Types of radiation and their effects on the human body

Radio waves

Humans can encounter some types of radiation everywhere. A prime example is radio waves. They are vibrations of an electromagnetic nature that can be distributed in space at the speed of light. Such waves carry energy from generators.

Radio wave sources can be divided into two groups.

Natural, these include lightning and astronomical units.
Artificial, that is, created by man. They include alternating current emitters. These can be radio communication devices, broadcasting devices, computers and navigation systems.

Human skin is capable of depositing this type of waves on its surface, so there are a number of negative consequences of their impact on humans. Radio wave radiation can slow down the activity of brain structures and also cause mutations at the gene level.

For persons who have a pacemaker, such exposure is fatal. These devices have a clear maximum permissible radiation level; rising above it introduces an imbalance in the operation of the stimulator system and leads to its failure.

All the effects of radio waves on the body have been studied only in animals; there is no direct evidence of their negative effect on humans, but scientists are still looking for ways to protect themselves. There are no effective methods as such yet. The only thing we can advise is to stay away from dangerous devices. Since household appliances connected to the network also create a radio wave field around themselves, it is simply necessary to turn off the power to devices that a person is not currently using.

Main sources of electromagnetic radiation

Power lines. At a distance of 10 meters, they pose a threat to human health, so they are placed at a high altitude or buried deep in the ground.
Electric transport. This includes electric cars, electric trains, subways, trams and trolleybuses, as well as elevators. The metro has the most harmful effects. It is better to travel on foot or by your own transport.
Satellite system. Fortunately, strong radiation, colliding with the surface of the Earth, is dissipated, and only a small part of the danger reaches people.
Functional transmitters: radars and locators. They emit an electromagnetic field at a distance of 1 km, so all airports and weather stations are located as far as possible from cities.

Radiation from household electrical appliances

Widespread sources of electromagnetic radiation are household appliances that are found in our homes.

Cell phones. The radiation from our smartphones does not exceed established standards, but when we call someone, after dialing the number, the base station connects to the phone. At this moment, the norm is greatly exceeded, so do not bring the phone to your ear immediately, but a few seconds after dialing the number.
Computer. The radiation also does not exceed the norm, but during long-term work, SanPin recommends taking a break of 5-15 minutes every hour.
Microwave. The microwave body provides protection from radiation, but not 100%. Being near a microwave is dangerous: radiation penetrates 2 cm under a person’s skin, triggering pathological processes. When operating the microwave oven, maintain a distance of 1-1.5 meters from it.
TV. Modern plasma TVs do not pose a great danger, but you should be wary of old ones with picture tubes and keep a distance of at least 1.5 m.
Hair dryer. When a hair dryer operates, it creates an electromagnetic field of enormous strength. At this time, we dry our hair long enough and hold the hair dryer close to our head. To reduce the danger, use a hair dryer maximum once a week. Drying your hair in the evening can cause insomnia.
Electric razor. Instead, buy a regular razor, and if you are used to it, buy a battery-powered electric razor. This will significantly reduce the electromagnetic load on the body.
Chargers create a field in all directions at a distance of 1 m. When charging your gadget, do not be close to it, and after charging, unplug the device from the outlet so that there is no radiation.
Electrical wiring and sockets. Cables coming from electrical panels pose a particular danger. The distance from the cable to the sleeping place must be at least 5 meters.
Energy-saving lamps also emit electromagnetic waves. This applies to fluorescent and LED lamps. Install a halogen or incandescent lamp: they do not emit anything and are not dangerous.

Infrared spectrum radiation

All types of radiation are interconnected in one way or another. Some of them are visible to the human eye. Infrared radiation is adjacent to the part of the spectrum that the human eye can detect. It not only illuminates the surface, but can also heat it.

The main natural source of infrared rays is the sun. Man has created artificial emitters, through which the necessary thermal effect is achieved.

Now we need to figure out how useful or harmful this type of radiation is for humans. Almost all long-wave radiation of the infrared spectrum is absorbed by the upper layers of the skin, so it is not only safe, but can also improve immunity and enhance regenerative processes in tissues.

As for short waves, they can go deep into tissues and cause overheating of organs. The so-called heat stroke is a consequence of exposure to short infrared waves. The symptoms of this pathology are known to almost everyone:

the appearance of dizziness in the head;
feeling of nausea;
increase in heart rate;
visual impairment characterized by darkening of the eyes.

How to protect yourself from dangerous influences? It is necessary to observe safety precautions, using heat-protective clothing and screens. The use of short-wave heaters must be strictly dosed; the heating element must be covered with heat-insulating material, with the help of which radiation of soft long waves is achieved.

Natural emitting objects

Perhaps the most striking example of radiation in nature is our star, the Sun. The temperature on the surface of the Sun is about 6000 K, so its maximum radiation occurs at a wavelength of 475 nm, that is, it lies within the visible spectrum.

The sun heats up the planets around it and their satellites, which also begin to glow. Here it is necessary to distinguish between reflected light and thermal radiation. Thus, our Earth can be seen from space in the form of a blue ball precisely due to reflected sunlight. If we talk about the thermal radiation of the planet, then it also occurs, but lies in the region of the microwave spectrum (about 10 microns).

Besides reflected light, it is interesting to give another example of radiation in nature, which is associated with crickets. The visible light they emit has nothing to do with thermal radiation and is the result of a chemical reaction between atmospheric oxygen and luciferin (a substance found in insect cells). This phenomenon is called bioluminescence.

X-ray radiation

If you think about it, all types of radiation can penetrate tissue. But it was X-ray radiation that made it possible to use this property in practice in medicine.

If we compare X-ray rays with light rays, the former are very long, which allows them to penetrate even opaque materials. Such rays are unable to be reflected or refracted. This type of spectrum has a soft and hard component. Soft consists of long waves that can be completely absorbed by human tissue. Thus, constant exposure to long waves leads to cell damage and DNA mutation.

There are a number of structures that are not able to transmit x-rays through themselves. These include, for example, bone tissue and metals. Based on this, photographs of human bones are taken to diagnose their integrity.

Currently, devices have been created that make it possible not only to take a fixed photograph, for example, of a limb, but also to observe the changes occurring in it “online”. These devices help the doctor perform surgery on the bones under visual control, without making wide traumatic incisions. Using such devices, it is possible to study the biomechanics of joints.

As for the negative effects of X-rays, prolonged contact with them can lead to the development of radiation sickness, which manifests itself in a number of signs:

neurological disorders;
dermatitis;
decreased immunity;
inhibition of normal hematopoiesis;
development of oncological pathology;
infertility.

To protect yourself from dire consequences, when coming into contact with this type of radiation, you need to use shields and linings made of materials that do not transmit rays.

Application

Solar radiation is used to extract and use solar energy. Solar batteries (Figure 3) allow you to accumulate solar energy and convert it for further human use.

Figure 3. Solar panels.

Airplane wings and the surfaces of airborne weather balloons are painted with silver paint (Figure 4). This is how they use the ability of bodies to absorb energy differently. They do this in order to reduce heat.

Figure 4. Airborne weather balloon.

Radiation is used for drying and heating materials, in night vision devices, and in medicine. Later in your training, you will examine the nature of this phenomenon in more detail.

Optical radiation

People are accustomed to simply calling this type of rays light. This type of radiation can be absorbed by the object of influence, partially passing through it and partially being reflected. Such properties are widely used in science and technology, especially in the manufacture of optical instruments.

All sources of optical radiation are divided into several groups.

Thermal, having a continuous spectrum. Heat is released in them due to current or combustion process. These can be electric and halogen incandescent lamps, as well as pyrotechnic products and electric lighting devices.
Luminescent, containing gases excited by streams of photons. Such sources are energy-saving devices and cathodoluminescent devices. As for radio- and chemiluminescent sources, the flows in them are excited due to radioactive decay products and chemical reactions, respectively.
Plasma, whose characteristics depend on the temperature and pressure of the plasma formed in them. These can be gas-discharge, mercury tube and xenon lamps. Spectral sources, as well as pulsed devices, are no exception.

Optical radiation acts on the human body in combination with ultraviolet radiation, which provokes the production of melanin in the skin. Thus, the positive effect lasts until a threshold exposure value is reached, beyond which there is a risk of burns and skin cancer.

Electromagnetic radiation protection

If you spend a lot of time at the computer, remember one rule: the distance between your face and the monitor should be about a meter.
The level of electromagnetic radiation from the household appliances you buy should not reach about. Contact your sales consultant. He will help you choose the safest technique.
Your bed should not be near any electrical wiring. Place your sleeping area at the opposite end of the room.
Install a protective screen on your computer. It is made in the form of a fine metal mesh and operates according to the Faraday principle: it absorbs all radiation, protecting the user.
Reduce your time on electrified public transport. Give preference to walking and cycling.

Ultraviolet radiation

The most famous and widely used radiation, the effects of which can be found everywhere, is ultraviolet radiation. This radiation has two spectra, one of which reaches the earth and participates in all processes on earth. The second is retained by the ozone layer and does not pass through it. The ozone layer neutralizes this spectrum, thereby performing a protective role. The destruction of the ozone layer is dangerous due to the penetration of harmful rays onto the surface of the earth.

The natural source of this type of radiation is the Sun. A huge number of artificial sources have been invented:

Erythema lamps that activate the production of vitamin D in the layers of the skin and help treat rickets.
Solariums not only allow you to sunbathe, but also have a healing effect for people with pathologies caused by a lack of sunlight.
Laser emitters used in biotechnology, medicine and electronics.

As for the effect on the human body, it is twofold. On the one hand, a lack of ultraviolet radiation can cause various diseases. A dosed load of such radiation helps the immune system, muscle and lung function, and also prevents hypoxia.

All types of influences are divided into four groups:

ability to kill bacteria;
relieving inflammation;
restoration of damaged tissues;
reduction of pain.

The negative effects of ultraviolet radiation include the ability to provoke skin cancer with prolonged exposure.
Melanoma of the skin is an extremely malignant type of tumor. Such a diagnosis almost 100 percent means impending death. As for the organ of vision, excessive exposure to ultraviolet rays damages the retina, cornea and membranes of the eye. Thus, this type of radiation should be used in moderation. If, under certain circumstances, you have to be in contact with a source of ultraviolet rays for a long time, then it is necessary to protect your eyes with glasses and your skin with special creams or clothing.

Types of radiation and their applications

Types of radiation and their application!

Davydova Olga

11 "A"

Types of radiation

Currently we know 6 types of radiation - gamma radiation, x-rays, ultraviolet radiation, optical radiation, infrared radiation and radio waves

Radio waves.

Radio waves were discovered back in the 19th century, they were observed by Hertz in his experiments, the first tests took place already in the 20th century in Leningrad.

Radio waves are electromagnetic waves that travel through space at the speed of light (300,000 km/s). Light also belongs to electromagnetic waves, which determines their very similar properties (reflection, refraction, attenuation, etc.).

Radio waves carry energy emitted by an electromagnetic oscillator through space. And they are born when the electric field changes, for example, when an alternating electric current passes through a conductor, or when sparks jump through space, i.e. a series of rapidly successive current pulses.

Electromagnetic radiation is characterized by frequency, wavelength and power of transferred energy.

Properties of radio waves.

The properties of radio waves allow them to pass freely through air or vacuum. But if a metal wire, antenna or any other conducting body meets on the path of the wave, then they give up their energy to it, thereby causing an alternating electric current in this conductor. But not all the wave energy is absorbed by the conductor; part of it is reflected from the surface. The use of electromagnetic waves in radar is based on this property.

The main property of radio waves is that they are able to transfer energy emitted by a generator of electromagnetic oscillations through space. Oscillations occur when the electric field changes.

Application of radio waves.

Radio waves, as a means for wireless transmission of sound, video and other information over fairly significant distances, have gained popularity and a wide range of use. It is radio waves that underlie the organization of many modern processes, including: radio broadcasting, television, radiotelephone communications, radio meteorology, and radiolocation.

Infrared radiation.

Infrared radiation is electromagnetic radiation that occupies the spectral region between the red end of visible light (λ = 0.74 μm) and microwave radiation (λ ~ 1-2 mm).

The optical properties of substances in infrared radiation differ significantly from their properties in visible radiation. For example, a layer of water of several centimeters is opaque to infrared radiation with λ = 1 μm. Infrared radiation makes up most of the radiation from incandescent lamps, gas-discharge lamps, and about 50% of the radiation from the Sun.

Infrared radiation was discovered in 1800 by the English astronomer W. Herschel. While studying the Sun, Herschel was looking for a way to reduce the heating of the instrument with which the observations were made. Using thermometers to determine the effects of different parts of the visible spectrum, Herschel discovered that the “maximum of heat” lies behind the saturated red color and, possibly, “beyond visible refraction.” This study marked the beginning of the study of infrared radiation.

Properties of infrared radiation.

The optical properties of substances (transparency, reflectance, refraction) in the infrared region of the spectrum, as a rule, differ significantly from the same properties in the visible region that is familiar to us.

For most metals, the reflectivity for infrared radiation is much greater than for visible light, and increases with wavelength.

Materials that are transparent to IR rays and have a high ability to reflect them are used to create IR devices

Applications of IR radiation

Infrared radiation is used in: medicine; remote control; when painting (for drying paint surfaces); for sterilization of food products; as an anti-corrosion agent (to prevent corrosion of surfaces coated with varnish); checking banknotes for authenticity; for heating the room.

X-ray radiation

X-RAY RADIATION - electromagnetic radiation invisible to the eye with a wavelength of 10−7—10−12 m. Discovered in 1895 in Germany. physicist V.K. Roentgen (1845-1923). Emitted during the deceleration of fast electrons in a substance (continuous spectrum) and during transitions of electrons from the outer electron shells of the atom to the inner ones (line spectrum). Sources are: some radioactive isotopes, X-ray tube, accelerators and electron storage devices (synchrotron radiation).

Properties of X-ray radiation.

The main properties of X-ray radiation: interference, diffraction of X-rays on a crystal lattice, high penetrating power, and causes fluorescence in some substances.

Application of X-ray radiation.

Using X-rays, you can “enlighten” the human body, as a result of which you can get an image of bones, and with modern devices, internal organs (radiography and fluoroscopy).

Detection of defects in products (rails, welds, etc.) using X-ray radiation is called X-ray flaw detection.

In materials science, crystallography, chemistry and biochemistry, X-rays are used to elucidate the structure of substances at the atomic level using X-ray diffraction scattering (X-ray diffraction). A well-known example is the determination of the structure of DNA.

Using X-rays, the chemical composition of a substance can be determined.

At airports, X-ray television introscopes are actively used, allowing one to view the contents of hand luggage and baggage.

Optical radiation

Optical radiation is light in the broad sense of the word, electromagnetic waves, the lengths of which are in the range with conventional boundaries from 1 nm to 1 mm. In addition to visible radiation perceived by the human eye, this type of radiation includes infrared radiation and ultraviolet radiation. Parallel to the term "O. And." The term “light” historically has less defined spectral boundaries - it often denotes not all optical radiation, but only its visible subrange. Optical research methods are characterized by the formation of directed radiation fluxes using optical systems, including lenses, mirrors, optical prisms, diffraction gratings, etc.

Properties of optical radiation

The wave properties of optical radiation determine the phenomena of light diffraction, light interference, light polarization, etc. At the same time, a number of optical phenomena cannot be understood without invoking the concept of optical radiation as a flow of fast particles - photons. This duality of nature. Optical radiation brings it closer to other objects of the microworld and finds a general explanation in quantum mechanics. The speed of propagation of optical radiation in a vacuum (the speed of light) is about 3·108 m/s. In any other medium, the speed of optical radiation is lower. The refractive index of the medium, determined by the ratio of these velocities (in vacuum and medium), is generally not the same for different wavelengths of optical radiation, which leads to dispersion of optical radiation.

Application: In agricultural production, infrared radiation is used mainly for heating young animals and poultry, drying and disinfestation of agricultural products (grain, fruits, etc.), pasteurization of milk, drying of paints and impregnating coatings

Ultraviolet radiation.

Ultraviolet radiation (ultraviolet, UV, UV) is electromagnetic radiation, occupying the range between the violet boundary of visible radiation and X-ray radiation (380 - 10 nm, 7.9 1014 - 3 1016 Hz). The range is conventionally divided into near (380-200 nm) and far, or vacuum (200-10 nm) ultraviolet, the latter so named because it is intensively absorbed by the atmosphere and is studied only by vacuum devices.

Properties of ultraviolet radiation

High chemical activity, invisible, high penetrating ability, kills microorganisms, in small doses has a beneficial effect on the human body (tanning), but in large doses it has a negative biological effect: changes in cell development and metabolism, effects on the eyes.

The reflectance of all materials (including metals) decreases with decreasing wavelength of radiation.

Wavelength from 10 – 400 nm. Wave frequency from 800*1012 - 3000*1013 Hz.

Application of ultraviolet radiation.

A black light lamp is a lamp that emits predominantly in the long-wave ultraviolet region of the spectrum (UVA range) and produces very little visible light.

To protect documents from forgery, they are often equipped with ultraviolet tags, which are visible only under ultraviolet lighting.

Disinfection with ultraviolet (UV) radiation. Sterilization of air and hard surfaces. Water disinfection is carried out by chlorination in combination, as a rule, with ozonation or disinfection with ultraviolet (UV) radiation. Chemical analysis, UV spectrometry. UV spectrophotometry is based on irradiating a substance with monochromatic UV radiation, the wavelength of which changes over time. The substance absorbs UV radiation at different wavelengths to varying degrees. A graph with the amount of transmitted or reflected radiation on the ordinate axis and the wavelength on the abscissa axis forms a spectrum. The spectra are unique for each substance, which is the basis for the identification of individual substances in a mixture, as well as their quantitative measurement. Catching insects. In medicine (room disinfection).

Gamma radiation.

Gamma radiation (gamma rays) is a type of electromagnetic radiation with an extremely short wavelength < 5·10−3 nm and, as a result, weakly expressed wave properties. On the scale of electromagnetic waves, gamma radiation borders on x-rays, occupying a range of higher frequencies and energies. In the region of 1-100 keV, gamma radiation and X-ray radiation differ only in source: if a quantum is emitted in a nuclear transition, then it is usually classified as gamma radiation; if during interactions of electrons or during transitions in the atomic electron shell - to x-ray radiation. From the point of view of physics, quanta of electromagnetic radiation with the same energy do not differ, so this division is arbitrary.

Properties of gamma radiation.

Gamma rays, unlike α-rays and β-rays, are not deflected by electric and magnetic fields and are characterized by greater penetrating power at equal energies and other equal conditions. The main processes that occur when gamma radiation passes through matter:

photoelectric effect - the energy of a gamma quantum is absorbed by an electron in the shell of an atom, and the electron, performing a work function, leaves the atom, which becomes ionized;

the effect of pair formation - a gamma quantum in the nuclear field turns into an electron and a positron;

nuclear photoelectric effect - at energies above several tens of MeV, a gamma quantum is capable of knocking nucleons out of the nucleus.

Application of gamma radiation.

Gamma flaw detection, inspection of products by transillumination with γ-rays.

Food preservation.

Sterilization of medical materials and equipment.

Radiation therapy.

Gamma altimeter, measuring the distance to the surface when landing spacecraft.

Gamma sterilization of spices, grains, fish, meat and other products to increase shelf life.

Impact of electromagnetic radiation on humans

The impact of electromagnetic fields (EMF) on a person depends on the field intensity, wavelength, exposure time and the functional state of the body. The depth of penetration of the field into a living organism depends on the wavelength. Long-wave EMFs penetrate deep into the body, affecting the spinal cord and brain. Microwave EMFs spend their energy mainly in the surface layer of the skin, leading to thermal effects. The organs that suffer most from this are those that are not protected by a fat layer and that are poor in blood vessels (eyes, brain, kidneys, gall and bladder, testes). Excess heat is removed from the body due to thermoregulation. However, starting from a certain value, called the thermal threshold, the body cannot cope with the removal of the generated heat and the body temperature rises. In this case, the higher the EMF frequency, the lower the value of the thermal threshold. For example, for decimeter waves the thermal threshold is 40 mW/cm2, and for millimeter waves - 7 mW/cm2. Constant exposure to EMF leads to functional disorders of the nervous, endocrine and cardiovascular systems; a person’s blood pressure decreases, the pulse slows down, reflexes are inhibited, and the composition of the blood changes. Thermal exposure can lead to overheating of the body and individual organs and disruption of their functional activity. Microwave EMFs lead to thermal cataracts (clouding of the lens of the eye). Subjectively, the manifestation of EMF exposure is expressed in increased fatigue, headache, irritability, shortness of breath, drowsiness, blurred vision, and increased body temperature. Permissible levels of exposure to EMF are given in GOST 12.1.006-84 “Electromagnetic fields of radio frequencies. Permissible levels at workplaces and requirements for monitoring.” GOST 12.1.006-84 sets the maximum permissible values for the energy flux density of the electromagnetic field. The maximum permissible values of electromagnetic field energy flux density are 25 μW/cm2 for 8 hours, 100 μW/cm2 for 2 hours, and the maximum value should not exceed 1000 μW/cm2. EMFs with a frequency from 60 kHz to 300 MHz are normalized separately for the electrical and magnetic components, since at these frequencies a person is affected by electric and magnetic fields independently of each other. For microwave range fields (300 MHz - 300 GHz), the maximum permissible energy flux density is standardized, which should not exceed 10 W/m2. If EMF values at workplaces exceed permissible limits, then it is necessary to provide appropriate methods for human protection. During the Soviet era, at military factories, research institutes, design bureaus, people associated with high-frequency radiation received: a 15% bonus for harmfulness, a shortened working day, and a reduction in the retirement age. The body's sensitivity to high-frequency radiation begins at levels much less than thermal exposure. Starting on the order of fractions of a microwatt per square centimeter; up to a few milliwatts, the phase of inhibition of the organism continues, then the phase of stimulation begins - improvement under the influence of high-frequency radiation of the general condition of the body or the sensitivity of its individual organs, and at a density of more than 10 mW/cm2 the phase of inhibition of the organism begins again.” A cell phone is a source of non-ionizing radiation in the 900 and 1800 MHz bands. Based on the impact on the human body, high-frequency radiation is conventionally divided into two types:

Gamma radiation

These are the so-called cosmic rays, which carry the nuclei of atoms of radioactive substances and elements. The gamma radiation flux has very high energy and is able to quickly penetrate the body's cells, ionizing their contents. Destroyed cellular elements act as poisons, decomposing and poisoning the entire body. The cell nucleus is necessarily involved in the process, which leads to mutations in the genome. Healthy cells are destroyed, and in their place mutant cells are formed that are unable to fully provide the body with everything it needs.

This radiation is dangerous because a person does not feel it at all. The consequences of exposure do not appear immediately, but have a long-term effect. The cells of the hematopoietic system, hair, genital organs and lymphoid system are primarily affected.

Radiation is very dangerous for the development of radiation sickness, but even this spectrum has found useful applications:

it is used to sterilize products, equipment and instruments for medical purposes;
measuring the depth of underground wells;
measuring the path length of spacecraft;
impact on plants in order to identify productive varieties;
In medicine, such radiation is used for radiation therapy in the treatment of oncology.

In conclusion, it must be said that all types of rays are successfully used by humans and are necessary. Thanks to them, plants, animals and people exist. Protection against overexposure should be a priority when working.

From X-ray to Gamma

The boundary at which the X-ray range gives way to gamma radiation is also arbitrary. It is usually associated with the energy of quanta that are emitted during nuclear reactions (or, conversely, can cause them). Another approach is due to the fact that thermal radiation is not usually attributed to the gamma range, no matter how high its energy. Relatively stable macroscopic objects heated to tens of millions of degrees are observed in the Universe - these are the central sections of accretion disks around neutron stars and black holes. But objects with temperatures of billions of degrees—for example, the cores of massive red giants—are almost always covered in an opaque shell. However, even the radiation in their depths is often called not soft gamma radiation, but superhard X-rays. There are no stable formations with temperatures above tens of billions of degrees in the modern Universe. This gives grounds to believe that gamma radiation is always generated by non-thermal means. The main mechanism is radiation from the collision of charged particles accelerated to near-light speeds by powerful electromagnetic fields, for example, in neutron stars.

Light range

Frequency: $10^{11} – 10^{18}$ Hz.
Wavelength: $3\times10^{-10} – 3\times10^{-3}$m.

Electromagnetic radiation in this range propagates like visible light, which is why the range is called light. However, visible light in it occupies only a narrow frequency band $3.5\times 10^{14}$ Hz – $7.5\times 10^{14}$ Hz. Lower frequencies are occupied by infrared radiation, which is generated by all heated bodies. Higher frequencies are occupied by ultraviolet radiation generated using special UV lamps.

Radiation in this range propagates well in the atmosphere and is reflected from solid and liquid surfaces. This determines the development of the visual analyzer in most living beings.

Radiation from charged particle systems

The simplest system that can radiate is an electric dipole with a variable dipole moment - a system of two oppositely charged oscillating particles. When the dipole field changes, e.g. When particles oscillate along the straight line connecting them (dipole axis) towards each other, part of the field breaks off and electromagnetic waves are formed. Such energy is nonisotropic, its energy varies. directions is not the same: it is maximum in the direction perpendicular to the axis of vibration of the particles, and is absent in the perpendicular direction; for intermediate directions its intensity is proportional to $\text{sin}\:\theta^2$ ($θ$ is the angle between the direction of vibration and the axis of vibration particles). Real emitters, as a rule, consist of a large number of oppositely charged particles, but often taking into account their location and details of movement far from the system are unimportant; in this case, it is possible to simplify the true distribution by “pulling” charges of the same name to certain centers of charge distribution. If the system as a whole is electrically neutral, then its electrical energy can be approximately considered electrical. dipole.

If there is no dipole I. of the system, then it can be represented as a quadrupole or a more complex system - a multipole. When charges move, electricity arises in it. quadrupole or multipole I. Sources of I. can also be systems that represent magnetic dipoles (for example, a circuit with current) or magnetic multipoles. The intensity of magnetic dipole radiation is, as a rule, $(v/c)^2$ times less than the intensity of electrical radiation. dipole I. and of the same order as electric. quadrupole radiation.