Another temptation for terrorists: homemade EMP weapons

Popular Mechanics ^ | Sept 2001 | Jim Wilson

[Psalm118]

In the blink of an eye, electromagnetic bombs could throw civilization back 200 years.

And terrorists can build them for $400.

BY JIM WILSON

Lead illustration by Edwin Herder

The next Pearl Harbor will not announce itself with a searing flash of nuclear light or with the plaintive wails of those dying of Ebola or its genetically engineered twin. You will hear a sharp crack in the distance. By the time you mistakenly identify this sound as an innocent clap of thunder, the civilized world will have become unhinged.

Fluorescent lights and television sets will glow eerily bright, despite being turned off. The aroma of ozone mixed with smoldering plastic will seep from outlet covers as electric wires arc and telephone lines melt.

Your Palm Pilot and MP3 player will feel warm to the touch, their batteries overloaded. Your computer, and every bit of data on it, will be toast. And then you will notice that the world sounds different too. The background music of civilization, the whirl of internal-combustion engines, will have stopped. Save a few diesels, engines will never start again. You, however, will remain unharmed, as you find yourself thrust backward 200 years, to a time when electricity meant a lightning bolt fracturing the night sky.

This is not a hypothetical, son-of-Y2K scenario. It is a realistic assessment of the damage the Pentagon believes could be inflicted by a new generation of weapons--

E-bombs.

The first major test of an American electromagnetic bomb is scheduled for next year. Ultimately, the Army hopes to use E-bomb technology to explode artillery shells in midflight. The Navy wants to use the E-bomb's high-power microwave pulses to neutralize antiship missiles. And, the Air Force plans to equip its bombers, strike fighters, cruise missiles and unmanned aerial vehicles with E-bomb capabilities. When fielded, these will be among the most technologically sophisticated weapons the U.S. military establishment has ever built.

There is, however, another part to the E-bomb story, one that military planners are reluctant to discuss. While American versions of these weapons are based on advanced technologies, terrorists could use a less expensive, low-tech approach to create the same destructive power. "Any nation with even a 1940s technology base could make them," says Carlo Kopp, an Australian-based expert on high-tech warfare. "The threat of E-bomb proliferation is very real."

POPULAR MECHANICS estimates a basic weapon could be built for $400.

An Old Idea Made New

The theory behind the E-bomb was proposed in 1925 by physicist Arthur H. Compton--not to build weapons, but to study atoms. Compton demonstrated that firing a stream of highly energetic photons into atoms that have a low atomic number causes them to eject a stream of electrons. Physics students know this phenomenon as the Compton Effect. It became a key tool in unlocking the secrets of the atom.

Ironically, this nuclear research led to an unexpected demonstration of the power of the Compton Effect, and spawned a new type of weapon. In 1958, nuclear weapons designers ignited hydrogen bombs high over the Pacific Ocean.

The detonations created bursts of gamma rays that, upon striking the oxygen and nitrogen in the atmosphere, released a tsunami of electrons that spread for hundreds of miles. Street lights were blown out in Hawaii and radio navigation was disrupted for 18 hours, as far away as Australia. The United States set out to learn how to "harden" electronics against this electromagnetic pulse (EMP) and develop EMP weapons.

America has remained at the forefront of EMP weapons development. Although much of this work is classified, it's believed that current efforts are based on using high-temperature superconductors to create intense magnetic fields. What worries terrorism experts is an idea the United States studied but discarded--the Flux Compression Generator (FCG).

A Poor Man's E-Bomb

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. "The propagating short has the effect of compressing the magnetic field while reducing the inductance of the stator [coil]," says Kopp. "The result is that FCGs will produce a ramping current pulse, which breaks before the final disintegration of the device. Published results suggest ramp times of tens of hundreds of microseconds and peak currents of tens of millions of amps." The pulse that emerges makes a lightning bolt seem like a flashbulb by comparison.

An Air Force spokesman, who describes this effect as similar to a lightning strike, points out that electronics systems can be protected by placing them in metal enclosures called Faraday Cages that divert any impinging electromagnetic energy directly to the ground. Foreign military analysts say this reassuring explanation is incomplete.

The India Connection The Indian military has studied FCG devices in detail because it fears that Pakistan, with which it has ongoing conflicts, might use E-bombs against the city of Bangalore, a sort of Indian Silicon Valley. An Indian Institute for Defense Studies and Analysis study of E-bombs points to two problems that have been largely overlooked by the West. The first is that very-high-frequency pulses, in the microwave range, can worm their way around vents in Faraday Cages. The second concern is known as the "late-time EMP effect," and may be the most worrisome aspect of FCG devices. It occurs in the 15 minutes after detonation. During this period, the EMP that surged through electrical systems creates localized magnetic fields. When these magnetic fields collapse, they cause electric surges to travel through the power and telecommunication infrastructure. This string-of-firecrackers effect means that terrorists would not have to drop their homemade E-bombs directly on the targets they wish to destroy. Heavily guarded sites, such as telephone switching centers and electronic funds-transfer exchanges, could be attacked through their electric and telecommunication connections.

Knock out electric power, computers and telecommunication and you've destroyed the foundation of modern society. In the age of Third World-sponsored terrorism, the E-bomb is the great equalizer.

In the 1980s, the Air Force tested E-bombs that used cruise-missile delivery systems.

To ignite an E-bomb, a starter current energizes the stator coil, creating a magnetic field. The explosion (A) expands the tube, short-circuiting the coil and compressing the magnetic field forward (B). The pulse is emitted (C) at high frequencies that defeat protective devices like Faraday Cages.

ILLUSTRATIONS BY JOHN BATCHELOR

[Psalm118]

We have been warned, I guess...(groooaaaannnn....)

BTW check out the excellent illustrations on the Website.

[Cicero]

Popular Mechanics is now in the business of giving detailed instructions to terrorists in how to build devices to destroy civilization?

Maybe this sort of thing increases their current circulation, but it could be very damaging to future sales if civilization vanishes, no?

[Libertarianize the GOP]

ping

[Pukin Dog]

Pure unadulterated nonsense.

The article fails to mention that the range of these so-called poor-mans EMP weapons is very, very small. That would mean that these devices would have to be deployed WITHIN a facility to do any damage at all. EMP weapons with any decent range are too large and way too sophisticated to be of any use to terrorists.

Our own government used to have to use a nuke to get enough available power for decent EMP ranging.

So, relax.

[palmer]

Hasn't this been debunked? Something about lack of range I think.

[palmer]

Yes, in fact it was debunked in post 4.

[bicycle thug]

This was the only real world weapon that humans in the movie the Matrix had against their machine enemy.

Interesting article. Scary as Hell too.

[hocndoc]

Are there instructions on how to shield electronics?

[Leroy S. Mort]

2 year old article. Could be a bit dated.

[Psalm118]

"The article fails to mention that the range of these so-called poor-mans EMP weapons is very, very small. That would mean that these devices would have to be deployed WITHIN a facility to do any damage at all. EMP weapons with any decent range are too large and way too sophisticated to be of any use to terrorists.

Our own government used to have to use a nuke to get enough available power for decent EMP ranging.

So, relax."

Okay boss, I'm relaxed...

...well...I AM TRYIN!

Now tell me what about going under some transmission line way way out in the boonies and firing one of 'em crackers at the overhead lines?. Still a dud, you say?.

[paulsy]

"Now tell me what about going under some transmission line way way out in the boonies and firing one of 'em crackers at the overhead lines?. Still a dud, you say?."

And didn't the big NE power outage last month start with just a few lines somewhere?

[Pukin Dog]

Yes, still a dud. Too much attenuation on those lines for the surge to travel far.

[NewRomeTacitus]

Wanted:
Tight-focus unidirectional EMP device to disrupt obnoxious neighbors' stereo. Not necessary to destroy circuitry but functional disruption a must. Most parts need to be obtainable at retail outlets.

[Lokibob]

No, it was a series of problems on different lines over a 4 hour period. HMMMMMMMMMM.......

[Abcdefg]

"Maybe this sort of thing increases their current circulation . . ."

Good one!

[Servant of the 9]

The effective radius of the largest proposed non nuclear EMP device is only a few hundred meters. It would take a saturation attack with thousands of weapons at once to take out even one city.

So9

[steplock]

You don't need to take out the entire city!

set one off atop the empire State bldg? wall street area?

One atop the tallest bldg in any city would be enough to cause massive damage and sheer terror.

Mission accomplished on the cheap!

[Willie Green]

Popular Mechanics is now in the business of giving detailed instructions to terrorists in how to build devices to destroy civilization?
2 year old article. Could be a bit dated.

But Popular Science just published a newer article that outlines how this technology can be applied to destroy our economy!

Making Small Change Smaller

The art of shrinking coins using copper coils, magnetic fields and enough energy to power a small city.

PUCKER MONEY
Five thousand joules shrinks most coins to about
half their normal size, surface details vividly intact.
(Photograph by Jeff Sciortino)

by Theodore Gray
Popular Science
October 2003

I remember driving past a fraternity house when I was a teenager and wondering why I could tell instantly that someone was playing the drums live, not on a stereo. Live drums, I realized, have a sharper attack than any electronic reproduction, and the distinction is obvious to the drums in our ears. But shouldn't it be possible to hit a speaker cone with a magnetic field just as hard as you can hit a drum with a stick?

It turns out it is, but frat boys simply don't have the technology. Engineers, on the other hand, can potentially go way beyond annoying the neighbors should they choose to get involved in the sport of hitting things really hard with magnetic fields. Take, for example, my friend Bert Hickman, a retired electrical engineer living outside Chicago: He rather enjoys using magnetic force to smash coins to roughly half their normal size. (He then sells them on eBay, of course.)

Bert's high-voltage equipment takes up most of his screened-in porch (from the looks of things, his wife drew a line at the sliding door—there's a clear border between tidy suburban house and chaotic suburban lab). Bert begins the coin-shrinking process by wrapping a quarter in copper wire and bolting the leads to copper bus bars, which are connected, by way of a triggered spark gap, to a 600-pound bank of 12,000-volt capacitors. A bulletproof blast shield encloses the coin and coil, and a high-voltage power supply charges up the capacitors. The only thing holding back the several thousand joules of energy stored in the capacitors is the tiny space between the spark gap's two brass discs.

Pressing a switch triggers the spark gap, which releases the entire charge through the coil in 25 millionths of a second. This creates a huge magnetic field, which induces a current and then a magnetic field inside the coin, which in turn pushes back against the field outside. The repulsion force between these two fields crushes the metal, instantly taking a quarter down to the size of a dime. A large amount of energy discharged in a short amount of time usually entails an explosion, and in this case the copper coil is blown apart with a brilliant flash and a satisfying bang. And, yes, the report is sharper than any drum, proving that you really can hit something as hard with magnetic force as you can with a drumstick.

Bert happily takes custom orders by mail (he charges a shrinking fee, though —visit www.teslamania.com for info). "Clad" U.S. coins, such as quarters, work best—they contain a conductive copper core sandwiched between a nickel-copper alloy—but most metal currencies will do the trick. Just don't send him your 1937 three-legged buffalo nickel by mistake.

[Lurker]

But could it destroy, say an obnnoxiously loud 'boom boom' type car stereo as it was passing my house?

Just asking for no reason....honest.

L

[Pukin Dog]

Now that it could do. Worth an investment if you ask me.