Beta radiation

Beta radiation (beta-rays) - a flow of electrons or positrons emitted during beta-radioactive decay of atoms (see Radioactivity). Radioactive isotopes (see), the disintegration of which is accompanied by beta radiation, called beta-emitters. If such a collapse is not accompanied by gamma rays, speak of pure beta-emitter. These include radioactive isotope of phosphorus (P32), sulfur (S35), calcium (CA45), and other
When passing through matter beta radiation interacts with electrons and nuclei of its atoms, spending their energy and slowing the traffic down to a complete stop. The path traversed a beta particle of a substance as is referred to as its mileage. Mileage beta particles, usually expressed in grams per square centimeter (g/cm2). In body tissues beta radiation penetrates to a depth of tenths of a millimeter to 1-2 see Due to such properties for protection against beta radiation is sufficient to have an adequate thickness of the screen made of organic glass.
At these properties based use of beta-radiation in medicine for surface, interstitial and intracavitary radiotherapy (see Beta-therapy). Many beta-emitters (14, P32, S35, CA45 and others) were used as a label for experimental purposes and radioisotope diagnostics (see). For the measurement of beta radiation are special beta counters, beta-spectrometers, ionization chambers. Cm. also Dosimeters ionizing radiation, ionizing Radiation, Radiation therapy, Counters nuclear radiation.

Beta radiation (beta rays, or beta-particles flux) - a flow of electrons or positrons emitted during radioactive beta decay of nuclei of some atoms.
Electrons or positrons are formed in the nucleus when converting a neutron into a proton or a proton into a neutron. Neutrino and antineutrino - stable particles with no charge and a mass of peace.
When e-beta decay, formed a new kernel with the number of protons in one more than before the collapse of the (increasing by one atomic number Z), and when positron beta decay, the nucleus charge and Z be decreased by one. Mass number in both cases does not change.
Electrons or positrons)emitted during radioactive beta decay, have different energies from zero up to some maximum energy Eat, for most radioactive isotopes does not exceed several MeV. Energy spectrum beta-rays is continuous. At the same time, the energy levels of the atomic nucleus discrete and, therefore, with every beta decay must be exempted certain amount of energy. The continuity of beta-spectra due to the fact that excess energy of the nucleus in the decay differently distributed between two emitted particles, for example, a positron, and a neutrino. In this regard, the spectrum of neutrinos emitted during beta decay, also continuous.
The transformation of a proton into a neutron can happen except for beta decay, also in a process called e, or K-capture. With the capture of the nucleus of the atom "captures" electron from one of the nearest electron shells, mostly in the so-called K-shell. With the capture of neutrinos emitted and the nucleus charge is reduced by one. To capture accompanied characteristic x-ray radiation.
Beta rays are a type of ionizing radiation see ionizing Radiation). Passing through a substance, beta rays lose energy, causing ionization and excitation of atoms and molecules environment. The absorption of energy in the environment may lead to a number of secondary processes in irradiated material, such as radiation and chemical reactions, luminescence, the change of crystal structure, and so on, as with other forms of ionizing radiation beta rays cause radiobiological effect (see Radiobiology).
The penetrating ability of beta-rays measured at their maximum mileage.
Cm. also Radioactivity, atomic Nucleus.