radioactivity called the property of spontaneous radiation of any substances, in the absence of external influences.

Radioactive properties were first discovered in uranium in 1896 by the French physicist Henri Becquerel (experiment with uranium salts)

Subsequently, it was found that all chemical elements with a serial number greater than 83 are radioactive.

Properties of radioactive radiation

1. Cause ionization of gases

2. Have a chemical effect

3. Radioactivity is not a molecular phenomenon, but an internal property of the atoms of a radioactive element

4. The radioactivity of the drug with any chemical composition equal to the radioactivity of pure radioactive elements, taken in the amount in which they are contained in this preparation

5. Radioactive radiation does not depend on external influences (heating, pressure increase), chemical reactions in which radioactive substances enter do not affect the radiation intensity.

6. As a result radioactive radiation a completely new type of substance is formed, completely different in its physical and chemical properties from the original. The chain of radioactive transformations ends with the formation of a non-radioactive (stable) isotope.

7. For each radioactive substance, there is a certain time interval during which the activity decreases by 2 times. This interval is called the half-life.

Half-life T- this is the time during which half of the available number of radioactive atoms decays.

– radioactive decay law

N 0 - number of radioactive atoms at the initial moment of time

N- number of radioactive atoms at the end time

t- time

T- half life

8. Distinguish between natural radioactivity (radioactivity of naturally occurring elements) and artificial radioactivity (radioactivity of elements obtained in nuclear reactions).

To discover complex composition radiation was carried out next experience: a radioactive preparation was placed at the bottom of a narrow channel in a piece of lead. A photographic plate was placed against the canal. At the exit from the channel, a strong magnetic field acted on the radiation, the lines of induction of which are perpendicular to the beam. The entire setup was placed in a vacuum.

In the absence of a magnetic field, a single dark spot was found on the photographic plate after development, exactly opposite the channel.

In a magnetic field, the beam split into three beams.

alpha radiation

This is a stream of positively charged particles - the nuclei of helium atoms. The velocities of alpha particles are much less than the speed of beta particles and lie in the range of 10,000-20,000 km/s. The kinetic energy of alpha particles is high: 4-10 MeV.

Alpha radiation has the least penetrating power. A layer of paper about 0.1 mm thick completely delays them.

Beta radiation

This is a stream of fast electrons escaping from the atoms of a radioactive substance. The speeds of beta particles are huge and amount to 0.99 of the speed of light. The energy of beta particles reaches several megaelectronvolts.

Beta radiation is average in its penetrating power. They are held back by an aluminum plate a few millimeters thick.

Gamma radiation

This is the flow electromagnetic waves very small length (10 -8 - 10 -11 cm). The speed of propagation of gamma rays in vacuum is the same as that of other electromagnetic waves, 300,000 km/s.

Gamma radiation has the highest penetrating power. A layer of lead 1 cm thick reduces the intensity of gamma radiation by half.

Gamma radiation and X-ray radiation of equal wavelength, except for the method of obtaining, do not differ from each other.

Article navigation:

Radiation and types of radioactive radiation, the composition of radioactive (ionizing) radiation and its main characteristics. The action of radiation on matter.

What is radiation

First, let's define what radiation is:

In the process of decay of a substance or its synthesis, the elements of the atom (protons, neutrons, electrons, photons) are ejected, otherwise we can say radiation occurs these elements. Such radiation is called ionizing radiation or what is more common radiation, or even easier radiation . Ionizing radiation also includes x-rays and gamma rays.

Radiation is the process of emission of charged substances elementary particles, in the form of electrons, protons, neutrons, helium atoms or photons and muons. The type of radiation depends on which element is emitted.

Ionization- is the process of formation of positively or negatively charged ions or free electrons from neutrally charged atoms or molecules.

Radioactive (ionizing) radiation can be divided into several types, depending on the type of elements of which it consists. Different types of radiation are caused by different microparticles and therefore have different energy effects on matter, different ability to penetrate through it and, as a result, different biological effects of radiation.

Alpha, beta and neutron radiation- These are radiations consisting of various particles of atoms.

Gamma and X-rays is the emission of energy.

alpha radiation

• emitted: two protons and two neutrons
• penetrating power: low
• source exposure: up to 10 cm
• radiation speed: 20,000 km/s
• ionization: 30,000 pairs of ions per 1 cm of run
• high

Alpha (α) radiation arises from the decay of unstable isotopes elements.

alpha radiation- this is the radiation of heavy, positively charged alpha particles, which are the nuclei of helium atoms (two neutrons and two protons). Alpha particles are emitted during the decay of more complex nuclei, for example, during the decay of uranium, radium, and thorium atoms.

Alpha particles have a large mass and are emitted at a relatively low speed of 20,000 km/s on average, which is about 15 times less than the speed of light. Since alpha particles are very heavy, upon contact with a substance, the particles collide with the molecules of this substance, begin to interact with them, losing their energy, and therefore the penetrating power of these particles is not great and even a simple sheet of paper can hold them.

However, alpha particles carry a lot of energy and, when interacting with matter, cause its significant ionization. And in the cells of a living organism, in addition to ionization, alpha radiation destroys tissues, leading to various damage to living cells.

Of all types of radiation, alpha radiation has the least penetrating power, but the consequences of irradiating living tissues with this type of radiation are the most severe and significant compared to other types of radiation.

Exposure to radiation in the form of alpha radiation can occur when radioactive elements enter the body, for example, with air, water or food, as well as through cuts or wounds. Once in the body, these radioactive elements are carried by the bloodstream throughout the body, accumulate in tissues and organs, exerting a powerful energy effect on them. Since some types of radioactive isotopes that emit alpha radiation have a long lifespan, when they get inside the body, they can cause serious changes in cells and lead to tissue degeneration and mutations.

Radioactive isotopes are not actually excreted from the body on their own, therefore, once inside the body, they will irradiate the tissues from the inside for many years until they lead to serious changes. The human body is not able to neutralize, process, assimilate or utilize the majority of radioactive isotopes that have entered the body.

neutron radiation

• emitted: neutrons
• penetrating power: high
• source exposure: kilometers
• radiation speed: 40,000 km/s
• ionization: from 3000 to 5000 pairs of ions per 1 cm of run
• biological effect of radiation: high

neutron radiation- this is man-made radiation that occurs in various nuclear reactors and during atomic explosions. Also, neutron radiation is emitted by stars in which active thermonuclear reactions take place.

Having no charge, neutron radiation, colliding with matter, weakly interacts with elements of atoms at the atomic level, therefore it has a high penetrating power. Neutron radiation can be stopped by using materials with a high hydrogen content, such as a container of water. Also, neutron radiation does not penetrate well through polyethylene.

Neutron radiation passing through biological tissues causes serious damage to cells, as it has a significant mass and a higher speed than alpha radiation.

beta radiation

• emitted: electrons or positrons
• penetrating power: average
• source exposure: up to 20 m
• radiation speed: 300,000 km/s
• ionization: from 40 to 150 pairs of ions per 1 cm of run
• biological effect of radiation: the average

Beta (β) radiation arises during the transformation of one element into another, while the processes occur in the very nucleus of the atom of matter with a change in the properties of protons and neutrons.

With beta radiation, a neutron is converted into a proton or a proton into a neutron, with this transformation an electron or positron (an antiparticle of the electron) is emitted, depending on the type of transformation. The speed of the emitted elements approaches the speed of light and is approximately equal to 300,000 km/s. The emitted elements are called beta particles.

Having an initially high radiation speed and small dimensions of the emitted elements, beta radiation has a higher penetrating power than alpha radiation, but has hundreds of times less ability to ionize matter compared to alpha radiation.

Beta radiation easily penetrates through clothes and partially through living tissues, but when passing through denser structures of matter, for example, through metal, it begins to interact with it more intensively and loses most of its energy, transferring it to the elements of matter. A metal sheet of a few millimeters can completely stop beta radiation.

If alpha radiation is dangerous only in direct contact with a radioactive isotope, then beta radiation, depending on its intensity, can already cause significant harm to a living organism at a distance of several tens of meters from the source of radiation.

If a radioactive isotope emitting beta radiation gets inside a living organism, it accumulates in tissues and organs, exerting an energy effect on them, leading to changes in the structure of tissues and causing significant damage over time.

Some radioactive isotopes with beta radiation have a long decay period, that is, when they enter the body, they will irradiate it for years until they lead to tissue degeneration and, as a result, to cancer.

Gamma radiation

• emitted: energy in the form of photons
• penetrating power: high
• source exposure: up to hundreds of meters
• radiation speed: 300,000 km/s
• ionization:
• biological effect of radiation: low

Gamma (γ) radiation- this is an energetic electromagnetic radiation in the form of photons.

Gamma radiation accompanies the process of decay of atoms of matter and manifests itself in the form of radiated electromagnetic energy in the form of photons released when the energy state of the atomic nucleus changes. Gamma rays are emitted from the nucleus at the speed of light.

When a radioactive decay of an atom occurs, then others are formed from some substances. Atom again formed substances are in an energetically unstable (excited) state. By acting on each other, neutrons and protons in the nucleus come to a state where the forces of interaction are balanced, and excess energy is emitted by the atom in the form of gamma radiation

Gamma radiation has a high penetrating power and easily penetrates through clothes, living tissues, and a little more difficultly through dense structures of a substance such as metal. To stop gamma radiation would require a significant thickness of steel or concrete. But at the same time, gamma radiation has a hundred times weaker effect on matter than beta radiation and tens of thousands of times weaker than alpha radiation.

The main danger of gamma radiation is its ability to overcome considerable distances and affect living organisms several hundred meters from the source of gamma radiation.

x-ray radiation

• emitted: energy in the form of photons
• penetrating power: high
• source exposure: up to hundreds of meters
• radiation speed: 300,000 km/s
• ionization: from 3 to 5 pairs of ions per 1 cm of run
• biological effect of radiation: low

x-ray radiation- this is an energetic electromagnetic radiation in the form of photons, arising from the transition of an electron inside an atom from one orbit to another.

X-ray radiation is similar in action to gamma radiation, but has a lower penetrating power, because it has a longer wavelength.

Having considered the various types of radioactive radiation, it is clear that the concept of radiation includes completely different types of radiation that have different impact on matter and living tissues, from direct bombardment by elementary particles (alpha, beta and neutron radiation) to energy impact in the form of gamma and X-ray radiation.

Each of the considered radiations is dangerous!

Comparative table with the characteristics of various types of radiation

characteristic	Type of radiation
	alpha radiation	neutron radiation	beta radiation	Gamma radiation	x-ray radiation
radiated	two protons and two neutrons	neutrons	electrons or positrons	energy in the form of photons	energy in the form of photons
penetrating power	low	high	average	high	high
source exposure	up to 10 cm	kilometers	up to 20 m	hundreds of meters	hundreds of meters
radiation speed	20,000 km/s	40,000 km/s	300,000 km/s	300,000 km/s	300,000 km/s
ionization, vapor per 1 cm of run	30 000	from 3000 to 5000	from 40 to 150	3 to 5	3 to 5
biological effect of radiation	high	high	the average	low	low

As can be seen from the table, depending on the type of radiation, radiation at the same intensity, for example, 0.1 Roentgen, will have a different destructive effect on the cells of a living organism. To take into account this difference, the coefficient k was introduced, which reflects the degree of exposure to radioactive radiation on living objects.

coefficient k
Type of radiation and energy range	Weight multiplier
Photons all energies (gamma radiation)	1
Electrons and muons all energies (beta radiation)	1
neutrons with energy < 10 КэВ (нейтронное излучение)	5
Neutrons from 10 to 100 keV (neutron radiation)	10
Neutrons from 100 keV to 2 MeV (neutron radiation)	20
Neutrons from 2 MeV to 20 MeV (neutron radiation)	10
Neutrons> 20 MeV (neutron radiation)	5
Protons with energies > 2 MeV (except for recoil protons)	5
alpha particles, fission fragments and other heavy nuclei (alpha radiation)	20

The higher the "coefficient k" the more dangerous the action of a certain type of radiation for the tissues of a living organism.

Video:

After the discovery of radioactive elements, research began on the physical nature of their radiation. In addition to Becquerel and the Curies, Rutherford did this.

The classical experiment that made it possible to detect the complex composition of radioactive radiation was as follows. The radium preparation was placed at the bottom of a narrow channel in a piece of lead. A photographic plate was placed against the canal. The radiation emerging from the channel was affected by a strong magnetic field, the lines of induction of which are perpendicular to the beam (Fig. 13.6). The entire setup was placed in a vacuum.

In the absence of a magnetic field, a single dark spot was found on the photographic plate after development, exactly opposite the channel. In a magnetic field, the beam split into three beams. The two components of the primary flow deviated in opposite directions. This indicated the presence of these radiations electric charges opposite signs. In this case, the negative component of the radiation was deflected magnetic field much stronger than positive. The third component was not deflected by the magnetic field at all. The positively charged component is called alpha rays, the negatively charged component is called beta rays and the neutral component is called gamma rays (α-rays, β-rays, γ-rays).

These three types of radiation differ greatly in penetrating power, that is, in how intensely they are absorbed. various substances. A-rays have the least penetrating power. A layer of paper about 0.1 mm thick is already opaque for them. If you cover a hole in a lead plate with a piece of paper, then no spot corresponding to alpha radiation will be found on the photographic plate.

Much less absorbed when passing through the substance β-rays. An aluminum plate completely delays them only with a thickness of a few millimeters. γ-rays have the greatest penetrating power.

The absorption intensity of γ-rays increases with the increase in the atomic number of the absorbent substance. But even a layer of lead 1 cm thick is not an insurmountable barrier for them. When the y-rays pass through such a layer of lead, their intensity weakens only by a factor of two.

The physical nature of α-, β- and γ-rays is obviously different.

Gamma rays. In their properties, γ-rays are very much like x-rays, but their penetrating power is much greater than that of x-rays. This suggested that γ-rays were electromagnetic waves. All doubts about this disappeared after the diffraction of γ-rays on crystals was discovered and their wavelength was measured. It turned out to be very small - from 10 -8 to 10 -11 cm.

On the scale of electromagnetic waves, γ-rays directly follow X-rays. The propagation speed of γ-rays is the same as that of all electromagnetic waves - about 300,000 km/s.

Beta rays. From the very beginning, α- and β-rays were considered as streams of charged particles. It was easiest to experiment with β-rays, since they are more strongly deflected in both magnetic and electric fields.

The main task of the experimenters was to determine the charge and mass of the particles. When studying the deflection of β-particles in electric and magnetic fields, it was found that they are nothing but electrons moving at speeds very close to the speed of light. It is essential that the speeds of β-particles emitted by any radioactive element are not the same. There are particles with a wide variety of velocities. This leads to the expansion of the beam of β-particles in a magnetic field (see Fig. 13.6).

It was more difficult to elucidate the nature of the α-particles, since they are weaker deflected by magnetic and electric fields. Rutherford finally managed to solve this problem. He measured the ratio of the charge q of a particle to its mass m from the deflection in a magnetic field. It turned out to be about 2 times less than that of a proton - the nucleus of a hydrogen atom. The charge of a proton is equal to the elementary one, and its mass is very close to the atomic mass unit 1 . Consequently, an α-particle has a mass equal to two atomic mass units per elementary charge.

1 The atomic mass unit (a.m.u.) is equal to 1/12 of the mass of a carbon atom; 1 a. e.m. ≈ 1.66057 10 -27 kg.

But the charge of the α-particle and its mass remained, nevertheless, unknown. Either the charge or the mass of the alpha particle had to be measured. With the advent of the Geiger counter, it became easier and more accurate to measure the charge. Through a very thin window, α-particles can penetrate into the counter and be registered by it.

Rutherford placed a Geiger counter in the path of the α-particles, which measured the number of particles emitted by a radioactive drug in a certain time. Then he replaced the counter with a metal cylinder connected to a sensitive electrometer (Fig. 13.7). With an electrometer, Rutherford measured the charge of α-particles emitted by the source into the cylinder over the same time (the radioactivity of many substances almost does not change with time). Knowing the total charge of α-particles and their number, Rutherford determined the ratio of these quantities, i.e., the charge of one α-particle. This charge turned out to be equal to two elementary ones.

Thus, he established that the alpha particle has two atomic mass units for each of its two elementary charges. Therefore, there are four atomic mass units for two elementary charges. The helium nucleus has the same charge and the same relative atomic mass. It follows from this that the α-particle is the nucleus of the helium atom.

Not satisfied with the result achieved, Rutherford then proved by direct experiments that it is precisely helium that is formed in radioactive a-decay. Collecting α-particles inside a special tank for several days, using spectral analysis, he made sure that helium accumulated in the vessel (each α-particle captured two electrons and turned into a helium atom).

During radioactive decay, α-rays (nuclei of the helium atom), β-rays (electrons) and γ-rays (short-wave electromagnetic radiation) are produced.

Question for a paragraph

Why did it turn out to be much more difficult to find out the nature of α-rays than in the case of β-rays?

It's no secret that radiation is harmful. Everyone knows this. Everyone heard about the terrible victims and the danger of radioactive exposure. What is radiation? How does it arise? Are there different types radiation? And how to protect yourself from it?

The word "radiation" comes from the Latin radius and stands for beam. In principle, radiation is all types of radiation existing in nature - radio waves, visible light, ultraviolet, and so on. But radiations are different, some of them are useful, some are harmful. We are in ordinary life accustomed to the word radiation to call harmful radiation arising from the radioactivity of certain types of matter. Let us analyze how the phenomenon of radioactivity is explained in physics lessons.

Radioactivity in physics

We know that the atoms of matter consist of a nucleus and electrons revolving around it. So the core is, in principle, a very stable formation that is difficult to destroy. However, the nuclei of atoms of some substances are unstable and can radiate various energies and particles into space.

This radiation is called radioactive, and it includes several components, which are named according to the first three letters of the Greek alphabet: α-, β- and γ-radiation. (alpha, beta and gamma radiation). These radiations are different, and their effect on a person and the measures of protection against him are also different. Let's take everything in order.

alpha radiation

Alpha radiation is a stream of heavy positively charged particles. Occurs as a result of the decay of atoms heavy elements such as uranium, radium and thorium. In the air, alpha radiation travels no more than five centimeters and, as a rule, is completely blocked by a sheet of paper or the outer dead layer of the skin. However, if a substance that emits alpha particles enters the body with food or air, it irradiates the internal organs and becomes dangerous.

beta radiation

Beta radiation is electrons that are much smaller than alpha particles and can penetrate several centimeters deep into the body. You can protect yourself from it with a thin sheet of metal, window glass and even ordinary clothing. Getting to unprotected areas of the body, beta radiation has an effect, as a rule, on the upper layers of the skin. During the accident on Chernobyl nuclear power plant in 1986, firefighters suffered skin burns from very high exposure to beta particles. If a substance that emits beta particles enters the body, it will irradiate the internal tissues.

Gamma radiation

Gamma radiation is photons, i.e. electromagnetic wave that carries energy. In the air it can pass long distances, gradually losing energy as a result of collisions with the atoms of the medium. Intense gamma radiation, if not protected from it, can damage not only the skin, but also internal tissues. Dense and heavy materials, such as iron and lead, are excellent barriers to gamma radiation.

As you can see, according to its characteristics, alpha radiation is practically not dangerous if you do not inhale its particles or eat it with food. Beta radiation can cause skin burns as a result of exposure. The most dangerous properties of gamma radiation. It penetrates deep into the body, and it is very difficult to get it out of there, and the impact is very destructive.

In any case, without special devices, it is impossible to know what kind of radiation is present in this particular case, especially since you can always accidentally inhale particles of radiation with air. That's why general rule one thing is to avoid such places, and if you already got there, then wrap yourself in as many clothes and things as possible, breathe through the fabric, do not eat or drink, and try to leave the place of infection as soon as possible. And then, at the first opportunity, get rid of all these things and wash yourself well.

The concept of "radiation" includes the entire range of electromagnetic waves, as well as electricity, radio waves, ionizing radiation. With the latter, the physical state of atoms and their nuclei changes, turning them into charged ions or products nuclear reactions. The smallest particles have energy, which is gradually lost when interacting with structural units. As a result of movement, the substance through which the elements penetrate is ionized. The penetration depth is different for each particle. Due to the ability to change substances, radioactive light harms the body. What types of radiation exist?

corpuscular emission. alpha particles

This type is a stream of radioactive elements, whose mass is different from zero. An example is alpha and beta radiation, as well as electron, neutron, proton and meson radiation. Alpha particles are the nuclei of atoms that are emitted when some radioactive atoms decay. They consist of two neutrons and two protons. Alpha radiation is the nuclei of helium atoms, which are positively charged. Natural emission is characteristic of unstable radionuclides of the thorium and uranium series. Alpha particles exit the nucleus at a speed of up to 20,000 km/sec. Along the way, they form a strong ionization of the medium, tearing off electrons from the orbits of atoms. Ionization by rays leads to chemical changes in the substance, as well as to the violation of its crystal structure.

Characterization of alpha radiation

Rays of this type are alpha particles with a mass of 4.0015 atomic units. Magnetic moment and spin are equal to zero, and the charge of particles is equal to twice the elementary charge. The energy of alpha rays is in the range of 4-9 MeV. Ionizing alpha radiation occurs when an atom loses its electron and becomes an ion. The electron is knocked out due to the large weight of alpha particles, which are almost seven thousand times larger than it. When passing through an atom and detaching each negatively charged element, the particles lose their energy and speed. The ability to ionize matter is lost when all the energy is spent and the alpha particle is converted into a helium atom.

beta radiation

This is the process by which electrons and positrons are produced from the beta decay of elements from the lightest to the heaviest. Beta particles cooperate with the electrons of atomic shells, transfer some of their energy to them and pull them out of their orbits. In this case, a positive ion and a free electron are formed. Alpha and beta radiation have different speeds of movement. So, for the second type of rays, it approaches the speed of light. Beta particles can be absorbed with a 1 mm thick aluminum layer.

gamma rays

They are formed during the decomposition of radioactive nuclei, as well as elementary particles. This is a short-wave type of electromagnetic radiation. It is formed during the transition of the nucleus from a more excited energy state to a less excited one. It has a short wavelength, therefore it has a high penetrating power, which can cause serious harm to human health.

Properties

Particles that are formed during the decay of the nuclei of elements can interact with the environment in different ways. Such a connection depends on the mass, charge, and energy of the particles. The properties of radioactive radiation include the following parameters:

1. Penetrating ability.

2. Ionization of the medium.

3. Exothermic reaction.

4. Impact on photographic emulsion.

5. The ability to cause the glow of luminescent substances.

6. With prolonged exposure, chemical reactions and the breakdown of molecules are possible. For example, the color of an object changes.

These properties are used in the detection of radiation due to the inability of a person to capture them with his senses.

Radiation sources

There are several reasons for particle emissions. These can be terrestrial or space objects that contain radioactive substances, technical devices that emit ionizing radiation. Also, the reasons for the appearance of radioactive particles can be nuclear installations, control and measuring devices, medicines, destruction of radioactive waste storage facilities. Hazardous sources are divided into two groups:

1. Closed. When working with them, radiation does not penetrate into the environment. An example would be radiation technology at nuclear power plants, as well as equipment in an X-ray room.
2. Open. In this case, the environment is exposed to radiation. Sources can be gases, aerosols, radioactive waste.

The elements of the uranium, actinium and thorium series are naturally occurring radioactive elements. When they decay, alpha and beta particles are emitted. The source of alpha rays is polonium with atomic mass 214 and 218. The latter is a decay product of radon. This is a poisonous gas in large quantities, which penetrates from the soil and accumulates in the basements of houses.

Sources of high-energy alpha radiation are a variety of charged particle accelerators. One such device is the phasotron. It is a cyclic resonant accelerator with a constant control magnetic field. Accelerating frequency electric field will change slowly with time. The particles move in an unwinding spiral and are accelerated to an energy equal to 1 GeV.

Ability to penetrate substances

Alpha, beta, gamma radiation have a certain range. Thus, the movement of alpha particles in the air is several centimeters, when beta particles are able to travel several meters, and gamma rays - up to hundreds of meters. If a person has experienced external alpha radiation, the penetrating power of which is equal to the surface layer of the skin, then he will be in danger only in case of open wounds on the body. Severe harm is caused by eating food irradiated with these elements.

Beta particles can penetrate the body only to a depth of no more than 2 cm, but gamma particles can cause radiation to the entire body. The rays of the last particles can only stop concrete or lead slabs.

Alpha radiation. Impact on a person

The energy of these particles, formed during radioactive decay, is not enough to overcome the initial layer of the skin, so external irradiation does not harm the body. But if an accelerator serves as a source of alpha particles and their energy reaches more than tens of MeV, then there is a threat to the normal functioning of the organism. Huge harm is caused by direct penetration into the body of a radioactive substance. For example, through inhalation of poisoned air or through the digestive tract. Alpha radiation is capable of causing a person to develop radiation sickness in minimal doses, which often ends in the death of the victim.

Alpha rays cannot be detected with a dosimeter. Once in the body, they begin to irradiate nearby cells. The body forces the cells to divide faster in order to renew the gap, but the newly born are again exposed to harmful effects. This leads to the loss of genetic information, mutations, and the formation of malignant tumors.

Permissible exposure limits

The norm of ionizing radiation in Russia is regulated by the “Radiation Safety Standards” and the “Basic Sanitary Rules for Working with radioactive substances and other sources of ionizing radiation”. According to these documents, exposure limits are developed for the following categories:

1. "A". It includes employees who work with a radiation source on a permanent or temporary basis. The permissible limit is calculated as an individual equivalent dose of external and internal radiation per year. This is the so-called maximum allowable dose.

2. "B". This category includes the part of the population that may be exposed to radiation sources by living or working near them. In this case, the allowable dose per year is also calculated, at which health damage will not occur for 70 years.

3. "B". The type includes the population of the region, region or country that has fallen under the radiation. Limitation of exposure occurs through the introduction of standards and control of the radioactivity of objects in environment, harmful emissions from nuclear power plants, taking into account the dose limits for the previous categories. The impact of radiation on the population is not subject to regulations, since exposure levels are very low. In cases of a radiation accident, all necessary safety measures are applied in the regions.

Security measures

Alpha radiation protection is not a problem. Radiation rays are completely blocked by a thick sheet of paper and even human clothing. The danger arises only with internal exposure. To avoid it, personal protective equipment is used. These include overalls (overalls, moleskin helmets), plastic aprons, oversleeves, rubber gloves, special shoes. Plexiglas shields are used to protect the eyes, dermatological agents (pastes, ointments, creams), respirators are also used. Enterprises resort to measures of collective protection. As for protection against radon gas, which can accumulate in basements, bathrooms, in this case it is necessary to ventilate the premises often, and isolate the basements from the inside.

Characterization of alpha radiation leads us to the conclusion that this species has a low throughput and does not require serious protection measures for external exposure. Great harm these radioactive particles are applied when they enter the body. Elements of this type extend to minimum distances. Alpha, beta, gamma radiation differ from each other in their properties, penetrating ability, and impact on the environment.