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Electromagnetic Pulse

Page 14

by Bobby Akart


  The selected case studies by the EMP Commission provide only an approximation of EMP effects. For example, the impact of the knowledge that widespread infrastructure disruption resulted from an intentional foreign attack are yet unknown. Past evidence points to people’s resilience in the immediate aftermath of disasters. However, during a lengthy recovery process, as would be expected following an EMP attack with widespread, long-duration effects, the psychological effects of the attack should not be underestimated.

  It appears clear that the most crucial question in the task of avoiding societal collapse is how to provide information to the populace without electricity immediately following an EMP attack. Without communication alternatives, it would be impossible to alert people to the availability of emergency supplies or inform them concerning emergency response activities. It also appears clear that greater awareness of the nature of an EMP attack and knowledge of what prudent preparations might be undertaken to mitigate its consequences would be desirable. The EMP Commission made the following recommendations.

  Recommendations

  The EMP Commission arrived at several common sense suggestions, most importantly, involving measures to ensure that the President can communicate effectively with the citizenry. The following recommendations were made:

  Because many citizens would be without power, communications, and other services for a significant period of time before full recovery could occur, it will be crucial to provide a reliable channel of information to all Americans. In particular:

  The Department of Homeland Security should play a leading role in spreading knowledge of the nature of prudent mitigation preparations for EMP attack to mitigate its consequences.

  The Department of Homeland Security should add content to Web sites it maintains, such as www.Ready.gov, which provides concise overviews of the threats posed by EMP attacks and geomagnetic storms, summarizes steps that people should take given an incident and identifies alternate or emergency communications channels.

  The Department of Homeland Security should work with state homeland security organizations to develop and exercise communications networks involving the organizations that normally operate in each community.

  After the EMP Commission’s term expired in 2008, the sense of urgency regarding these simple suggestions began to fall off our lawmaker’s radar. In 2015, that changed as the NDAA, for Fiscal Year 2016, revived the Commission. It is time to increase awareness, once again.

  PART SEVEN

  EMP SHIELDING – FARADAY CAGES

  From the simplistic to the sophisticated

  Chapter Eighteen

  Meet Michael Faraday

  "Faraday is, and must always remain, the father of that enlarged science of electromagnetism."

  ~ James Clerk Maxwell, renowned Scottish Scientist

  Michael Faraday, who came from a destitute family, became one of the greatest scientists in history. His achievement was remarkable, in a time when science was the preserve of people born into privileged households. His work may save all of our lives someday.

  Inspiration

  It was Ben Franklin who helped inspire many of the ideas behind Michael Faraday’s scientific work. Franklin, of course, spent part of his illustrious career flying kites in thunderstorms in attempts to attract lightning and thus was already acquainted with the concepts of electricity.

  In 1755, Franklin began toying with electricity in new ways. He electrified a silver pint can and dropped an uncharged cork ball attached to a non-conductive silk thread into it. He lowered the ball until it touched the bottom of the can and observed that the ball wasn't attracted to the interior sides of the can. Yet when Franklin withdrew the cork ball and dangled it near the electrified can's exterior, the ball was immediately drawn to the can's surface.

  Franklin was mystified by the interplay of electricity and the charged and uncharged objects. He admitted as much in a letter to a colleague: "You require the reason; I do not know it. Perhaps you may discover it, and then you will be so good as to communicate it to me."

  Decades later, an English physicist and chemist, named Michael Faraday, made other pertinent observations -- namely, he realized that an electrical conductor—such as a metal cage—when charged, exhibited that charge only on its surface. It had no effect on the interior of the conductor.

  Education and Early Life

  Michael Faraday was born on September 22, 1791, in London, England, UK. He was the third child of James and Margaret Faraday. His father was a blacksmith who endured ill health. Before marriage, his mother had been a servant. The family lived in a degree of poverty.

  Faraday attended a local school until he was thirteen, where he received a basic education. To earn money for the family, he started working as a delivery boy for a bookshop. He worked hard and impressed his employer. After a year, he was promoted to become an apprentice bookbinder.

  Faraday was eager to learn more about the world; he did not restrict himself to binding the shop’s books. After working hard each day, he spent his free time reading the books he had bound. Gradually, he found he was reading more and more about science. Two books, in particular, captivated him:

  · The Encyclopedia Britannica – his source for electrical knowledge and much more

  · Conversations on Chemistry – 600 pages of chemistry for ordinary people written by Jane Marcet

  He became so fascinated, that he started spending part of his meager pay on chemicals and apparatus to confirm the truth of what he was reading. He immersed himself in the world of chemistry and science. He took notes and then made so many additions to the notes that he produced a 300-page handwritten book, which he bound and distributed.

  At this time, Faraday had begun more sophisticated experiments at the back of the bookshop, building an electric battery using copper coins and zinc discs, separated by moist, salty paper. He used his battery to decompose chemicals—such as magnesium sulfate. A scientist was born.

  Faraday’s Scientific Achievements and Discoveries

  It would be easy to fill a book with details of all of Faraday’s discoveries – in both chemistry and physics. It is no accident that Albert Einstein used to keep photographs of three scientists in his office: Isaac Newton, James Clerk Maxwell and Michael Faraday. Faraday was a man devoted to discovery through experimentation, and he was famous for never giving up on any ideas that came from his scientific intuition. If he thought an idea was a good one, Faraday would keep experimenting through multiple failures until he achieved the desired result, or until he finally decided that Mother Nature had shown his intuition to be wrong. History would prove that in Faraday’s case, this was rare.

  Here are some of his most notable discoveries:

  1821: Discovery of Electromagnetic Rotation

  This was a glimpse of what would eventually develop into the electric motor, based on Hans Christian Oersted’s discovery that a wire carrying electric current has magnetic properties.

  1823: Gas Liquefaction—the conversion of a gas into a liquid state, and subsequent refrigeration of gas

  1825: Discovery of Benzene

  Historically benzene is one of the most important substances in chemistry, both in a practical sense – i.e. making new materials, and in a theoretical sense – i.e. understanding chemical bonding. Faraday discovered benzene in the oily residue left behind from producing gas for lighting during his days in London.

  1831: Discovery of Electromagnetic Induction

  This was an enormously important discovery for the future of both science and technology. Faraday discovered that a varying magnetic field caused electricity to flow through an electric circuit. For example, moving a horseshoe magnet over a wire produces an electric current, because the movement of the magnet caused a varying magnetic field.

  Previously, people had only been able to produce electric current with a battery. Now Faraday had shown that movement could be turned into electricity – or in more scientific language, kinetic energy could be co
nverted into electrical energy. Most of the power in our homes today is produced using this principle. Rotation, kinetic energy, is converted into electricity using electromagnetic induction. The rotation can be generated by high-pressure steam from coal, gas, or nuclear energy turning turbines, by hydroelectric plants, and by wind-turbines.

  1834: Faraday’s Laws of Electrolysis

  Faraday was one of the major players in the founding of the science of electrochemistry—what happens at the interface of an electrode with an ionic substance. Electrochemistry is the science that has produced the Lithium-ion battery and the metal hydride battery, both capable of powering modern mobile technology. Faraday’s laws are vital to our understanding of electrode reactions.

  1836: Invention of the Faraday Cage

  Faraday discovered that when an electrical conductor becomes charged, all of the extra charge sits on the outside of the conductor. This means that the additional charge does not appear on the inside of a room or cage made of metal. In addition to offering protection for people, sensitive electrical or electrochemical experiments can be placed inside a Faraday Cage to prevent interference from the external electrical activity. Faraday cages can also create dead zones for mobile communications.

  1845: Discovery of the Faraday Effect – a magneto-optical effect

  This was another vital experiment in the history of science. Faraday was the first to link electromagnetism and light – a link finally described fully by James Clerk Maxwell’s equations in 1864, which established that light is an electromagnetic wave. Faraday discovered that a magnetic field causes the plane of light polarization to rotate.

  Michael Faraday died in London, aged 75, on August 25, 1867. He was survived by his wife, Sarah. They had no children. He had been a devout Christian all of his life.

  He will be remembered by the following quote:

  Nature is our kindest friend and best critic in experimental science if we only allow her intimations to fall unbiased on our minds.

  Pieter Zeeman, 1902 Nobel Prize in Physics, wrote about Faraday when recalling the two titles of Faraday’s fundamental work: Magnetization of light and Illumination of lines of force.

  "They appear to us to be almost prophesies, because we have now seen that light can in fact be magnetized, and in nature itself, in the northern lights, an example of illumination of the magnetic lines of force of the Earth by the electrons escaping from the sun."

  Prophetic indeed.

  Chapter Nineteen

  Introduction to the Faraday Cage

  A Faraday cage or Faraday shield is an enclosure formed by conductive material or by a mesh of such material, used to block electric fields. Faraday cages sometimes go by other names. They can be called Faraday boxes, RF (radio frequency) shields, or EMF (electromotive force) cages. No matter what you call them, Faraday cages are most often used in scientific labs, either in experiments or product development.

  A Faraday cage operates because an external electrical field causes the electric charges within the cage's conducting material to be distributed such that they cancel the field's effect in the cage's interior. This phenomenon is used to protect sensitive electronic equipment from external radio frequency interference. Faraday cages are also used to enclose devices that produce radio frequencies, such as radio transmitters, to prevent their radio waves from interfering with other nearby equipment. They are also used to protect people and equipment against actual electric currents, such as lightning strikes and electrostatic discharges, since the cage conducts the electric current around the outside of the enclosed space and none passes through to the interior.

  Faraday cages cannot block static or slowly varying magnetic fields, such as the Earth's magnetic field (a compass will still work inside). To a large degree, though, they shield the interior from external electromagnetic radiation if the conductor is thick enough and any holes are significantly smaller than the wavelength of the radiation. For example, certain computer forensic test procedures of electronic systems that require an environment free of electromagnetic interference can be carried out within a screened room. These are separate spaces that are completely enclosed by one or more layers of a fine metal mesh or perforated sheet metal. The metal layers are grounded to dissipate any electric currents generated from external or internal electromagnetic fields. Thus, they block a large amount of the electromagnetic interference.

  A Faraday cage is designed to protect against an electromagnetic pulse that may be the result of a high-altitude nuclear detonation resulting in an EMP. A Faraday cage protects electronics by three different principles:

  · the conductive layer reflects incoming fields

  · the conductor absorbs incoming energy

  · the cage acts to create opposing fields.

  In concert, these principles safeguard the contents from excessive energy levels.

  For most geomagnetic storms, a Faraday cage is not necessary to protect against the size and scope of the most common coronal mass ejections because solar disturbances are at much lower, E3-level frequencies. A solar event doesn’t transfer energy in sufficient amounts into small electronics, except through wires coming into the system, which act as an antenna. A simple precaution against solar events is to unplug electronics or use high-quality surge suppressors.

  Faraday cages may have holes as long as they are small. This is why fine conductive/shielding fabric can be used when constructing a Faraday cage. In practice, the cage’s lid or door usually causes the most leakage. Taping the seam with aluminum tape prevents gaps. The gaps and seams must remain tiny for the item to be effective.

  A lot has been written about the grounding of a Faraday cage. The grounding of the cage, by attaching it to a steel rod driven into the earth, has little effect on the field levels seen inside the Faraday cage itself. Grounding primarily helps to keep the cage from becoming charged and perhaps re-radiating. In practice, an ungrounded Faraday cage protects the contents from harmful electromagnetic pulses as well as a grounded one.

  Some experts argue that grounding your Faraday cage is a bad idea. Although EMPs and lightning strikes are very different regarding intensity, you might consider how lightning strikes affect a flying plane. The metal shell of the aircraft acts as a giant Faraday cage, dispersing the electromagnetic energy around the plane. The airplane isn’t grounded. Therefore the effects of lightning strikes are minimal.

  A recent invention, the anti-static bag, is readily available to protect electronic components against EMPs. They can be purchased in many different sizes, including some large enough to hold radio equipment. Dr. Arthur T. Bradley, author and recognized preparedness expert, opined that while they do offer shielding from EMP, not all products are created equal. He found testing confirmed that products certified to MIL-PRF-8170 and/or MIL-PRF-131 provide the greatest protection from an EMP. Further, when selecting an anti-static bag, consider not only the shielding effectiveness, but also the physical ruggedness of the bag. A tear or large hole can compromise the bag by allowing EMP energy to enter.

  Storing a larger set of electronics might require a closet or more considerable space. A DIY shield room can be made by lining a small closet with conductive/shielding mesh, covering the entire room, and then sealing the gaps left by the entry with aluminum tape.

  There are three principal methods of protecting vulnerable electronic devices from a damaging EMP attack and natural EMP events;

  · Put equipment in a shielded room based on Faraday Cage principles

  · Hide it deep into mountain plants or underground bunkers

  · Place it in the center of a substantial building behind thick reinforced concrete walls and roof – primarily underground.

  The first alternative typically gives necessary protection, assuming that correct and solid construction is met.

  The protection effectiveness in a mountain plant or bunker depends on several factors like type of rock and soil, the degree of coverage, cable length, protection devices like gates
and other barriers in front of the tunnel, etc.

  The last alternative gives only a limited level of protection and is normally not sufficient unless it’s combined with additional solutions; like a Faraday Cage.

  Chapter Twenty

  Construct a Simple Faraday Cage

  The primary method to protect electronic equipment from lightning strikes, electrostatic discharges and EMP is the Faraday Cage. For the majority of household electronics, such as audio-visual, communication, or appliances that can be unplugged from their power source, a Faraday Cage is the easiest way of protecting the smallest electrical equipment. Generally speaking, a Faraday Cage could be a metal box, a trash can, or a manufactured mesh structure designed to divert the electromagnetic pulse. It is important that the objects placed inside the Faraday Cage be insulated from the inside surface of the box, ensuring the object will not be affected by the electronic pulse traveling around the outside metal surface of the box.

  A simple and inexpensive design can be achieved through DIY containers suitable for most Faraday Cage purposes. Some examples include cookie tins, ammunition cans, microwave ovens, metal filing cabinets, and galvanized steel trash cans. Faraday Cages do NOT have to be airtight, due to the long wavelength of an electromagnetic pulse. However, the design of the Faraday Cage using a conductive mesh needs to be impeccable. A Faraday Cage can be made of wire screen or other porous metal and provide the necessary protection for your devices.

 

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