Accelerator complex based on DC-60 cyclotron

DC-60 heavy ion accelerator, put into operation in 2006, according to its specifications - spectrum, charge and energy of accelerated ions, has the high scientific, technological and educational potential. The highest possible universality both by spectrum of accelerated ions and acceleration energy and regimes was built in DC-60 heavy ion accelerator designing. The new interdisciplinary research complex based on cyclotron DC-60 makes it possible to create a highly-developed scientific-technological and educational environment in the new capital of Kazakhstan..

Accelerator complex based on DC-60 cyclotron

DC-60 heavy ion accelerator, put into operation in 2006, according to its specifications - spectrum, charge and energy of accelerated ions, has the high scientific, technological and educational potential. The highest possible universality both by spectrum of accelerated ions and acceleration energy and regimes was built in DC-60 heavy ion accelerator designing. The new interdisciplinary research complex based on cyclotron DC-60 makes it possible to create a highly-developed scientific-technological and educational environment in the new capital of Kazakhstan..

Effect of Irradiation with Heavy Xe22+ Ions with Energies of 165–230 MeV on Change in Optical Characteristics of ZrO2 Ceramic

The aim of this work is to study the effect of irradiation with heavy Xe22+ ions with energies of 165 MeV, 200 MeV, and 230 MeV on the change in the optical properties of ZrO2 ceramic. The choice of ion energies, as well as irradiation fluences of 1013-1014 ion/cm2, is primarily due to the possibility of simulating radiation damage in ceramics that occurs when overlapping damaged areas in the material, comparable to damage from fission fragments of uranium nuclei in an atomic reactor. Using UV–Vis spectroscopy methods, changes in the throughput of ceramics were evaluated depending on the irradiation fluence and the energy of incident ions. It was found that a change in the irradiation conditions leads to the formation of irradiation-induced defects with an energy of 2.4–2.45 eV in the structure, the concentration of which increases with the irradiation dose. Changes in the band gap and refractive index depending on irradiation fluence and incident ions energy indicate a change in the electronic and optical density of ceramics, as well as the formation of additional absorbing centers in the structure. © 2021 Elsevier B.V.This work was supported by the Grant No. BR09158499 ( Development of complex scientific research in the field of nuclear and radiation physics on the basis of Kazakhstan accelerator complexes) of the Ministry of Energy of the Republic of Kazakhstan

Radiation Swelling and Hardness of High-Entropy Alloys Based on the TiTaNbV System Irradiated with Krypton Ions

The aim of this work is to study the effect of irradiation with low-energy Kr14+ ions with an energy of 280 keV on radiation swelling and a decrease in the strength characteristics of high-entropy alloys based on the TiTaNbV system. The prospects of these studies are due to the possibility of obtaining new data on the radiation resistance of high-entropy alloys, which have great potential for use as structural materials for new-generation reactors. The choice of this type of irradiation and a dose of 5 × 1015 Kr/cm2 made it possible to simulate the effect of radiation swelling arising at a displacement per atom of 30–50 dpa in a small surface layer no more than 100–150 nm thick. During the studies carried out, it was found that the formed medium- and high-entropy alloys TaNbV and TiTaNbV have increased resistance to swelling and deformation of the crystal structure. At the same time, alloys of the NbV and TaNbV type have the highest degree of resistance to softening, while the TiTaNbV alloy has a lower resistance to swelling, since the addition of titanium leads to a decrease in the density and hardness of the alloy. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature

Study of the Effect of Doping ZrO2 Ceramics with MgO to Increase the Resistance to Polymorphic Transformations under the Action of Irradiation

The purpose of this study is to assess the effect of doping ZrO2 ceramics with MgO on radiation swelling and polymorphic transformations, as a result of irradiation with heavy ions. Interest in these types of materials is due to the great prospects for their use as structural materials for new-generation reactors. The study established the dependences of the phase composition formation and changes in the structural parameters following a change in the concentration of MgO. It has been established that the main mechanism for changing the structural properties of ceramics is the displacement of the cubic c-ZrO2 phase by the Zr0.9Mg0.1O2 substitution phase, which leads to an increase in the stability of ceramic properties to irradiation. It has been deter-mined that an increase in MgO concentration leads to the formation of an impurity phase Zr0.9Mg0.1O2 due to the type of substitution, resulting in changes to the structural parameters of ceramics. During studies of changes in the strength properties of irradiated ceramics, it was found that the formation of a phase in the Zr0.9Mg0.1O2 structure leads to an increase in the resistance to cracking and embrittlement of the surface layers of ceramics. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (No. АР09259476)

Study of the Effect of Doping ZrO2 Ceramics with MgO to Increase the Resistance to Polymorphic Transformations under the Action of Irradiation

The purpose of this study is to assess the effect of doping ZrO2 ceramics with MgO on radiation swelling and polymorphic transformations, as a result of irradiation with heavy ions. Interest in these types of materials is due to the great prospects for their use as structural materials for new-generation reactors. The study established the dependences of the phase composition formation and changes in the structural parameters following a change in the concentration of MgO. It has been established that the main mechanism for changing the structural properties of ceramics is the displacement of the cubic c-ZrO2 phase by the Zr0.9Mg0.1O2 substitution phase, which leads to an increase in the stability of ceramic properties to irradiation. It has been determined that an increase in MgO concentration leads to the formation of an impurity phase Zr0.9Mg0.1O2 due to the type of substitution, resulting in changes to the structural parameters of ceramics. During studies of changes in the strength properties of irradiated ceramics, it was found that the formation of a phase in the Zr0.9Mg0.1O2 structure leads to an increase in the resistance to cracking and embrittlement of the surface layers of ceramics

Study of the Mechanisms of Polymorphic Transformations in Zirconium Dioxide upon Doping with Magnesium Oxide, as Well as Establishing the Relationship between Structural Changes and Strength Properties

The aim of this work is to study the mechanisms of polymorphic transformations in ZrO2 ceramics doped with MgO with different concentrations during thermal isochronous annealing, as well as the effect of the phase composition of ceramics on the change in strength properties and resistance to mechanical stress. Solving the problem of polymorphic transformations in zirconium dioxide by doping them with MgO will increase the resistance of ceramics to external influences, as well as increase the mechanical strength of ceramics. According to the data of X-ray phase analysis, it was found that the addition of the MgO dopant to the composition of ceramics at the chosen thermal annealing temperature leads to the initialization of polymorphic transformation processes, while changing the dopant concentration leads to significant differences in the types of polymorphic transformations. In the case of an undoped ZrO2 ceramic sample, thermal annealing at a temperature of 1500 °C leads to structural ordering due to the partial removal of deformation distortions of the crystal lattice caused by mechanochemical grinding. During the study of the effect of MgO doping and polymorphic transformations in ZrO2 ceramics on the strength properties, it was found that the main hardening effect is due to a change in the dislocation density during the formation of a ZrO2/MgO type structure. At the same time, polymorphic transformations of the m—ZrO2 → t—ZrO2 type have a greater effect on hardening at low dopant concentrations than t—ZrO2 → c—ZrO2 type transformations

Structure and Phase Composition of WNb Alloy Formed by the Impact of Compression Plasma Flows

The results of a tungsten–niobium alloy synthesis by the impact of pulsed compression plasma flows are presented. Tungsten plates with a 2 μm thin niobium coating were treated with dense compression plasma flows generated by a quasi-stationary plasma accelerator. The plasma flow with an absorbed energy density of 35–70 J/cm2 and pulse duration of 100 μs melted the niobium coating and a part of the tungsten substrate, which caused liquid-phase mixing and WNb alloy synthesis. Simulation of the temperature distribution in the top layer of the tungsten after the plasma treatment proved the formation of the melted state. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to determine the structure and phase composition. The thickness of the WNb alloy was 10–20 μm and a W(Nb) bcc solid solution was found