What are isotopes in medicine? How are radioactive isotopes used? The effect of radioactive radiation on humans

Bartsaeva Vika, 9th grade student of Municipal Educational Institution "Gymnasium No. 20" Saransk

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Presentation on the topic: “The use of radioactive isotopes in medicine”

The uses of radioactive isotopes are varied and varied. It is difficult to imagine all the possibilities of its use. Humanity is taking its first steps in using atomic energy for peaceful purposes, but it is already clear today that atomic energy is a powerful means of technical progress. The purpose of my work is to study the real use of atomic energy in medicine

The method of radioactive isotopes makes it possible to use the properties of radioactive elements in practice. This method takes advantage of the fact that, in chemical and many physical properties, a radioactive isotope is indistinguishable from stable isotopes of the same element. The method of radioactive isotopes has found very wide application in medicine. Significant contribution to method development early diagnosis Russian scientists introduced diseases by introducing radioactive isotopes into the body. Thus, G. E. Vladimirov (1901-1960), a famous biochemist, was one of the first to use radioactive isotopes (labeled compounds) to study metabolic processes in nervous and muscle tissues. The first experiments on the practical application of this method were carried out by biologists V. M. Klechkovsky and V. I. Spitsyn. Radioisotope diagnostic methods are based on the fact that in the blood, in Airways, radioactive isotopes are introduced into the digestive tract - substances that have the properties of radioactive radiation (most often these are gamma rays). These isotopes are mixed with substances that accumulate predominantly in one or another organ. Radioactive isotopes, therefore, are a kind of markers, by which one can already judge the presence of certain drugs in the organ.

Co60 (cobalt) is used to treat malignant tumors located both on the surface of the body and inside the body. To treat tumors located superficially (for example, skin cancer), cobalt is used in the form of tubes that are applied to the tumor, or in the form of needles that are injected into it. The tubes and needles containing radiocobalt are kept in this position until the tumor is destroyed. In this case, the healthy tissue surrounding the tumor should not suffer much. If the tumor is located deep in the body (stomach or lung cancer), special γ-installations containing radioactive cobalt are used. This installation creates a narrow, very powerful beam of γ-rays, which is directed to the place where the tumor is located. Radiation does not cause any pain, patients do not feel it.

Digital radiographic camera for fluorographic devices KRTS 01-"PONI"

Mammograph is a modern mammography system, with a low radiation dose and high resolution, which provides high-quality images of the breast necessary for accurate diagnosis

The digital fluorographic device FC-01 "Electron" is intended for conducting mass preventive X-ray examinations of the population in order to timely detect tuberculosis, cancer and other pulmonary diseases with low radiation exposure.

computed tomograph Computed tomography – layer-by-layer method x-ray examination organs and tissues. It is based on computer processing of multiple X-ray images of the transverse layer taken at different angles.

Brachytherapy is not a radical, but an almost outpatient operation, during which we inject titanium grains containing an isotope into the affected organ. This radioactive nuclide kills the tumor to death. In Russia, so far only four clinics perform such an operation, two of which are in Moscow, one in Obninsk and one here, in Yekaterinburg, although the country needs 300-400 centers where brachytherapy is used.

Traces of atomic explosions were found in human hearts The deepest traces of atomic explosions are kept in the hearts of people born in the 50s of the last century

Nuclear tests in the atmosphere helped prove that the living “pump” that pumps blood itself restores its damaged tissues. A few years ago it was generally accepted that nerve cells do not recover. They say that a person has as many of them as he received from birth. And it doesn't get any bigger with age. Only less - after all, nerve cells die irrevocably. It turned out that this was not the case. And new neurons can appear during life. And they thought about the heart that it was not capable of regeneration. But this persistent medical misconception was refuted by Ratan Bhardwaz. “We have shown that new cells grow in the heart of an adult,” says the scientist. The researcher was helped to make the discovery by nuclear tests in the atmosphere, which were carried out in the 50s of the last century. Then they heavily polluted the surrounding cuttings with a radioactive isotope - carbon-14. But its level fell after explosions were banned in 1963. atomic bombs in the atmosphere.

Radioactive isotopes helped establish the time when new heart cells appeared in people. The heart cells of people who were exposed to nuclear explosions on land “sucked in” the isotope in increased concentration. It was this that scientists used for so-called radiocarbon dating of living tissues. Carbon-14 allowed us to determine the age of the cells. And it turned out that they - heart cells - appeared at different times. That is, along with the old ones, new ones were born. Bhardwaj and his colleagues estimate that the heart of a 25-year-old person is capable of producing newborn cells at a rate of up to 1 percent per year of the organ's mass. By age 75, factory productivity drops to 0.45 percent.

Dangers and complications of radioisotope research. During the study, the patient receives a certain dose of radiation. This dose does not exceed the levels of radioactive radiation to which the body is exposed during chest x-rays and computed tomography. You should also know that the radioactive isotopes used in research are quickly eliminated from the body and thus do not have a damaging effect. In a number of countries, radiopharmaceuticals are produced and used for proton-ion and boron neutron capture therapy and early diagnosis of cancer and other diseases, as well as anesthetics. So, radioactive isotopes have found their application in medicine in general and in surgery in particular. Today, radioactive isotopes are widely used both for a variety of diagnostic methods (for detection, recognition and localization of internal malignant formations) and for the treatment of human diseases. RDIs have their own advantages, among which we should highlight increased economic and environmental safety, reduced cost and improved performance characteristics. The method of using radioactive isotopes for diagnosis and treatment in surgery is constantly being improved and developed, as evidenced by the dynamics of its use in major cities Russia, in general, in Russian Federation and developed countries.

Literature I. Aladyev “Atomic energy and its use for peaceful purposes” S. Feinberg “Research reactors” V. Duzhenkov “Use of radiation in chemical industry» G. Jordan “Use of radiation from radioisotopes in measuring technology” M. Rozanov “Use of radioisotopes in medicine”

Prepared by: student of grade 9 B, Municipal Educational Institution “Gymnasium No. 20”, Saransk Bartsaeva Victoria

Isotopes, especially radioactive isotopes, have numerous uses. In table 1.13 provides selected examples of some industrial applications of isotopes. Each technique mentioned in this table is also used in other industries. For example, the technique for determining the leakage of a substance using radioisotopes is used: in the beverage industry to determine leakage from storage tanks and pipelines; in the construction of engineering structures for

Table 1.13. Some uses of radioisotopes

determining leakage from underground water pipelines; in the energy industry to detect leaks from heat exchangers in power plants; in the oil industry to detect leaks from underground oil pipelines; in the wastewater and sewerage control service to determine leaks from main sewers.

Isotopes are also widely used in scientific research. In particular, they are used to identify mechanisms chemical reactions. As an example, we point out the use of water labeled with the stable oxygen isotope 180 to study the hydrolysis of esters like ethyl acetate (see also Section 19.3). Using mass spectrometry to detect the 180 isotope, it was found that during hydrolysis, the oxygen atom from the water molecule is transferred to acetic acid, and not to ethanol

Radioisotopes are widely used as labeled atoms in biological research. In order to trace metabolic pathways in living systems, radioisotopes carbon-14, tritium, phosphorus-32 and sulfur-35 are used. For example, the uptake of phosphorus by plants from soil treated with fertilizers can be monitored using fertilizers that contain an admixture of phosphorus-32.

Radiation therapy.

Ionizing radiation can destroy living tissue. Malignant tumor tissues are more sensitive to radiation than healthy tissues. This makes it possible to treat cancer with the help of -rays emitted from a source, which uses the radioactive isotope cobalt-60. The radiation is directed to the area of the patient’s body affected by the tumor; The treatment session lasts a few minutes and is repeated daily for 2-6 weeks. During the session, all other parts of the patient's body must be carefully covered with radiation-impermeable material to prevent the destruction of healthy tissue.

Determining the age of samples using radiocarbon.

A small portion of the carbon dioxide in the atmosphere contains a radioactive isotope. Plants absorb this isotope during photosynthesis. Therefore, the fabrics of all

plants and animals also contain this isotope. Living tissues have a constant level of radioactivity, because its decrease due to radioactive decay compensated by a constant supply of radiocarbon from the atmosphere. However, as soon as the death of a plant or animal occurs, the flow of radiocarbon into its tissues stops. This leads to a gradual decrease in the level of radioactivity in dead tissue.

The radioactivity of the isotope is due to -decay

The radiocarbon method of geochronology was developed in 1946 by U.F. Libby, who received for it Nobel Prize in chemistry in 1960. This method is now widely used by archaeologists, anthropologists and geologists to date specimens up to 35,000 years old. The accuracy of this method is approximately 300 years. Best results obtained by determining the age of wool, seeds, shells and bones. To determine the age of a sample, p-radiation activity (number of decays per minute) is measured per 1 g of carbon contained in it. This allows the age of the sample to be determined using the radioactive decay curve for the isotope.

The half-life for is 5700 years. Living tissue in active contact with the atmosphere has an activity of 15.3 dispersion/min per 1 g of carbon. Based on this data, you need to:

a) determine the decay constant for

b) construct a decay curve for

c) calculate the age of Lake Oregon Crater in the USA), which is of volcanic origin. It has been established that a tree turned over during

The eruption that resulted in the appearance of the lake has an activity of 6.5 dispersion/min per 1 g of carbon.

a) The decay constant can be found from the equation

b) A decay curve is a graph of activity versus time. The data needed to construct this curve can be calculated by knowing the half-life and initial activity of the sample (living tissue activity); these data are given in table. 1.14. The decay curve is shown in Fig. 1.32.

c) The age of a lake can be determined using a decay curve (see dashed lines in Fig. 1.32). This age is 7000 years.

Table 1.14. Data for constructing a carbon radioactive decay curve used in determining the age of samples

Rice. 1.32. Radioactive decay curve of an isotope

Many rocks on Earth and the Moon contain radioisotopes with half-lives on the order of years. By measuring and comparing the relative content of these radioisotopes with the relative content of their decay products in samples of such rocks, their age can be determined. The three most important methods of geochronology are based on determining the relative abundance of isotopes (half-life years). (half-life years) and (half-life years).

Potassium and argon dating method.

Minerals such as mica and some feldspars contain small amounts of the radioisotope potassium-40. It decays by undergoing electron capture and turning into argon-40:

The age of a sample is determined based on calculations that use the sample's relative abundance of potassium-40 compared to argon-40.

Dating method using rubidium and strontium.

Some of the oldest rocks on Earth, such as granites from the west coast of Greenland, contain rubidium. Approximately a third of all rubidium atoms are radioactive rubidium-87. This radioisotope decays into the stable isotope strontium-87. Calculations based on the use of data on the relative content of rubidium and strontium isotopes in samples make it possible to determine the age of such rocks.

Dating method using uranium and lead.

Isotopes of uranium decay into isotopes of lead. The age of minerals such as apatite, which contain uranium impurities, can be determined by comparing the content of certain isotopes of uranium and lead in their samples.

All three methods described have been used to date terrestrial rocks. The resulting data indicates that the age of the Earth is years. These methods were also used to determine the age of lunar rocks brought to Earth from space missions. The age of these breeds ranges from 3.2 to years.

Study of the Alpharad radiometer and

study of radon-222 activity in the air"

Devices and accessories: radiometer RRA-01M-01.

Tasks and progress of work:

1. Familiarize yourself with educational material on the use of radioactive isotopes in medicine and the purpose of radiometry.

2. Using the passport and operating instructions for the radiometer,

· Reveal it specifications;

· Study the device and principle of operation of the radiometer, features of its operation;

· Prepare the device for operation and perform test measurements in 1-air modes; 3-Integral; 4-Ffon.

3. Perform experimental studies to determine activity (1-air mode) first in the classroom air, and then in the outside air (air intake on the windowsill of an open window); The measurement results are presented in the form of a table. Repeat the experiment at least three times.

4. Construct graphs of volumetric activity versus time.

BASICS OF WORK THEORY

The use of radioactive isotopes in medicine and radiometry

Medical applications of radioactive isotopes can be represented in two groups. One group is methods that use isotopic tracers (labeled atoms) for diagnostic and research purposes. Another group of methods is based on the use of ionizing radiation from radioactive isotopes for biological effects with therapeutic purpose. This group also includes the bactericidal effect of radiation.

The tagged atom method involves introducing radioactive isotopes into the body and determining their location and activity in organs and tissues. For example, to diagnose thyroid disease, radioactive iodine or iodine is injected into the body, part of which is concentrated in the gland. A counter located near it records the accumulation of iodine. Based on the rate of increase in the concentration of radioactive iodine, a diagnostic conclusion can be made about the condition of the gland.

Thyroid cancer can metastasize to different organs. The accumulation of radioactive iodine in them can provide information about metastases.

To detect the distribution of radioactive isotopes in different organs of the body, a gamma topograph (scintigraph) is used, which automatically records the intensity distribution of the radioactive drug. A gamma topograph is a scanning counter that gradually passes over large areas over the patient's body. Registration of radiation is recorded, for example, by a line mark on paper. In Fig. 1, A The meter path is schematically shown, and in Fig. 1, b– registration card.

Using isotope tracers, you can monitor the metabolism in the body. The volume of fluids in the body is difficult to measure directly; the tagged atom method allows us to solve this problem. So, for example, by introducing a certain amount of a radioactive isotope into the blood and waiting time for its uniform distribution throughout the circulatory system, it is possible to find its total volume by the activity of a unit of blood volume.

The gamma topograph gives a relatively rough distribution of ionizing radiation in the organs. More detailed information can be obtained using autoradiography.

Radioactive atoms are introduced into a living organism in such small quantities that neither they nor their decay products cause virtually any harm to the body.

Known medicinal use radioactive isotopes emitting mainly g-rays (gamma therapy). A gamma installation consists of a source, usually , and a protective container within which the source is placed; the patient is placed on the table.

The use of high-energy gamma radiation makes it possible to destroy deep-lying tumors, while superficially located organs and tissues are subject to less destructive effects.

Thus, the biological effect of ionizing radiation is the destruction of intramolecular bonds and, as a consequence, the cessation of the vital activity of the body’s cells. Cells are most susceptible to destruction during the division phase, when the helices of DNA molecules are isolated and unprotected. On the one hand, it is used in medicine to stop the division of malignant tumor cells; on the other hand, this leads to a violation of the hereditary characteristics of the body transmitted by germ cells.

The development of nuclear energy and the widespread introduction of sources of ionizing radiation in various fields of science, technology and medicine have created a potential threat of radiation danger to humans and environmental contamination with radioactive substances. The number of people who have direct professional contact with radioactive substances is growing. Some production processes and the use of atomic energy and powerful accelerators create the risk of radioactive waste entering the environment, which can pollute the air, water sources, soil, and cause adverse effects on the body.

Ionizing radiation includes flows of electrons, positrons, neutrons and other elementary particles, α-particles, as well as gamma and x-ray radiation. When ionizing radiation interacts with molecules of organic compounds, highly active excited molecules, ions, and radicals are formed. By interacting with molecules of biological systems, ionizing radiation causes destruction cell membranes and nuclei and, therefore, lead to disruption of body functions.

One of the tasks of medicine is to protect humans from ionizing radiation. Doctors must be able to control the degree of radioactive contamination production premises and environmental objects, calculate protection from radioactive radiation.

The purpose of radiometry is to measure the activity of radioactive sources. Instruments that measure activity are called radiometers.

Isotopes, especially radioactive isotopes, have numerous uses. In table 1.13 provides selected examples of some industrial applications of isotopes. Each technique mentioned in this table is also used in other industries. For example, the technique for determining the leakage of a substance using radioisotopes is used: in the production of drinks - to determine leakage from storage tanks and pipelines; in the construction of engineering structures-For

Table 1.13. Some uses of radioisotopes

A male tsetse fly sterilized with a weak source of radioactive radiation is marked for later detection (Burkina Faso). This procedure is part of an experiment conducted to study the tsetse fly and establish effective control measures to prevent the widespread occurrence of trypanosomiasis (sleeping sickness). The tsetse fly carries this disease and infects people, domestic animals and wild livestock. Sleeping sickness is extremely common in parts of Africa.

determining leakage from underground water pipelines; in the energy industry - to determine leaks from heat exchangers in power plants; in the oil industry - to determine leaks from underground oil pipelines; in the wastewater and sewer water control service - to determine leaks from main sewers.

Isotopes are also widely used in scientific research. In particular, they are used to determine the mechanisms of chemical reactions. As an example, we point out the use of water labeled with the stable oxygen isotope 18O to study the hydrolysis of esters like ethyl acetate (see also Section 19.3). Using mass spectrometry to detect the 18O isotope, it was found that during hydrolysis, an oxygen atom from a water molecule is transferred to acetic acid, and not to ethanol

Radioisotopes are widely used as labeled atoms in biological research. In order to trace metabolic pathways * in living systems, radioisotopes carbon-14, tritium, phosphorus-32 and sulfur-35 are used. For example, the uptake of phosphorus by plants from soil treated with fertilizers can be monitored using fertilizers that contain an admixture of phosphorus-32.

Radiation therapy. Ionizing radiation can destroy living tissue. Malignant tumor tissues are more sensitive to radiation than healthy tissues. This makes it possible to treat cancer with the help of y-rays emitted from a source, which uses the radioactive isotope cobalt-60. The radiation is directed to the area of the patient’s body affected by the tumor; The treatment session lasts a few minutes and is repeated daily for 2-6 weeks. During the session, all other parts of the patient's body must be carefully covered with radiation-impermeable material to prevent the destruction of healthy tissue.

Determining the age of samples using radiocarbon. A small part of the carbon dioxide that is in the atmosphere contains the radioactive isotope "bC. Plants absorb this isotope during photosynthesis. Therefore, the tissues of all

* Metabolism is the totality of all chemical reactions occurring in the cells of living organisms. As a result of metabolic reactions, nutrients are converted into useful energy or into cell components. Metabolic reactions usually occur in several simple steps - stages. The sequence of all stages of a metabolic reaction is called a metabolic pathway (mechanism).

Radioisotopes are used to monitor sediment deposition mechanisms in estuaries, ports and docks.

Using radioisotopes to obtain a photographic image of a jet engine combustion chamber at the Non-Damage Testing Facility at London Heathrow Airport. (The posters read: Radiation. Stay away.) Radioisotopes are widely used in industry for non-damaging testing.

Living tissues have a constant level of radioactivity because its decrease due to radioactive decay is compensated by the constant supply of radiocarbon from the atmosphere. However, as soon as the death of a plant or animal occurs, the flow of radiocarbon into its tissues stops. This leads to a gradual decrease in the level of radioactivity in dead tissue.

Radiocarbon dating has revealed that charcoal samples from Stonehenge are about 4,000 years old.

The radiocarbon method of geochronology was developed in 1946 by U.F. Libby, who received the Nobel Prize in Chemistry for it in 1960. This method is now widely used by archaeologists, anthropologists and geologists to date samples up to 35,000 years old. The accuracy of this method is approximately 300 years. The best results are obtained when determining the age of wool, seeds, shells and bones. To determine the age of a sample, the p-radiation activity (number of decays per minute) is measured per 1 g of carbon contained in it. This allows you to determine the age of the sample using the radioactive decay curve for the 14C isotope.

How old are the Earth and Moon?

Many rocks on Earth and the Moon contain radioisotopes with half-lives of the order of 10-9 -10-10 years. By measuring and comparing the relative abundance of these radioisotopes with the relative abundance of their decay products in samples of such rocks, their age can be determined. The three most important methods of geochronology are based on determining the relative abundance of K isotopes (half-life 1.4-109 years). "Rb (half-life 6 1O10 years) and 2I29U (half-life 4.50-109 years).

Potassium and argon dating method. Minerals such as mica and some feldspars contain small amounts of the radioisotope potassium-40. It decays by undergoing electron capture and turning into argon-40:

The age of a sample is determined based on calculations that use data on the relative content of potassium-40 in the sample compared to argon-40.

Dating method for rubidium and strontium. Some of the oldest rocks on Earth, such as granites from the west coast of Greenland, contain rubidium. Approximately a third of all rubidium atoms are radioactive rubidium-87. This radioisotope decays into the stable isotope strontium-87. Calculations based on the use of data on the relative content of rubidium and strontium isotopes in samples make it possible to determine the age of such rocks.

Dating method using uranium and lead. Isotopes of uranium decay into isotopes of lead. The age of minerals such as apatite, which contain uranium impurities, can be determined by comparing the content of certain isotopes of uranium and lead in their samples.

All three methods described have been used to date terrestrial rocks. The resulting data indicates that the age of the Earth is 4.6-109 years. These methods were also used to determine the age of lunar rocks brought to Earth from space missions. The age of these breeds ranges from 3.2 to 4.2 *10 9 years.

nuclear fission and nuclear fusion

We have already mentioned that the experimental values of isotope masses turn out to be less than the values calculated as the sum of the masses of all elementary particles included in the nucleus. The difference between the calculated and experimental atomic mass is called the mass defect. The mass defect corresponds to the energy required to overcome the repulsive forces between particles of the same charge in the atomic nucleus and bind them into a single nucleus; for this reason it is called binding energy. The binding energy can be calculated through the mass defect using the Einstein equation

where E is energy, m is mass and c is the speed of light.

Binding energy is usually expressed in megaelectronvolts (1 MeV = 106 eV) per subnuclear particle (nucleon). An electron volt is the energy that a particle with a unit elementary charge (equal in absolute value to the charge of an electron) gains or loses when moving between points with an electric potential difference of 1 V (1 MeV = 9.6 * 10 10 J/mol).

For example, the binding energy per nucleon in a helium nucleus is approximately 7 MeV, and in a chlorine-35 nucleus it is 8.5 MeV.

The higher the binding energy per nucleon, the greater the stability of the nucleus. In Fig. Figure 1.33 shows the dependence of binding energy on the mass number of elements. It should be noted that elements with a mass number close to 60 are most stable. These elements include 56Fe, 59Co, 59Ni and 64Cu. Elements with lower mass numbers can, at least from a theoretical point of view, increase their stability as a result of increasing their mass number. In practice, however, it seems possible to increase the mass numbers of only the lightest elements, such as hydrogen. (Helium has an anomalously high stability; the binding energy of nucleons in a helium nucleus does not fit the curve shown in Fig. 1.33.) The mass number of such elements increases in a process called nuclear fusion(see below).

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State autonomous educational institution

average vocational education -

Novokuybyshevsk State College of Humanities and Technology

Essay

by discipline:"Chemistry"

topic: “The use of radioactive isotopes in technology”

Grazhdankina Daria Igorevna

1st year students group 16

specialty 230115

2013

1. What are isotopes and their production

Bibliography

radioactive isotope atom flaw detection

1. What are isotopes?

Isotopes are varieties of any chemical element in the periodic table D.I. Mendeleev, having different atomic weights. Different isotopes of any chemical element have the same number of protons in the nucleus and the same number of electrons on the shells of the atom, have the same atomic number and occupy certain places in the D.I. table, characteristic of a given chemical element. Mendeleev. The difference in atomic weight between isotopes is explained by the fact that the nuclei of their atoms contain different numbers of neutrons.

Radioactive isotopes are isotopes of any element of D.I. Mendeleev’s periodic table, the atoms of which have unstable nuclei and pass into a stable state through radioactive decay accompanied by radiation. For elements with atomic numbers greater than 82, all isotopes are radioactive and decay by alpha or beta decay. These are the so-called natural radioactive isotopes, usually found in nature. The atoms formed during the decay of these elements, if they have an atomic number above 82, in turn undergo radioactive decay, the products of which can also be radioactive. It turns out to be a sequential chain, or a so-called family of radioactive isotopes. There are three known natural radioactive families, called after the first element of the series, the families of uranium, thorium and actinouranium (or actinium). The uranium family includes radium and radon. The last element of each series transforms as a result of decay into one of the stable isotopes of lead with serial number 82. In addition to these families, certain natural radioactive isotopes of elements with serial numbers less than 82 are known. These are potassium-40 and some others. Of these, potassium-40 is important, as it is found in any living organism.

Radioactive isotopes of all chemical elements can be obtained artificially.

There are several ways to obtain them. Radioactive isotopes of elements such as strontium, iodine, bromine and others, occupying middle places in the periodic table, are fission products of the uranium nucleus. From a mixture of such products obtained in a nuclear reactor, they are isolated using radiochemical and other methods. Radioactive isotopes of almost all elements can be produced in a particle accelerator by bombarding certain stable atoms with protons or deuterons. A common method of producing radioactive isotopes from stable isotopes of the same element is by irradiating them with neutrons in a nuclear reactor. The method is based on the so-called radiation capture reaction. If a substance is irradiated with neutrons, the latter, having no charge, can freely approach the nucleus of an atom and, as it were, “stick” to it, forming a new nucleus of the same element, but with one extra neutron. In this case, a certain amount of energy is released in the form of gamma radiation, which is why the process is called radiation capture. Nuclei with an excess of neutrons are unstable, so the resulting isotope is radioactive. With rare exceptions, radioactive isotopes of any element can be obtained in this way.

When an isotope decays, an isotope that is also radioactive can be formed. For example, strontium-90 turns into yttrium-90, barium-140 into lanthanum-140, etc.

Transuranium elements unknown in nature with a serial number greater than 92 (neptunium, plutonium, americium, curium, etc.), all isotopes of which are radioactive, were artificially obtained. One of them gives rise to another radioactive family - the neptunium family.

During the operation of reactors and accelerators, radioactive isotopes are formed in the materials and parts of these installations and surrounding equipment. This "induced activity", which persists more or less for a long time after the installations stop operating, it represents an unwanted source of radiation. Induced activity also occurs in a living organism exposed to neutrons, for example during an accident or an atomic explosion.

The activity of radioactive isotopes is measured in units of curie or its derivatives - millicurie and microcurie.

In terms of chemical and physicochemical properties, radioactive isotopes are practically no different from natural elements; their admixture to any substance does not change its behavior in a living organism.

It is possible to replace stable isotopes in various chemical compounds with such labeled atoms. The properties of the latter will not change as a result, and if introduced into the body, they will behave like ordinary, unlabeled substances. However, thanks to radiation, it is easy to detect their presence in the blood, tissues, cells, etc. The radioactive isotopes in these substances thus serve as indicators, or indicators, of the distribution and fate of substances introduced into the body. That's why they are called "radioactive tracers." A variety of inorganic and organic compounds labeled with various radioactive isotopes have been synthesized for radioisotope diagnostics and for various experimental studies.

2. Application of radioactive isotopes in technology

One of the most outstanding studies carried out using “tagged atoms” was the study of metabolism in organisms. It has been proven that in a relatively short time the body undergoes almost complete renewal. The atoms that make it up are replaced by new ones. Only iron, as experiments on isotope studies of blood have shown, is an exception to this rule. Iron is part of the hemoglobin of red blood cells. When radioactive iron atoms were introduced into food, it was found that the free oxygen released during photosynthesis was originally part of water, not carbon dioxide. The scope of application of radioactive isotopes in industry is extensive. One example of this is the following method for monitoring piston ring wear in engines internal combustion. By irradiating the piston ring with neutrons, they cause nuclear reactions in it and make it radioactive. When the engine operates, particles of ring material enter the lubricating oil. By examining the level of radioactivity in the oil after a certain time of engine operation, ring wear is determined. Radioactive isotopes make it possible to judge the diffusion of metals, processes in blast furnaces, etc.

Powerful gamma radiation from radioactive drugs is used for research internal structure metal castings in order to detect defects in them.

Radioactive isotopes that emit gamma rays can be used instead of bulky X-ray units for transilluminating products, since the properties of gamma rays are similar to the properties of x-rays. A gamma ray source is placed on one side of the product being tested, and photographic film is placed on the other. This testing method is called gamma flaw detection. In this way, ferrous and non-ferrous castings, finished products (steel products up to 300 mm thick) and the quality of welds are currently checked. With the help of radioactive isotopes, it is easy to measure the thickness of a metal strip or rolled metal sheets on the go and without contact and automatically maintain a constant thickness. A source of beta particles is placed under the moving belt running out from under the rollers of the machine. A change in the thickness of the tape therefore leads to a change in the current in the meter. This current is amplified and sent either to a measuring device or to an automatic machine, which will instantly bring the rollers closer together or, conversely, push them apart. Devices of this type are also used in the paper, rubber and leather industries. Radioisotope sources created electrical energy. They use the heat generated in a sample that absorbs radiation. With the help of thermocouples this heat is converted into electricity. A source weighing several kilograms provides power of several tens of watts for 10 years of uninterrupted operation. Such sources are used to power automatic beacons and automatic weather stations operating in hard-to-reach areas. More powerful sources were installed on Soviet lunar rovers launched to the Moon. They worked reliably at temperatures from -140 to +120.

One of the most outstanding studies carried out using “tagged atoms” was the study of metabolism in organisms. It has been proven that in a relatively short time the body undergoes almost complete renewal. The atoms that make it up are replaced by new ones. Only iron, as experiments on isotope studies of blood have shown, is an exception to this rule. Iron is part of the hemoglobin of red blood cells. When radioactive iron atoms were introduced into food, it was found that the free oxygen released during photosynthesis was originally part of water, not carbon dioxide. Radioactive isotopes are used in medicine both for diagnosis and for therapeutic purposes. Radioactive sodium, injected in small quantities into the blood, is used to study blood circulation; iodine is intensively deposited in the thyroid gland, especially in Graves' disease. By observing radioactive iodine deposition using a meter, a diagnosis can be made quickly. Large doses of radioactive iodine cause partial destruction of abnormally developing tissues, and therefore radioactive iodine is used to treat Graves' disease. Intense cobalt gamma radiation is used in the treatment of cancer (cobalt gun).

List of used literature

1. Gaisinsky M.N., Nuclear chemistry and its applications, trans. from French, M., 1961

2. Experimental Nuclear Physics, ed. E. Segre, trans. from English, vol. 3, M., 1961; INTERNET tools

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