Vol 3, No 4 (2019)
286-299 398

The year 2019 has been declared by UNESCO as the year of the Periodic Table of Elements. 150 years ago, an outstanding Russian scientist D.I. Mendeleev systematized the chemical elements known at that time by chemical properties and created a table of elements. Since then, almost 60 chemical elements have been added to those known 150 years ago. Now the table has 118 chemical elements, most of which were synthesized artificially, in particular, on charged particle accelerators. Especially vigorous growth in the synthesis and research of new heavy transfermium elements was observed during the last 20 years, when about 20 new heavy and super heavy elements were synthesized in various world research centers with powerful accelerator complexes. In the present article, the authors discuss the current situation in the synthesis of new elements with an atomic number greater than 110 and the prospects for further advancement in the region of super heavy elements.

300-306 461

The experiments of detailed study of No and Rf isotopes radioactive decay properties in complete fusion reactions50Ti+208Pb and48Ca+208,206,204Pb with subsequent neutron evaporation from the excited compound nucleus at the kinematic separator SHELS were performed in FLNR JINR. The data of the256Rf decay properties and preliminary data of250No decay properties are presented.

307-318 466

The nuclear shell model and its application to studying the structure of nuclei with deformed and spherical shapes are discussed. Calculations of level energies and wave functions in the shell model of deformed and spherical nuclei are performed for7,8,11Li nuclei. A detailed calculation scheme for solving theradial Schrödinger equation is presented.

319-329 429

In this paper the experimental data on the differential cross sections for elastic scattering of9Be ions on28Si nucleus at the energies of the incident nucleus ranging from 12 to 201.6 MeV were analyzed in the framework of the double folding model using the Paris NN-potential CDM3Y. A good agreement with the experimental angular distributions of differential cross sections for elastic scattering was obtained and the values of the total reaction cross sections were calculated. When the double folding potential was used as real and imaginary parts, no manifestation of the threshold anomaly was detected. The reason for such a behavior of the potential can be explained by the presence of break up and/or transfer channels at low energies.

330-338 432

The methods of vacuum ultraviolet and thermal activation spectroscopy were used to measure the excitation spectra of impurity radiation in the fundamental absorption band of K2SO4-Cu crystals at 15 K and 300 K. An energy transfer was detected from the base to Cu+ impurities. The band gap of crystals K2SO4 was estimated. In K2SO4-Cu crystals, recombination radiation bands were detected at 2.95 ÷ 3.0 eV corresponding to electron hole capture centers.

339-347 425

The paper presents the results of a study of the influence of copper phthalocyanine (CuPc) nanostructures on the generation and transfer of charge carriers in the photoactive P3HT/PCBM layer. It was shown that the observed broadening and the shift in the maxima of the absorption spectra of P3HT/PCBM upon the addition of nanostructures to the polymer are associated with an increase in the degree of crystallization of the film. Using the method of impedance spectroscopy, it was found that CuPc nanostructures enhance the rate of recombination of charge carriers, which is probably due to the formation of surface defects. These defects are electron capture centers through which carrier recombination occurs. Despite that polymer solar cells with CuPc nanostructures have enhanced recombination rate, their photovoltaic properties were better than pure polymer solar cells due to enhanced light absorption and increased film conductivity.

348-354 428

Operational dosimetry solves the problem of implementing the principle of optimizing radiation safety, which is closely related to regulation and justification and implies a realistic achievable reduction in the dose load on a person when using ionizing radiation sources by reducing operating time, increasing the distance to radioactive material and shielding for attenuation of ionization flux. The article describes two ways of determining the thickness of shielding under necessity of making operational decision to protect a person from radionuclide source of known activity or the dose rate created by it. Based on the required multiplicity of its attenuation, which allows determining the number of half attenuation layers in the shield or its thickness, is also dependent on the energy of radiation, emitted by the source.

355-362 479

This work is devoted to the research of the influence of the technological parameters of electrolytic plasma surface hardening on the structure and tribological properties of the surface of samples of the retaining steel mark 2. In the electrolytic plasma surface hardening was carried out in an electrolyte from an aqueous solution of 20% urea and 20% sodium carbonate. According to the result of metallographic and X-ray diffraction analysis, it was determined that the phase composition of steel mark 2 after processing varies, and fine martensite with a small amount of troostite and iron oxide is formed on the surface of the samples. Tribological experiments of samples without lubrication were carried out. These experiments have shown that all the studied samples have an increased wear resistance, which may be associated with the formation of a fine grained martensitic structure. It was shown that from the point of view of the complex of the properties obtained, the most promising is electrolytic plasma action with a treatment time of 2 s.

363-370 393

As known silicon nitride ceramics is considered as a candidate material for inert matrix fuel hosts used for transmutation of minor actinides. Unfortunately, by now very limited data is devoted to investigate of its stability under high energy heavy ion irradiation simulating fission fragment impact. Aim of our present study is a comparative analysis of parameters of latent tracks induced with swift Xe ion irradiation in polycrystalline Si3N4 using molecular dynamic (MD) simulation and high resolution transmission electron microscopy (TEM). Silicon nitride samples were irradiated with 220 MeV xenon ions at room temperature to fluence 5 × 10 11 cm-2 that correspond to ion track non overlapping regime and allows to analyze single ion track regions. The calculated MD and experimental TEM values of track diameter for 220 MeV Xe irradiation are found to be in a good agreement and equal about 2 nm, whereas the threshold ionizing energy loss for track formation predicted by MD is lower than threshold value from TEM measurements (11.5 keV/nm vs 15 keV/nm). The averaging of all presented data gives the threshold energy loss level ∼ 13 ± 2 keV/nm

ISSN 2522-9869 (Print)
ISSN 2616-8537 (Online)