Pushpendra


Electromagnetic Bomb

By Pushpendra Singh

INDEX
1.Abstract
2.Introduction of bomb
3.Types of bomb
4.Types of conventional bomb
General-Purpose Bombs,
Fragmentation Bombs
Incendiary Bomb
Chemical and Biological Weapons
Guided Bombs
Terrorist Bombs
5.Fusion Warheads
Free-Fall Bombs
Free-Fall Bomb Ranges
6.Conventional Bombs (Non-Nuclear)
7.NUCLEAR WEAPON
Types of nuclear Weapons
Fission Bomb
Fusion Bombs
8.Advanced nuclear Weapons Designs
Cobalt Bomb
Neutron Bombs
Antimatter Bombs
9.Effects of a Nuclear Explosion
Blast Damage
Thermal Radiation
Ionizing Radiation
Nuclear Fallout
10.E BOMB
History
Introduction
What is an E-Bomb?
Block diagram of E bomb
The Nuclear EMP Threat
The Basic Idea

11.The EMP Effect:
Effect of Radiation on Electronic Device
Effect of radiation on computers
Significance of EMP effect in military




12.The Technology Base for Conventional Electromagnetic Bombs
12.1Explosively Pumped Flux Compression Generators
Specification:
Principle:
Working:
12.2Explosive and Propellant Driven MHD Generators
Principle:
Working:
12.3High Power Microwave Sources
Vircator:
- Specification
- Principle and working
13.The Lethality of Electromagnetic Warheads
14.Coupling Modes
Front Door Coupling
Back Door Coupling
15.Maximizing Electromagnetic Bomb Lethality
Coupling in low frequency bomb
Coupling in microwave bomb
16.Targeting Electromagnetic Bombs
17.Delivery of E Bombs
18.Defence Against Electromagnetic Bombs
19.Various method for defence against electromagnetic bomb
20.Limitations of Electromagnetic Bombs
21.The Proliferation of Electromagnetic Bombs
22.A Doctrine for the Use of Conventional Electromagnetic Bombs
Electronic Combat Operations using Electromagnetic Bomb
Strategic Air Attack Operations using Electromagnetic Bombs
Offensive Counter Air (OCA) Operations using Electromagnetic Bombs
Maritime Air Operations using Electromagnetic Bombs
Battlefield Air Interdiction Operations using Electromagnetic Bombs
Defensive Counter-Air (DCA) and Air Defence Operations using Electromagnetic Warheads
A Strategy of Graduated Response
23.Conclusion
24.Refernces


ACKNOWLEDGEMENT


There is always a sense of gratitude one expresses to others for the helpful and needy services they render. During all the phases of our LRP, We would like to express our gratitude towards all those who have been helpful to us and have assisted us in their own ways to get this report finally written.
We would like to convey our sincere thanks to Dr.P.K.Roy Sc’G’ (Programme director) for giving us this opportunity to undertake a project. We would also like to thank
DR V.A Deshmukh ‘Chairman’, SHRI A.K.Dixit ‘Sc D’ and others for their kind co-operation and knowledge assistance in giving shape to this project. We believe that without their guidance, the successful completion of this project was not possible.
Actually, we are highly obliged to all those people who have assisted us and have paid attention towards our queries and giving possible help in solving them.

ABSTRACT
In our report we described about various types of bomb from ancient to the future like conventional bombs, non-conventional bombs, nuclear bombs and forthcoming electromagnetic bombs. We have focused mainly on electromagnetic bombs and its effects on various fields. High Power Electromagnetic Pulse generation techniques and High Power Microwave technology have matured to the point where practical E-bombs (Electromagnetic bombs) are becoming technically feasible, with new applications in both Strategic and Tactical Information Warfare. The development of conventional E-bomb devices allows their use in non-nuclear confrontations. We have discusses aspects of the technology base, weapon delivery techniques and proposes a doctrinal foundation for the use of such devices in warhead and bomb applications.









Introduction to Bomb
Bomb, device containing explosives, chemicals, or other materials, designed to be detonated in the region of a target so as to kill people or cause damage by blast, heat, shrapnel, or other effects. Bombs are the most destructive weapons so far devised. They are an essential component of warfare as well as being used increasingly by terrorists.
Bombs are delivered by specially equipped aircraft against enemy troops, tanks, fortifications, industrial plants, or cities. A bomb discharged against a submarine is called a depth charge. Bombs can be dropped from high altitudes, released from an aircraft approaching the target at low altitude, or lofted at the target. Before the advent of air warfare, shells fired by artillery pieces were designated bombs but are now known as projectiles. The term “bomb” is also applied to small, relatively simple explosive devices planted or aimed manually, such as those used by terrorists. When carried on a missile, a bomb is known as a warhead.
Types of Bomb
The two basic types of bombs are
· Conventional bomb
· Nuclear bomb
History
Conventional bombing from aircraft began as early as 1911, when Italian aviators attacked Arab forces in Libya during the Italo-Turkish War. Almost 2 million tons of bombs were dropped on Germany by Allied forces during World War II. Nuclear weapons, which were used by the United States against the Japanese cities of Hiroshima and Nagasaki in World War II, are far more destructive and energy are based on the principles of atomic fission and fusion. Conventional bombs are made of chemical explosives, which depend on the release of from the atom's electrons, while nuclear bombs release vast amounts of nuclear energy from atoms of uranium or plutonium.
II


Conventional Bombs
Conventional bombs, comprising high explosive, incendiary, and chemical or biological types, generally have cylindrical metal bodies filled with explosives or chemicals. They range in weight from about 2 kg (4.4 lb) up to about 1,360 kg (3,000 lb), depending on type and intended use. The nose is pointed or rounded, with fins at the rear to stabilize flight and retardation panels to slow down the bomb's fall. Bombs are detonated by various types of fuses that become armed, that is, activated to explode, only after release from the aircraft. The fuses are commonly designed to explode on impact with the target (contact fuse), but they may also be set for aerial explosion over the target (proximity fuse), or for delayed detonation at a predetermined time after impact (time fuse).
Heaviest Conventional Bomb
The heaviest conventional bomb used operationally was the British Royal Air Force’s "Grand Slam", which weighed 9,980 kg (22,000 lb.). The bomb was used against Germany in 1945. A bomb weighing 19,050 kg was tested by the US Air Force in 1949.
Types of Conventional Bombs
General-Purpose Bombs
General-purpose bombs are used against troops and emplacements or on cities. They usually contain the high explosive TNT (trinitrotoluene), sometimes combined with other explosives such as cyclonite (RDX) and ammonium nitrate. Among the destructive effects that wreak devastation are the blast wave of air pressure immediately following the explosion, which blows down buildings and other structures and smashes windows; fragmentation of pieces of the bomb, which fly at high speed into people and buildings; and shock waves through the area of land or sea where the bomb has exploded. These effects are also applicable to nuclear bombs, which have an additional effect (radiation). Some of the largest general-purpose bombs weighing over 6,000 kg were used by the US Army during the Vietnam War to defoliate vast areas.
Fragmentation Bombs
Fragmentation bombs explode and distribute metal splinters, and are used against troop concentrations. Cluster bombs dropped from aircraft scatter dozens of small “bomblets” over a target area, some exploding on contact and others only when disturbed later by people or vehicles, killing by fragmentation. Armour-piercing bombs, equipped with a hard steel nose, which penetrates and destroys warships, are among special-purpose or delayed-action bombs for use against tanks, ships, and buildings.
Incendiary Bombs
Incendiary bombs, or firebombs, much used in World War II, are designed to ignite flammable structures and contain petrol compounds. Small bombs can be dropped by the hundreds to start fire storms. Another type of incendiary device, the napalm bomb, is used against dug-in enemy forces. Spreading an explosive of jellied petrol, it not only causes severe burns but consumes the oxygen in any closed space. Fuel-air bombs, which were also used in the Vietnam War to burn large areas of jungle and blow up buried mines, spread an igniting cloud of explosive fuel.
Chemical and Biological Weapons
The other two types of conventional bombs, chemical (gas) and biological weapons, depend on the dispersal of the contents of a delivery canister rather than on the direct effects of an explosive. Bombs can also be used to deliver incapacitating, toxic, or nerve gases against enemy concentrations to decrease their resistance to attack, or to destroy them. Non-lethal gases cause mental confusion and also reduce the effectiveness of enemy forces by making necessary the deployment of other personnel to provide assistance to those incapacitated. Biological weapons also incapacitate or kill, but their effects may be more widespread and of longer duration.
Guided Bombs
In the early 1970s new types of conventional bombs, the so-called guided or “smart” bombs were developed for precision bombing in the Vietnam war and more recently were observed in the bombing of Iraqi targets during the gulf war. Maneuverable bombs guided by a laser beam directed from the aircraft and reflected from the target can destroy such targets as tanks or troop emplacements on contact. Other types can be designed to guide themselves to targets radiating heat—such as power plants—or can be guided to the target from the delivery aircraft. In the latter case a television camera on board the bomb transmits a picture of the target. Remote operating devices can then guide the bomb into direct contact with a bridge, for example, or other objective. Laser-guided bombs can be used at night; television camera-guided weapons are, however, limited to daylight use.
These smart bombs have steering fins and a small rocket motor in addition to advanced targeting systems. With the rocket motor, they are even able to pursue a moving target. However, they are limited to a range of an extra one-half mile (0.8km) in addition to the normal drop altitude range. These bombs will automatically hit a large stationary target like a building or bridge or blanket a specific area. They have a +6 to strike a moving target. Volleys can all strike the same target or they can each veer away to hit a different target. Remember that bombs do NOT benefit from the strike bonuses of the pilot. Smart bombs cost an extra 30,000 credits (i.e. add 30,000 to the price).
Terrorist Bombs
Although many bombs used by terrorists are small enough to be planted manually, the car bomb, used particularly by the IRA and other paramilitary groups, became a preferred weapon in the 1970s, reaching a peak of destruction in July 1974 when more than 20 car bombs exploded in one day in Belfast. Technological advances have resulted in both greater destructiveness and compactness of bombs used by terrorist groups. One of the most devastating terrorist bomb attacks was the bombing of the World Trade Center in New York in 1993which killed six people and caused an estimated US$600 million in damage. The IRA, regarded as the world's most experienced terrorist bombers, have used bombs ranging from small hand-held incendiary devices to lorry bombs weighing hundreds of pounds, such as the 230 kg (500 lb) bomb exploded at Canary Wharf, London, in 1996. Using mainly gelignite, fertilizer derivatives and, in recent years, Semtex high explosive—which requires relatively small amounts to do maximum damage—IRA bomb-makers have employed sophisticated timing devices based on those used in video recorders, allowing bombs to be placed, such as the one which blew up the Grand Hotel in Brighton in October 1984, several weeks before detonation. Mortar bombs, such as the one used in the IRA attack on Downing Street, London, in February 1991, are constructed from steel pipes and fired from industrial tubing, concealed within ordinary vehicles. Hamas, the Palestinian Islamic insurrectionary group, has on many occasions used the suicide bomb attack—such as the one in central Tel Aviv on October 19, 1994, which killed 23 people. The rebel Liberation Tigers of Tamil Eelam (LTTE), a group seeking to create a separate nation for the Tamil minority in the northern and eastern parts of Sri Lanka, has also often used this tactic, as when President Premadasa was assassinated by a suicide bomber in 1991.
Fusion Warheads
Fusion warheads are non-nuclear explosives that are much more powerful than other warheads of comparable size. Generally, only nuclear weapons are more powerful for their size. Fusion warhead technology is quite advanced, therefore only the most high-tech nations and city-states (such as CS, NGR, Republic of Japan) will possess these. These weapons do not emit deadly radiation, an EMP, or any of the other side effects normally associated with nuclear weapons.
Free-Fall Bombs
Unlike smart bombs, free-fall bombs cannot deviate to strike moving or alternate targets. Free-fall bombs do however, possess crude steering fins which can be used to steer the bomb toward the target.. Because free-fall bombs do not need to devote space to rockets or guidance systems, they can carry a slightly larger payload (increase damage and blast radius by 15%).
Free-Fall Bomb Ranges
The horizontal range of a free-fall bomb depends upon the altitude from which it was dropped. The higher the altitude, the longer the possible horizontal travel of the bomb.
Drop Altitude
Maximum Horizontal Range
0-1000ft (0-305m)
100ft (30.3m)
1001-4000ft (306-1219m)
2500ft (762m)
4001-10 000ft (1220-3048m)
5500ft (1676m)
10 001-20 000ft (3049-6096m)
10 500ft (1.99 miles/3.2km)
20 001-30 000ft (6097-9144m)
16 500ft (3.13 miles/5.03km)
30 001-40 000ft (9145-12192m)
22 000ft (4.16 miles/6.7km)
40 001-50 000ft (12193-15240m)
28 000ft (5.3 miles/8.5km)
50 000+ft (15241+m)
33 500ft (6.3 miles/10.2km)




Conventional Bombs (Non-Nuclear)
Conventional explosives make up the vast majority of bombs carried by aircraft. There exist a variety of types of bombs and each type usually comes in several sizes.
Other bomb sizes can be carried in varying amounts:
· Light: Two light bombs may be carried per every space.
· Medium: Three medium bombs may be carried per every two spaces.
· Heavy: One heavy bomb may be carried per space.
· X-heavy: Two x-heavy bombs may be carried per every three spaces.
Warhead
Damage
Maximum
Range
Blast Radius
M.D.C.
Price
High Explosive (light)
2D6x10
1/2 mile (0.8km)
30ft (9.1m)
10
7000
High Explosive (medium) *
3D6x10
1/2 mile (0.8km) *
40ft (12.2m)
15
12,000
High Explosive (heavy) *
4D6x10
1/2 mile (0.8km) *
50ft (15.2m)
25
20,000
High Explosive (x-heavy) *
5D6x10
1/2 mile (0.8km) *
60ft (18.2m)
35
30,000
Fragmentation (light)

1/2 mile (0.8km)
80ft (24.4m)
10
7500
Fragmentation (medium) *
3D4x10
1/2 mile (0.8km) *
100ft (30.3m)
15
11,000
Fragmentation (heavy) *
4D4x10
1/2 mile (0.8km) *
120ft (36.4m)
25
17,000
Fragmentation (x-heavy) *
4D6x10
1/2 mile (0.8km) *
150ft (45.5m)
35
22,000
Armor Piercing (light)
3D4x10
1/2 mile (0.8km)
5ft (1.5m)
10
15,000
Armor Piercing (medium) *
3D6x10
1/2 mile (0.8km) *
15ft (4.6m)
15
25,000
Armor Piercing (heavy) *
4D6x10
1/2 mile (0.8km) *
25ft (7.6m)
25
40,000
Armor Piercing (x-heavy) *
5D6x10
1/2 mile (0.8km) *
35ft (10.6m)
35
60,000
Plasma/Heat (light)
3D6x10
1/2 mile (0.8km)
15ft (1.5m)
10
20,000
Plasma/Heat (medium) *
4D6x10
1/2 mile (0.8km) *
30ft (9.1m)
15
38,000
Plasma/Heat (heavy) *
5D6x10
1/2 mile (0.8km) *
50ft (15.2m)
25
55,000
Plasma/Heat (x-heavy) *
6D6x10
1/2 mile (0.8km) *
80ft (24.4m)
35
75,000
Fusion (light) *
6D6x10
1/2 mile (0.8km) *
80ft (24.4m)
10
80,000
Fusion (medium) *
1D4x100
1/2 mile (0.8km) *
100ft (30.3m)
15
90,000
Fusion (heavy) *
1D6x100
1/2 mile (0.8km) *
120ft (36.4m)
25
105,000
Fusion (x-heavy) *
2D4x100
1/2 mile (0.8km) *
150ft (45.5m)
35
125,000
Tear Gas (medium) *
None
1/2 mile (0.8km) *
80ft (24.4m)
15
7000
Smoke (medium) *
None
1/2 mile (0.8km) *
80ft (24.4m)
15
7000
Fire Retardent (medium) *
None
1/2 mile (0.8km) *
80ft (24.4m)
15
7000

NUCLEAR WEAPON
A nuclear weapon is a weapon that derives its energy from nuclear reactions and has enormous destructive power even the smallest nuclear weapons are much more powerful than most conventional explosives, while the largest can destroy entire metropolitan regions. Nuclear weapons have been used twice for war, when the United States dropped two such bombs on the Japanese cities of Hiroshima and Nagasaki during World War II. They have been used around 2000 times since then, but only for the nuclear testing undertaken by seven countries (U.S., Soviet Union, France, United Kingdom, China, India, and Pakistan). The declared nuclear powers are, the United States, Russia, the United Kingdom, France, the People's Republic of China, India and Pakistan. In addition, Israel almost certainly has nuclear weapons, though it refuses to publicly state whether it possesses them or not. North Korea has stated publicly that it has a nuclear stockpile. Ukraine may possess a nuclear stockpile due to a clerical error; and Iran is allegedly developing the capacity to produce its own nuclear arsenal. See the list of countries with nuclear weapons for more details. Non-weaponized nuclear explosives have also been proposed for various civilian uses.
Types of nuclear Weapons
Fission Bomb
Fission bombs derive their power from nuclear fission, where heavy nuclei (uranium or plutonium) split into lighter elements when bombarded by neutrons (producing more neutrons which bombard other nuclei, triggering a nuclear chain reaction). These are historically called atom bombs or A-bombs, though this name is not precise due to the fact that chemical reactions release energy from atomic bonds too, and fusion is no less atomic than fission. Despite this possible confusion, the term atom bomb has still been generally accepted to refer specifically to nuclear weapons, and most commonly to pure fission devices. In general, fission bombs are powered by using chemical explosives to compress a sub-critical amount of either uranium-235 or plutonium into a dense, super-critical mass, which is then subjected to a source of neutrons. This begins an uncontrollable nuclear chain reaction, and produces a very large amount of energy. One pound of U-235 can release over 37 million joules of energy. This is 82 terajoules per kilogram (TJ/kg). A typical duration of the chain reaction is 1 µs, so the power is 82 EW/kg (30 µW or 200 MeV/s per atom; related to the duration of one generation of the chain reaction: 3mW/atom, i.e., the power of a chain reaction just at criticality is 3mW in the case of consecutive fissions, one at a time).
Fusion Bombs
Fusion bombs are based on nuclear fusion where light nuclei such as hydrogen and helium combine together into heavier elements and release large amounts of energy. Weapons that have a fusion stage are also referred to as hydrogen bombs or H-bombs because their fusion fuel is often a form of hydrogen, or thermonuclear weapons because fusion reactions require extremely high temperatures for a chain reaction to occur. This latter name can be somewhat confusing, as thermonuclear reactions can take place in nuclear weapons that are not considered "true" fusion bombs (the United States' George test of 1951 was one such device, the Soviet Union's Joe 4 device was another, both of which were fission bombs utilizing some fusion fuel to increase their yield). Generally speaking, hydrogen bombs work by having a "primary" device (a fission bomb) detonate and begin the fusion reactions in the "secondary" device (fusion fuel). A virtually limitless number of large "secondaries" can be chained together (each fusion reaction beginning the next) in this fashion, creating weapons with far larger yields than could be achieved with simple fission alone.

Advanced nuclear Weapons Designs
The most powerful modern weapons include a fissionable outer shell of uranium. The intense fast neutrons from the fusion stage of the weapon will cause natural (that is un enriched) uranium to fission, increasing the yield of the weapon many times.
Cobalt Bomb
The cobalt bomb uses cobalt in the shell, and the fusion neutrons convert the cobalt into cobalt-60, a powerful long-term (5 years) emitter of gamma rays. In general this type of weapon is referred to as a salted bomb and variable fallout effects can be obtained by using different salting isotopes. Gold has been proposed for short-term fallout (days), tantalum and zinc for fallout of intermediate duration (months), and cobalt for long term contamination (years). The primary purpose of this weapon is to create excess radioactive fallout making a large region uninhabitable. No cobalt or other salted bomb has been built or tested publicly.
Neutron Bombs
A final variant of the thermonuclear weapons is the enhanced radiation weapon, or neutron bomb, which is a small thermonuclear weapon in which the burst of neutrons generated by the fusion reaction is intentionally not absorbed inside the weapon, but allowed to escape. The X-ray mirrors and shell of the weapon are made of chromium or nickel so that the neutrons are permitted to escape. This intense burst of high-energy neutrons is a highly destructive mechanism, although the bomb will still produce damaging thermal and shock effects, only with a lower magnitude than a standard thermonuclear weapon. Neutrons are more penetrating than other types of radiation so many shielding materials that work well against gamma rays are less effective against neutrons. They are also more biologically harmful than gamma rays, and this knowledge led some to envision a weapon that would do little physical damage while killing all the people in a certain area (a so-called "landlord bomb"). This appears to be somewhat of an exaggeration, as the bomb would still create at least some significant blast and fire damage. The term "enhanced radiation" refers only to the burst of ionizing radiation released at the moment of detonation, not to any enhancement of residual radiation in fallout (as in the salted bombs discussed above).
Antimatter Bombs
Some of these hypothetical devices would not literally be nuclear weapons because they do not involve the energy derived from altering the nucleus of an atom either by fission or fusion reactions. They also are not dependent upon a chain reaction of neutron emission. But as these would generate much greater blast per weight than do conventional explosives, and would also radiate gamma rays as do nuclear weapons, often they are lumped together with the latter. Antiprotons or antineutrons striking the nuclei of matter atoms could also cause secondary nuclear reactions by annihilating protons or neutrons. There has been some speculation as to the use of antimatter as the source for a weapon of some sort. Antimatter reactions give off more energy even than fusion reactions, and, it is imagined, would produce neither radioactive nuclear fallout nor neutron radiation. Further, unlike nuclear weapons, there would be no minimum size. There have been indications that the U.S. Air Force has pursued research in this direction, but as there are as of yet no technologies for production and storage of antimatter in sufficient quantities, the whole affair is viewed by many with considerable scepticism. See antimatter weapon for more information.
Effects of a Nuclear Explosion
The energy released from a nuclear weapon comes in four primary categories:
Blast—40-60% of total energy
Thermal radiation—30-50% of total energy
Ionizing radiation—5% of total energy
Residual radiation (fallout)—5-10% of total energy


Blast Damage
Much of the destruction caused by a nuclear explosion is due to blast effects. Most buildings, except reinforced or blast-resistant structures, will suffer moderate to severe damage when subjected to moderate overpressures. The blast wind may exceed several hundred kilometers per hour. The range for blast effects increases with the explosive yield of the weapon. Two distinct, simultaneous phenomena are associated with the blast wave in air:
Static overpressure, i.e., the sharp increase in pressure exerted by the shock wave. The overpressure at any given point is directly proportional to the density of the air in the wave.
Dynamic pressures, i.e., drag exerted by the blast winds required to form the blast wave. These winds push, tumble and tear objects.
Most of the material damage caused by a nuclear air burst is caused by a combination of the high static overpressures and the blast winds. The long compression of the blast wave weakens structures, which are then torn apart by the blast winds. The compression, vacuum and drag phases together may last several seconds or longer, and exert forces many times greater than the strongest hurricane.
Thermal Radiation
Nuclear weapons emit large amounts of electromagnetic radiation as visible, infrared, and ultraviolet light. The chief hazards are burns and eye injuries. On clear days, these injuries can occur well beyond blast ranges. The light is so powerful that it can start fires that spread rapidly in the debris left by a blast. The range of thermal effects increases markedly with weapon yield. Since thermal radiation travels in straight lines from the fireball (unless scattered) any opaque object will produce a protective shadow. If fog or haze scatters the light, it will heat things from all directions and shielding will be less effective. When thermal radiation strikes an object, part will be reflected, part transmitted, and the rest absorbed. The fraction that is absorbed depends on the nature and colour of the material. A thin material may transmit a lot. A light colored object may reflect much of the incident radiation and thus escape damage. The absorbed thermal radiation raises the temperature of the surface and results in scorching, charring, and burning of wood, paper, fabrics, etc. If the material is a poor thermal conductor, the heat is confined to the surface of the material. Actual ignition of materials depends on how long the thermal pulse lasts and the thickness and moisture content of the target. Near ground zero where the light is most intense, what can burn, will. Farther away, only the most easily ignited materials will flame. Incendiary effects are compounded by secondary fires started by the blast wave effects such as from upset stoves and furnaces. In Hiroshima, a tremendous fire storm developed within 20 minutes after detonation. A fire storm has gale force winds blowing in towards the center of the fire from all points of the compass. It is not, however, a phenomenon peculiar to nuclear explosions, having been observed frequently in large forest fires and following incendiary raids during World War II.
Ionizing Radiation
About 5% of the energy released in a nuclear air burst is in the form of neutrons, gamma rays, alpha particles, and electrons moving at incredible speeds. The neutrons result almost exclusively from the fission and fusion reactions, while the initial gamma radiation includes that arising from these reactions as well as that resulting from the decay of short-lived fission products. The intensity of initial nuclear radiation decreases rapidly with distance from the point of burst because the radiation spreads over a larger area as it travels away from the explosion. It is also reduced by atmospheric absorption and scattering. The character of the radiation received at a given location also varies with distance from the explosion. Near the point of the explosion, the neutron intensity is greater than the gamma intensity, but with increasing distance the neutron-gamma ratio decreases. Ultimately, the neutron component of initial radiation becomes negligible in comparison with the gamma component. The range for significant levels of initial radiation does not increase markedly with weapon yield and, as a result, the initial radiation becomes less of a hazard with increasing yield. With larger weapons, above 50 kt (200 TJ), blast and thermal effects are so much greater in importance that prompt radiation effects can be ignored. The neutron radiation serves to transmute the surrounding matter, often rendering it radioactive. When added to the dust of radioactive material released by the bomb itself, a large amount of radioactive material is released into the environment. This form of radioactive contamination is known as nuclear fallout and poses the primary risk of exposure to ionizing radiation for a large nuclear weapon.
Nuclear Fallout
The residual radioactive contamination hazard from a nuclear explosion is in the form of radioactive fallout and neutron-induced activity. Residual ionizing radiation arises from:
Fission products. These are intermediate weight isotopes which are formed when a heavy uranium or plutonium nucleus is split in a fission reaction. There are over 300 different fission products that may result from a fission reaction. Many of these are radioactive with widely differing half-lives. Some are very short, i.e., fractions of a second, while a few are long enough that the materials can be a hazard for months or years. Their principal mode of decay is by the emission of beta and gamma radiation. Approximately 60 grams of fission products are formed per kiloton of yield (14 g/TJ). The estimated activity of this quantity of fission products 1 minute after detonation is equal to that of 1.1 × 1021 Bq (30 gigagrams of radium) in equilibrium with its decay products.
Unfissioned nuclear material. Nuclear weapons are relatively inefficient in their use of fissionable material, and much of the uranium and plutonium is dispersed by the explosion without undergoing fission. Such unfissioned nuclear material decays slowly by the emission of alpha particles and is of relatively minor importance.
Neutron-induced activity. If atomic nuclei capture neutrons when exposed to a flux of neutron radiation, they will, as a rule, become radioactive (neutron-induced activity) and then decay by emission of beta and gamma radiation over an extended period. Neutrons emitted, as part of the initial nuclear radiation will cause activation of the weapon residues. In addition, atoms of environmental material, such as soil, air, and water, may be activated, depending on their composition and distance from the burst. For example, a small area around ground zero may become hazardous as a result of exposure of the minerals in the soil to initial neutron radiation. This is due principally to neutron capture by various elements, such as sodium, manganese, aluminum and silicon in the soil. This is a negligible hazard because of the limited area involve.
Yield
The explosive yield of a nuclear weapon is expressed in the equivalent mass of trinitrotoluene (TNT), either in kilotons (thousands of tons of TNT) or megatons (million of tons of TNT). Examples of nuclear weapon yields:
Davy Crockett tactical nuclear weapon: variable yield 0.01-1 kt — mass only 23 kg (51 lb), lightest ever deployed by the United States (same warhead as Special Atomic Demolition Munition)
Hiroshima's "Little Boy": 12-15 kt — gun type uranium-235 fission bomb (the first of the only two nuclear weapons that have ever been used in warfare)
Nagasaki's "Fat Man": 20-22 kt — implosion type plutonium-239 fission bomb (the second of the two nuclear weapons used in warfare)
W-76 warhead 100 kt (10 of these may be in a MIRVed Trident II missile)
B-61 Mod 3 gravity bomb: 4 yield options ("dial-a-yield"): 0.3 kt, 1.5 kt, 60 kt, and 170 kt
W-87 warhead: 300 kt (10 of these are in a MIRVed LG-118A Peacekeeper)
W-88 warhead: 475 kt (8 of these may be in a Trident II missile)
Castle Bravo device: 15 Mt — largest tested by the US
EC17/Mk-17, the EC24/Mk-24, and the B41 (Mk41) (largest nuclear weapons ever built by the United States): 25 Mt — gravity bombs carried by B-36 bomber (retired by 1957)
Tsar Bomba device: 50 Mt — USSR, largest yield explosive device ever, mass of 27 short tons (24 metric tons), in
As a comparison, the Oklahoma City bombing, using a truck-based fertilizer bomb, was a mere 0.002 kt. The "yield per ton", the amount of weapons yield compared to the mass of the weapon, is for current US weapons 600 kt/t (2.5 TJ/kg) to 2.2 Mt/t (9.2 TJ/kg). By comparison, for the Davy Crockett it was 40 kt/t (0.167 TJ/kg) and for the Tsar Bomba it was 2 Mt/t (8 TJ/kg).













ELECTROMAGNETIC BOMB
History
The Electromagnetic Pulse (EMP) effect was first observed during the early testing of high altitude airburst nuclear weapons - a rather radical way of creating an E-bomb The threat of the E-bomb increased in 1994 when Gen. Loborev, Director of the Central Institute of Physics and Technology in Moscow, distributed a landmark paper at the EUROEM Conference in Bordeaux, France. In this paper Dr. A. B. Prishchepenko, the Russian inventor of a family of compact explosive driven RF munitions, described how RF munitions might be used against a variety of targets including communications systems. The concepts "went public" in articles in Russian naval journals and in other professional journals and magazines. On June 17, 1997, the US Joint Economic Committee (JEC) ., in which it heard about a new class of weapons, radio frequency weapons (RF), and the impact of these new weapons on the civilian and military electronic infrastructure of the United States. This was followed up by a further hearing in February 25, 1998. In June 2000, James O’Bryon, deputy director of Live Fire Test & Evaluation at the US Department of Defense flew to a conference in Scotland to address the issue. "What we’re trying to do is look at what people might use if they wanted to do something damaging," he said. The UK magazine, New Scientist published a popularist article on the subject on 1 July 2000.
Introduction
The prosecution of a successful Information Warfare (IW) campaign against an industrialised or post industrial opponent will require a suitable set of tools. As demonstrated in the Desert Storm air campaign, air power has proven to be a most effective means of inhibiting the functions of an opponent's vital information processing infrastructure. This is because air power allows concurrent or parallel engagement of a large number of targets over geographically significant areas .

While Desert Storm demonstrated that the application of air power was the most practical means of crushing an opponent's information processing and transmission nodes, the need to physically destroy these with guided munitions absorbed a substantial proportion of available air assets in the early phase of the air campaign. Indeed, the aircraft capable of delivery laser guided bombs were largely occupied with this very target set during the first nights of the air battle.
The efficient execution of an IW campaign against a modern industrial or post-industrial opponent will require the use of specialised tools designed to destroy information systems. Electromagnetic bombs built for this purpose can provide, where delivered by suitable means, a very effective tool for this purpose.
What is an E-Bomb?
The E-bomb (Electromagnetic bomb) is a very short (hundreds of nanoseconds) but intense electromagnetic pulse (EMP), strongest at its source and weakening with distance. EMP is effectively an electromagnetic shock wave. It produces a powerful electromagnetic field that produce short lived transient voltages of thousands of Volts (kilovolts) on exposed electrical conductors, such as wires, or conductive tracks on printed circuit boards, where exposed. Depending on the electromagnetic "hardness" of the equipment, equipment hit by EMP can be severely damaged or destroyed – silently, discreetly and at low risk. This applies to electrical and electronic equipment, particularly computers and communication devices and radio or radar receivers. Security systems, building management systems and premises surveillance equipment could all be affected. The damage caused by EMP can look almost like the results of a lightning strike. Commercial computer equipment is particularly vulnerable to EMP because key components include high density Metal Oxide Semiconductor (MOS) devices, which are very sensitive to exposure to high voltage transients. Very little energy is required to permanently wound or destroy the MOS devices, any voltage in typically in excess of tens of Volts can produce an effect termed gate breakdown, which effectively destroys the device. Even if the pulse is not powerful enough to produce thermal damage, the power supply in the equipment will readily supply enough energy to complete the destructive process. Wounded devices may still function, but their reliability will be seriously impaired. Shielding electronics by equipment chassis provides only limited protection, as any cables running in and out of the equipment will behave very much like antennae, in effect guiding the high voltage transients into the equipment. Computers used in IT systems, communications systems, displays, industrial control applications, including road and rail signalling, and those embedded in military equipment, including signal processors, electronic flight controls and digital engine control systems, are all potentially vulnerable to EMP. EMP may also destroy other electronic devices and electrical equipment. Telecommunications equipment can be highly vulnerable, because copper cables between devices act as conductors. Receivers of all types are particularly sensitive to EMP, as the highly sensitive miniature high frequency transistors and diodes in such equipment are easily destroyed by exposure to high voltage electrical transients. Therefore radar and electronic warfare equipment, satellite, microwave, UHF, VHF, HF and low band communications equipment and television equipment are all potentially vulnerable to the EMP effect. High Power Electromagnetic Pulse generation techniques and High Power Microwave technology have matured to the point where practical E-bombs are becoming technically feasible, with new applications in warfare: but, more to the point, the technology is simple enough to be applied by almost any competent physicist intent on wreaking damage. The components for an E-bomb are readily available-bombs could be the new terrorism, a source of extortion, or of commercial warfare. Indeed, there is a serious possibility that attacks have started already, but because the weapon leaves no clues it is difficult to prove this.
BLOCK DIAGRAM OF E BOMB USING COAXIAL FCG.
It involves three stages,
Start Current Generator
First stages contain start current generator which contain power supply and coaxial capacitor bank. The initial magnetic field in the FCG prior to explosive initiation is produced by a start current. The start current is supplied by an external source, such a a high voltage capacitor bank (Marx bank), a smaller FCG or an MHD device.

Electromagnetic pulse generator
Second stages contain electromagnetic pulse generator ,its consists coaxial FCG, explosive switch and coaxial load. It generate high power electromagnetic pulses by flux compression generator. Which is sent through antenna to destroy the target.
EMP Radiator
In third stage theoutput(which is high power elecromagnetic pulses) is fed to an antenna, possibly via some wave-shaping electronics; capacitors and inductors. The output pulse is converted directly into a radio pulse which can damage electronics
The Nuclear EMP ThreatE-bombs started popping up in headlines only recently, but the concept of EMP weaponry has been around for a long time. From the 1960s through the 1980s, the United States was most concerned with the possibility of a nuclear EMP attack. This idea dates back to nuclear weapons research from the 1950s. In 1958, American tests of hydrogen bombs yielded some surprising results. A test blast over the Pacific Ocean ended up blowing out streetlights in parts of Hawaii, hundreds of miles away. The blast even disrupted radio equipment as far away as Australia.Researchers concluded that the electrical disturbance was due to the Compton effect, theorized by physicist Arthur Compton in 1925. Compton's assertion was that photons of electromagnetic energy could knock loose electrons from atoms with low atomic numbers. In the 1958 test, researchers concluded, the photons from the blast's intense gamma radiation knocked a large number of electrons free from oxygen and nitrogen atoms in the atmosphere. This flood of electrons interacted with the Earth's magnetic field to create a fluctuating electric current, which induced a powerful magnetic field. The resulting electromagnetic pulse induced intense electrical currents in conductive materials over a wide area.
The Basic IdeaThe basic idea of an e-bomb or more broadly, an electromagnetic pulse (EMP) weapon is pretty simple. These sorts of weapons are designed to overwhelm electrical circuitry with an intense electromagnetic field. The radio signals that transmit AM, FM, television and cell phone calls are all electromagnetic energy, as is ordinary light microwaves and x-raysFor our purposes, the most important thing to understand about electromagnetism is that electric current generates magnetic fields and changing magnetic fields can induce electric current. This page explains that a simple radio transmitter generates a magnetic field by fluctuating electrical current in a circuit. This magnetic field, in turn, can induce an electrical current in another conductor, such as a radio receiver antenna. If the fluctuating electrical signal represents particular information, the receiver can decode it. A low intensity radio transmission only induces sufficient electrical current to pass on a signal to a receiver. But if you greatly increased the intensity of the signal (the magnetic field), it would induce a much larger electrical current. A big enough current would fry the components in the radio, disintegrating it beyond repair.Picking up a new radio would be the least of your concerns, of course. The intense fluctuating magnetic field could induce a massive current in just about any other electrically conductive object for example phone lines, power lines and even metal pipes. These unintentional antennas would pass the current spike on to any other electrical components down the line (say, a network of computers hooked up to phone lines). A big enough surge could burn out semiconductor devices, melt wiring, fry batteries and even explode transformers.The EMP Effect:
The electro magnetic pulse effect was first observed during the early testing of high altitude airburst nuclear weapons. EMP is caused by the rapid release of gamma radiation from the nuclear explosion. The release of these particles at the speed of light will produce regions of positive and negative charges as atmospheric molecules are stripped of their electrons. These charges will propagate through the air at the speed of light and can have significant effects on all electromagnetic signals within line of sight of the nuclear detonation. The electromagnetic pulse is in fact an electromagnetic shock wave. The EMP energy produces such a storm of electromagnetic field that it produces short lived transient voltage of thousands of volts (Kilovolts) on exposed electrical conductors like wire or conductive tracks on printed circuits boards where exposed.
One significant factor in EMP effect is the amount of coverage desired. The area of exposure depends upon the size of the yield. It was also observed that high altitude Electro Magnetic Pulse became the highest concern as the entire electromagnetic spectrum could get affected. It was also found out that high altitude burst could produce large amplitude EMP field over thousands of kilometers. Peak energy fields can reach levels of 50 kilovolts per meter. The peak levels can be reached very quickly and will have large broadband frequency coverage extending from Direct Current to 100 Mhz frequencies.
The covert testing of the weapon in an active field of Yugoslavia has demonstrated that the EMP bomb is round the corner and that the US will not hesitate to use the same in any future conflict considering its negligible collateral damage making capability. The idea would be to immobilize the enemy before destroying him Development of this type of weapon has more or less become a necessity because of the changed environment. Information flow to be strengthened for own side and for the enemy it has to be stopped. This could be the cleanest bomb, a clean match winner. No doubt this is a future requirement.
While carrying out spectrum comparison it was determined that EMP spreads in a waveform. Diagrammatic representation of the same is shown in Fig 1.
This waveform has been broken down into three segments. The first is called early time EMP, and is the most devastating segment of the waveform; maximum levels of energy are produced in a very short time. Because of the intensity of the energy and the speed of the waveform, unprotected circuitry will be damaged or destroyed. On the other hand Late Time will occur at about one second after generation and can last up to 1000 seconds. During late time EMP low levels of energy are induced into the varying magnetic fields in the earth, which results in electrical fields being determined by the earth's surface resistance. This energy can pose a threat to long landlines such as telephone, power and submarine cables.

Effect of Radiation on Electronic Devices
Present generation electronic devices like diodes, transistors, gate arrays and ICs are based on pure silicon slices. Their electrical properties depend upon the regularity and uniformity of the basic silicon crystal lattices. The initial total damage from Neutron radiation is proportional to the neutron influence, but there is a subsequent annealing process during which there is some degree of recovery. This apart, the damage could be permanent. Also it may be made clear here that it makes no difference whether the device is working equipment or kept on the shelf for future use. However, the annealing process will be longer in such cases.
Commercial computer equipment is particularly vulnerable to EMP effects. It is basically built with high-density Metal Oxide Semiconductors (MOS) devices, which are very sensitive to exposure to high voltage transients. MOS can sustain permanent damage with very little energy. Any voltage typically in excess of tens of Volts can produce an effect termed gate breakdown, which effectively destroys the device. Even if the pulse is not powerful enough to produce thermal damage, the power supply in the equipment will readily supply enough energy to complete the destructive process. Wounded devices may still function but their reliability will be seriously impaired. Similarly computers used in data processing systems, communications systems, displays, industrial control applications, including road and rail signaling in the advanced nations and those embedded in military equipment, such as signal processors, electronic flight control and digital engine control system are all potentially vulnerable to EMP effects. Degradation effect on few of the key elements employed in electromagnetic equipments are given below:
· Light Emitting Diodes (LEDs): LED can suffer degradation in optical output by 10 to 20 per cent.
· Photo Diodes and Photo Transistors. These are extremely sensitive to damage by Neutron radiation and Phototransistors may suffer a loss in optical sensitivity.
· Diodes. In case of diodes, there is a permanent increase in the forward voltage drop. This would require provision of additional heat sinking for high power devices.
· Bipolar Transistors. Reduction in current gain and increase in collector emitter saturation voltage. This may point out about a requirement of high power high voltage transistor.
Effect of radiation on computer:
Computers used in data processing systems, communications systems, displays, industrial control applications, including road and rail signalling, and those embedded in military equipment, such as signal processors, electronic flight controls and digital engine control systems, are all potentially vulnerable to the EMP effect.
Telecommunications equipment can be highly vulnerable, due to the presence of lengthy copper cables between devices. Receivers of all varieties are particularly sensitive to EMP, as the highly sensitive miniature high frequency transistors and diodes in such equipment are easily destroyed by exposure to high voltage electrical transients. Therefore radar and electronic warfare equipment, satellite, microwave, UHF, VHF, HF and low band communications equipment and television equipment are all potentially vulnerable to the EMP effect.


Significance of EMP effect in military:
It is this aspect of the EMP effect which is of military significance, as it can result in irreversible damage to a wide range of electrical and electronic equipment, particularly computers and radio or radar receivers. Subject to the electromagnetic hardness of the electronics, a measure of the equipment's resilience to this effect, and the intensity of the field produced by the weapon, the equipment can be irreversibly damaged or in effect electrically destroyed. The damage inflicted is not unlike that experienced through exposure to close proximity lightning strikes, and may require complete replacement of the equipment, or at least substantial portions thereof.
It is significant that modern military platforms are densely packed with electronic equipment, and unless these platforms are well hardened, an EMP device can substantially reduce their function or render them unusable.

The Technology Base for Conventional Electromagnetic Bombs
The technology base which may be applied to the design of electromagnetic bombs is both diverse, and in many areas quite mature.
Key technologies, which could be used in the near future, are discussed here:
· Explosively Pumped Flux Compression Generator (FCG).
· HPM devices based on Virtual Cathode Ray Oscillator or Vircator.
· Propellant driven magneto-hydrodynamic generators.



A. Explosively Pumped Flux Compression Generators
It was in the late fifties that the first demonstration of FCG was carried out at Los Alamos National Laboratory. The explosively pumped FCG is the most mature technology applicable to bomb designs. Since that time a wide range of FCG configurations has been built and tested, both in the US and the USSR.
Specification:
Electrical energy produced: tens of Mega Joules in tens to hundreds of microseconds of time
Peak power level: TeraWatts to tens of Tera Watts.
Current generated: ten to a thousand times greater than that produced by a typical lightning stroke .
Usable frequency band :below 1 Mhz
Explosive used: B and C-type compositions to machined blocks of PBX-9501
Principle: The central idea behind the construction of FCG is that of using a fast explosive to rapidly compress a magnetic field, transferring much energy from the explosive into the magnetic field

working:
A cylindrical copper tube forms the armature of typical coaxial FCG as indicated above. The tube is filled with a high energy explosive. The armature is surrounded by a helical heavy copper coil, which forms the FCG stator. The stator winding can be split into segments with wires bifurcating at the boundaries of the segments. This could optimise the electromagnetic inductance of the armature coil. A structural jacket made of concrete or Fibreglasses hardened with Epoxy can be used to prevent the FCG from disintegrating at an early stage due to intense magnetic force. The weight of the bomb, supply of start current, and matching the FCG to the intended load carrier are the major technical issues of a FCG. In applications where weight is an issue, such as air delivered bombs or missile warheads, a glass or Kevlar Epoxy composite would be a viable candidate.
It is typical that the explosive is initiated when the start current peaks. This is usually accomplished with a explosive lense plane wave generator which produces a uniform plane wave burn (or detonation) front in the explosive. Once initiated, the front propagates through the explosive in the armature, distorting it into a conical shape (typically 12 to 14 degrees of arc). Where the armature has expanded to the full diameter of the stator, it forms a short circuit between the ends of the stator coil, shorting and thus isolating the start current source and trapping the current within the device. The propagating short has the effect of compressing the magnetic field, whilst reducing the inductance of the stator winding. The result is that such generators will producing a ramping current pulse, which peaks before the final disintegration of the device. The current multiplication (ie ratio of output current to start current) achieved varies with designs, but numbers as high as 60 have been demonstrated. In ammunition application, where space and weight are at a premium, the smallest possible start current source is desirable. These applications can exploit cascading of FCG, where a small FCG is used to prime a larger FCG with a start current.
The principal technical issues in adapting the FCG to weapons applications lie in packaging, the supply of start current, and matching the device to the intended load. Interfacing to a load is simplified by the coaxial geometry of coaxial and conical FCG designs. Significantly, this geometry is convenient for weapons applications, where FCGs may be stacked axially with devices such a microwave Vircators. The demands of a load such as a Vircator, in terms of waveform shape and timing, can be satisfied by inserting pulse shaping networks, transformers and explosive high current switches.
Disadvantages of FCG:
Many target sets will be difficult to attack even with very high power levels at high frequencies, moreover focussing the energy output from FCG will be problematic

B.Explosive and Propellant Driven MHD Generators
The design of explosive and propellant driven Magneto-Hydrodynamic generators is a much less mature art that that of FCG design. Technical issues such as the size and weight of magnetic field generating devices required for the operation of MHD generators suggest that MHD devices will play a minor role in the near term.

Principle:
The fundamental principle behind the design of MHD devices is that a conductor moving through a magnetic field will produce an electrical current transverse to the direction of the field and the conductor motion.
Working:
In an explosive or propellant driven MHD device, the conductor is a plasma of ionised explosive or propellant gas, which travels through the magnetic field. Current is collected by electrodes which are in contact with the plasma jet.
The electrical properties of the plasma are optimised by seeding the explosive or propellant with suitable additives, which ionise during the burn . Cartridges of such propellant can be loaded much like artillery rounds, for multiple shot operation.
Best advantage of MHD generators are: their compactness (liquid-metal MHD generators) and the absence of rotary parts. MHD can be used very easily as a compact source of electrical energy and that would be attractive for military applications.
C.High Power Microwave Sources - The Vircator
Various types of HPM devices: Relativistic Klystrons, Magnetrons, Slow Wave Devices, Reflex triodes, Spark Gap Devices and Vircators. From the perspective of a bomb or warhead designer, the device of choice will be at this time the Vircator, or in the nearer term a Spark Gap source.



Vircator:
The Vircator is a one shot device capable of producing a very powerful single pulse of radiation, yet it is mechanically simple, small and robust, and can operate over a relatively broad band of microwave frequencies.
Specification:
Power level achieved: 170 kilowatts to 40 giga watts.
Frequency used: decimentric and centimetic band
Output pulse generation: in order of microsecond
Principle and working
The physics of the Vircator tube are substantially more complex than those of the preceding devices. The fundamental idea behind the Vircator is that of accelerating a high current electron beam against a mesh (or foil) anode. Many electrons will pass through the anode, forming a bubble of space charge behind the anode. Under the proper conditions, this space charge region will oscillate at microwave frequencies. If the space charge region is placed into a resonant cavity which is appropriately tuned, very high peak powers may be achieved. Conventional microwave engineering techniques may then be used to extract microwave power from the resonant cavity. Because the frequency of oscillation is dependent upon the electron beam parameters, Vircators may be tuned or chirped in frequency, where the microwave cavity will support appropriate modes. Power levels achieved in Vircator experiments range from 170 kiloWatts to 40 GigaWatts over frequencies spanning the decimetric and centimetric bands
types of vircator:
· Axial Vircator (AV)
· Transverse Vircator (TV).

The Axial Vircator is the simplest by design, and has generally produced the best power output in experiments. It is typically built into a cylindrical waveguide structure. Power is most often extracted by transitioning the waveguide into a conical horn structure, which functions as an antenna. AVs typically oscillate in Transverse Magnetic (TM) modes. The Transverse Vircator injects cathode current from the side of the cavity and will typically oscillate in a Transverse Electric (TE) mode.
Technical issues in Vircator design are output pulse duration, which is typically of the order of a microsecond and is limited by anode melting, stability of oscillation frequency, often compromised by cavity mode hopping, conversion efficiency and total power output. Coupling power efficiently from the Vircator cavity in modes suitable for a chosen antenna type may also be an issue, given the high power levels involved and thus the potential for electrical breakdown in insulators.
Advantage of vircator.
1. its output power may be tightly fo used
2. it has a much better ability to couple energy into many target types.
The Lethality of Electromagnetic Warheads
The calculation of electromagnetic field strength achievable at a given radius for a given device is not difficult. But determining a kill probability for given targets under such conditions is complex and difficult because target types are very diverse in their design, frequency range and electromagnetic hardness. The second major problem area in determining lethality is that of coupling efficiency, which is a measure of how much power is transferred from the field produced by the weapon into the target. Only power coupled into the target can cause useful damage. Microwave can couple more easily than weapons of lower frequency range. That is why microwave weapons are more lethal.
Coupling Modes
In assessing how power is coupled into targets, two principal coupling modes are recognized in the literature:
Front Door Coupling: occurs typically when power from a electromagnetic weapon is coupled into an antenna associated with radar or communications equipment. The antenna subsystem is designed to couple power in and out of the equipment, and thus provides an efficient path for the power flow from the electromagnetic weapon to enter the equipment and cause damage.
Back Door Coupling :occurs when the electromagnetic field from a weapon produces large transient currents (termed spikes, when produced by a low frequency weapon) or electrical standing waves (when produced by a HPM weapon) on fixed electrical wiring and cables interconnecting equipment, or providing connections to mains power or the telephone network [Equipment connected to exposed cables or wiring will experience either high voltage transient spikes or standing waves which can damage power supplies and communications interfaces if these are not hardened. Moreover, should the transient penetrate into the equipment, damage can be done to other devices inside.
A low frequency weapon will couple well into a typical wiring infrastructure, as most telephone lines, networking cables and power lines follow streets, building risers and corridors. In most instances any particular cable run will comprise multiple linear segments joined at approximately right angles. Whatever the relative orientation of the weapons field, more than one linear segment of the cable run is likely to be oriented such that a good coupling efficiency can be achieved.
It is worth noting at this point the safe operating envelopes of some typical types of semiconductor devices. Manufacturer's guaranteed breakdown voltage ratings for Silicon high frequency bipolar transistors, widely used in communications equipment, typically vary between 15 V and 65 V. Gallium Arsenide Field Effect Transistors are usually rated at about 10V. High density Dynamic Random Access Memories (DRAM), an essential part of any computer, are usually rated to 7 V against earth. Generic CMOS logic is rated between 7 V and 15 V, and microprocessors running off 3.3 V or 5 V power supplies are usually rated very closely to that voltage. Whilst many modern devices are equipped with additional protection circuits at each pin, to sink electrostatic discharges, sustained or repeated application of a high voltage will often defeat these .
Communications interfaces and power supplies must typically meet electrical safety requirements imposed by regulators. Such interfaces are usually protected by isolation transformers with ratings from hundreds of Volts to about 2 to 3 kV.
It is clearly evident that once the defence provided by a transformer, cable pulse arrestor or shielding is breached, voltages even as low as 50 V can inflict substantial damage upon computer and communications equipment. The author has seen a number of equipment items (computers, consumer electronics) exposed to low frequency high voltage spikes (near lightning strikes, electrical power transients), and in every instance the damage was extensive, often requiring replacement of most semiconductors in the equipment .
HPM weapons operating in the centimetric and millimetric bands however offer an additional coupling mechanism to Back Door Coupling. This is the ability to directly couple into equipment through ventilation holes, gaps between panels and poorly shielded interfaces. Under these conditions, any aperture into the equipment behaves much like a slot in a microwave cavity, allowing microwave radiation to directly excite or enter the cavity. The microwave radiation will form a spatial standing wave pattern within the equipment. Components situated within the anti-nodes within the standing wave pattern will be exposed to potentially high electromagnetic fields.
Because microwave weapons can couple more readily than low frequency weapons, and can in many instances bypass protection devices designed to stop low frequency coupling, microwave weapons have the potential to be significantly more lethal than low frequency weapons.
What research has been done in this area illustrates the difficulty in producing workable models for predicting equipment vulnerability. It does however provide a solid basis for shielding strategies and hardening of equipment.
The diversity of likely target types and the unknown geometrical layout and electrical characteristics of the wiring and cabling infrastructure surrounding a target makes the exact prediction of lethality impossible.
A general approach for dealing with wiring and cabling related back door coupling is to determine a known lethal voltage level, and then use this to find the required field strength to generate this voltage. Once the field strength is known, the lethal radius for a given weapon configuration can be calculated.
A trivial example is that of a 10 GW 5 GHz HPM device illuminating a footprint of 400 to 500 metres diameter, from a distance of several hundred metres. This will result in field strengths of several kiloVolts per metre within the device footprint, in turn capable of producing voltages of hundreds of volts to kiloVolts on exposed wires or cables . This suggests lethal radii of the order of hundreds of metres, subject to weapon performance and target set electrical hardness.
Maximizing Electromagnetic Bomb Lethality
To maximise the lethality of an electromagnetic bomb it is necessary to maximise the power coupled into the target set.
1.The first step in maximising bomb lethality is to maximise the peak power and duration of the radiation of the weapon. For a given bomb size, this is accomplished by using the most powerful flux compression generator (and Vircator in a HPM bomb) which will fit the weapon size, by maximising the efficiency of internal power transfers in the weapon. Energy which is not emitted is energy wasted at the expense of lethality.
2.The second step is to maximise the coupling efficiency into the target set. A good strategy for dealing with a complex and diverse target set is to exploit every coupling opportunity available within the bandwidth of the weapon.
Couping in low frequency bomb
A low frequency bomb built around an FCG will require a large antenna to provide good coupling of power from the weapon into the surrounding environment. Whilst weapons built this way are inherently wide band, as most of the power produced lies in the frequency band below 1 MHz compact antennas are not an option.
Possible scheme for a bomb approaching its programmed firing altitude
1.deploy five linear antenna elements.
These are produced by firing off cable spools, which unwind several hundred metres of cable. Four radial antenna elements form a "virtual" earth plane around the bomb, while an axial antenna element is used to radiate the power from the FCG. The choice of element lengths would need to be carefully matched to the frequency characteristics of the weapon, to produce the desired field strength. A high power coupling pulse transformer is used to match the low impedance FCG output to the much higher impedance of the antenna, and ensure that the current pulse does not vapourise the cable prematurely.
2.Simply guide the bomb very close to the target,
simply guide the bomb very close to the target, and rely upon the near field produced by the FCG winding, which is in effect a loop antenna of very small diameter relative to the wavelength. Whilst coupling efficiency is inherently poor, the use of a guided bomb would allow the warhead to be positioned accurately within metres of a target. An area worth further investigation in this context is the use of low frequency bombs to damage or destroy magnetic tape libraries, as the near fields in the vicinity of a flux generator are of the order of magnitude of the coercivity of most modern magnetic materials.

Coupling in microwave bomb
Microwave bombs have a broader range of coupling modes and given the small wavelength in comparison with bomb dimensions, can be readily focused against targets with a compact antenna assembly. Assuming that the antenna provides the required weapon footprint, there are at least two mechanisms, which can be employed to further maximise lethality.
how can we improve coupling efficiency?
· The first is sweeping the frequency or chirping the Vircator. This can improve coupling efficiency in comparison with a single frequency weapon, by enabling the radiation to couple into apertures and resonance’s over a range of frequencies. In this fashion, a larger number of coupling opportunities are exploited.
· The second mechanism that can be exploited to improve coupling is the polarization of the weapon's emission. If we assume that the orientations of possible coupling apertures and resonance’s in the target set are random in relation to the weapon's antenna orientation, a linearly polarised emission will only exploit half of the opportunities available. A circularly polarised emission will exploit all coupling opportunities.
The practical constraint is that it may be difficult to produce an efficient high power circularly polarised antenna design, which is compact and performs over a wide band. Some work therefore needs to be done on tapered helix or conical spiral type antennas capable of handling high power levels, and a suitable interface to a Vircator with multiple extraction ports must devised .in the above diagram 5.2,the power is coupled from the tube by stubs which directly feed a multi-filar conical helix antenna. An implementation of this scheme would need to address the specific requirements of bandwidth, beamwidth, efficiency of coupling from the tube, while delivering circularly polarised radiation.

Detonation altitude
Another aspect of electromagnetic bomb lethality is its detonation altitude, and by varying the detonation altitude, a tradeoff may be achieved between the size of the lethal footprint and the intensity of the electromagnetic field in that footprint.



This provides the option of sacrificing weapon coverage to achieve kills against targets of greater electromagnetic hardness, for a given bomb size as shown in above diagram. This is not unlike the use of airburst explosive devices.
Targeting Electromagnetic Bombs
Certain categories of target affected by e bomb:
1.some target will be very easy to identify and engage.
These targets are typically geographically fixed and thus may be attacked providing that the aircraft can penetrate to weapon release range. With the accuracy inherent in GPS/inertially guided weapons, the electromagnetic bomb can be programmed to detonate at the optimal position to inflict a maximum of electrical damage.
Eg:Buildings housing government offices and thus computer equipment, production facilities, military bases and known radar sites and communications nodes are all targets which can be readily identified through conventional photographic, satellite, imaging radar, electronic reconnaissance and humint operations.
2.Mobile and Camouflaged target
Mobile and camouflaged targets, which radiate overtly, can also be readily engaged.
While radiating, their positions can be precisely tracked with suitable Electronic Support Measures (ESM) and Emitter Locating Systems (ELS) carried either by the launch platform or a remote surveillance platform. In the latter instance target coordinates can be continuously datalinked to the launch platform. As most such targets move relatively slowly, they are unlikely to escape the footprint of the electromagnetic bomb during the weapon's flight time.
EG: Mobile and relocatable air defence equipment, mobile communications nodes and naval vessels
3.Army target
Army targets would be difficult to detect because those would be heavily camouflaged and do not radiate overtly. These could only be detected by tracking the Unintentional Emission (UE) also known as Van Eck radiation. Due to poor shielding electronic emissions leak out from various equipments used at the war front. Detection and demodulation of the same could give adequate target intelligence to attack them with electromagnetic weapons with impunity. There is no doubt that smart emitter locator could locate the emissions from computer networking cables, superheterodine receivers etc. Deployment of UAVs over the suspected target areas could reap rich dividends.
Delivery of E Bombs
As with explosive warheads, electromagnetic warheads will occupy a volume of physical space and will also have some given mass (weight) determined by the density of the internal hardware. Like explosive warheads, electromagnetic warheads may be fitted to a range of delivery vehicles.
Cruise Missiles.
Known existing applications involve fitting an electromagnetic warhead to a cruise missile airframe. The choice of a cruise missile airframe will restrict the weight of the weapon to about 340 kg (750 lb), although some sacrifice in airframe fuel capacity could see this size increased. A limitation in all such applications is the need to carry an electrical energy storage device, eg a battery, to provide the current used to charge the capacitors used to prime the FCG prior to its discharge. Therefore the available payload capacity will be split between the electrical storage and the weapon itself.
In wholly autonomous weapons such as cruise missiles, the size of the priming current source and its battery may well impose important limitations on weapon capability. Air delivered bombs, which have a flight time between tens of seconds to minutes, could be built to exploit the launch aircraft's power systems. In such a bomb design, the bomb's capacitor bank can be charged by the launch aircraft enroute to target, and after release a much smaller onboard power supply could be used to maintain the charge in the priming source prior to weapon initiation.
Surface-to-Surface Missile. E Bomb placed on a Surface-to-Surface missile would comprise an electromagnetic device, an electrical converter and an on board storage device such as a battery. The battery is drained as the weapon is pumped. Missile on board fusing system would detonate the electromagnetic device.
Delivery by Conventional Aircraft. Delivery of these types of weapons by aircraft could score over other systems. Because the launch aircraft having its own power system could prime the weapon optimally without any loss of power. In such a situation the bombs capacitor bank can be charged by the launch aircraft en route to target, and after release, a much smaller on-board power supply could be used to maintain the charge in the priming source for weapon initiation. Every aircraft capable of delivering a standard weapon should be in apposition to deliver an E Bomb. And should the weapon ballistic criteria remain the same, then no software changes for the delivering aircraft would be required. Stand off delivery of these kinds of weapons could be the only answer because of its lethal radius. Cruise missile or delivery by any other type of missiles would pose no problems. Delivery of E Bombs from conventional aircraft would require careful planning lest the aircraft becomes victim of the bomb itself. Fire and forget type guidance system would be suitable for all types of air delivery weapons like air-to-air, air to surface and glide bombs. The launch aircraft must gain sufficient separation of several miles before the bomb detonates. This could be carried out either by toss bombing and delivering a glide bomb. The recently built GPS satellite navigation kits for conventional bombs and glide bombs has increased the accuracy of the weapon to a large extent. Therefore toss bombing both from low level and high level could be the answer. Importance of glide bombs could be manifold. The glide bomb can be released from outside the effective radius of target air defence, minimizing the risk for attacking aircraft. Large stand off distance means that the aircraft can remain well clear of the bomb's effects.
The bomb's autopilot may be programmed to shape the terminal trajectory of the weapon, in a way that the target may be engaged from the most suitable altitude and aspect.
Search and Kill by UAV. An easy electrical kill could be achieved by using UAVs armed with emission locator and E weapons. Because of their inherent advantages an UAV could loiter over a target for a considerable period of time away from the base and once the emission is located distinctly, it could launch its on-board weapon
The importance of glidebombs as delivery means for HPM warheads is threefold. Firstly, the glidebomb can be released from outside effective radius of target air defences, therefore minimising the risk to the launch aircraft. Secondly, the large standoff range means that the aircraft can remain well clear of the bomb's effects. Finally the bomb's autopilot may be programmed to shape the terminal trajectory of the weapon, such that a target may be engaged from the most suitable altitude and aspect.
A major advantage of using electromagnetic bombs is that they may be delivered by any tactical aircraft with a nav-attack system capable of delivering GPS guided munitions. As we can expect GPS guided munitions to be become the standard weapon in use by Western air forces by the end of this decade, every aircraft capable of delivering a standard guided munition also becomes a potential delivery vehicle for a electromagnetic bomb. Should weapon ballistic properties be identical to the standard weapon, no software changes to the aircraft would be required.
Because of the simplicity of electromagnetic bombs in comparison with weapons such as Anti Radiation Missiles (ARM), it is not unreasonable to expect that these should be both cheaper to manufacture, and easier to support in the field, thus allowing for more substantial weapon stocks. In turn this makes saturation attacks a much more viable proposition.
Defence Against Electromagnetic Bombs
In any future war our defence forces are going to face some kind of EM weapons and it would be necessary to pay attention towards the defence against this emerging threat of the future. No air defence system could provide total safety from air attacks and therefore those systems that could suffer probable damage by such a new menace must be electro magnetically hardened.
Various method for defence against electomagnetic bomb
1.The most effective defence against electromagnetic bombs is to prevent their delivery by destroying the launch platform or delivery vehicle, as is the case with nuclear weapons. This however may not always be possible, and therefore systems, which can be expected to suffer exposure to the electromagnetic weapons effects, must be electro magnetically hardened.
2.The most effective method is to wholly contain the equipment in an electrically conductive enclosure, termed a Faraday cage, which prevents the electromagnetic field from gaining access to the protected equipment. However, most such equipment must communicate with and be fed with power from the outside world, and this can provide entry points via which electrical transients may enter the enclosure and effect damage. While optical fibres address this requirement for transferring data in and out, electrical power feeds remain an ongoing vulnerability. Where an electrically conductive channel must enter the enclosure, electromagnetic arresting devices must be fitted. A range of devices exist, however care must be taken in determining their parameters to ensure that they can deal with the rise time and strength of electrical transients produced by electromagnetic devices. Reports from the US indicate that hardening measures attuned to the behaviour of nuclear EMP bombs do not perform well when dealing with some conventional microwave electromagnetic device designs.
It is significant that hardening of systems must be carried out at a system level, as electromagnetic damage to any single element of a complex system could inhibit the function of the whole system. Hardening new build equipment and systems will add a substantial cost burden. Older equipment and systems may be impossible to harden properly and may require complete replacement. In simple terms, hardening by design is significantly easier than attempting to harden existing equipment.

3.An interesting aspect of electrical damage to targets is the possibility of wounding semiconductor devices thereby causing equipment to suffer repetitive intermittent faults rather than complete failures. Such faults would tie down considerable maintenance resources while also diminishing the confidence of the operators in the equipment's reliability. Intermittent faults may not be possible to repair economically, thereby causing equipment in this state to be removed from service permanently, with considerable loss in maintenance hours during damage diagnosis. This factor must also be considered when assessing the hardness of equipment against electromagnetic attack, as partial or incomplete hardening may in this fashion cause more difficulties than it would solve. Indeed, shielding which is incomplete may resonate when excited by radiation and thus contribute to damage inflicted upon the equipment contained within it.

Limitations of Electromagnetic Bombs
1.demand better accuracy for their delivery
The accuracy of delivery and achievable lethal radius must be considered against the allowable collateral damage for the chosen target. Where collateral electrical damage is a consideration, accuracy of delivery and lethal radius are key parameters. An inaccurately delivered weapon of large lethal radius may be unusable against a target should the likely collateral electrical damage be beyond acceptable limits. This can be a major issue for users constrained by treaty provisions on collateral damage.
2.inefficient for thermo ionic devices
thermionic technology (ie vacuum tube equipment) is substantially more resilient to the electromagnetic weapons effects than solid state (ie transistor) technology. Therefore a weapon optimised to destroy solid state computers and receivers may cause little or no damage to a thermionic technology device. Therefore a hard electrical kill may not be achieved against such targets unless a suitable weapon is used.

3.difficulty in kill assessment
Radiating targets such as radars or communications equipment may continue to radiate after an attack even though their receivers and data processing systems have been damaged or destroyed. This means that equipment which has been successfully attacked may still appear to operate. Conversely an opponent may shut down an emitter if attack is imminent and the absence of emissions means that the success or failure of the attack may not be immediately apparent.
4.decays in lethal effect with increasing distance
An important factor in assessing the lethal coverage of an electromagnetic weapon is atmospheric propagation. While the relationship between electromagnetic field strength and distance from the weapon is one of an inverse square law in free space, the decay in lethal effect with increasing distance within the atmosphere will be greater due quantum physical absorption effects. This is particularly so at higher frequencies, and significant absorption peaks due water vapour and oxygen exist at frequencies above 20 GHz. These will therefore contain the effect of HPM weapons to shorter radii than are ideally achievable in the K and L frequency bands.

The Proliferation of Electromagnetic Bombs
The United States and the CIS 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 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. 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.
A Doctrine for the Use of Conventional Electromagnetic Bombs
A fundamental tenet of IW is that complex organisational systems such as governments, industries and military forces cannot function without the flow of information through their structures. Information flows within these structures in several directions, under typical conditions of function. A trivial model for this function would see commands and directives flowing outward from a central decision making element, with information about the state of the system flowing in the opposite direction. Real systems are substantially more complex.
This is of military significance because stopping this flow of information will severely debilitate the function of any such system. Stopping the outward flow of information produces paralysis, as commands cannot reach the elements, which are to execute them. Stopping the inward flow of information isolates the decision-making element from reality, and thus severely inhibits its capacity to make rational decisions, which are sensitive to the currency of information at hand.
The recent evolution of strategic (air) warfare indicates a growing trend toward targeting strategies, which exploit this most fundamental vulnerability of any large and organised system. The Desert Storm air war of 1991 is a good instance, with a substantial effort expended against such targets. Indeed, the model used for modern strategic air attack places leadership and its supporting communications in the position of highest targeting priority .No less importantly, modern Electronic Combat concentrates upon the disruption and destruction of communications and information gathering sensors used to support military operations. Again the Desert Storm air war provides a good illustration of the application of this method.
A strategy which stresses attack upon the information processing and communications elements of the systems which it is targeting offers a very high payoff, as it will introduce an increasing level of paralysis and disorientation within its target. Electromagnetic bombs are a powerful tool in the implementation of such a strategy.
Electronic Combat Operations using Electromagnetic Bombs
The central objective of Electronic Combat (EC) operations is the command of the electromagnetic spectrum, achieved by soft and hard kill means against the opponent's electronic assets. The underlying objective of commanding the electromagnetic spectrum is to interrupt or substantially reduce the flow of information through the opponent's air defence system, air operations environment and between functional elements of weapon systems.
In this context the ability of electromagnetic bombs to achieve kills against a wide range of target types allows their general application to the task of inflicting attrition upon an opponent's electronic assets, be they specialised air defence assets or more general Command-Control-Communications (C3) and other military assets.
Electromagnetic bombs can be a means of both soft and hard electrical kill, subject to the lethality of the weapon and the hardness of its target. A hard electrical kill by means of an electromagnetic device will be achieved in those instances where such severe electrical damage is achieved against a target so as to require the replacement of most if not all of its internal electronics.
Electronic combat operations using electromagnetic devices involve the use of these to attack radar, C3 and air defence weapon systems. These should always be attacked initially with an electromagnetic weapon to achieve soft or hard electrical kills, followed up by attack with conventional munitions to preclude possible repair of disabled assets at a later time. As with conventional SEAD operations, the greatest payoff will be achieved by using electromagnetic weapons against systems of strategic importance first, followed in turn by those of operational and tactical importance.
In comparison with an AntiRadiation Missile (ARM - a missile which homes on the emissions from a threat radar), the established and specialised tool in the conduct of SEAD operations, an electromagnetic bomb can achieve kills against multiple targets of diverse types within its lethal footprint. In this respect an electromagnetic device may be described as a Weapon of Electrical Mass Destruction (WEMD). Therefore electromagnetic weapons are a significant force multiplier in electronic combat operations.
A conventional electronic combat campaign, or intensive electronic combat operations, will initially concentrate on saturating the opponent's electronic defences, denying information and inflicting maximum attrition upon electronic assets. The force multiplication offered by electromagnetic weapons vastly reduces the number of air assets required to inflict substantial attrition, and where proper electronic reconnaissance has been carried out beforehand, also reduces the need for specialised assets such as ARM firing aircraft equipped with costly emitter locating systems.
The massed application of electromagnetic bombs in the opening phase of an electronic battle will allow much faster attainment of command of the electromagnetic spectrum, as it will inflict attrition upon electronic assets at a much faster rate than possible with conventional means.
Whilst the immaturity of conventional electromagnetic weapons precludes an exact analysis of the scale of force multiplication achievable, it is evident that a single aircraft carrying an electromagnetic bomb capable of concurrently disabling a SAM site with its collocated acquisition radar and supporting radar directed AAA weapons, will have the potency of the several ARM firing and support jamming aircraft required to accomplish the same result by conventional means. This and the ability of multirole tactical aircraft to perform this task allows for a much greater concentration of force in the opening phase of the battle, for a given force size.
In summary the massed application of electromagnetic weapons to Electronic Combat operations will provide for a much faster rate of attrition against hostile electronic assets, achievable with a significantly reduced number of specialised and multirole air assets .This will allow even a modestly sized force to apply overwhelming pressure in the initial phase of an electronic battle, and therefore achieve command of the electromagnetic spectrum in a significantly shorter time than by conventional means.

Strategic Air Attack Operations using Electromagnetic Bombs
The modern approach to strategic air warfare reflects in many respects aspects of the IW model, in that much effort is expended in disabling an opponent's fundamental information processing infrastructure. Since we however are yet to see a systematic IW doctrine, which has been tested in combat, this paper will approach the subject from a more conservative viewpoint and use established strategic doctrine.
Modern strategic air attack theory is based upon Warden's Five Rings model, which identifies five centres of gravity in a nation's war fighting capability. In descending order of importance, these are the nation's leadership and supporting C3 system, its essential economic infrastructure, its transportation network, its population and its fielded military forces.
Electromagnetic weapons may be productively used against all elements in this model, and provide a particularly high payoff when applied against a highly industrialised and geographically concentrated opponent. Of particular importance in the context of strategic air attack, is that while electromagnetic weapons are lethal to electronics, they have little if any effect on humans. This is a characteristic, which is not shared with established conventional and nuclear weapons.
This selectivity in lethal effect makes electromagnetic weapons far more readily applicable to a strategic air attack campaign, and reduces the internal political pressure, which is experienced by the leadership of any democracy which must commit to warfare. An opponent may be rendered militarily, politically and economically ineffective with little if any loss in human life.
The innermost ring in the Warden model essentially comprises government bureaucracies and civilian and military C3 systems. In any modern nation these are heavily dependent upon the use of computer equipment and communications equipment. What is of key importance at this time is an ongoing change in the structure of computing facilities used in such applications, as these are becoming increasingly decentralised. A modern office environment relies upon a large number of small computers, networked to interchange information, in which respect it differs from the traditional model of using a small number of powerful central machines.
This decentralisation and networking of information technology systems produces a major vulnerability to electromagnetic attack. Whereas a small number of larger computers could be defended against electromagnetic attack by the use of electromagnetic hardened computer rooms, a large distributed network cannot. Moreover, unless optical fibre networking is used, the networking cables are themselves a medium via which electromagnetic effects can be efficiently propagated throughout the network, to destroy machines. Whilst the use of distributed computer networks reduces vulnerability to attack by conventional munitions, it increases vulnerability to attack by electromagnetic weapons.
Selective targeting of government buildings with electromagnetic weapons will result in a substantial reduction in a government's ability to handle and process information. The damage inflicted upon information records may be permanent, should inappropriate backup strategies have been used to protect stored data. It is reasonable to expect most data stored on machines which are affected will perish with the host machine, or become extremely difficult to recover from damaged storage devices.
The cost of hardening existing computer networks is prohibitive, as is the cost of replacement with hardened equipment. Whilst the use of hardened equipment for critical tasks would provide some measure of resilience, the required discipline in the handling of information required to implement such a scheme renders its utility outside of military organisations questionable. Therefore the use of electromagnetic weapons against government facilities offers an exceptionally high payoff.
Other targets which fall into the innermost ring may also be profitably attacked. Satellite link and importantly control facilities are vital means of communication as well as the primary interface to military and commercial reconnaissance satellites. Television and radio broadcasting stations, one of the most powerful tools of any government, are also vulnerable to electromagnetic attack due the very high concentration of electronic equipment in such sites. Telephone exchanges, particularly later generation digital switching systems, are also highly vulnerable to appropriate electromagnetic attack.
In summary the use of electromagnetic weapons against leadership and C3 targets is highly profitable, in that a modest number of weapons appropriately used can introduce the sought state of strategic paralysis, without the substantial costs incurred by the use of conventional munitions to achieve the same effect.
Essential economic infrastructure is also vulnerable to electromagnetic attack. The finance industry and stock markets are almost wholly dependent upon computers and their supporting communications. Manufacturing, chemical, petroleum product industries and metallurgical industries rely heavily upon automation which is almost universally implemented with electronic PLC (Programmable Logic Controller) systems or digital computers. Furthermore, most sensors and telemetry devices used are electrical or electronic.
Attacking such economic targets with electromagnetic weapons will halt operations for the time required to either repair the destroyed equipment, or to reconfigure for manual operation. Some production processes however require automated operation, either because hazardous conditions prevent human intervention, or the complexity of the control process required cannot be carried out by a human operator in real time. A good instance are larger chemical, petrochemical and oil/gas production facilities. Destroying automated control facilities will therefore result in substantial loss of production, causing shortages of these vital materials.
Manufacturing industries, which rely heavily upon robotic and semiautomatic machinery, such as the electronics, computer and electrical industry, precision machine industry and aerospace industries, are all key assets in supporting a military capability. They are all highly vulnerable to electromagnetic attack. Whilst material-processing industries may in some instances be capable of function with manual process control, the manufacturing industries are almost wholly dependent upon their automated machines to achieve any useful production output.
Historical experience suggests that manufacturing industries are highly resilient to air attack as production machinery is inherently mechanically robust and thus a very high blast overpressure is required to destroy it. The proliferation of electronic and computer controlled machinery has produced a major vulnerability, for which historical precedent does not exist. Therefore it will be necessary to reevaluate this orthodoxy in targeting strategy.
The finance industry and stock markets are a special case in this context, as the destruction of their electronic infrastructure can yield, unlike manufacturing industries, much faster economic dislocation. This can in turn produce large systemic effects across a whole economy, including elements which are not vulnerable to direct electromagnetic attack. This may be of particular relevance when dealing with an opponent which does not have a large and thus vulnerable manufacturing economy. Nations which rely on agriculture, mining or trade for a large proportion of the their gross domestic product are prime candidates for electromagnetic attack on their finance industry and stock markets. Since the latter are usually geographically concentrated and typically electromagnetically "soft" targets, they are highly vulnerable.
In summary there is a large payoff in striking at economic essentials with electromagnetic weapons, particularly in the opening phase of a strategic air attack campaign, as economic activity may be halted or reduced with modest expenditure of the attacker's resources. An important caveat is that centres of gravity within the target economy must be properly identified and prioritised for strikes to ensure that maximum effect is achieved as quickly as possible.
Transport infrastructure is the third ring in the Warden model, and also offers some useful opportunities for the application of electromagnetic weapons. Unlike the innermost rings, the concentration of electronic and computer equipment is typically much lower, and therefore considerable care must be taken in the selection of targets.
Railway and road signalling systems, where automated, are most vulnerable to electromagnetic attack on their control centres. This could be used to produce traffic congestion by preventing the proper scheduling of rail traffic, and disabling road traffic signalling, although the latter may not yield particularly useful results.
Significantly, most modern automobiles and trucks use electronic ignition systems which are known to be vulnerable to electromagnetic weapons effects, although opportunities to find such concentrations so as to allow the profitable use of an electromagnetic bomb may be scarce.
The population of the target nation is the fourth ring in the Warden model, and its morale is the object of attack. The morale of the population will be affected significantly by the quality and quantity of the government propaganda it is subjected to, as will it be affected by living conditions.
Using electromagnetic weapons against urban areas provides the opportunity to prevent government propaganda from reaching the population via means of mass media, through the damaging or destruction of all television and radio receivers within the footprint of the weapon. Whether this is necessary, given that broadcast facilities may have already been destroyed, is open to discussion. Arguably it may be counterproductive, as it will prevent the target population from being subjected to friendly means of psychological warfare such as propaganda broadcasts.
The use of electromagnetic weapons against a target population is therefore an area which requires requires careful consideration in the context of the overall IW campaign strategy. If useful objectives can be achieved by isolating the population from government propaganda, then the population is a valid target for electromagnetic attack. Forces constrained by treaty obligations will have to reconcile this against the applicable regulations relating to denial of services to non-combatants .
The outermost and last ring in the Warden model are the fielded military forces. These are by all means a target vulnerable to electromagnetic attack, and C3 nodes, fixed support bases as well as deployed forces should be attacked with electromagnetic devices. Fixed support bases which carry out depot level maintenance on military equipment offer a substantial payoff, as the concentration of computers in both automatic test equipment and administrative and logistic support functions offers a good return per expended weapon.
Any site where more complex military equipment is concentrated should be attacked with electromagnetic weapons to render the equipment unservicable and hence reduce the fighting capability, and where possible also mobility of the targeted force. As discussed earlier in the context of Electronic Combat, the ability of an electromagnetic weapon to achieve hard electrical kills against any non-hardened targets within its lethal footprint suggests that some target sites may only require electromagnetic attack to render them both undefended and non-operational. Whether to expend conventional munitions on targets in this state would depend on the immediate military situation.
In summary the use of electromagnetic weapons in strategic air attack campaign offers a potentially high payoff, particularly when applied to leadership, C3 and vital economic targets, all of which may be deprived of much of their function for substantial periods of time. The massed application of electromagnetic weapons in the opening phase of the campaign would introduce paralysis within the government, deprived of much of its information processing infrastructure, as well as paralysis in most vital industries. This would greatly reduce the capability of the target nation to conduct military operations of any substantial intensity.
Because conventional electromagnetic weapons produce negligible collateral damage, in comparison with conventional explosive munitions, they allow the conduct of an effective and high tempo campaign without the loss of life which is typical of conventional campaigns. This will make the option of a strategic bombing campaign more attractive to a Western democracy, where mass media coverage of the results of conventional strategic strike operations will adversely affect domestic civilian morale.
The long term effects of a sustained and concentrated strategic bombing campaign using a combination of conventional and electromagnetic weapons will be important. The cost of computer and communications infrastructure is substantial, and its massed destruction would be a major economic burden for any industrialised nation. In addition it is likely that poor protection of stored data will add to further economic losses, as much data will be lost with the destroyed machines.
From the perspective of conducting an IW campaign, this method of attack achieves many of the central objectives sought. Importantly, the massed application of electromagnetic weapons would inflict attrition on an opponent's information processing infrastructure very rapidly, and this would arguably add a further psychological dimension to the potency of the attack. Unlike the classical IW model of Gibsonian CyberWar, in which the opponent can arguably isolate his infrastructure from hostile penetration, parallel or hyperwar style massed attack with electromagnetic bombs will be be extremely difficult to defend against.
Offensive Counter Air (OCA) Operations using Electromagnetic Bombs
Electromagnetic bombs may be usefully applied to OCA operations. Modern aircraft are densely packed with electronics, and unless properly hardened, are highly vulnerable targets for electromagnetic weapons.
The cost of the onboard electronics represents a substantial fraction of the total cost of a modern military aircraft, and therefore stock levels of spares will in most instances be limited to what is deemed necessary to cover operational usage at some nominal sortie rate. Therefore electromagnetic damage could render aircraft unusable for substantial periods of time.
Attacking airfields with electromagnetic weapons will disable communications, air traffic control facilities, navigational aids and operational support equipment, if these items are not suitably electromagnetic hardened. Conventional blast hardening measures will not be effective, as electrical power and fixed communications cabling will carry electromagnetic induced transients into most buildings. Hardened aircraft shelters may provide some measure of protection due electrically conductive reinforcement embedded in the concrete, but conventional revetments will not.
Therefore OCA operations against airfields and aircraft on the ground should include the use of electromagnetic weapons as they offer the potential to substantially reduce hostile sortie rates.
Maritime Air Operations using Electromagnetic Bombs
As with modern military aircraft, naval surface combatants are fitted with a substantial volume of electronic equipment, performing similar functions in detecting and engaging targets and warning of attack. As such they are vulnerable to electromagnetic attack, if not suitably hardened. Should they be hardened, volumetric, weight and cost penalties will be incurred.
Conventional methods for attacking surface combatants involve the use of saturation attacks by anti-ship missiles or coordinated attacks using a combination of ARMs and anti-ship missiles. The latter instance is where disabling the target electronically by stripping its antennae precedes lethal attack with specialised anti-ship weapons.
An electromagnetic warhead detonated within lethal radius of a surface combatant will render its air defence system inoperable, as well as damaging other electronic equipment such as electronic countermeasures, electronic support measures and communications. This leaves the vessel undefended until these systems can be restored, which may or may not be possible on the high seas. Therefore launching an electromagnetic glidebomb on to a surface combatant, and then reducing it with laser or television guided weapons is an alternate strategy for dealing with such targets.
Battlefield Air Interdiction Operations using Electromagnetic Bombs
Modern land warfare doctrine emphasises mobility, and manoeuvre warfare methods are typical for contemporary land warfare. Coordination and control are essential to the successful conduct of manoeuvre operations, and this provides another opportunity to apply electromagnetic weapons. Communications and command sites are key elements in the structure of such a land army, and these concentrate communications and computer equipment. Therefore they should be attacked with electromagnetic weapons, to disrupt the command and control of land operations.
Should concentrations of armoured vehicles be found, these are also profitable targets for electromagnetic attack, as their communications and fire control systems may be substantially damaged or disabled as a result. A useful tactic would be initial attack with electromagnetic weapons to create a maximum of confusion, followed by attack with conventional weapons to take advantage of the immediate situation.
Defensive Counter-Air (DCA) and Air Defence Operations using Electromagnetic Warheads
Providing that compact electromagnetic warheads can be built with useful lethality performance, then a number of other potential applications become viable. One is to equip an Air-Air Missile (AAM) with such a warhead. A weapon with datalink midcourse guidance, such as the AIM-120, could be used to break up inbound raids by causing soft or hard electrical kills in a formation (raid) of hostile aircraft. Should this be achieved, the defending fighter will have the advantage in any following engagement as the hostile aircraft may not be fully mission capable. Loss of air intercept or nav attack radar, EW equipment, mission computers, digital engine controls, communications and electronic flight controls, where fitted, could render the victim aircraft defenceless against attack with conventional missiles.
This paradigm may also be applied to air defence operations using area defence SAMs. Large SAMs such as the MIM-104 Patriot, RIM-66E/M and RIM-67A Standard, 5V55/48N6 (SA-10) and 9M82/9M83 (SA-12) could accommodate an electromagnetic warhead comparable in size to a bomb warhead. A SAM site subjected to jamming by inbound bombers could launch a first round under datalink control with an electromagnetic warhead to disable the bombers, and then follow with conventional rounds against targets which may not be able to defend themselves electronically. This has obvious implications for the electromagnetic hardness of combat aircraft systems.
A Strategy of Graduated Response
The introduction of non-nuclear electromagnetic bombs into the arsenal of a modern air force considerably broadens the options for conducting strategic campaigns. Clearly such weapons are potent force multipliers in conducting a conventional war, particularly when applied to Electronic Combat, OCA and strategic air attack operations.
The massed use of such weapons would provide a decisive advantage to any nation with the capability to effectively target and deliver them. The qualitative advantage in capability so gained would provide a significant advantage even against a much stronger opponent not in the possession of this capability.
Electromagnetic weapons however open up less conventional alternatives for the conduct of a strategic campaign, which derive from their ability to inflict significant material damage without inflicting visible collateral damage and loss of life. Western governments have been traditionally reluctant to commit to strategic campaigns, as the expectation of a lengthy and costly battle, with mass media coverage of its highly visible results, will quickly produce domestic political pressure to cease the conflict.
An alternative is a Strategy of Graduated Response (SGR). In this strategy, an opponent who threatens escalation to a full scale war is preemptively attacked with electromagnetic weapons, to gain command of the electromagnetic spectrum and command of the air. Selective attacks with electromagnetic weapons may then be applied against chosen strategic targets, to force concession. Should these fail to produce results, more targets may be disabled by electromagnetic attack. Escalation would be sustained and graduated, to produce steadily increasing pressure to concede the dispute. Air and sea blockade are complementary means via which pressure may be applied.
Because electromagnetic weapons can cause damage on a large scale very quickly, the rate at which damage can be inflicted can be very rapid, in which respect such a campaign will differ from the conventional, where the rate at which damage is inflicted is limited by the usable sortie rate of strategic air attack capable assets .
Should blockade and the total disabling of vital economic assets fail to yield results, these may then be systematically reduced by conventional weapons, to further escalate the pressure. Finally, a full scale conventional strategic air attack campaign would follow, to wholly destroy the hostile nation's warfighting capability.
Another situation where electromagnetic bombs may find useful application is in dealing with governments which actively implement a policy of state sponsored terrorism or info-terrorism, or alternately choose to conduct a sustained low intensity land warfare campaign. Again the Strategy of Graduated Response, using electromagnetic bombs in the initial phases, would place the government under significant pressure to concede.
Importantly, high value targets such as R&D and production sites for Weapons of Mass Destruction (nuclear, biological, chemical) and many vital economic sites, such as petrochemical production facilities, are critically dependent upon high technology electronic equipment. The proliferation of WMD into developing nations has been greatly assisted by the availability of high quality test and measurement equipment commercially available from First World nations, as well as modern electronic process control equipment. Selectively destroying such equipment can not only paralyse R&D effort, but also significantly impair revenue generating production effort. A Middle Eastern nation sponsoring terrorism will use oil revenue to support such activity. Crippling its primary source of revenue without widespread environmental pollution may be an effective and politically acceptable punitive measure.
As a punitive weapon electromagnetic devices are attractive for dealing with belligerent governments. Substantial economic, military and political damage may be inflicted with a modest commitment of resources by their users, and without politically damaging loss of life.
11. Conclusions
Electromagnetic bombs are Weapons of Electrical Mass Destruction with applications across a broad spectrum of targets, spanning both the strategic and tactical. As such their use offers a very high payoff in attacking the fundamental information processing and communication facilities of a target system. The massed application of these weapons will produce substantial paralysis in any target system, thus providing a decisive advantage in the conduct of Electronic Combat, Offensive Counter Air and Strategic Air Attack.
Because E-bombs can cause hard electrical kills over larger areas than conventional explosive weapons of similar mass, they offer substantial economies in force size for a given level of inflicted damage, and are thus a potent force multiplier for appropriate target sets.
The non-lethal nature of electromagnetic weapons makes their use far less politically damaging than that of conventional munitions, and therefore broadens the range of military options available.
This paper has included a discussion of the technical, operational and targeting aspects of using such weapons, as no historical experience exists as yet upon which to build a doctrinal model. The immaturity of this weapons technology limits the scope of this discussion, and many potential areas of application have intentionally not been discussed. The ongoing technological evolution of this family of weapons will clarify the relationship between weapon size and lethality, thus producing further applications and areas for study.
E-bombs can be an affordable force multiplier for military forces which are under post Cold War pressures to reduce force sizes, increasing both their combat potential and political utility in resolving disputes. Given the potentially high payoff deriving from the use of these devices, it is incumbent upon such military forces to appreciate both the offensive and defensive implications of this technology. It is also incumbent upon governments and private industry to consider the implications of the proliferation of this technology, and take measures to safeguard their vital assets from possible future attack. Those who choose not to may become losers in any future wars.