetic effect to a target. The problem is this: dispersion cripples such notional weapons, or as a scientist might say, any effect is constrained by the law of inverse squares. Nature's laws, fortunately for us, aren't subject to whimsical change.

"The intensity of the influence at any given radius r is the source strength divided by the area of the sphere," explains a page at a university physics department. "Being strictly geometric in its origin, the inverse square law applies to diverse phenomena. Point sources of gravitational force, electric field, light, sound or radiation obey the inverse square law. It is a subject of continuing debate with a source such as a skunk on top of a flag pole; will it's smell drop off according to the inverse square law?"

A bit of scientific humor, the latter bit about the skunk.

But there is never any humor associated with stories of electromagnetic pulse bombs. It is always deadly serious stuff.

"It’s a big deal!" said a scientist on the teat of Departmant of Defense electromagnetic pulse spending to IEEE. The EMP bomb is said to have been finally (maybe) shrunk to a size the military might be able to use. "The military would be able to actually use these."

And then there is the jargon-laden discussion about FCG's and vircators, and later, Marx generators.

"The 1.5-meter Texas Tech [EMP bomb] contains three main components: a power generator in the form of a flux compression generator (FCG), a microwave source called a vircator (for virtual cathode oscillator), and an antenna that radiates the resultant high-power microwave radiation," reads the piece.

"The FCG is like a battery that runs on a stick of dynamite," Michael Giesselmann, the weapon's developer at Texas Tech tells the reporter.

And the weapon, they can't resist, is simple and cheap, even though it's still not actually taking part in a real world test.

"The major advantage of an FCG is that it can be relatively cheap," says one expert from England, Bucur Novac, to the publication. "Depending on how big it is, from about US $100 for the 20-centimeter size to a few thousand dollars for the 1-meter size."

"It’s actually one of the simplest [EMP weapons] you can make," adds the bomb's developer.

Another problem associated with electromagnetic pulse bomb production is also easy to relate in common language. And this is why most electromagnetic pulse bomb scientists try to avoid it.

Since the bomb uses an explosive to generate an electromagnetic effect, if the explosive is too large, on the order of a conventional weapons, and the EM effect is trivial, the bomb is not non-lethal. It's just another high explosive bomb with fancy parts. If the explosive component is too small, the notional generation of its electromagnetic effect becomes weaker, requiring the weapon be much closer to its target upon detonation. If, theoretically, a weapon with the explosive power of, say, a stick of dynamite or two or three could generate an electromagnetic effect capable of frying the processor of a computer at ten or twenty feet, would you stand with the computer? Would you even care that such a thing could be demonstrated on a testing range at a US military installation?

Another way of looking at it is in the effect of a lightning bolt, another form of suddenly generated electromagnetic flux. If a lightning bolt hits your computer while you're sitting at it, it's a goner. And perhaps you are, too. But lightning bolts are not particularly cost effective weapons.

Readers see where DD is going. A megaton nuclear explosion creates a significant electromagnetic pulse. But it's rather secondary to the ... well, heh-heh, you know.

Near the end of the electromagnetic pulse bomb story, the EMP raygun system is also mentioned as a possibility. It could be used to stop cars, for instance.

"It requires a big truck to even bring the unassembled parts to the test army," says an Army overseer, a man with an unusually pragmatic air. This particular device "is not a consideration" for anything, ever.

Why the print space, then?

Well, consider that any theoretical electromagnetic pulse bombs are weapons which no longer have much use. Who would the US military sic them on? Somali pirates? The Taliban in Afghanistan? People living in buildings in Swat, Pakistan? Insurgents or rabble and crowds around the globe? Invading Martians?

In fact, the electromagnetic pulse bomb is not congruent with new defense priorities as recently discussed by Secretary of Defense Bob Gates.

And here one can speculate that this is exactly why an article about a test has been published in IEEE Spectrum. It is -- perhaps -- needed to show progress, to signal the existence of something in a program which has been funded for a very long time, one which has produced little but which might be coming to the end of its natural life. In another way of speaking, a press release by weapons developers afraid they may run short of DoD welfare.


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