Gamma radiation

Gamma radiation (gamma rays) is electromagnetic radiation with a wavelength of less than 1A, propagating with the speed of light; occurs gamma-radiation in the decay of the nuclei of some natural and artificial radioactive isotopes (see), inhibition of charged particles and other nuclear reactions.
Currently in medicine as sources of gamma radiation (gamma emitters) mostly use artificial radioactive isotopes (radioactive cobalt With60, caesium Cs -137 and Cs -134, silver Ag111, tantalum Ta182, iridium Ir192, sodium Na24 and others). From naturally radioactive sources of gamma-radiation are used (balneology) radon Rn222, radium Ra226 and radium-Mesohori MsTh228 (in oncological practice). Gamma quantum energy of radioactive isotopes vary from 0,1 up to 2.6 MeV. Gamma quantum energy of some isotopes (With60, Cs -137, Tu170) homogeneous, other (radium, tantalum and other) - has a wide range. For therapeutic purposes should homogeneous radiation (the same energy); therefore, use metal filters for absorption of beta particles (see Beta-radiation) and soft gamma-radiation. For filtration of soft beta radiation sufficient filters of Nickel, aluminium, of a thickness of 0,1 mm For the absorption of beta-particles more energy and soft gamma-radiation necessary filters made of platinum, gold thickness of 0.5-1 mm Gamma radiation, like other types of ionizing radiation at interaction with tissues of the organism causes ionization and excitation of atoms and molecules, causing radiation-chemical reactions. They cause changes of morphological and functional properties of cells in the first place tumor, because radiation therapy radiation always concentrate in the area of the tumor. At sufficiently high doses of radiation can cause the death of tumor cells and replacing them with scar tissue. Cm. also Gamma-therapy, ionizing Radiation.