How to protect against alpha radiation
The discovery of radioactivity and its unusual properties has generated great interest in the scientific world and has caused many questions.
A great breakthrough in the study of this phenomenon was the classic experience of the English scientist E. Rutherford, who placed a radioactive emitter in a magnetic field. To the surprise of experimenters, the radioactive beam was divided into 3 parts. The rays that experienced minimal deviation were called alpha rays.
What is alpha radiation? What has it become for mankind - friend, helper or enemy? What is the harm from it and how to protect against alpha radiation?
What is alpha radiation
Continuing his experiments, Rutherford found that this radiation undergoes a noticeable deviation not only in a magnetic field, but also in an electric field. And obviously the negative pole. A whole series of similar experiments performed in vacuum installations made it possible to determine what alpha radiation is - these are positive particles, the parameters of which exactly coincide with the parameters ... of helium nuclei. An ordinary helium atom has only two electrons. Parting with them, it turns out twice ionized atom, that is, the nucleus of helium. Therefore, speaking of α-radiation, it is perfectly valid to say that these are doubly ionized helium atoms.
There are several natural and artificial sources of alpha radiation.
- Nuclear alpha decay of heavy elements (radium, thorium, etc.), at which helium nuclei are emitted.
- Accelerated helium nuclei, tending to embrace the earth from the depths of the cosmos along with interstellar gas flows.
- Experiments conducted in radioisotope laboratories and charged particle accelerators.
- Uranium industry facilities and nuclear reactors.
How alpha radiation behaves in different environments
The initial velocity of alpha particles lies in the range of 14–20 thousand km / s. And since these are quite heavy particles (they are 7,300 times as massive as beta particles!), Their ionizing ability is quite large.
Thus, depending on the initial energy, the alpha particle, moving in air at 15 ° C and normal atmospheric pressure, is capable of creating 150,000–250,000 ion pairs. Energy costs for ionization are very high, so the lifetime of these particles is very short. As these particles slow down, their ionization capacity increases.
The free path of alpha particles in the air is in the range of 3–11 cm, and in solid and liquid media of the whole - hundredths of a millimeter.
How can you protect against alpha radiation
In direct proportion to the length of the free path is the damaging ability of alpha radiation. She is very small. With high ionizing ability, alpha particles penetrate into the tissues of the human body only to a shallow depth, damaging only the surface of the skin. It is believed that external α-irradiation is not dangerous. But getting these fairly massive particles inside the body (with food, water or through damaged skin) is fraught with serious poisoning due to their strong ionizing action, the formation of oxidants, free hydrogen and oxygen. Their accumulation in the pituitary, adrenal cortex and other tissues leads to pathology in the work of various systems and organs, to a decrease in the adaptive properties of the organism.
Of all the types of ionizing radiation, the flux of alpha particles is considered the most innocuous, since it does not require special means of protection under external irradiation. It is enough to move away from the radiation source by 10–20 centimeters. However, the screen is made of ordinary paper, cloth or a thin layer of aluminum and clothing completely absorbs this radiation.
The real danger arises only under the threat of internal exposure. In order to avoid this trouble, you should prevent the penetration of radionuclides into the body, as well as the use of personal protective equipment:
overalls, helmets, sleeves and shoes made of special materials;
- to protect the eyes from danger, it is enough to use plexiglass shields;
- Dermatological pastes and creams should be used to protect sensitive skin.
Among the recommendations explaining how to defend against alpha radiation are interesting information on the effect of certain foods on the process of removing radionuclides from the body.
Products with vitamins B and C possess this ability. Quail eggs are used with a fairly good effect for the treatment of small doses of radiation. They are extremely rich in vitamins, amino acids and other substances with preventive radioprotective action. Among the plants that do not accumulate radioactive elements is Jerusalem artichoke.
Conventional dosimeters cannot be used to detect alpha radiation due to its low penetrating power. But the Geiger counter with its clear, dry clicks will warn of the presence of such a threat, which will take measures to protect against alpha radiation.
Use of alpha radiation
The knowledge gained about the physicochemical properties of these rays made it possible not only to learn how to defend against alpha radiation, but also to develop an alpha therapy tactic. It uses alpha-emitting isotopes — radon, thoron, which have short life spans and are rapidly eliminated from the body.
The range of possible procedures includes:
- radon baths;
- drinking radon water;
- radon applications and irrigation;
- inhalation of air with a radon component.
Doctors believe that the use of alpha particles in therapy is more effective and safe for patients than beta radiation. Their effects are more focused and a much smaller number of procedures are required to kill cancer cells.
Alpha therapy has anti-inflammatory, analgesic and sedative effect, therefore, it is indicated for the treatment of gynecological, cardiovascular diseases, as well as problems with the musculoskeletal system.
So, a huge research work of a whole group of physicists allowed to establish the limits of the danger of this radiation, methods of prevention and protection from its impact. And the developed technique of alpha-therapy returned health to a huge number of patients.