The currently applied classification of disposable radioactive wastes adopted in Russia is considered, and also it is compared with the classification recommended in IAEA public materials. The rationale for the expediency of introducing radioactive waste new categories (exempt waste, and also very short lived waste), the “critical moments” in the existing classification of solid radioactive wastes adopted in the Russian Federation are presented. Based on the “critical moments,” recommendations that were necessary to be introduced into existing legislation to improve the classification of radioactive waste were made, taking into account the public recommendations of the International Atomic Energy Commission of the IAEA and the practices of various countries.

1.    The efficiency of the laser-induced desorption method as a detector of hydrogen isotopes under pulsed laser irradiation (wavelength 1064 nm, 100 mJ, duration 10 ns) for different power densities of incident radiation on deuterium-saturated thin titanium films was investigated. When the power flow density increases by 16 times, the intensity of the thermal desorption peak increases by more than 2 orders of magnitude. Longterm repeated irradiation of the surface does not lead to significant depletion of the content of hydrogen isotopes in the studied layers, allowing their further ex-situ analysis.

   Erosion and redeposition processes of plasma-facing materials in fusion devices are the essential factors affecting near-wall and core plasma parameters and device lifetime. To determine the possibility of in situ analyzing these processes we developed the experimental model of built-in surface analyzer utilizing low-energy proton scattering spectroscopy. We present the results of experimental approbation of the proposed method. The processes of erosion and redeposition of plasma-facing materials in fusion devices are some of the most important factors affecting the plasma parameters and the resource of the first wall. The method of analyzing thin layers on a surface using keV-energy proton scattering expands the functionality of determining the rate of erosion and deposition of layers with a large atomic number on a substrate from a light element, or, conversely, light layers on a heavy substrate, which is typical for modern fusion installations. The analysis of deposition and/or erosion consists in placing special marker targets with layers of material with a low atomic number and/or material with a large atomic number in the places of the installation in which it is supposed to study the rate of erosion and/or deposition, with the subsequent analysis of energy spectra of hydrogen ions reflected from exposed targets with energies in the kiloelectron-volt range. In this paper, estimates of the applicability of this technique directly in a fusion device are given, considering the characteristic parameters of the near-wall plasma.

   The cross sections of neutrino absorption by the gallium-71 nucleus are obtained for neutrinos from artificial 37Ar, 51Cr, and 65Zn sources. The calculations rely on the new measurement of the energy threshold of this absorption reaction, and contributions of germanium-71 excited states to the total cross section are estimated by invoking the data on the 71Ga(3He,t)71Ge charge-exchange reaction. The results are important for searches for sterile neutrinos in calibration experiments.

   The phase diagram of quantum chromodynamics under different external parameters, such as temperature, baryon density, and magnetic field strength is investigated by means of lattice simulations. Calculations are perfomed with three light quarks and imaginary chemical potential. For real values of chemical potential , the results are obtained by means of analytical continuation. Using renormalised chiral condensate and Polyakov loop, we determine the position (critical temperature) and width of the confinement−deconfinement and chiral symmetry breaking−restoration phase transitions as functions of magnetic field and baryon density.

   First, the case of (0 + 1)-dimensional nonequilibrium quantum mechanics is considered by solving the Yukawa model in an external scalar field φcl (t) = m/L+a/L*t. It is shown that the exact fermion propagators do not change with time, and the growth of bosonic propagators is determined by the contribution to the quantum average of the field and corresponds to the so-called “tadpole” diagrams. Then, the Yukawa theory of the interacting massive Dirac field and the massless real scalar field in the (1 + 1)-dimensional Minkowski space with the signature (+1, –1) is considered. In this theory we first calculate a classical current, and then quantum corrections for the Dirac field in an external coordinate-dependent scalar field with Yukawa interaction. We study the response of the production of fermion pairs to an external bosonic field linearly dependent on the coordinate.

   We study the changes in the topological properties of four-dimensional compact lattice electrodynamics. The requirement of the model to be compact leads to the appearance of topological defects (monopoles) creating magnetic currents. Available calculations have demonstrated the presence of a phase transition for the production of monopoles. In this work a phase transition between various states inside this phase and indications of the possibility of separating a single “monopoly” phase into smaller ones, which differ in the ordering of the arrangement of magnetic currents and their intensity, are found. The regularity of such a consideration is justified, as well as the consequences confirming the presence of a second phase transition in the model. The dependence of the correlation properties of magnetic currents on the direction is demonstrated. A new method of phase transitions analysis using geometric construction is proposed, revealing the changes that occur with flows in various states.

   The test results of the prototype of the secondary-emission probe operating in the mode of self-oscillatory sweep intended for diagnosing nonequilibrium plasma in the presence of epithermal group of electrons are given. Earlier, the method of self-oscillatory probe was tested using an aluminum water-cooled contact surface with formation of a nanoscale thick high-emission oxide coating. The structure of the described probe is peculiar owing to application of refractory tantalum, which is capable of working in the mode of radiation cooling, which simplifies the structure and increases the reliability of the probe. It is shown that, owing to secondary-emission characteristics, oxide-coated tantalum allows under plasma loading obtaining a pronounced N-type current–voltage characteristic with a large excess in the electron-emission current component against the ion saturation current and satisfies all requirements for realization of the method of self-oscillatory probe.

   One of the most important design elements of a tokamak is a vacuum discharge chamber, which has specific requirements related to the induction method of plasma generation and, accordingly, the presence of variable magnetic fields that additionally affect the chamber. In addition, the chamber should not only provide the possibility of creating and retaining current plasma in it, but also provide the possibility of diagnosing its parameters through the appropriate pipes. The small spherical tokamak is under construction at MEPhI, intended for both educational and research purposes, has an extensive program of such research, so the discharge chamber must not only quickly create a vacuum, withstand variable magnetic fields, but also be convenient for measuring. This paper describes design, calculations of mechanical stability and results of manufactured chamber tests.

   In the Laboratory of High-Energy Physics, 16-channels prototypes of detectors (with SiPM readout produced by Ketek and Hamamatsu) were developed for their application in zero-degree calorimetry and for measuring the profile of a low-energy neutron beam. This paper presents the method for determining the voltage of the breakpoint of the noise characteristic of the silicon photomultipliers in the multichannel detector and its temperature dependence in the range from 27.7 to 39.1°C. The response of SiPM to the LED source of calibrated light pulses has been studied and the time resolution has been obtained.