Vol 4, No 4 (2020)
274-280 469

The availability of new radioactive ion beams has broadened the study of nuclear reactions and nuclear structure. The main mechanism to produce the secondary beams is the fragmentation of the projectile. An alternative method for the production of the exotic nuclei is the multinucleon transfer. We measured production cross section for the B, C, N and O isotopes in the reaction18O + Ta and the beam energy at 10 MeV/nucleon. The cross sections were obtained by integrating the momentum distributions of the isotopes. It was shown that in deep inelastic processes the production yields of different isotopes could be well described using statistical models and could also be explained by the Qgg-systematic.

281-290 471

The work is devoted to determining the response function of the detector NaI(Tl) for γ-quanta with energy of 4.43 MeV, formed during inelastic scattering of neutrons with energy of 14.1 MeV on the nuclei 12 C. In gamma spectrometry, output pulses are recorded, the amplitudes of which are proportional to the energy lost in the detection medium by incident photons. One of the main tasks of radiation detection is to restore radiation characteristics from signals measured at the outputs of detectors. For this, it is necessary to know, first of all, the general characteristics of detectors as converters of radiation into signals. The main characteristic of the detector is its response function, which can be defined as the probability that a particle with given properties generates a certain signal in the detector that will be registered by the device. The article presents the results of modeling the response function of a scintillation detector based on a NaI(Tl) crystal for gamma radiation from inelastic fast neutron scattering in order to study the mechanism of its formation.

291-308 445

The work presents study results of the applicability of high-temperature heat treatment (500-700°C) of nitride ceramics irradiated with protons with an energy of 1.5 MeV and a dose of 10 16 cm 􀀀2 . It was found that heat treatment for 60 minutes at a temperature of 700°C allows us to significantly reduce the density of radiation-induced defects and distortions in ceramics structure due to partial annihilation and relaxation of point defects. Dependences of changes in the strength and mechanical characteristics of ceramics on the temperature of post-irradiation annealing are shown. Based on the data obtained, a conclusion was made about prospects of using post-irradiation annealing to maintain the strength of ceramics subjected to loading during operation.

309-318 411

The results of the efficiency of using Fe x Ni 100􀀀x nanotubes as anode materials for lithium-ion batteries have been obtained. In the course of research, it was found that an increase in the concentration of nickel in the structure to 40 and 60 at.% leads to a sharp increase in the resource number of cycles by more than two times in comparison with iron nanotubes. Such a difference in the resource lifetime is due to the higher stability of Fe x Ni 100􀀀x nanotubes with a nickel concentration of more than 40 at.% to destruction, as well as resistance to oxidation.

319-326 465

The article studied the effect of annealing on the structure and properties of zirconium dioxide coatings obtained by detonation spraying. Detonation spraying was realized on a computerized detonation spray ing complex of the new generation CCDS2000. Determined that coatings made of zirconium dioxide are characterized by high adhesive strength of adherence to the substrate. Thermal annealing of coated samples was performed at temperatures of 900-1200C. It was determined that the microhardness of zir conium dioxide coatings increases by 10-25% depending on the annealing temperature after annealing. The results of nanoindentation showed that the nanohardness of the coatings after annealing at 1000C increases by 50%. It was determined that after annealing at 1000C, the elastic modulus of the coatings increases, which indicates a decrease in plasticity and an increase in the strength of the coatings. X-ray diffraction analysis showed that the phase composition of coatings before and after annealing consists of t-ZrO2. After annealing occurs there is an increase in the degree of t-ZrO2 tetragonality. Electron microscopic analysis showed that an increase in the number and size of micro-continuity in the form of thin layers after annealing. Determined that increase the hardness of zirconium dioxide after annealing at 900-1200C is associated with a higher degree of tetragonality t-ZrO2 phase.

327-335 450

The article presents the results of studying the process of electrolytic-plasma hardening of 0.34Cr-1NiMo- Fe steel by surface hardening, as well as the results of the current-voltage characteristics of the cathodic electrolytic-plasma process depending on the composition of the electrolyte. Temperature-time and special modes of electrolytic-plasma hardening of steel 0.34Cr-1Ni-Mo-Fe were determined. The optimal composition of the electrolyte for electrolytic-plasma hardening has been determined, providing a relatively high heating rate and high hardness of the steel surface. It has been determined that after the electrolytic-plasma hardening, the microhardness of 34KhN1M steel increases 2.9 times due to the formation of fine martensite. In this case, the basis of the material does not change, it consists of a ferrite-pearlite structure.

336-343 510

The main objective of current study is to assess the dose burden and health status of workers at the uranium processing hydrometallurgical plant in order to develop measures aimed at reducing their incidence. This article presents the results of radiation monitoring and data on the health status of workers at the hydrometallurgical plant of the Stepnogorsk Mining and Chemical Combine (SMCC). The data of the accumulated effective dose for the entire length of service, as well as data on the incidence rate for the period 2013-2019, obtained from the base of the Industrial Radiation and Epidemiological Register, have been analyzed. Based on the results of measurements of the uranium content in urine, the expected effective dose of internal irradiation of the enterprise personnel was calculated. The assessment of the health status of workers was carried out based on the materials of outpatient and hospital visits, as well as the results of mandatory periodic medical examinations over the past 5 years. Based on the results, an excess of the expected effective dose of internal irradiation was revealed based on the analysis of a urine sample by 3 times. The most typical for the studied contingent of the main group turned out to be diseases of the eye and its adnexa (23%).

344-350 467

Radon is a noble gas that is one of the natural radioactive decay products of radium resulting from the disintegration of uranium. Humans are exposed to sources of natural radiation activity, being radon and its progeny breathing air responsible for more than 50% of the annual dose received from natural radiation. The aim of this study was to determine the radon concentration in the air in settlements’ dwellings and social objects and calculate the annual effective dose of population from radon on the territory mining activities in Stepnogorsk area. The study has shown that activity concentrations of indoor radon in the buildings ranged from 8 to 870 Bq · m 􀀀3 in Aqsu, 3-540 Bq · m 􀀀3 in Kvartsitka located close to former gold mining sites. The Einh corresponding to the activity concentrations ranged from 1-27 mSv · y 􀀀1 received by the settlements’ public. The highest value of Einh in Aqsu School reaches up to 68 mSv · y 􀀀1 received by the critical group of public was found at the territory of former mining the Stepnogorsk area. The results of this study show significant radiation hazards in Aqsu School which located at the territory of former mining site, and there is evidence of radon health risk to the members of the public.

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