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A powerful electromagnetic pulse (EMP) occurs due to a burst of energy that is emitted or conducted by a source such as the sun or an explosive device. If your survivalist arsenal contains electrical or electronic devices, it is necessary to provide them with EMP protection so that they can continue to work after the outbreak of hostilities or a natural or man-made disaster.

What is an electromagnetic pulse

Whenever it passes through the wires, it produces electric and magnetic fields that emanate perpendicular to the flow of current. The size of these fields is proportional to the current strength. The length of the wire directly affects the current strength of the induced electromagnetic pulse. In addition, even a normal power-up produces a short burst of electrical and magnetic energy.

In this case, the splash is so small that it is barely noticeable. For example, switching actions in electrical circuits, engines and ignition systems for gas engines also produce small EMI pulses that can cause interference on a nearby radio or television. To absorb them, filters are used to remove minor bursts of energy and interference from them.

A large release of energy is produced when a certain charge of electricity is quickly discharged. This electrostatic discharge (ESD) can shock a person or cause dangerous sparks around fuel vapors. Many also remember that as children we would rub our feet on the carpet and then touch our friends, creating an ESD discharge. This is also a form of ESD.

The stronger the pulse energy, the more it can damage buildings and affect people. For example, lightning is a powerful form of EMP. can be very dangerous and cause a disaster. Fortunately, most lightning is shorted to ground, where the electrical charge is absorbed. The lightning rod was invented by Benjamin Franklin, thanks to which many buildings and structures are preserved today.

Events such as nuclear explosions, high-altitude non-nuclear explosions, and solar storms can create powerful EMP that causes damage to electrical and electronic equipment located close to the source of the event. All of this threatens the power grid and the functioning of most electrical and electronic devices in our lives.

Damaging factors of electromagnetic pulse

The danger of EMP is that it affects life support and transport systems. Therefore, for example, when exposed to a powerful electromagnetic pulse, modern unprotected vehicles fail. This is especially true for cars manufactured after 1980. Therefore, in the event of a man-made disaster, the outbreak of hostilities, or a surge in solar activity, it is optimal to use old-style vehicles.

In addition, the electromagnetic pulse affects:

Computers.
Displays.
Printers.
Routers.
Transformers.
Generators.
Power supplies.
Landline phones.
Any electronic circuits.
TVs.
Radio, DVD players.
Gaming devices.
Media centers
Amplifiers.
Communication systems (transmitters, receivers)
Cables (data, telephone, coaxial, USB, etc.)
Wires (especially long ones).
Antennas (external and internal).
Electrical power cords.
Ignition systems (cars and aircraft).
Microwave electrical circuits.
Air conditioners.
Batteries (all types).
Flashlights.
Relay.
Alarm systems.
Charge controllers.
Converters.
Calculators.
Power tools.
Electronic spare parts.
Chargers.
Control devices (CO2, smoke detectors, etc.).
Pacemakers.
Hearing aids.
Medical monitoring devices, etc.

Factors that determine EMP damage

The strength of the incoming electromagnetic pulse.
Distance to the pulse source.
The angle of the line of impact from the source to your position on the rotating Earth.
The size and shape of objects that receive and collect EMR.
The degree of isolation of instruments and devices from things that can collect and transmit EMR energy.
Protecting or shielding instruments and devices.

How to protect yourself from EMP: first steps

It is highly likely that small systems will not be affected by EMP if they are isolated from the mains. Therefore, if you receive a warning about an impending EMP, unplug all appliances and devices plugged into the electrical outlet. Don't forget ventilation and thermostats. Disconnect the solar panels and the entire house from the mains, open the shut-off switches between the solar panels and the inverter, and between the inverter and the power distribution panel. With coordinated action, this will take a few minutes.

General protection against electromagnetic radiation

Suggested protective actions:

Turn off electronic devices when not in use.
Unplug electrical appliances when not in use.
Do not leave components such as printers and scanners in standby mode.
Use short cables for work.
Install protective induction around the components.
Use components with self-contained batteries.
Use loop antennas.
Connect all ground wires to one common ground point.
Whenever possible, use smaller devices that are less sensitive to EMR.
Install MOV (Metal Oxide Varistor) transition protectors on portable generators.
Use a UPS to protect electronics from EMP surge.
Use device locking.
Use hybrid protection (for example, a bandpass filter followed by a lightning arrester).
Keep sensitive instruments and devices away from long cable or electrical runs, antennas, guy wires, metal towers, corrugated metal, steel fences, and railroad tracks.
Install the cable underground, in shielded cable ducts.
Build one or more Faraday cages.

You should think through the protective system in advance. For example, a backup generator would likely not be damaged by a solar storm, but EMP could damage sensitive electronic controllers, so shielding is advisable. Conversely, a device such as an uninterruptible power supply (UPS) can be useful in its own right as a protection component. If EMP occurs, the surge may destroy the UPS, but it will most likely protect connected devices and components from destruction.

How to build a Faraday cage

A Faraday cage can be made at home from metal containers such as a trash can or bucket, a closet, a safe, or an old microwave oven. Any three-dimensional object that has a continuous surface without gaps or large holes will do. A tight-fitting lid is required.

Install non-conductive material (cardboard, wood, paper, sheets of foam or plastic) on all interior sides of the Faraday cage to keep the contents away from metal. You can also wrap each item in bubble wrap or plastic. All devices that are inside must be isolated from everything else and especially from the metal container.

What to put in a Faraday cage

Place inside the cage the entire electronic and electrical arsenal that is included in the NC, and those components that were purchased for future use. It is also necessary to place there everything that may be sensitive to EMR in case of receiving a warning signal. Including:

Batteries for radio.
Walkie-talkies.
Portable TVs.
LED flashlights.
Solar charger.
Computer (laptop or tablet).
Cell phones and smartphones.
Various light bulbs.
Charging cords for mobile phones, tablets, etc.

How to protect important information from EMP

Keep in mind that an electromagnetic pulse can disrupt infrastructure for a long time, and in this case, permanently. Therefore, it is worth preparing in advance and backing up important files and placing them on different media in different Faraday cages.

Instead of an afterword

If an EMP warning was not received, but you see a bright flash followed by a power outage, use your best judgment. After all, it is impossible to know in advance how heavy and dangerous the electromagnetic pulse will be, the range of which in some types of explosions reaches 1000 km. But through preparation and advance planning, we can determine how realistically we can survive in a post-EMP world.

And you will be safe!

From short distances. Naturally, I immediately wanted to make a similar homemade product, since it is quite impressive and demonstrates in practice the work of electromagnetic pulses. The first models of the EMR emitter had several high-capacity capacitors from disposable cameras, but this design does not work very well due to the long “recharging” time. So I decided to take a Chinese high voltage module (commonly used in stun guns) and add a "punch" to it. This design suited me. But unfortunately, my high-voltage module burned out and therefore I could not film an article on this homemade product, but I filmed a detailed video on the assembly, so I decided to take some points from the video, I hope the Administrator will not mind, since the homemade product is really very interesting.

I would like to say that all this was done as an experiment!

And so for the EMR emitter we need:
-high voltage module
-two 1.5 volt batteries
-box for batteries
-body, I use a 0.5 plastic bottle
-copper wire with a diameter of 0.5-1.5 mm
-button without lock
-wires

The tools we need are:
-soldering iron
-thermo glue

And so, the first thing you need to do is wind a thick wire of about 10-15 turns around the top of the bottle, turn to turn (the coil greatly affects the range of the electromagnetic pulse; a spiral coil with a diameter of 4.5 cm has shown to work best) then cut off the bottom of the bottle

Before this homemade product, I made an EMR based on a glove, but unfortunately I only shot a video of the tests; by the way, I went to an exhibition with this glove and took second place due to the fact that I showed the presentation poorly. The maximum range of the EMP glove was 20 cm. I hope this article was interesting to you, and be careful with high voltage!

Here is a video with tests and an EMP glove:

Electromagnetic pulse (EMP) is the damaging factor of nuclear weapons, as well as any other sources of EMP (for example, lightning, special electromagnetic weapons, a short circuit in high-power electrical equipment, or a nearby supernova explosion, etc.). The damaging effect of an electromagnetic pulse (EMP) is caused by the occurrence of induced voltages and currents in various conductors. The effect of EMR manifests itself primarily in relation to electrical and radio-electronic equipment. The most vulnerable are communication, signaling and control lines. In this case, insulation breakdown, damage to transformers, damage to semiconductor devices, etc. can occur. A high-altitude explosion can create interference in these lines over very large areas.

The nature of the electromagnetic pulse

A nuclear explosion produces huge amounts of ionized particles, powerful currents, and an electromagnetic field called an electromagnetic pulse (EMP). It has no effect on humans (at least within the limits of what has been studied), but it damages electronic equipment. The large amount of ions left behind from the explosion interferes with shortwave communications and radar operation. The height of the explosion has a very significant influence on the formation of EMR. EMP is strong in explosions at altitudes below 4 km, and is especially strong at altitudes above 30 km, but is less significant for the range of 4-30 km. This is due to the fact that EMR is formed when gamma rays are asymmetrically absorbed in the atmosphere. And at medium altitudes, just such absorption occurs symmetrically and evenly, without causing large fluctuations in the distribution of ions. The origin of EMP begins with an extremely short but powerful emission of gamma rays from the reaction zone. Over the course of ~10 nanoseconds, 0.3% of the explosion energy is released in the form of gamma rays. A gamma quantum, colliding with an atom of any gas in the air, knocks out an electron from it, ionizing the atom. In turn, this electron itself is capable of knocking out its fellow from another atom. A cascade reaction occurs, accompanied by the formation of up to 30,000 electrons for each gamma ray. At low altitudes, gamma rays emitted towards the ground are absorbed by it without producing many ions. Free electrons, being much lighter and more agile than atoms, quickly leave the region in which they originated. A very strong electromagnetic field is generated. This creates a very strong horizontal current, a spark, giving rise to broadband electromagnetic radiation. At the same time, on the ground, under the site of the explosion, electrons are collected, “interested” in the accumulation of positively charged ions directly around the epicenter. Therefore, a strong field is also created along the Earth.

And although a very small part of the energy is emitted in the form of EMR - 1/3x10-10, this happens in a very short period of time. So the power it develops is enormous: 100,000 MW. At high altitudes, ionization of the dense layers of the atmosphere located below occurs. At cosmic altitudes (500 km), the region of such ionization reaches 2500 km. Its maximum thickness is up to 80 km. The Earth's magnetic field twists the trajectories of electrons into a spiral, forming a powerful electromagnetic pulse for several microseconds. Within a few minutes, a strong electrostatic field (20-50 kV/m) arises between the Earth's surface and the ionized layer until most of the electrons are absorbed due to recombination processes. Although the peak field strength during a high-altitude explosion is only 1-10% of the ground level, the formation of an EMP takes 100,000 more energy - 1/3x10-5 of the total released, the strength remains approximately constant under the entire ionized region.

Impact of EMR on equipment. The ultra-strong electromagnetic field induces high voltage in all conductors. Power lines will actually be giant antennas; the voltage induced in them will cause insulation breakdown and failure of transformer substations. The majority of specially not protected semiconductor devices will fail. In this regard, microcircuits will give a big head start to the good old lamp technology, which does not care about either strong radiation or strong electric fields.

A nuclear explosion is accompanied by electromagnetic radiation in the form of a powerful short pulse that mainly affects electrical and electronic equipment.

Sources of electromagnetic pulse (EMP) occurrence. By its nature, EMR, with some assumptions, can be compared with the electromagnetic field of nearby lightning, which creates interference for radio receivers. Wavelengths range from 1 to 1000 m or more. EMR occurs mainly as a result of the interaction of gamma radiation generated during an explosion with atoms of the environment.

When gamma rays interact with atoms of the medium, the latter are imparted an energy impulse, a small fraction of which is spent on ionization of atoms, and the main part is spent on imparting translational motion to electrons and ions formed as a result of ionization. Due to the fact that much more energy is imparted to an electron than to an ion, and also due to the large difference in mass, electrons have a higher speed compared to ions. We can assume that the ions practically remain in place, and the electrons move away from them at speeds close to the speed of light in the radial direction from the center of the explosion. Thus, a separation of positive and negative charges occurs in space for some time.

Due to the fact that the air density in the atmosphere decreases with altitude, an asymmetry in the distribution of electric charge (electron flow) results in the area surrounding the explosion site. The asymmetry of the electron flow can also arise due to the asymmetry of the gamma ray flow itself due to the different thickness of the bomb shell, as well as the presence of the Earth’s magnetic field and other factors. The asymmetry of the electric charge (electron flow) at the site of the explosion in the air causes a current pulse. It emits electromagnetic energy in the same way as passing it through a radiating antenna.

The region where gamma radiation interacts with the atmosphere is called the EMR source region. The dense atmosphere near the earth's surface limits the area of ​​distribution of gamma rays (the mean free path is hundreds of meters). Therefore, in a ground explosion, the source area occupies an area of ​​only a few square kilometers and approximately coincides with the area where other damaging factors of a nuclear explosion are exposed.

During a high-altitude nuclear explosion, gamma rays can travel hundreds of kilometers before interacting with air molecules and, due to its rarefaction, penetrate deep into the atmosphere. Therefore, the size of the EMR source area is large. Thus, with a high-altitude explosion of ammunition with a power of 0.5-2 million tons, an EMP source area with a diameter of up to 1600-3000 km and a thickness of about 20 km can be formed, the lower boundary of which will pass at an altitude of 18-20 km (Fig. 1.4).

Rice. 1.4. The main options for the EMP situation: 1 - EMP situation in the source area and the formation of radiation fields from ground and air explosions; 2 - underground EMP situation at some distance from the explosion near the surface; 3 - EMP situation of a high-altitude explosion.

The large size of the source area during a high-altitude explosion generates intense EMR directed downwards over a significant part of the earth's surface. Therefore, a very large area may find itself in conditions of strong EMP influence, where other damaging factors of a nuclear explosion have practically no effect.

Thus, during high-altitude nuclear explosions, printing objects located outside the source of nuclear damage may be strongly affected by EMR.

The main parameters of EMR that determine the damaging effect are the nature of the change in the strength of the electric and magnetic fields over time - the shape of the pulse and the maximum field strength - the amplitude of the pulse.

The EMR of a ground-based nuclear explosion at a distance of up to several kilometers from the center of the explosion is a single signal with a steep leading edge and a duration of several tens of milliseconds (Fig. 1.5).

Rice. 1.5. Change in the field strength of the electromagnetic pulse: a - initial phase; b - main phase; c is the duration of the first quasi-half cycle.

EMR energy is distributed over a wide frequency range from tens of hertz to several megahertz. However, the high-frequency part of the spectrum contains a small fraction of the pulse energy; the bulk of its energy occurs at frequencies up to 30 kHz.

The amplitude of EMR in this zone can reach very large values ​​- in the air, thousands of volts per meter during the explosion of low-power ammunition and tens of thousands of volts per meter during explosions of high-power ammunition. In soil, the amplitude of EMR can reach hundreds and thousands of volts per meter, respectively.

Because the amplitude of EMP decreases rapidly with increasing distance, EMP from a ground-based nuclear explosion only affects a few kilometers from the center of the explosion; over long distances it has only a short-term negative effect on the operation of radio equipment.

For a low air explosion, the EMP parameters remain basically the same as for a ground explosion, but as the height of the explosion increases, the amplitude of the pulse at the ground surface decreases.

With a low air explosion with a power of 1 million tons, EMR with damaging field strengths spreads over an area with a radius of up to 32 km, 10 million tons - up to 115 km.

The amplitude of EMR in underground and underwater explosions is significantly less than the amplitude of EMR in explosions in the atmosphere, so its damaging effect in underground and underwater explosions is practically not manifested.

The damaging effect of EMR is caused by the occurrence of voltages and currents in conductors located in the air, ground, and on equipment of other objects.

Since the amplitude of EMR quickly decreases with increasing distance, its damaging effect is several kilometers from the center (epicenter) of a large-caliber explosion. Thus, with a ground explosion with a power of 1 Mt, the vertical component of the EMR electric field at a distance of 4 km is 3 kV/m, at a distance of 3 km - 6 kV/m, and at 2 km - 13 kV/m.

EMR does not have a direct effect on humans. Receivers of EMR energy - bodies that conduct electric current: all overhead and underground communication lines, control lines, alarms (since they have an electrical strength not exceeding 2-4 kV DC voltage), power transmission, metal masts and supports, aerial and underground antennas devices, above-ground and underground turbine pipelines, metal roofs and other structures made of metal. At the moment of explosion, a pulse of electric current appears in them for a fraction of a second and a potential difference appears relative to the ground. Under the influence of these voltages, the following can occur: breakdown of cable insulation, damage to input elements of equipment connected to antennas, overhead and underground lines (breakdown of communication transformers, failure of arresters, fuses, damage to semiconductor devices, etc., as well as burnout of fuse links included in the lines to protect the equipment. High electrical potentials relative to ground arising on screens, cable cores, antenna-feeder lines and wired communication lines can pose a danger to persons servicing the equipment.

EMP poses the greatest danger to equipment that is not equipped with special protection, even if it is located in particularly strong structures that can withstand large mechanical loads from the shock wave of a nuclear explosion. EMR for such equipment is the main damaging factor.

Power lines and their equipment, designed for voltages of tens and hundreds of kW, are resistant to the effects of electromagnetic pulses.

It is also necessary to take into account the simultaneous impact of a pulse of instantaneous gamma radiation and EMR: under the influence of the first, the conductivity of materials increases, and under the influence of the second, additional electric currents are induced. In addition, their simultaneous impact on all systems located in the explosion area should be taken into account.

High electrical voltages are generated (induced) on cable and overhead lines caught in the zone of powerful pulses of electromagnetic radiation. The induced voltage can cause damage to the input circuits of the equipment at fairly remote sections of these lines.

Depending on the nature of the impact of EMR on communication lines and the equipment connected to them, the following protection methods are recommended: the use of two-wire symmetrical communication lines, well insulated from each other and from the ground; exclusion of the use of single-wire external communication lines; shielding of underground cables with copper, aluminum, lead sheathing; electromagnetic shielding of units and equipment components; use of various types of protective input devices and lightning protection equipment.

Instructions

Take an unnecessary pocket film camera with a flash. Remove the batteries from it. Put on rubber gloves and disassemble the device.

Discharge the flash storage capacitor. To do this, take a resistance of about 1 kOhm and a power of 0.5 W, bend its leads, clamp it in small pliers with insulated handles, then, holding the resistor only with the help of pliers, close the capacitor with it for several tens of seconds. After this, finally discharge the capacitor , closing it with the blade of a screwdriver with an insulated handle for a few more tens of seconds.

Measure the voltage - it should not exceed a few volts. If necessary, discharge the capacitor again. Solder a jumper to the terminals of the capacitor.

Now discharge the capacitor in the sync contact circuit. It has a small capacity, so to discharge it, it is enough to briefly close the sync contact. At the same time, keep your hands away from the flash lamp, since when the sync contact is triggered, it receives pulse high voltage.

Connect the coil in series with the flash storage capacitor. If the camera does not have a flash test button, connect a well-insulated button, for example, a bell, in parallel with the sync contact.

Make small recesses in the body of the device to lead out the wires from the button and coil. They are so that when assembling the case these wires do not get pinched, which threatens to break them. Remove the jumper from the flash storage capacitor. Assemble the device, then remove the rubber gloves.

Insert batteries into the device. Turn it on by turning the flash away from you, wait until the capacitor charges, and then insert a screwdriver blade into the coil. Hold the screwdriver by the handle so that it does not fly out, and press the button. Simultaneously with the flash, an electromagnetic pulse, which will magnetize the screwdriver.

If the screwdriver is not magnetized well enough, you can repeat the operation several more times. As the screwdriver is used, it will lose magnetization. There is no need to worry about this - after all, you have a device with which you can always restore it. Please note that not all home craftsmen like magnetized screwdrivers. Some people find them very comfortable, others - on the contrary, very inconvenient.

Please note

Be careful when working with any high voltage devices.

Skeptical people at answer to the question about actions for nuclear explosion they will say that you need to wrap yourself in a sheet, go out into the street and form lines. to accept death as it is. But experts have developed a number of recommendations that will help you survive a nuclear explosion.

Instructions

If you receive information about a possible nuclear explosion in the area where you are, you should, if possible, go down to an underground shelter (bomb shelter) and not leave until you receive other instructions. If this is not possible, you are on the street and there is no way to get into the room, take cover behind any object that can provide protection; in extreme cases, lie flat on the ground and cover your head with your hands.

If you are so close to the epicenter of the explosion that the flash itself is visible, remember that you need to take shelter from the radioactive fallout that will appear in this case within 20 minutes, it all depends on the distance from the epicenter. It is important to remember that radioactive particles are carried hundreds of kilometers by wind.

Do not leave your shelter without an official statement from authorities that it is safe to do so. Try to make your stay in the shelter as comfortable as possible, maintain proper sanitary conditions, use water and food sparingly, give more food and drink to children, the sick and the elderly. If possible, provide assistance to the managers of the bomb shelter, because staying in a confined space of a large number of people can be unpleasant, and the duration of such forced cohabitation
can vary from one day to a month.

When returning to your home, it is important to remember and follow several rules. Before entering the house, make sure that it is intact, damaged, and that there is no partial collapse of the structure. When entering an apartment, first remove all flammable liquids, medications and any other potentially hazardous substances. Water, gas and electricity can only be turned on when you have clear confirmation that all systems are functioning normally.

When traveling in the area, stay away from blast-damaged areas and areas marked with “hazardous materials” and “radiation hazard” signs.

Please note

It will be invaluable to have a radio with you to listen to official messages from local authorities. Always follow what you receive, since the authorities always have more information than those around them.

Electromagnetic low power is not capable of causing gigantic destruction, demolishing everything in its path, such as that resulting from a nuclear explosion. You can generate a low-power impulse at home.

Instructions

First, get a film camera that you no longer need, preferably one with a flash.