Alexander Sergeevich Kubankin

The generation of polarization radiation by electron beams passing near dielectric objects has attracted considerable attention due to its potential applications, such as beam parameter diagnostics and the generation of intense electromagnetic radiation in the THz and sub-THz frequency ranges. Among the various forms of this radiation, Cherenkov diffraction radiation (ChDR) is particularly noteworthy. ChDR arises when high-energy electrons travel parallel to and in close proximity to a long dielectric interface. The characteristics of this radiation are influenced by the properties of the charged particles, the target material, and its configuration. To produce radiators with the required precision, advanced technologies for fabricating dielectric samples with complex geometries are essential. One promising approach is 3D printing using fused filament fabrication (FFF) of plastics. However, before implementing this method, a thorough investigation into the dielectric properties of these plastics must be conducted to ensure their suitability.

Recently, it was established that the X-ray generation intensity increases in a certain range of temperature variation rates (6–8°C/min) of lith

A wire scanner designed to measure the spatial characteristics of beams of relativistic and nonrelativistic charged particles, as well as beams of X-ray and gamma radiation, is proposed. The scanner contains several wires of different materials located along the beam axis and capable of moving across the beam. During scanning, characteristic X-ray radiation is generated in the wires under the action of the beam, the spectra of which are recorded by an energy-dispersive X-ray detector. Determination of the transverse profiles of the studied beam consists in measuring the radiation-intensity dependence on the impact parameter of the wires. Matching of the obtained profiles with specific wires is performed according to the energy of characteristic X-ray radiation. The data obtained during scanning allows determination of the transverse dimensions, shape, trajectory, divergence and emittance of the beam.

The samples of ceramics (Y,Ce,Mg,Sr)O_2-δ; 10YCe3Mg5Sr; 10SmCe3Mg5Sr were obtained by the method of standard solid-state reaction. According to X-ray analysis, all systems have the fluorite cubic structure, but in the (Y,Ce,Mg,Sr)O_2-δ system, the presence of the second orthorhombic phase was observed. The microstructure of powders and synthesized tablets were characterized by electron-microscopy. The average particle size of the powder was shown to be 23.88 nm; 22.32 nm; and 13.4 nm for the compositions (Y,Ce,Mg,Sr)O_2-δ; 10YCe3Mg5Sr; and 10SmCe3Mg5Sr, respectively. After the sintering at temperature 1450 °C; the grain size increased to 5.1 μm; 3.95 μm; 5.07 μm for (Y,Ce,Mg,Sr)O_2-δ; 10YCe5Mg5Sr; and 10SmCe5Mg5Sr, respectively. The ionic conduction of the obtained samples was defined by ac impedance spectroscopy. The activation energy was then calculated. The 10SmCe5Mg5Sr system was found to have the highest electrical conductivity, reaching 20.5 mS/cm at a temperature of 700 °C. The activation energy was 0.62 eV in the temperature range of 600–800 °C. The results of the density, microhardness, and crack resistance measurements of the solid solutions under investigation were obtained.

We study the conductivity and magnetoresistance of the α‴ phase solid solution of (Cd_1−xZn_x)₃As₂ (x = 0.45). Single crystals of (Cd_1−xZn_x)₃As₂ are obtained by the modified Bridgman method. The space group and tetragonal lattice parameters of single crystals are found to be I4₁/amd and a = b = 8.56(5) Å, c = 24.16(6) Å. The temperature dependence of the conductivity and magnetoresistance is studied in the temperature range of 1.6–320 K and in the presence of a transverse magnetic field from 0 to 10 T. Mixed conductivity is analyzed using Hall resistivity data and standard quantitative mobility spectrum analysis. The concentration and mobility of holes are determined at different temperatures. The presence of two types of holes with different mobilities is demonstrated in the temperature range of 1.6–19 K, while with increasing temperature, just one type of charge carrier is observed in the mobility spectrum.

The K -shell ionization cross sections of titanium and copper atoms were determined by analyzing the spectra of characteristic X-ray radiation generated by an electron beam with energies of 1 and 2 GeV in metal foils. New data obtained for these energies demonstrate the influence of the density effect on the ionization cross sections values. The results were compared with previous experimental data and calculations based on pure theoretical and semi-empirical models.

The paper presents the results of experimental studies of the passage of electrons through a ceramic macrocapillary with energy of 10 keV in the position when the axis of the channel is parallel to the axis of the incident beam. Measurements were made of the current and energy spectrum of electrons passing through the channel, depending on the value of the current of the beam incident into it and the irradiation time of the channel. The change in the transmission of electrons through the sample as a function of time after the formation of a conductive carbon deposit on the inner surface of both ends of the channel is demonstrated.

In the coming years, the compact monoenergetic neutron generators (CNG) producing up to 10⁴ n/s may become an alternative to the standard neutron sources based on radioactive isotopes for the calibrations of neutrino and dark matter detectors. Such neutron generators have a typical size of about several centimetres, they may be manufactured using low-background materials and may require only low voltage power supply for operation. We discuss the advantages and disadvantages of two main types of the compact neutron generators, namely a pyroelectric neutron source and a high voltage neutron generator. Also the results of the technical analysis of the possibilities to apply such sources for the calibration of low-background experiments are given, the variant of the internal device design is shown and the full-size compact neutron generator prototype are presented.