EMFC Explosive Magnetic Flux Compressor FCG Flux Compression Generator EMP Directed Energy Weapons Active Duty Military Army Navy Air

EMFC Explosive Magnetic Flux Compressor FCG Flux Compression Generator EMP Directed Energy Weapons Active Duty Military Army Navy Air Force Marines Coast Guard Reserves Veterans

Magnetic Flux Compression Generators (Magnetocumulative Generators, MCGs) were independently invented by A. Sakharov in Russia and C.M. Fowler in the United States. They are the most powerful Pulsed Power devices ever built. Till the end of the Cold War, the applications of this technology were classified. Today it is possible to give international lectures on these devices and some of their applications.

The EMP Page The "E" Bomb

Flux Compression Generator

C.M. Fowler, Los Alamos National Laboratories, USA
L. Altgilbers, U.S. Army Space and Missile Defense Command, USA
I. Smith, University of Loughborough, UK

A Flux Compression Generator (FCG) is basically a Directed ElectroMagnetic Pulse (DEMP) gun. There are a number of uses for this technology but most of them are warefare related.

(from a Popular Mechanics article)

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.

Now for a bit of background:

The ElectroMagnetic Pulse (EMP) effect was first observed during the early testing of high altitude airburst nuclear weapons. The effect is characterised by the production of a very short but intense electromagnetic pulse, which propagates away from its source with diminishing intensity. The ElectroMagnetic Pulse is in effect an electromagnetic shock wave.

Computer equipment is very vulnerable to EMP effects, as it is largely built up of high density Metal Oxide Semiconductor devices, these devices are very sensitive to high voltages. Very little energy is actually required to permanently destroy them. Voltage in excess of ten Volts can effectively destroy the device. If the pulse is not powerful enough to produce any immidiate damage, the power supply in the equipment will readily supply enough additional energy to complete the job. With the constant miniaturisation of semiconductor devices the EMP danger increases.

Shielding the electronics only provides limited protection, as any cables running in and out of the equipment will behave very much like an antenna, in effect guiding the high voltage into the equipment.

One of the offshoots of this research was the Flux Compression Generator, which is essentially a very simple weapon.

It consists of a metal tube packed with explosives which is then wrapped with a copper coil. The coil is energised by a bank of capacitors and promptly detonated at the peak of the magnetic field.

Once detonation occurs the metal tube flares outward causing the coil to short circuit along its length, this propagating short circuit has the effect of compressing the magnetic field while reducing the inductance of the coil.

This will produce an rapidly increasing current pulse, which breaks before the final disintegration of the device.

The effects of EMP can be prevented/reduced by using a Faraday Cage. There are currently a few known weaknesses in this method.

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, which occurs around 15 minutes after the detonation; the EMP that surged through electrical systems creates localised magnetic fields. When these magnetic fields break down, they can cause electric surges to travel back through the power and telecommunication systems, this effect is a known concern.

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.

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).

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 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.

THE U.L HAS ALREADY used the CBU-94a munitions dispenser dropped from dive-bombing F- I 17s-that dispensed submunitions which drifted to the ground on parachutes and on the way ejected rolls of high-conductivity carbon-graphite wire that short-circuited transformer yards and electric grids at power plants. The attacks temporarily cut off electrical power to large parts of Yugoslavia (AW&ST May 10, p. 34). Last week, the tactics became more harsh as the U.S. began using conventional high-explosive weapons to destroy the production of electricity and cut off power for a much longer time.

A former director of non-lethal weapons development at Los Alamos, retired Army Col. John Alexander, has just written Future War, a book that includes accounts of how both the HPMs or electromagnetic pulse weapons (EMPs), and carbon-graphite fiber or ribbon bombs, could be used.

While the effects of the carbon-graphite ribbon attacks are now well-documented from raids on Baghdad in 1991 and on Belgrade earlier this year, the HPM weapon is less well known. He describes a fictional raid on Libya. Buried telephone and fiber-optic links had been destroyed by air attacks and special forces teams that planted explosives on the lines. Certainly land lines and hilltop microwave relay stations in Yugoslavia were destroyed by U.S. bombing. In Alexander's scenario, once the foe was reliant on wireless radio communications, the electric-pulse weapon was used to complete the isolation of commanders from troops in the field.

"Cruise missiles with EMP warheads were flown adjacent to the target and detonated, frying the sensitive internal electronics," Alexander wrote. "What little radio communications remained were effectively jammed with conventional electronic warfare equipment."

Explosive Pulsed-Power Developments and Modeling

C. M. Fortgang (LANSCE Division)

LANSCE is advancing the technology of explosive pulsed-power by making systems more compact and by optimizing them for more specific applications. Flux-compression generators (FCGs) are the primary explosive pulsed-power sources we use. Over the past two years we have concentrated on three areas of explosively-driven FCGs: replacing the external capacitor bank that provides the initial seed current (and magnetic) flux with permanent magnets, developing and testing high-voltage air-core transformers used to couple electrical loads of various impedance to the FCG, and developing better computer models that help us design and optimize the performance of these devices.

Los Alamos has a more than a 40-year history of developing and using explosively-driven pulsed-power sources and related power-conditioning technology. LANSCE is advancing the technology of explosive pulsed-power by making systems more compact and by optimizing them for more specific applications. The primary explosive pulsed-power sources we use are FCGs, which operate on the principle of magnetic-flux conservation. They work in the following manner.

In an electrical circuit, current generates a magnetic field and thus magnetic flux (proportional to the magnetic-field strength times the cross-sectional area through which the magnetic-field lines cross). A simple example of such a system is a magnetic solenoid. In electrical engineering terms the magnetic flux is given by the product of the circuit inductance and the electrical current. The inductance of a circuit depends solely on its geometry. If magnetic flux is conserved, the current must increase when the system inductance decreases. However, magnetic energy scales proportionately to the inductance times the square of the current, producing a net increase in energy.

Schematic of one important type of FCG, called a helical flux compressor.In an explosively driven FCG, high explosives are used to decrease circuit inductance. Therefore, FCGs are single-shot devices. Their appeal, however, lies in the very high magnetic fields and energy densities they can achieve. The increase in electromagnetic energy actually comes from the high explosive, which is doing work (via chemical energy) on the circuit as it compresses the magnetic flux. Figure 1 is a schematic of one important type of FCG, called a helical flux compressor. Here the magnetic flux that is being compressed lies in the volume between the aluminum tube (or armature) and copper helix (or stator). The armature is filled with explosive and is detonated from one end. As the armature expands in the radially, it forms a cone whose apex travels along the axis, compressing but conserving the flux while the inductance of the circuit element formed by the armature and stator decreases. The current increases exponentially as the generator inductance approaches zero.Cutaway view of a flux compressor.Figure 2 is a cutaway view of a flux compressor. The aluminum tube is detonated at the end extending out and beyond the copper-wire helix. On the other end a transformer enables the generator to work more efficiently into the electrical load.

For the past two years, we have concentrated on three main areas of explosively driven FCGs: replacing the external capacitor bank that provides the initial seed current (and magnetic flux) with permanent magnets; developing and testing high-voltage, air-core transformers used to couple electrical loads of various impedance to the FCG; and developing better computer models that help us design and optimize the performance of these devices.

Permanent-Magnet Seeded Flux Compressors

All flux compressors need a seed source of magnetic flux. Conventionally, this flux has been supplied by capacitor banks discharged into the circuit just before the high explosive is ignited.

This small generator has an energy gain of about 100, yielding an output of energy of several hundred joules. That energy and current then can be fed cascade fashion into a subsequent generator and amplified further.

However, capacitor banks are bulky, not easily transported, and require special high-voltage switches that need maintenance and are sometimes unreliable. We are working on designs that eliminate the capacitors and switches by using permanent magnets to supply the seed magnetic flux. The permanent magnets are arranged around the outside of a small flux compressor so as to generate a magnetic field inside, between the aluminum tube and copper helix. Although the initial magnetic energy is only a few joules, a small generator such as the one shown in Figure 3 has an energy gain of about 100, yielding an output energy of several hundred joules. That energy and current then can be fed cascade fashion into a subsequent generator and amplified further. We have tested two such devices and have demonstrated output currents of about 25 kA. We presently are working toward our goal of an energy gain of 100. High-Voltage Pulse Transformers

Magnetic flux compressors are low-impedance sources. That is, they work best at high current (10⁶ amps) and relatively low voltage (10s of kilovolts). Typically, the load is an inductor in the range of 20 to 500 nH. However, there are applications that have higher load impedance that, if directly connected to the flux compressor, would significantly degrade performance. By using a transformer, one can make a high-impedance load appear to the generator as a low-impedance load. When designing high-voltage pulse transformers there is a trade-off between good coupling (which requires a tight spacing between primary and secondary windings) and high-voltage standoff (which requires insulation and thus more spacing between primary and secondary windings). Iron core transformers are not an option due to saturation effects. We have developed and used air-core transformers that have coupling constants of about 0.94 and output voltages of about 300 kV. These transformers are of a coaxial geometry and have 12 turns of several parallel wires in the secondary around a single-turn primary made of aluminum tubing. These transformers perform better than those used in the past. We still are testing these newly designed transformers to find their ultimate voltage limit.

Flux Compressor Modeling

Accurate modeling of flux compressors is difficult. Some three-dimensional (3-D) effects make simple modeling using symmetry inaccurate. The problems of magnetic diffusion and unwanted resistive losses result in magnetic flux being only approximately conserved. In addition, there are usually stray inductance and resistance that should be accounted for and included in a model. The problem usually is solved by coupling two systems of equations. One system calculates how the circuit inductance and resistance are changing in time; it entails keeping track of the changing geometry and its inductance, the diffusion of magnetic flux, and heating and resistance of the current-carrying conductors. At each time step, these results are fed into a circuit equation solver, which then calculates the new currents and voltages. This is a work in progress but we already have improved our modeling of the 3-D aspects of the helix by including the pitch effect. Also, the azimuthal currents induced on the armature as it expands are now self-consistently calculated. We are working on including the effects of magnetic diffusion and resistive heating of the copper wires. Figure 4 compares our most recent computer modeling and an actual flux compressor.

Alexander believes the concept, comparable to a lightning bolt strike in the vicinity of computers or other electronic equipment, is feasible as a result of his own work at Los Alamos. The very intense pulse of electromagnetic power can get into the electronic equipment by two paths-front door and back door coupling, he said. The front doors are antennas or other paths open to the outside and lead directly to the targeted equipment. If the frequency of a target is known, the pulse can be tailored to create an even higher level of damage. Back door coupling results from a standing wave of energy that may come indirectly into the equipment through wiring, power cables, poorly shielded frames, telephone lines or even holes in the black boxes.

Two problems are associated with protecting electrical devices from EMP and HPM. The process, called electronic hardening, is too expensive to do extensively. There also appears to be different electronic characteristics for EMP and HPM pulses. As a result, traps for one don't always work for the other.

It is thought that Air Force research on an HPM weapon concentrated on conventional explosives wrapped around a coil with an active electrical field. Once detonated, the explosives squeezed the field to produce the electronic pulse. This device is called an explosively pumped flux-compression generator. Researchers at Los Alamos increased peak power output of such devices to tens of terrawatts, Alexander said.

Meanwhile, the development of precision-guided weapons would allow planners to pinpoint targets so small the limited area covered by the burst of power would be little problem. If the weapon explodes virtually over the target, the power requirements to damage it are lower, therefore the amount of explosives and the size of the weapon required is reduced, he said.

By: IZAKOVIC

UPDATED 11-09-00

ABSTRACT

The efficient attack against modern industrial opponent will require the use of electromagnetic pulse weapons capable of disrupting electronic monitoring, communications, control and information systems in limited area, leaving other structured intact and without radioactive contamination.

The Electromagnetic Pulse (EMP) effect was first observed in 1962 when a 1.4 megaton nuclear weapon was detonated in Test Shot Starfish. The Starfish shot was conducted 400 kilometers high above the mid-Pacific and the electromagnetic pulse from it destroyed satellite equipment and blocked high frequency radio communications across the Pacific for 30 minutes.

The effect itself is characterized by the production of a very short and intense shock wave, producing a powerful electromagnetic field whose intensity rapidly decreases with the distance from the pulse source. This field can be made sufficiently strong to produce short-lived transient voltages of thousands of Volts in exposed electrical wires, or conductive tracks on printed circuit boards, therefore causing irreversible damage to a wide range of electrical and electronic devices, particularly telecommunications equipment, computers, radio and/ or radar receivers.

As modern military platforms are dependent on densely packed electronic equipment, an EMP device can render them unusable in an instant. Shielding of their electronics gives limited results in that any cables running out of the equipment behave like antennae, guiding the high voltage transients into the equipment.

EMP warhead technology and production cost levels are low, making them ideal choice for many national armies. There are indications that, for some time, this weapons are in operative use.

TECHNOLOGY

1. The operation principle behind one of most advanced versions of EMP devices is that which uses chemical explosion to rapidly compress magnetic field, which was initially produced by a start current, transferring much of energy from the explosion into the magnetic field. At this stage its peak power reaches order of tens of TW, equaling that of ten to a thousand typical lightings.

Typical representative of this kind of devices is called explosively pumped Coaxial Flux Compression Generator (FCG), consisting of cylindrical copper tube filled with a fast high energy explosive, surrounded by a helical coil of heavy wire, typically copper, and structural jacket of a non-magnetic material. Start current can be sourced from platform, condenser or FCG cascade, where a small FCG is used to prime a larger one.

Weapons built this way produce most of the power in the frequency band below 1 MHz, making target focusing difficult.

2. The Vircator is high power microwave source (HPM) whose output power may be tightly focused and it has a much better ability to couple energy into many target types.

It is mechanically simple, small and robust device, capable of producing a very powerful single pulse of radiation, which is, at the moment, ranging from 170 kW to 40 GW, over frequencies spanning the decimetric and centimetric bands.

Main difference between the FCG and HPM weapons is that latter, owing to its frequency range, has ability to directly couple into equipment through ventilation holes, gaps between panels and poorly shielded interfaces, forming a spatial standing wave patterns within the equipment exposing it to potentially high electromagnetic fields.

KNOWN US DEPLOYMENTS

1. In 1993. it was reported that an electromagnetic warhead, presumably of Vircator type, was fitted to the USAF AGM-86 Air Launched Cruise Missile airframe.

More on AGM-86 at http://www.fas.org/nuke/guide/usa/bomber/alcm.htm

AGM-154 JSOW (Joint Stand Off Weapon) glide bomb. 2. The Journal of Electronic Defense reported in 1996 USAF Phillips Laboratory at Kirtland awarding a $6.6M HPM SEAD weapon technology demonstration program contract to Hughes Missile Systems Co. It is believed that the devices produced by these program were to become the first operationally fielded HPM electromagnetic bombs for delivery by combat aircraft.

3. During an unclassified briefing in 1995, McDonnell Douglas Corporation released that B-2 bomber shall be equipped with Northrop GAM (GPS Aided Munition), GPS (inertially guided) GBU-29/30 JDAM (Joint Direct Attack Munition) and AGM-154 JSOW (Joint Stand Off Weapon) glide bombs.

This weapons have glide range up to 70 km providing necessary stand-off distance necessary to repair the launch platform from the EMP of nuclear or conventional origin.

4. On December 15, 1997 Raytheon TI Systems (formerly precision-guided 2000lb GBU-32 JDAM bomb Texas Instruments Defense Systems & Electronics) announced that its AGM-154A JSOW has been recommended by the Navy for fleet release. In a report released on October 9th, the Navy's Operational Test and Evaluation Force found JSOW to be operationally effective, operationally suitable and recommended it for fleet release.

5. Today it is known that the B-2's main conventional weapon is the precision-guided 2000lb GBU-32 JDAM (right).

PROLIFERATION

Relative simplicity of the FCG and the Vircator suggests that any nation in possession of engineering drawings and specifications for such weapons, could manufacture them. A two stage FCG could be fabricated for a cost as low as $1.000-2.000. Or less.

With Russia and China, a major players in this field, suffering significant economic difficulties, the threat of electromagnetic bomb proliferation is very real.

INDICATIONS FROM RUSSIA

Some time ago, Machine-Building Research and Production Association (MBR&PA) from Moscow (RUSSIA YAKHONT anti-ship missile ), which has equipped all domestic submarines, and most of the surface vessels with anti-ship missiles up to date, entered a new stage in its history, successfully deploying a fourth generation anti-ship missile system designated YAKHONT.

Application of an array of unique design solutions and technology-intensive components and, above all, a supersonic ramjet sustainer motor using liquid propellant, capable of operating in a broad range of speeds up to 2.5 Mach at all altitudes, a noise-adaptive radar homing head, and a powerful onboard computer makes this missile unique. It can be deployed at and launched from submerged submarines, surface ships and land vehicles. It is designed to carry warhead weighting around 200 kg suggesting the use of nuclear or EMP payload only.

There are indications that it was deployed on Kursk submarine (click to separate article) short time prior to its sinking.

More details regarding EMP weapons technology can be found in the article by renown military analyst, Mr. Carlo Crop at http://www.cs.monash.edu.au/~carlo

Not by Nukes
April 1, 2002
By bkl

The possibility that the Homeland Security force empowered by "22-Caliber George" might inadvertently "allow" a nuke to slip through and send a quarter of a million Americans to meet that Great Supreme Court Judge In The Sky is low. Possible, I admit, but low.

According to the press, any ten-year-old with a modem and a five-minute attention span can download plans to make an atomic bomb out of old TV parts and enriched uranium available on EBay ("Divorce Final, Must Sell") . But it's not quite true. Although fission bombs are simple to build in theory, a weapons-of-mass-destruction hobbyist would need two identical bombs -- one for a test, and one for the Real Thing. It's not just a matter of building an off-the-shelf uranium gun with a pipe, some C-4 and an electric egg timer. It might work, and it might not. And a successful test would draw attention from a hundred nuclear explosion sensors in place around the world and in orbit.

Far easier to build, build in big numbers, and build discreetly, are EMP bombs. They aren't very good at bombing, but they're extremely good at generating EMPs. "EMP" is the acronym for "Electro-Magnetic Pulse", like the electrical surge that a nuclear explosion generates during the first 500 nanoseconds after its detonation. One kind of low-tech EMP bomb, a Flux Compression Generator (or FCG), could be built for well under $1000; the Popular Mechanics article cited below quotes $400. Although the actual explosion itself might be piddling, no semiconductor would survive in the area affected by the EMP, except one in a well-designed Faraday Cage. For a good introduction, visit this website.

Here's few paragraphs from a more technical article by Carlo Kopp that describes several approaches to EMP warfare:

9. The Proliferation of Electromagnetic Bombs

At the time of writing, the United States and the CIS (Commonwealth of Independent States, the Yeltsin-era name for what had been called the USSR --bkl) are the only two nations with the established technology base and the depth of specific experience to design weapons based upon this technology. However, the relative simplicity of the FCG and the Vircator (Virtual Cathode-Ray Tube generator --bkl) suggests that any nation with even a 1940s technology base, once in possession of engineering drawings and specifications for such weapons, could manufacture them.

As an example, the fabrication of an effective FCG can be accomplished with basic electrical materials, common plastic explosives such as C-4 or Semtex, and readily available machine tools such as lathes and suitable mandrels for forming coils. Disregarding the overheads of design, which do not apply in this context, a two stage FCG could be fabricated for a cost as low as $1,000-2,000, at Western labour rates (REINOVSKY85). This cost could be even lower in a Third World or newly industrialised economy.

While the relative simplicity and thus low cost of such weapons can be considered of benefit to First World nations intending to build viable war stocks or maintain production in wartime, the possibility of less developed nations mass producing such weapons is alarming. The dependence of modern economies upon their information technology infrastructure makes them highly vulnerable to attack with such weapons, providing that these can be delivered to their targets.

Of major concern is the vulnerability resulting from increasing use of communications and data communications schemes based upon copper cable media. If the copper medium were to be replaced en masse with optical fibre in order to achieve higher bandwidths, the communications infrastructure would become significantly more robust against electromagnetic attack as a result. However, the current trend is to exploit existing distribution media such as cable TV and telephone wiring to provide multiple Megabit/s data distribution (eg cable modems, ADSL/HDSL/VDSL) to premises. Moreover, the gradual replacement of coaxial Ethernet networking with 10-Base-T twisted pair equipment has further increased the vulnerability of wiring systems inside buildings. It is not unreasonable to assume that the data and services communications infrastructure in the West will remain a "soft" electromagnetic target in the forseeable future.

At this time no counter-proliferation regimes exist. Should treaties be agreed to limit the proliferation of electromagnetic weapons, they would be virtually impossible to enforce given the common availability of suitable materials and tools.

With the former CIS suffering significant economic difficulties, the possibility of CIS designed microwave and pulse power technology leaking out to Third World nations or terrorist organisations should not be discounted. The threat of electromagnetic bomb proliferation is very real.

(From http://www.airpower.maxwell.af.mil/airchronicles/kopp/apjemp.html)

EMP bombs are frightening because they are cheap, low-tech, and would create a "blackout" zone of 500-2000 meters' radius. If you are in that zone, say goodbye to not only electrical power, radios, TV and most of your appliances, but all the data on your hard drive, floppy disks, cassette and VCR tapes and custom-recorded CDs.

Want more? God help anyone in a hospital dependent on even fairly low-tech medical devices. For instance, intravenous solution drip controllers contain some complex microprocessor circuitry. And most people with pacemakers would simply die of immediate cardiac arrest -- the rest might have a period of fatal arrhythmia.

Are you paying attention, Mr. Cheney?

Twenty flux-compression EMP bombs detonated within NYC would cause little or no explosive damage; however, Manhattan Island would be dark and silent for weeks, maybe months, and the damage to electronic devices would total in the tens of billions of dollars. Secondary losses would be at least as great, with a many people dependent on electronic technology simply dying. An EMP attack in midwinter during a cold snap would condemn hundreds of infants, the poor, the elderly, and the infirm to death from hypothermia.

A huge chunk of the world economy, stored inside electromagnetic and semiconductor devices in New York City, would simply evaporate. The total loss to the economy would be far more extreme than the destruction of the World Trade Center, which also involved the loss of financial data (not to mention approximately 3000 human lives).

Even a single EMP bomb detonation in a car parked outside a major broadcast studio would do major damage. The car would be totaled, and the studio would be off-the-air. A detonation near a military base would take the base out in one stroke, as well as cause an immediate "red alert" in the Department of Defense.

Nearly none of the devices killed by the pulse would be repairable. So whatever "evil-doer" uses EMP for warfare or terrorism, the effect on our lives would be quick, deep, and painful.

If you want to read up on this, type the keywords "EMP Bomb" into your favorite search engine, and you will find hundreds of articles, most of which are either written for the lay audience, or are easily understandable to a scientifically-literate reader. Add the search term "FCG" to focus on articles about Flux Compression generators.

Can the Ordinary Joe take "countermeasures" against EMP bombs? Yes, some. You can get an old tube-powered AM/FM that can run for a while on batteries -- thousands were built in the middle 1960s and can be found in thrift shops. Most cars built before the introduction of electronic ignition and on-board computers would still work. Ambitious technology fans could build a tight Faraday Cage, preferably underground (maybe in that Fallout Shelter your Dad -- or Granddad -- built in 1955!) and store an extra computer system or two, along with radios, cell phones, FRS walkie-talkies, scanners, and other high-tech doo-dads.

Those who are amused by such things should note that a Faraday Cage for one's electronic "toys" is the ultimate "Tinfoil Hat"!

With or without a Faraday Cage "chip cellar", the late Douglas Adams' advice is well worth taking: Don't Panic. And that's good advice in any situation.

EXPLOSIVE POWER GENERATORS

The following information was converted from Fire, Fusion, & Steel 1st edition using the 07 DEC 1994 errata.

EXPLOSIVE POWER GENERATION
Also known as an Explosive Magnetic Flux Compressor (EMFC) or Flux Compression Generator (FCG), this technology uses the detonation of an explosive to generate power. It's primary use is to generate an large pulse of current to be employed in directed energy weapons.

TL	Type	Weight	Volume	Cost	Density
9/9	Chemical Explosive Cartridge (CXC)	.0088	.000027	$1	250J/g
10/9	Chemical Plasma Cartridge (CPC)	.00528	.0000162	$5	417J/g
12/10	Pulse Plasma Cartridge (PPC)	.00264	.0000081	$10	833J/g
14/11	Pulse Fusion Cartridge (PFC)	.00176	.0000054	$25	1250J/g
16/13	Gravitic Compression Fusion (GCF)	.00088	.0000027	$50	2500J/g

TL: Tech Level. The first number is the Traveller Tech Level (TTL) of introduction. The second number is the GURPS Tech Level (GTL) of introduction.
Weight: Multiply the energy output of the EPG generator (in kJ) to find the weight (lbs.).
Volume: Multiply the volume given by the EPG output (in kJ) to find the volume.
Cost: Multiply the cartridges weight by this value to get the actual cost.
Density: The energy density of the technology. Measured in Joules per gram.
Dimensions: The physical dimensions of the cartridge are:
Radius(R): .376 x (Volume/27)^(1/3) Volume in cubic feet. Radius in meters.
Diameter: 2 x R
Length: 6 x R

For example, an 12MJ output TL10 EPG cartridge would be 31.68lbs (rounded to 32 lbs), .0972 cf (rounded to .1), and cost $317. It would measure 116 x 348mm.

[NOTE: This compares to 12lbs, .12 cf, and $1200 for an TL8 Explosive Generator from the Vehicles Additions.]

DESIGNING A FEED SYSTEM
EPG cartridges are expended once they are used, and any power that is not immediately transfered or used by other systems is lost. To condition the power and load new cartridges an feed system is required.

To determine the weight and cost of this system design it as a conventional weapon (p. 106, V2ed), using the diameter of the cartridge in place of bore size. Also assume an extremely short barrel and extra low power. The loading mechanism will determine how fast the cartridges can be expended. Single shot devices typically use breechloaders. Double the final cost but apply no other modifiers.

For example, the 12MJ PPC cartridge has a diameter of 116mm. For a slow autoloader this works out to B (116) x B (116) x L (.1) xP (.25) x S (.375) x T (.6) x R (.75) = 56.7675lbs (rounded to 57 lbs). Final cost is $8550. It has a ROF of 1/6.

USES
Using them in RF/EMP weapons seems like the most likely candidate (since its where heavy research is going in real life). I'm unsure how to model this in Vehicles even using the Vehicles Additions files (probably something based on the EMP beam).

Another use is obviously powering beam weapons, that is what they were used for in Traveller and also in real life.