The effectiveness of thin plasma coatings with titanium nitride (TiN) applied by the method of condensation in ion baths (IB) on the working surface of molds under the pressure of copper alloys (steel 4Kh5MFS and 5KhNM) was investigated. It has been shown that coating with a thickness of up to 5 m significantly increases the durability of molds: before the first regrinding by 1.5–2.5 times (3–5 thousand cycles versus 2 thousand without coating), and the core life before failure by 5–6 times (not less than 12 thousand cycles). It has been established that after removing the coating (when regrinding to a depth of ≥20 µm), the drying function is preserved due to the diffusion of titanium in the near-surface steel balls during thermal cycling. Titanium, which diffuses, creates dispersed inclusions of a foldable structure (Ti-N and Ti-V-N) with a size of 2…10 μm, which plays the role of the essential phase, moving between the dislocation and the moving support of the thermal fatigue. The microhardness of the surface ball after operation and regrinding increases up to 750…800 MPa (versus 450…480 MPa for uncoated steel). The phenomenon of the mechanism of “self-adhesive” value for the structure of cerated diffusion of titanium and the creation of non-metallic inclusions of optimal size has not been described before in the literature with ionplasma coatings and is still new approach to increasing the resource of molds for casting under the pressure of aggressive copper alloys.

A comprehensive theoretical analysis of reactions of protons with an energy of 50 MeV on nuclei 12C, 14N, and 16O was performed using the TALYS-1.96 code. The calculated cross-sections are compared with fundamental experimental data obtained by the photoemulsion method. It has been established that standard statistical models (Hauser-Feshbach) and pre-equilibrium models in TALYS satisfactorily describe a number of channels, in particular 16O(p, pn)15N. At the same time, calculations quantitatively confirm that channels with neutron emission, not taken into account in [1], constitute 39…46% of the total inelastic cross-section, which explains ≈ 40% of unidentified events in the original experiment [1]. Analysis of intermediate resonances shows that the cross-sections of formation 8Be and 9B are significant (up to 71 mb), confirming their dominant role in cascade decays. A key finding is the critical discrepancy for the channel 16O(p, p4α): the experimental cross-section (78.1 mb) [1] cannot be explained by statistical models (TALYS prediction gives < 17 mb) [5], indicating the dominance of direct cluster mechanisms of the reaction.

For spent nuclear fuel (SNF) Ukraine built a Central Storage Facility (CSF). But now there are risks during the transportation and of the СSF's proximity to the border. The work proposes the use of an additional spend fuel pool, where SNF can be stored for more than ten years, followed by relocation to closed dry storage. The roof over the containers provides several advantages for long-term retention. For the final placement of SNF after the shutdown of the NPP, it is proposed the containment. The optimization the wall thickness ratio of the building and the ventilated container has been considered.

A complex approach has been developed to increase the design time of the fuel campaign of nuclear reactors, based on increasing the nominal power and upgrading the thermal resistance of fuel elements. Increasing the nominal power of the reactor can be ensured with upgrading the neutron-physical parameters of nuclear fuel. It has been recognized that the maximum permissible increase in the nominal power is determined by the conditions for the start of thermoacoustic instability of the coolant in the reactor core that can lead to deformation and leakage of the fuel elements. The maximum permissible increase in the nominal power (other things being equal) qualifies the maximum time of the fuel campaign as no more than 15 months. Increasing the time of the fuel campaign with upgrading the thermal resistance of fuel elements can be ensured by optimizing the thermal resistances of the two-phase fuel matrix model. The optimization criterion is the identity of the fuel cladding temperature of the design and upgraded thermal resistances of the fuel elements in the reactor operating modes at the design nominal power. Optimization parameters are the thermal resistances of the surface and central zones of the fuel matrix. The maximum time of the fuel campaign with upgrading the thermal resistance of the fuel elements is 18 months. It has been recognized that a complex approach to increasing the time of the fuel campaign, based on increasing the nominal power and upgrading the thermal resistance of the fuel elements, can provide a maximum time of the fuel campaign of no more than 21 months. The qualified maximum time of the fuel campaign is determined assuming the independence of the burn-up rate of nuclear fuel from temperature. This may be the subject of further study.

This paper presents the results of an FTIR spectroscopy study on the physical and chemical structural modifications induced by gamma irradiation in HDPE polymer and HDPE/GaAs<Te> composite films in absorbed dose range of Фγ = 50…350 kGy. It has been shown that gamma irradiation causes changes in the degree of crystallinity and the formation of polyene (–C=C–) and carbonyl (C=O) groups in polymer and composite films. The dose dependencies for these modifications exhibit a similar trend, indicating a direct relationship between the degree of crystallinity and the crosslinking process. Comparative analysis confirms that composite films are more radiation resistant than the polymer films.

Experimental silicon carbide (SiC) samples size of 25x25x4 mm with different Cr additives content (from 0.3 to 0.5 wt.%) were manufactured using high-speed hot pressing method. The initial powder materials and the obtained samples were characterized by X-ray diffraction analysis, elemental analysis (proton backscattering spectrometry) and corrosion (hydrothermal) tests in the conditions, simulating the environment of the WWER-1000 reactor coolant. X-ray diffraction identified two polytypes SiC-6H and SiC-4H, as well as small amount of carbon in the sintered samples. Diffraction peaks of pure Cr were not detected. Proton backscattering spectrometry with energy of 1.52 MeV revealed that after hydrothermal tests the oxygen content in the Cr-doped samples increased to a value that approximately corresponds to the stoichiometry of Cr2O3. Obtained result indicates formation of protective Cr2O3 oxide film on the surface of the Cr-doped SiC samples.

This study proposes a method for calculating the field emission parameters using two linear regions of FowlerNordheim plots. The method allows to get the values of the work function, field enhancement factor and area efficiency of emission. Based on this method, an analysis of the emission properties of titanium nitride synthesized using reactive Arc-PVD was carried out. The calculated work function values are in good agreement with the values reported in other studies. The obtained relationships between the field enhancement factor and area efficiency of emission for materials with the same composition can be explained by the features of the surface morphology.

The results of the development of the multifunctional accelerator complex of the NSC KIPT are considered. The magneto-optical structure of the recirculator, which is the basis of the complex, is presented, which ensures the production of an electron beam with a maximum energy of about 600 MeV when the beam passes through the superconducting accelerating structure three times. Variants of obtaining beams of electrons, gamma quanta, positrons and neutrons for performing fundamental and applied research in the field of nuclear physics and energy, solid-state physics, and nuclear medicine are presented.

The hydrodynamic stability of a water vapor nanobubble in water under normal conditions is investigated. The hydrodynamic equation describing the motion of the bubble boundary taking into account the bubble charge and the dependence of the surface tension coefficient on the radius, as well as the heat balance equation of the nanobubble are used for the study. Taking into account the nanobubble charge leads to a competition between capillary and electrostatic forces, which affects the hydrodynamic stability of the nanobubble. The main equations are written down, and an analysis of the stability of small disturbances is carried out. The characteristic equation is obtained and the stability conditions of the nanobubble are determined. It is shown that the radius of a stationary nanobubble is equal to the Tolman radius, since at this radius its energy is minimal. The value of the surface charge density and the charge of a vapor nanobubble in water are determined.

A variant of a high-current linear accelerator of medium-energy protons with combined RF focusing is considered. The results of numerical modeling of beam dynamics in the accelerating-focusing beamline in the energy range 3...70 MeV are presented. It is shown that the maximum current of charged particles accelerated without losses in the accelerating path is 160 mA at an acceleration rate of 5 MeV/m. A scheme for implementing this type of beamline based on short RF resonators is proposed.