Electromagnetic Pulse

Figure 1: Illustration of an Electromagnetic Bomb being detonated

Introduction:

      When most people think of nuclear weapons, they see images of buildings being obliterated, mushroom clouds rising, and cities being decimated to the point that they are unrecognizable. What people fail to notice about the capabilities of nuclear weapons is that the blast is only the beginning. Other properties of nuclear weapons such as the deadly radiation they admit are frequently overlooked. One form of radiation that is emitted by the nuclear device is the electromagnetic pulse or E.M.P. The electromagnetic pulse by definition is a very powerful electric field, created by a variation of the Compton effect called Compton recoil, that sweeps outward from the blast nucleus producing strong electrical currents that render most electrical components useless especially semi-conductor electrical devices. This pulse is not limited to stationary devices on the ground either helicopters, planes and other airborne electrical devices are at risk as well. In fact, anything that uses electricity in the electromagnetic pulse's path will become nothing more than an oversized paperweight.

How is an Electromagnetic Pulse Created:

      The electromagnetic pulse as stated above is created by a variation of the Compton Effect namely the phenomenon of Compton recoil. Compton recoil takes place within a high concentration of gamma rays, such as those emitted by a nuclear device, and can be described as:

"...a gamma ray (primary) photon collides with an electron and some of the energy of the photon is transferred to the electron. Another (secondary) photon, with less energy, then moves off in a new direction at an angle to the direction of motion of the primary photon. Consequently, Compton interaction results in a change of direction (or scattering) of the gamma-ray photon and degradation in its energy. The electron which, after colliding with the primary photon, recoils in such a manner as to conserve energy and momentum is called a Compton (recoil) electron." (Glasstone and Dolan, 1977)


Figure 2: Illustration of the Compton Effect

      When many of these Compton recoil electrons start to travel away from the blast the positive ions lag behind forming a separation of charge and in effect a very powerful electric field. In addition the electrons of lower energy begin colliding with positive ions from the Compton electrons and a current is produced which flows opposite the electric field. (Glasstone and Dolan, 1977) This current, brought about by the Compton effect is what will destroy the many electrical devices that the current comes into contact with and in addition produces voltage drops on the magnitude of thousands of volts. When this powerful current and corresponding voltages attach to power lines, train tracks, and other electrical power supplies the results are disastrous and irreversible. In addition as stated above this large current will cause large amounts of heat to be produced and this heat will cause semi-conductor electronics to burn up and become useless as well. Now that we know where the electromagnetic pulse is created who first discovered it?

How the Electromagnetic Pulse was Discovered:

      The discovery of this self-induced electromagnetic pulse occurred in 1958 while the United States Navy was testing their new high altitude nuclear bombs over the Pacific Ocean. After detonation of the nuclear bombs, blackouts and strong electrical interference were reported in Hawaii and Australia (Wilson 2001). After much analysis and research it was concluded that since nuclear bombs were created through the use of fusion and not fission, a "bonus" effect of nuclear devises was discovered and was initially overlooked by scientist. This so called "bonus" effect was a huge electromagnetic pulse that is sent out for miles in all directions once the nuclear devise is detonated knocking out all electrical devises in its path. This electromagnetic pulse that is emitted by the nuclear explosion is the very same pulse that was used on the atomic scale by Compton in his early testing with atoms in the 1920's.

      Since the involuntary discharge of electromagnetic waves by the United States Navy in 1958, the United States government has been developing a breed of weaponry all of which take advantage of the properties of the electromagnetic pulse. These electromagnetic weapons, or electrical weapons as they are classified, are the newest developments that have evolved from the works of Compton.

Electromagnetic Pulse Technology:

      With the everyday increase knowledge of electromagnetics and there possible applications, it is a given that the United States government is well aware of the awesome power of the electromagnetic pulse. As a result the United States government is current working on more robust ways to harness this advancement and use it to develop more effective electromagnetic bombs, or e-bombs as they are classified.

      The development of an electromagnetic bomb would definitely be very useful in the operations performed by the United States military and very recently it has been speculated that the cause of power loss in Iraq during the early stages of Operation Iraqi Freedom was due to the release of an electromagnetic bomb of low intensity. Why would the United States wish to cause such a power loss? Because this loss of power allows for the first wave of American Marines to make there move. The first step that the Marines take before moving on to their primary objective is to secure their location of interest. In other words, they cut off the facility in question from the outside world. Usually, this entails a Marine or group of Marines infiltrating a highly secure area in order to cut power and telephone lines. These initial operation are very dangerous, the safety of the infiltrating Marine or Marines, as well as, the secrecy of the operation is at high risk. Therefore by eliminating these types of operations and using an EMP weapon, you can save lives as well as the secrecy of the Marines presence and also place more attention on the actual objective.

      Another benefit of this technological development would be to prevent enemy aircraft from attacking American soil. Instead of relying on anti-aircraft missiles that are currently being used by our government, we can just send out a controlled electromagnetic pulse and let it take out the enemy aircraft's electrical power. If this is done far enough out at sea, the plane will either crash into the ocean or we will scramble our fighters to intercept a crippled enemy. Either way no harm will come to the Americas. There are an endless number of possibilities that electromagnetic weapons can be used for and it is well worth the time and effort of our government to continue pursuing this new form of technology if not for our benefit then for our protection from the enemy using this development against us.

      Like most technology, it is great when it is working for you but could be disastrous when it is working against you. Therefore in addition to the advancement of electrical weapons, it is a safe assumption that our government is also working towards a solution to protect against electrical attacks. The best solution that we the American public is aware of to date are faraday cages. The faraday cage acts just as a lightning arrestor would if it were hit by lightning. Meaning that the faraday cage is capable of catching an electromagnetic pulse and then sending the pulse to a ground extinguishing it before infecting the item under protection by the faraday cage. Faraday cages are implement very commonly in the structure of most skyscrapers and government office buildings as well as in most power plants. Faraday cages are simply composed of a copper or metal wiring that when in contact with an electromagnetic pulse will absorb all of the conductive current and send it else where leaving the object in the cage unharmed. (Stair) Although this is a very effective means of EMP protection, the downside to these cages is that they can only with stand a certain magnitude of current created by the electromagnetic pulse before they stop functioning. In other words the copper becomes completely saturated with current and starts to let current leak inside the cage destroying whatever is inside. Due to this lack of effectiveness of the Faraday cage with regards to electrical pulses of mass destruction, the government is currently working on classified operations in order to develop a stronger defense against such attacks (Kopp, 2001). Figure 3: Illustration of three basic Faraday Cage
Conclusion:

      Since the discovery of the electromagnetic pulse in 1958 we have significantly increased our knowledge and ability to control this very powerful phenomenon. In addition, our government is currently continuing to develop new uses for this technology through the use of past and present electromagnetic theories such as the Compton effect or more specifically Compton recoil. With this in mind we must also remember to respect the power that EMP technology holds and be sure to not let it fall into the wrong hands because the results could be disastrous.

Figure 4: Military High-Archy of Potential EMP Targets

References:

(2001, October 3). Arthur Holly Compton - Biography. Nobel e-museum. Retrieved: November 14, 2003 from the World Wide Web: http://www.nobel.se/physics/laureates/1927/compton-bio.html.

(1997, February 01). The Electromagnetic Pulse. Retrieved: November 14, 2003 from the World Wide Web: http://www.geocities.com/CapeCanaveral/5971/emp.html .

Eng, Paul. (2001, October 19). E-Bombs could spell digital doomsday. ABC News. Retrieved: November 14, 2003 from the World Wide Web: http://abcnews.go.com/sections/scitech/CuttingEdge/empbombs011019.html.

Giffin, Noel. (1996, January 23). Compton Scattering. Retrieved: November 16, 2003 from the World Wide Web: http://www.triumf.ca/safety/rpt/rpt_2/node19.html .

Glasstone, Samuel and Phillip J. Dolan, The Effects of Nuclear Weapons. Department of the Army, Washington D. C., 1977, pp. 353-54. Retrieved: November 14, 2003 from the World Wide Web: http://www.geocities.com/CapeCanaveral/5971/emp.html.

Kopp, Carlo. (2001). The Electrical Bomb - a Weapon of Electrical Mass Destruction. Retrieved: November 14, 2003 from the World Wide Web: http://www.airpower.maxwell.af.mil/airchronicles/kopp/apjemp.html.

Stair, Miles. Making Faraday Cages. Retrieved: November 14, 2003 from the World Wide Web: http://www.endtimesreport.com/faraday_cages.html.

Wilson, Jim. (2001, September). E-BOMB. Popular Mechanics Magazine. Retrieved: November 14, 2003 from the World Wide Web: http://popularmechanics.com/science/military/2001/9/e-bomb/print.phtml.

Report by Thomas Krappweis Jr.
ECE 305
November 17, 2003