Protection against ionizing radiation
Currently, ionizing radiation is widely used in industry, engineering, agriculture, medicine and scientific research. Distinguish ionizing radiation arising from the decay of radionuclides, as well as radiation generated in research and industrial installations (charged particle accelerators, X-ray tubes, nuclear reactors, etc.).
The ionizing radiation includes corpuscular (alpha, beta, neutron) and electromagnetic (gamma, X-ray, etc.) radiation, the interaction of which with the medium leads to the formation of electric charges of different signs. Ionizing radiation is the highest frequency of the electromagnetic radiation under consideration. The use of radioactive substances and other sources of ionizing radiation poses a potential threat to the health and lives of people. The danger is aggravated by the fact that the effect of ionizing (radioactive) radiation is not detected until the manifestation of a particular lesion. But if the necessary protective measures are taken, ionizing radiation can be safe.
Sources and characteristics of ionizing radiation
Sources of radiation are divided into natural and artificial, open and closed. The natural radioactive background has always existed. It is created by cosmic rays (0.37 mSv/year), radioactive substances distributed on the Earth and the upper soil layer (0.38 mSv/year); (1.35 mSv/year), with the most weight contributing radon, which is released from the earth (1 mSv/year). In brick and reinforced concrete buildings, the radioactive background (0.8-1 mSv/year) is created by building materials. The artificial sources of ionizing radiation are nuclear reactors, X-ray machines, artificial radioactive isotopes, etc. For example, with a chest X-ray, a person receives a dose of 9 mSv.
Corpuscular radiation consists of particles with a nonzero rest mass.
Alpha radiation is a stream of helium nuclei emitted by matter in the decay of nuclei or in nuclear reactions. Possessing a relatively large mass, alpha particles quickly lose their energy when interacting with substances, which causes their low penetrating ability and high specific ionization of the medium.
Beta radiation - the flow of electrons or positrons that occur during radioactive decay. The ionizing ability of beta particles is lower, and the penetrating power is higher than that of alpha particles, since they have a significantly lower mass and have a smaller charge with the same alpha particles.
Neutrons (the flux of which forms neutron radiation) transform their energy in elastic and inelastic interactions with atomic nuclei; During inelastic interactions, secondary radiation appears, while in elastic interactions, neutron deceleration occurs. The penetrating power of neutrons depends on their energy and the atomic mass of the matter with which they interact.
Gamma radiation is the electromagnetic (photon) radiation emitted during nuclear transformations or particle annihilation (for example, secondary radiation from a neutron flux). Gamma radiation has a large penetrating power and a low ionizing effect.
X-ray tubes, electron accelerators, in the environment surrounding the source of beta radiation, and is a set of inhibitory and characteristic photon radiations, respectively, with continuous spectrum (radiation emitted when the kinetic energy of charged particles changes) and with the discrete spectrum (radiation emitted when the energy state of an atom changes). Distinguish between long-wave (soft) X-ray radiation with a wavelength λ & gt; 25 pm and short-wave (hard) - with λ & lt; 25 pm. Like gamma radiation, X-ray radiation has a low ionizing capacity and a large depth of penetration.
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