A new “dry” ion-plasma chamber deactivation technology is developed for the first time to deactivate irradiated graphite blocks. The technology is based on a homogenous shortened plasma discharge in an inert gas (argon) for the ion and thermal treatment of all graphite block surfaces simultaneously in a special chamber. The deactivation of graphite block of the reactor masonry is carried out by the ion sputtering of radionuclides from the block surfaces, as well as due to the thermal diffusion of radionuclides from the graphite block volume under plasma discharge heating. The technology provides a maintenance of the graphite masonry blocks integrity during the deactivation process for the effective burial of radionuclides. The thermophysical parameters of the ion plasma in chamber technology for the deactivation of the grade GR-280 reactor graphite have been obtained.

Ti–B–C coatings of various compositions have been obtained by magnetron sputtering using a TiB₂–TiC heterophase target and have been deposited on a Si(111) substrate. The studies have been carried out using glow discharge optical emission spectroscopy, X-ray diffraction and scanning electron microscopy. The electrical resistivity has been measured using the four-probe method. The coatings had a dense, low-defect structure based on the hexagonal TiB₂ phase and have been characterized by a uniform distribution of elements throughout the thickness. It has been established that the electrical resistivity decreases from 314 to 249 μΩ cm with an increase in the titanium content in coatings from 27 to 42 at %.

A multiscale study of the structure of spherical particles (granules) of rapidly quenched powder of a heat-resistant (α + β) titanium-based alloy obtained by the PREP method, which has been subsequently used for the manufacture of products using PM HIP technology, has been carried out. Metallography LM, SEM, EDX, OIM methods are used to study the structure of granules of different sizes. The influence of the granule size and vacuum heat treatment at temperatures in the fields of (α + β) and β phases on the regularities of the formation of the microstructure of granules has been revealed. The dendrite microstructure of grains of the metastable β phase has been found in the particles (granules) of the original rapidly quenched PREP powder. Dendrite segregation of alloying elements is clearly revealed in larger particles, for example, for Mo. In smaller particles, the formation of a more highly dispersed structure has been observed. The controlling effect of granule size decreasing on the reduction of dendrite structure size parameter (SDAS) has been determined. Schematic TTT diagrams of phase transformations in the studied alloy, including crystallization, martensitic transformation, and normal diffusion transformation β → (α + β), have been constructed.

Heat-resistant dielectric composite materials based on organosilicon polymers for the manufacture of parts for low-thrust space engines, for example, the discharge chamber of a high-frequency ion engine, which is one of the types of electric rocket engines, have been synthesized and their properties have been studied. A composition of a polymer−ceramic material based on dimethylsiloxane rubber reinforced with α-phase silicon dioxide powder has been proposed. The composite meets a wide range of requirements for the material of discharge chambers, among which vibration resistance, radio transparency, and heat resistance up to 400°C should be highlighted. A relationship has been established between the heating rate during post-vulcanization of a polymer−ceramic composite and its mass loss. It has been shown that the temperature regime during pre-vulcanization/annealing of the composite in vacuum significantly affects the operational properties of the discharge chambers. The results of the study have allowed us to successfully produce samples of discharge chambers from this composite for a laboratory model of a high-frequency ion engine with a beam diameter of 100 mm.

The probability P_NEET of excitation in the nuclear plasma of multiply charged ions due to transitions in their electronic shells is considered for the case where the energy difference between nuclear and electronic transitions ΔE_NEET becomes small due to the deformation of the electron shells of ions during their collisions. It is shown that such a resonance is possible only in a two-component plasma containing singly charged ions along with multiply charged ions. For ΔE_NEET up to ~100 eV, the occurrence of resonance can increase the probability P_NEET by several orders of magnitude. It is noteworthy that resonant conversion of the excitation of nuclei into the excitation of their electron shells in the plasma is also possible.

Limited flat and cylindrical layers of a material streamlined by a coolant flow are considered. Dependences of the heat transfer describing the entire period of the solidification process have been presented for the limited flat layer streamlined by the coolant flow. Analytical dependences of heat exchange for the whole period of the solidification process have been obtained for the cylindrical layer washed from the inside and outside by the coolant flow.

A calibration procedure with ²²Na radioactive sources for the counters of gamma-nuclear transition spectrometer, which is fully integrated in the infrastructure of the Hyperon+ setup, including trigger and data acquisition systems, is proposed and implemented.

The design of a large ring laser gyroscope with the record sensitivity to variations in the rotation speed and angular inclinations of the laboratory base surface, as well as to the rotational asymmetry of the refractive index of the optical medium, including vacuum is presented. Such an instrument placed in an underground observatory will allow one to obtain information relevant to particle physics, quantum field theory, laser physics, astrometry, global geodynamics, and seismology. In addition, it can be applied to forecast global cataclysms such as earthquakes. As a practical step to support the project, the results of trial experiments with a small-sized laser gyroscope (LG) are presented.

The parameters of a glow discharge in helium with a nonuniform distribution of the density of neutral particles along the discharge gap have been calculated for a one-dimensional axisymmetric geometry. This formulation of the problem corresponds to the condition of generating a discharge between a Laval nozzle with a central body, which is the anode, and a ring cathode coaxial with the central body at low pressures. In this case, a supersonic gas flow is generated through the Laval nozzle, which creates an increased gas pressure near the central body (anode), and high vacuum is maintained outside the supersonic jet. Thus, the internal structure of this discharge will depend on the density of gas particles in different regions of the interelectrode space. It has been established that this method of organizing a glow discharge in a supersonic gas flow makes it possible to control the spatial distribution of the internal characteristics of the discharge.

Universal features of dynamic failure and turbulence phenomena are considered on the basis of research results and literature data analyses. The absorbed energy density causing the failure is comparable to the energy parameter of the crystal lattice E, which is fractions of electronvolt per atom in the range of nonequilibrium states t ~ 3 ⋅ 10^–10–10^–6 s. Macrofailure, changing the body connectivity, arises when approaching the critical density of the failure center cascade, i.e., percolation cluster, through the cascade of bifurcations. Fully developed turbulence is a chaotic dynamics, which is related to the stochastic instability of the transition through a sequence of period-doubling bifurcations, through intermittency etc. At present, a strict mathematically grounded theory of dynamic failure phenomena of condensed matters and turbulence theories are absent, which implies the application of scaling relations and phenomenological approaches for their description. On the basis of design-theoretical studies and literature data analysis, it has been shown that phenomena of dynamic metal failure and fully developed turbulence are analogous, meaning that these processes have close values of critical exponents and belong to one universality class.

The solution to relevant problems of nuclear power industry such as the deactivation of nuclear power plants, hot cell, equipment for isotope separation, reprocessing of spent nuclear fuel for the effective closure of the nuclear fuel cycle is discussed. The ion-plasma “dry” technology developed to solve these problems is reported. The operating parameters of the ion-plasma technology for decontamination and reprocessing of spent nuclear fuel have been obtained, including inert gas pressure 0.1–1 atm., flow rate of the inert carrier gas 1–10 m/s, and current density 1–5 A/cm² at the operating voltage of 100–1000 V. Using the example of spent nuclear fuel reprocessing, the ranges of partial pressures and deposition temperatures of spent nuclear fuel elements during the process of its separation according to elemental composition have been calculated. Due to the difference in the condensation temperature ranges of each spent fuel element, purification of uranium and plutonium from most fission products of MOX and SNUP spent fuel with a purity of at least 99% is demonstrated.

The strategy for detecting collapsing stars in the Galaxy using a pair of instruments including the OGRAN optoacoustic gravitational detector and the BPST neutrino scintillation telescope, located in the ground laboratories of the Baksan Neutrino Observatory, Institute for Nuclear Research, Russian Academy of Sciences is discussed. A key element of the strategy is the search for correlated responses from both detectors, the so-called. search for “neutrino-gravitational correlations.” The efficiency of various algorithms for joint data processing, including analysis of the CH1987A event, is assessed. The processing technique is illustrated using the current output signals of the mentioned instruments.

Events of the α-fragmentation of the ¹²C and ¹⁶O nuclei in nuclear track emulsion in inelastic interactions with 7 GeV/c positively charged hadrons has been studied in the 4φ geometry. The accumulated event statistics has allowed us to estimate the cross section for the ¹²C(h, h')3α and ¹⁶O(h, h')4α fragmentation reactions induced by a hadron beam.