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Information × Registration Number 0217U002890, 0116U006351 , R & D reports Title Research and implementation of radiation technologies reactor WWR-10M INR NASU for radiation-resistant materials with improved properties. popup.stage_title Head Litovchenko Piotr. G., Registration Date 15-12-2017 Organization Sceintific Center "Inststute for nuclear reaseach National Academy of sciences Ukraine popup.description2 Object of research - radiation technologies for obtaining radiation-resistant materials. The purpose of the work is the development and implementation of promising radiation technologies at the WWR-M reactor of the INR NAS of Ukraine. The research method is neutron-transmutation doping of semiconductor materials, which allows to obtain silicon with the best properties. As sources of neutrons for neutron-transmutation doping, radioactive sources, accelerators of charged particles and nuclear reactors can be used. However, for practical purposes of doping, the most appropriate intensity and neutron energy is a nuclear reactor based on the use of fission of uranium nuclei. The features of the design of a nuclear reactor are the presence of an active zone in the form of a compact assembly of fuel cells containing uranium enriched with isotopes U235, as well as a moderator, which uses distilled water. The reactor is characterized by a certain ratio of the number of thermal and fast neutrons, thermal neutrons are of interest for neutron doping, and rapid neutrons create radiation defects. Depending on the design of the active zone and the channels of different applications, this ratio may vary significantly within the reactor. The greater the ratio of the flow of thermal neutrons to the fast, the softer the neutron spectrum and the more favorable conditions for neutron-transmutation doping An important factor for neutron-transmutation doping is the degree of density of the neutron flux along the length and radius of the active zone, since it depends on the uniform irradiation of the samples. On a WWR-M reactor with an accuracy of 5-10% it can be assumed that the constant neutron flux density at the height of the active zone is 250 mm. In the radial direction, the density of the neutron flux changes within the active zone is not significant, but outside it changes in exponentiality. The possibility of irradiation of materials is carried out with the help of vertical and horizontal channels in which our devices are mounted. It is important to choose the dose of radiation to obtain the material with the given parameters, as well as the layout of the ingots by their properties in the containers for exposure. No less important operation of radiation technology is the annealing of radiation defects. With neutron-transmutation doping, crystals are exposed to relatively high doses of fast neutrons, resulting in accumulation of radiation defects that need to be removed by annealing. Ultimately, the electrophysical properties of neutron-transmutational silicon depend on this. Keywords - nuclear reactor, vertical and horizontal channels, neutron flux density, device, annealing. Product Description popup.authors Варніна Валентина Іванівна Волох Олексій Пилипович Кочкін Василь Іванович Ластовецький Володимир Францевич Макуха Олександр Миколайович Петренко Ігор Віталійович Старчик Маргарита Іванівна Тартачник Володимир Петрович Шевель Валерій Миколайович popup.nrat_date 2020-04-02 Close