bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation Doses of Pine Stands in the Belarusian Sector of the 30-Kilometer Zone Around the Chernobyl Nuclear Power Plant at the Present Stage
Authors: Perevolotskaya Т. V. , Perevolotsky А. N. , Geras’kin S. А.
Published: April 2024

The article presents the results of assessing the dose of external and internal irradiation of the tree tier of pine stands growing on the northern trace of the Belarusian sector of the 30-kilometer zone around the Chernobyl nuclear power plant at the present stage. It was found that in the most polluted experimental sites, the total dose of external and internal irradiation of the stand can reach 160 mGy/year. It is shown that internal irradiation is formed by beta radiation of radionuclides accumulated by aboveground phytomass, its contribution to the total dose can be 80%. The external irradiation of the stand is determined by the gamma radiation of 137Cs located in the soil. The results obtained are important for understanding the processes of formation of radiation-induced effects and assessing the effects of irradiation of living organisms.
Ionizing Radiation and Inflammatory Reaction. Formation Mechanisms and Implications
Authors: Ponomarev D. B. , Stepanov A. V. , Seleznyov A. B. , Ivchenko E. V.
Published: April 2024

Ionizing radiation induces a complex of genetic, biochemical, structural and functional changes in the body. The inflammatory response development is acknowledged as one of the manifestations of systemic bodily response to ionizing radiation exposure, and this response, through the activation of immunity, acts both as protector and leads to the development of undesirable early, delayed and off-target effects. Its underlying molecular and cellular mechanisms are defined by DNA damage, free radical metabolic changes (primarily reactive oxygen and nitrogen species), oxidative stress development, inflammasome activation, “danger signals” release and pro-inflammatory cytokines production. The role of non-apoptotic cell death forms (ferroptosis and pyroptosis) is described in the genesis of post-radiation inflammatory response and subsequent tissue, organ, and system damages. The post-radiation inflammatory reaction’s ability to take form of a time-stable self-sustaining process – that increases the radiation-induced damage severity – due to the presence of a positive feedback between different components of its pathogenesis is noted.
Risk of Depressions after Radiation
Authors: Zasukhina G. D. , Maximova T. N.
Published: April 2024

The review provides data from a number of authors on the risk of developing psychogenic disorders, mainly depression as the most severe pathology, after accidents at nuclear power plants: Three Mile Island, Chernobyl, Fukushima. At the same time, it is important to develop depression even many years after the accident. The second part of the review provides information on the development of depression in patients with head and neck cancer who received head radiotherapy. The number of pathologies in this group significantly exceeds the indicator of the development of pathologies in patients with other types of cancer. The role of non-coding RNAs in the pathogenesis of radio-induced depression is discussed. They are supposed to be used as targets for specific therapy of depression.
Irisin at the Crossroad of Autophagy and BNDF Signaling for Neuroplasticity Regulation
Authors: Andyarzhanova E. A. , Voronina T. A.
Published: April 2024

Neuroplasticity is an integral feature of both the developing brain and the brain maintaining functional homeostasis and implementing adaptive changes at normal conditions and upon compensation for pathology. Support of neuroplasticity mechanisms of is one of the targets for therapeutic intervention in the treatment of neurodegenerative and stress-associated diseases. Progress in understanding the mechanisms of interaction between the muscular system and the brain points to the role of the myokine irisin in mediating the procognitive and antidepressant activity of physical exercises. Irisin being released upon myocytes activation in the periphery can cross the blood-brain barrier and is thought to stimulate cellular autophagy. Autophagy-mediated activation of protein and macromolecule recycling promotes adaptive restructuring of synaptic contacts, and the release of proteases, including matrix metalloproteinase 9, which are determining the reformatting of the extracellular matrix, maturation of brain-derived neurotrophic factor (BDNF), and, therefore, the positive regulation of BDNF signaling. Recent findings allow one to consider factors stimulating autophagy as prerequisites for successful treatment of neurological and psychiatric disorders, as well as age-related dementia. Therefore, irisin, as a physiological regulator of autophagy, appears as a prototype molecule for the creation of new therapeutic agents for the correction of neurodegenerative conditions and stress-associated brain disorders.
The Origins and Background of the Creation of the Nootropics Concept
Authors: Shabanov P. D.
Published: April 2024

The concept of nootropics was introduced into pharmacology in the early 1970s by Corneliu Giurgea, a Belgian pharmacologist of Romanian origin, based on the study of 2-oxo-1-pyrrolidine derivatives, which later became known as racetams. The paper substantiates the position that the emergence of modern ideas about nootropics and similar compounds (psychoenergizers, antihypoxants, actoprotectors) in a certain sense was preceded by the concept of adaptogens by N.V. Lazarev (1953–1958), whose theoretical development went towards concretization of certain provisions of this concept. The formation of the problem of nootropics, their place in modern pharmacology, the origins and prospects for the development of the concept, the search for new pharmacological agents with nootropic properties are considered. Nootropic activity is analyzed from the standpoint of the mechanisms of action of racetams, neuropeptides, GABA derivatives, benzimidadols.
The Role of TNF-α, TNFRSF1A, and CD40 Genes Polymorfisms in Multiple Sclerosis in Tomsk Region
Authors: Titova M. A. , Alifirova V. M. , Musina N. F. , Nikolaeva T. N.
Published: April 2024

We studied the role of polymorphisms rs1800629 of the TNF-α gene; rs4149584 of the TNFRSF1A gene; rs6074022, rs1883832, rs1535045, rs11086996 of the CD40 gene in the onset, clinical course and response to treatment in multiple sclerosis (MS) in a group of 152 patients, living in Tomsk region. 707 volunteers without autoimmune diseases and pathology of the nervous system were included in control group. The allele C of the rs6074022 polymorphism of CD40 gene was associated with the risk of MS and contributed to the high rate of disease progression. The T allele of the rs6074022 polymorphism of CD40 gene showed a significant association with the average rate of disease progression, and the GA genotype of rs1800629 polymorphism of TNF-α gene was associated with a higher frequency of MS exacerbations. Other polymorphisms did not demonstrate an association with both the risk of disease, the clinical features and response to treatment.
Neurodevelopmental Disorders in Children: Neuroplasticity and Possibilities of Nootropic Pharmacotherapy
Authors: Zavadenko N. N.
Published: April 2024

Neurodevelopmental Disorders (NDD) are characterized by disturbances of the formation of cognitive functions, communication skills, behavior characteristics and / or motor skills, which are caused by abnormalities in the course of the processes of neuroontogenesis. Factors of the etiology and pathogenesis of NDD include genetic mechanisms, early damage to the developing brain, and adverse external influences. Most forms of NDD manifest themselves in the early stages of development and before the child begins school eduction. The most common NDD, with which medical doctors of various specialties constantly meet, include speech development disorders and attention deficit hyperactivity disorder (ADHD). Since disorders of neuroplasticity processes are considered among the mechanisms of the NDD pathogenesis, their therapy should be aimed at restoring and stimulating the neuroplasticity potential. Manifestations of NDD, undergoing age-related evolution, significantly disrupt normal life and have an adverse effect on various functional areas not only in children, but also in adolescents and adults. The increase in symptoms in patients with NDD at one age or another is not due to the progressive nature of cerebral changes, but to increased difficulties of adaptation with increasing loads, including educational, social, professional ones. Therefore, in most cases, they require many years of complex management and the use of pharmacotherapy, the prospects of which are primarily associated with nootropic drugs. The data of new studies on the effectiveness of nootropics in developmental dysphasia and ADHD are discussed, and possible mechanisms of the nootropics influence on neuroplasticity processes are considered.
Central Effects of Peripherically Introduced Immune Cells Modulated by an Original Anticonvulsant in Experimental Alcoholism
Authors: Markova E. V. , Savkin I. V. , Serenko E. V. , Knyazheva M. A. , Shevchenko Yu. A.
Published: April 2024

Violation of neuroimmune regulatory interrelation, caused, in particular, by a change in the immune cell’s functional phenotype due to chronic ethanol intoxication, is an essential link in the pathogenesis of alcoholism. The unidirectional influence of most psychoactive drugs on the cells of the nervous and immune systems allows to consider immune cells as model objects for influencing intersystem functional interrelation. Based upon our own priority data on the presence of immunomodulatory properties in chronic alcohol intoxication at the original anticonvulsant acting on the molecular targets of ethanol influence in the central nervous system and the immune system, the aim of the present study was to evaluate the central effects of peripherally injected lymphocytes with in vitro modulated functional activity by a synthetic ligand of the GABAA-receptor complex meta-chlorobenzhydrylurea in long-term alcoholized animals. It was shown that transplantation of lymphocytes pre-cultivated with the anticonvulsant in syngeneic long-term alcoholic recipients achieves a decrease in alcohol motivation and stimulation of behavioral activity in the “open field” test. Editing of behavioral patterns characteristic for chronic alcohol intoxication was recorded against the background of a decrease in pathogenetically significant brain structures of pro-inflammatory cytokines IL-1β, IL-6, TNF-α, IFN-γ and an increase in the anti-inflammatory cytokine IL-10, as well as an increase in the level of BDNF in the hippocampus, which allows us to consider a decrease in neuroinflammation and stimulation neuroplasticity as possible mechanisms for editing the behavior of recipients. Visualization of functionally active lymphocytes pre-cultured with meta-chlorobenzydrylurea in the brain’s parenchyma of long-term alcoholized recipients also suggests a direct effect of injected lymphocytes on CNS cells. Thus, immune cells modulated in vitro with meta-chlorobenzydrylurea by relatively independent mechanisms have positive psychoneuromodulating effects in chronic ethanol intoxication, which makes it possible to consider adoptive immunotherapy as a promising method in the treatment of alcoholism.
Elevated Level of Small Extracellular Vesicles in the Serum of Patients with Depression, Epilepsy and Epilepsy with Depression
Authors: Yakovlev A. A. , Druzhkova T. A. , Stefanovich A. , Moiseeva Yu. V. , Lazareva N. A. , Zinchuk M. S. , Rider F. K. , Guekht A. B. , Gulyaeva N. V.
Published: April 2024

Small extracellular vesicles (sEVs) properties and sEVs composition are far from being well-studied for now, especially in the context of mental disorders. To elucidate the role of sEVs in disease we performed a quantitative analysis of the blood sEV in patients with focal epilepsy and patients with focal epilepsy with depression, psychogenic non-epileptic seizures with depression, pure depression, and bipolar affective disorder with the current depressive episode (cDE). Small EVs were isolated from the serum by gel filtration or PEG precipitation, and both methods showed very similar results. Subsequently, we precipitated neuronal sEVs and quantified it with several methods. Activity of lysosomal enzymes was determined in the sEVs fraction. The concentration of the blood sEVs in patients with depression, focal epilepsy, or depression with focal epilepsy was higher than in healthy controls. No difference was found between patients and controls in terms of neuronal sEVs concentration. Another finding of our work is that sEVs in the serum of patients contains various lysosomal enzymes. We suppose that the concentration of the blood sEVs in patients with depression or epilepsy is higher due to the sEVs secretion by the immune cells. Finding sEVs in the blood of patients with depression and focal epilepsy grants validity for future attempts to use sEVs as diagnostic tools for these disorders.
Theoretical Study of Charge Transfer between a Metal Surface and a Hydrogen Atom in the Excited p-State
Authors: Moskalenko S. S. , Gainullin I. K.
Published: April 2024

Some features of the charge transfer between ions and the metal surface, which are due to its atomic structure, were numerically investigated. The simulation was based on a three-dimensional implementation of the wave packet propagation method. The studied system consisted of an Al(110) metal surface and an excited hydrogen atom with an electron in the p-state, which does not have spherical symmetry. When considering a model static problem, it was shown that electron exchange is more efficient when the symmetry axis of the p-orbital was oriented perpendicular to the Al surface, rather than parallel. Also, analysis of the obtained data showed that the time dependence of the atomic population function has an exponential decay. The solution of the “dynamic” problem showed that for an excited hydrogen atom moving along the metal surface, the electron exchange does not depend on the orientation of the p-orbital symmetry axis with respect to the direction of motion of the atom. The study of the dynamics of the charge transfer with a metal surface made it possible to observe for p-orbitals, the symmetry axis of which was directed parallel to the metal surface, the separation of the electron density passing to the surface into two parts, which diverge relative to the p-orbital symmetry plane.
Modeling of the Influence of Temperature on the Emission Properties of a Cathode with a Thin Insulating Film in a Glow Gas Discharge and the Discharge Voltage–Current Characteristic
Authors: Bondarenko G. G. , Kristya V. I. , Fisher M. R.
Published: April 2024

A model of glow gas discharge in the presence of a thin insulating film on the cathode is formulated. It takes into account that under discharge current flow, due to the bombardment of the cathode by ions, positive charges accumulate on the film and generate strong electric field in it. As a result, field emission of electrons from the cathode metal substrate into the film starts, which, with an increase in its temperature, transforms into thermal-field emission. Electrons move in the film, being accelerated by the electric field and decelerated in collisions with phonons, and some of them leave the film into the discharge, increasing the effective ion-electron emission yield of the cathode. The electric field strength in the film is determined from the condition that the density of the discharge current and the density of the emission current from the cathode metal substrate into the film are equal. The dependences of the film emission efficiency, the effective ion-electron emission yield of the cathode, and the discharge characteristics on the cathode temperature are calculated. It is shown that already at a temperature exceeding room temperature by several hundred degrees, the temperature enhancement of field electron emission from the metal substrate into the film can noticeably influence the cathode emission properties and the discharge voltage-current characteristic.
Changes in the Morphology and Strength Properties of the Vanadium Surface under the Influence of Helium Ions and Pulsed Laser Irradiation
Authors: Borovitskaya I. V. , Korshunov S. N. , Mansurova А. N. , Bondarenko G. G. , Gaidar A. I. , Matveev E. V. , Kazilin E. E.
Published: April 2024

The effect of high-power pulsed laser irradiation generated in a GOS 1001 installation in the Q-switched mode (power density q = 1.2 × 1012 W/m2, pulse duration τ0 = 50 ns, number of pulses N = 1–4) in vacuum on a porous structure of the vanadium sample surface is studied, as well as on its hardness determined in two ways based on the recovered print method and on the kinetic indentation method. The porous structure is formed during implantation of helium ions (energy 30 keV, dose 2.0 × 1023 m–2, ion flux density 4.8 × 1018 m–2 · s–1, temperature ~500 K). It is shown that irradiation with helium ions causes vanadium hardening by about a factor of two, and the microhardness values determined by the recovered print method are slightly lower than the kinetic hardness values. It is found that in both cases, as a result of the target destruction under the laser radiation, a crater appears, surrounded by a breastwork, behind which there is a zone of thermal influence. Erosion is observed in this zone, caused by the destruction of the domes of bubbles-blisters filled with implanted helium and impurity atoms (C, O, N) present in the liquid metal. It is found that with an increase in the number of laser pulses, the microhardness in the crater decreases, while the narrow area around it hardens, and with further distance from the crater, the microhardness approaches values corresponding to that of vanadium implanted with helium ions.
Structures of Nanodiamonds with Photoactive Modifiers
Authors: Lebedev V. T. , Kulvelis Yu. V. , Soroka M. A. , Kyzyma O. A. , Vul A. Ya.
Published: April 2024

For the first time, binary and ternary complexes of fullerenes and diphthalocyanines of europium with detonation nanodiamonds have been obtained, which can serve as platforms for the delivery of these hydrophobic molecules into aqueous biological media for the tasks to improve magnetic resonance imaging, photodynamic therapy, and diagnostics using luminescent labels. Detonation nanodiamonds (size ~4–5 nm) had a positive potential (30–70 mV) in an aqueous medium due to groups (CH, COH) grafted onto the surface as a result of heat treatment in a hydrogen atmosphere. During the interaction of positively charged diamonds with electronegative hydrated fullerenes in an aqueous medium, the initial aggregates of each of the components were destroyed, and their electrostatic bonding led to the formation of stable compact complexes ~20 nm in size according to the data of dynamic light scattering and small-angle neutron scattering in colloids under normal conditions (20°С). Binary complexes included, on average, two fullerene molecules per 30–40 diamond particles. The introduction of diphthalocyanine molecules into a binary colloid resulted in the formation of stable ternary structures. The obtained complexes of diamonds, fullerenes, and diphthalocyanine molecules are promising for biomedical applications due to the luminescent and magnetic properties of the components.
Studying the Influence of Polymer-Colloid Drilling Fluid on the Pore Space of Rocks
Authors: Kuzmin V. A. , Skibitskaya N. A.
Published: April 2024

Using electron microscopy methods, the effect of polymer-colloidal drilling fluids on the pore space in carbonate reservoirs of an oil and gas condensate field, was studied. It is shown that the impact of polymers included in drilling fluids changes the surface of the pore space of rocks. This affects the technology of developing oil fields and the intensification of oil production. At the same time, due to the deposition of polymer components in the pore space of the rock, the properties of the samples change. This must be taken into account when conducting petrophysical studies on samples, as well as in geophysical studies of the bottom-hole zone using methods with a small study radius. The results of morphological studies in the electron microscope of the pore space of rocks after the impact of polymer-colloidal drilling fluids, are presented. Polymer films formed from drilling fluid components are studied. It has been established that after drilling horizontal wells, the change in the wettability of the pore space is associated with the formation of a polymer film on carbonate crystals. The thickness of this film, measured by the direct method, is 60–200 µm in the studied samples. It is noted that these changes in the future can lead to errors in determining the petrophysical properties.
Energy Spectra of Hydrogen Atoms Reflected from a Tungsten Surface
Authors: Mikhailov V. S. , Babenko P. Yu. , Tensin D. S. , Zinoviev A. N.
Published: April 2024

Computer simulations were used to calculate the energy spectra and angular distributions of reflected particles during bombardment of the tungsten surface with hydrogen and deuterium atoms with energies of 0.1–10 keV. A model was proposed that qualitatively explained the main regularities in the behavior of the spectra. The similarity of the energy spectra upon bombardment by hydrogen and deuterium atoms at the same collision velocities has been established. The angular distribution of reflected particles was universal in a wide range of initial energies of the bombarding atoms.
Influence of Low-Energy Ion Bombardment on the Texture and Microstructure of Pt Films
Authors: Selyukov R. V. , Naumov V. V. , Izyumov M. O. , Vasilev S. V. , Mazaletskiy L. A.
Published: April 2024

The influence of low-energy ion bombardment on the texture and microstructure of an 80-nm-thick Pt film deposited at room temperature was investigated. The treatment was carried out in inductively coupled Ar plasma with a negative bias of 45–125 V applied to the specimens and an ion current density of 3.3 mA/cm2. As a result of a series of treatments at each bias, the film was thinned; after each treatment, its structural parameters were determined using X-ray diffraction and compared with those of Pt films 20–60 nm thick deposited under the same conditions. Treatment at 75–125 V led to a decrease in the average size of coherent scattering regions by 10–25%; in the 45 V mode, such a decrease was not observed. These results were explained by the formation and accumulation of radiation defects, the rate of their generation was lower at bias of 45 V. Film sputtering in all modes did not worsen the sharpness of the film texture.
On the Effect of Magnetic Pulsed Treatment on the Surface Structure and Magnetic Properties of Tape Amorphous Alloys Fe(Ni, Cu)(SiB)
Authors: Shipko M. N. , Kaminskaya T. P. , Stepovich M. A. , Viryus A. A. , Tikhonov A. I.
Published: April 2024

The methods of scanning electron, atomic force, and magnetic force microscopy, together with measurements of the magnetic characteristics before and after exposure to pulses of a weak magnetic field (10–100 kA/m) of low frequency (10–20 Hz), were used to study the features of the surface state that determine the domain structure, magnetic properties and magnetic losses during magnetization reversal of ribbon amorphous Fe(Ni, Cu)(SiB) alloys obtained by ultrafast cooling by melt spraying on a rotating drum. Both surfaces of the foils were studied: the surfaces of the samples adjacent to the copper drum, which had an inhomogeneous structure characteristic of all rapidly quenched samples, and other sides of the foils, the surfaces of which were more even, which made them look shiny. When studying the surfaces of foils by atomic force microscopy after their magnetic pulse processing, no changes in the nature of the surface structure were found. The changes were recorded on the images of the shiny side of the samples by magnetic force microscopy. If no domain structure was observed before magnetic pulse treatment, then after magnetic pulse treatment, stripe domains with a width of 0.6–0.8 nm and closing domains with a width of 1.0–1.6 nm were found on structural defects, and in some areas of the surface, along with this, a weak magnetic contrast in the form of large and small domains with a shape close to triangular. It has been established that the magnetization reversal losses are largely related to the losses caused by eddy currents and are related to the domain width (about 1.5 nm), which depends only slightly on the modes of magnetic pulse processing. The obtained research results can be used to refine the technique for relieving stresses arising in the process of manufacturing amorphous ribbons.
Peculiarities of Interaction of Low-Energy Noble Gas Atoms with Methyl Groups on the Low-K-Surface
Authors: Solovykh A. A. , Sycheva A. A. , Voronina E. N.
Published: April 2024

In the current work the computer simulations were performed to study the possibility of surface functionalization of low-K materials that are used as interlayer insulators within ultralarge integration devices with low-energy (up to 30 eV) noble gas atoms. The simulations were carried out using the ab initio density functional theory method assisted with molecular dynamics algorithms implemented in VASP package. The detailed trajectory analysis revealed the conditions under which the irradiation of incident He, Ne, Ar, Xe atoms with the energy up to 30 eV may result in the illumination of near-surface methyl groups responsible for hydrophobic properties of dielectric surface. Based on the data obtained the threshold energy (the minimum atom energy for CH3-radical formation) was evaluated, and the mechanism peculiarities of such a process under light and heavy atom irradiation were studied. It was shown that in the energy range under consideration the interaction Ne, Ar, and Xe with methyl groups has mainly collisional mechanism, therefore with increase in mass of the incident particle the threshold energy increases. He atom irradiation, on the contrary, is capable to induce the perturbations of the electronic density around the methyl group that stimulate fast atom vibrations and result in CH3-detachment.
Effect of Electron Fluence on the Concentration of Color Centers in Aluminum Oxide Hollow Particles
Authors: Iurina V. I. , Dudin A. N. , Neshimenko V. V. , Mikhailov M. M.
Published: April 2024

The effect of fluence (1–7) × 1016 cm–2 electrons with an energy of 30 keV on the concentration of color centers in aluminum oxide hollow particles micron-sized in comparison with bulk Al2O3 microparticles was studied. The analysis was carried out using diffuse reflectance spectra in the range from 250 to 2500 nm in situ. The radiation resistance of the microspheres under study was evaluated relative to micropowders from the difference diffuse reflectance spectra obtained by subtracting the spectra after irradiation from the spectra of non-irradiated samples. Changes in the difference diffuse reflection spectra of aluminum oxide microparticles and microspheres obtained with different electron fluences showed that with an increase in the induced electron fluence, absorption increases throughout the spectrum. It was found that the radiation resistance of aluminum oxide microspheres to the effects of electrons with an energy of 30 keV a fluence (1–7) × 1016 cm–2 greater than the radiation resistance of Al2O3 microparticles. The increase in the radiation resistance of aluminum oxide hollow microparticles compared to the radiation resistance of aluminum oxide bulk microparticles is due to the low concentration of induced defects of the anionic sublattice.
Change in the Local Atomic Structure of the Fe–Ni Alloy Due to Irradiation by Argon Ions
Authors: Averkiev I. K. , Kolotov A. A. , Bakieva O. R.
Published: April 2024

In this work, the surface of the N18 alloy was modified with argon ions in a repetitively pulsed regime. In situ electron spectroscopy methods were used to study changes in the chemical composition and local atomic structure caused by ion action on the surface. The chemical composition was determined by Auger electron spectroscopy using argon ion profiling. The analysis of the local atomic structure was carried out by the method of spectroscopy of extended thin structures of electron energy losses. The excitation spectra of the iron M2,3-edge and the K-edge of oxygen were obtained in the geometry of backscattering from the surface. The variation in the energy of the incident electron beam made it possible to obtain a signal from the excitation of oxygen and iron atoms from the same depth. The analysis of experimental data was carried out by the method of solving the inverse problem for finding pair correlation functions using regularization according to Tikhonov. The study of the local atomic structure was carried out at profiling depths of 5, 25, and 50 nm. It is shown that the ion-modified layer within the projective range of argon ions consists mainly of iron oxides. At a profiling depth of 50 nm, the parameters of the local environment of Fe atoms are close to those of unoxidized iron. Nickel as a result of surface diffusion is found at a depth of more than 50 nm.
On the Possibility of Observing the Effect of Quantization of the Orbital Momentum, during the Passage of Laser Radiation through an Optical Fiber
Authors: Kalashnikov N. P. , Olchak A. S.
Published: April 2024

The speed of propagation of optical radiation in an optical fiber is noticeably lower than the speed of light in vacuum. This fact opens the possibility to consider the propagation of light in fiber in the so-called comoving frame of reference. This type of consideration proved to be very useful and helping, for example, in studying the motion of ultrarelativistic charged particles and gamma rays in ordered media (channeling effect). This type of consideration makes it possible to notice some simple, albeit rather unexpected, macroscopic quantum effects that can manifest themselves when laser radiation passes through optical fibers. In particular, when photons propagate along an optical fiber twisted into a helix, at certain parameters of the helix, the effect of quantization of the moment of the photon momentum should reveal itself. Attracting attention to the possibility of such an effect is the goal of this note, which contains the formulation of the conditions and estimates of the parameters under which the effect of quantization of the angular momentum of photons moving along a spiral trajectory should be observed.
On the Moving Charged Particle’s Position Monitoring Using Its Diffraction Radiation on the Metal Sphere
Authors: Syshchenko V. V. , Tarnovsky A. I.
Published: April 2024

The uniformly moving charged particle generates the transition radiation under the motion in the non-uniform medium (in particular, under crossing the interface between two media) and the transition radiation under the motion near the non-uniformities of the medium without crossing theid boundaries. Both diffraction and transition radiation can be used for detection of the charged particles and beam monitoring. While the methods based on the transition radiation from both relativistic and non-relativistic particles are widely used, the utilization of the diffraction radiation for that goals are still under study. The diffraction radiation generation is weakly perturbing for the particle’s motion that permits to develop the non-destructive methods of the beam diagnostics. The description of the diffraction radiation from the charged particle on the conducting sphere has been developed earlier using the method of images known from electrostatics. The method of finding the parameters of the particle’s flying by the sphere based on that approach using the single point detector sensitive to both intensity and polarization of diffraction radiation was proposed earlier. Here we propose the scheme with three detectors that solves the same problem without registration of the polarization.
Influence of Implantation of Ions Ba+ on the Composition and Electronic Structure of Silicate Glasses
Authors: Tashmukhamedova D. A. , Urokov A. N. , Abdurakhmanov G. , Umirzakov B. E.
Published: April 2024

In this work, using the methods of Auger electron spectroscopy, ultraviolet photoelectron spectroscopy and light absorption spectroscopy, the influence of the implantation of Ba+ ions into silicate glass and subsequent annealing on the composition, density of electronic states and parameters of energy bands was investigated. It has been shown that nonstoichiometric oxides Si, Pb, and Ba, as well as unbound atoms of the same elements, are formed in the ion-implanted layer after ion implantation. As a result, there is a significant change in the electronic structure of silicate glass, in particular, the band gap decreases by ∼2 eV. After annealing at T = 1000 K, unbound Si, Pb, and Ba atoms disappear in the ion-implanted layer (within the sensitivity of the Auger electron spectrometer) and stoichiometric oxides such as SiO2, PbO, and BaO are formed.
Debugging Software for Data Acquisition and Processing for a Neutron Detector with an Architecture of Two Circular-Buffers
Authors: Golubev M. A. , Polyushkin A. O. , Solovei V. A.
Published: April 2024

A technique for debugging the software of a data acquisition and processing device with a network interface for a 2D position-sensitive thermal neutron detector with a delay line readout is described. The original software transfers data through two ring buffers. Changes are proposed in the software code to check the possibility of ring buffer overflow. It is shown that there is no data loss in the ring buffers at input pulse frequencies up to 1 MHz. The corresponding registration dead time is on the order of 1 μs.
Thin-Layer InAlPSbAs/InAs Heterostructures: Growth Kinetics, Morphology, Structure
Authors: Lunin L. S. , Lunina M. L. , Alfimova D. L. , Pashchenko A. S. , Pashchenko O. S. , Donskaya A. V.
Published: April 2024

The results of growing of InAlPSbAs/InAs thin-layer heterostructures by the floating-zone recrystallization with a temperature gradient are discussed. In a model of regular solutions, an analysis of heterophase equilibria in the In–Al–P–Sb–As system is carried out. The growth kinetics is studied as a function of the thickness of the liquid phase (l), and the element concentrations, the substrate temperature (T), and the temperature gradient (G). The growth regimes are investigated and an analysis is carried out for spinodal decompositions of solid solutions. It is shown that the substrate temperature and the temperature gradient have a significant effect on the growth kinetics. Auger electron spectroscopy is used to study the elemental depth profiles of the InAlPSbAs solid solution and show the advantages from liquid phase replenishment to obtain layers of constant composition. The structural perfection of InAlPSbAs solid solutions on an InAs substrate is studied. It is established that the best structural perfection of the layers is achieved at T 873 K, G 20 K/cm, and liquid zone thickness 80 l 120 µm. The surface morphology of InAlPSbAs solid solutions on InAs has been studied by scanning probe microscopy. It is shown that at T 873 K, G 20 K/cm, and liquid zone thickness 80  l 120 µm the root-mean-square surface roughness does not exceed 1 nm.
Magnetic Structure of Dy–Co Superlattice near the Compensation Temperature
Authors: Makarova M. V. , Kravtsov E. A. , Proglyado V. V. , Subbotin I. A. , Pashaev E. M. , Kholin D. , Khaydukov Yu. N.
Published: April 2024

The magnetic ordering of the multilayer structure of Dy–Co was studied using complementary methods of polarized neutron reflectometry and Kerr magnetometry. It was found that during the deposition of a layered structure, the Dy and Co layers are partially mixed with the formation of the DyCo2 intermetallic compound. The profiles of the magnetization of individual layers at the atomic level were determined. It was managed to describe a noncollinear magnetic structure of the layers near the compensation point using the neutron reflectometry data. The triple hysteresis loops observed in the same temperature range most likely indicated the non-identity of the outer and inner superlattice layers. The inhomogeneity profile of the DyCo2 layer magnetization distribution can be explained by the strong exchange interaction at the interfaces. In a small applied magnetic field, the interlayer exchange interaction dominates over by the Zeeman energy. The antuparallel ordering of the magnetic moments of the Co and DyCo2 layers was distorted by the magnetic field; as a result, the angle between the magnetization vectors was maximum at the Co/DyCo2 interfaces only.
Prototype of a Two-Coordinate Position-Sensitive Detector Based on a 6LiF/ZnS(Ag) Scintillator
Authors: Podlesnyy M. M. , Milkov V. M. , Bogdzel A. A. , Bodnarchuk V. I. , Hassan A. A.
Published: April 2024

A prototype of a two-coordinate position-sensitive detector based on a small-area 6LiF/ZnS(Ag) scintillator, fabricated using square-section spectrum-shifting optical fibers, is presented. The size of the square active area of the detecting surface (96 × 96 cm) corresponds to 16 channels along the X axis and 16 channels along the Y axis. The obtained neutron detection efficiency is 8%.
Composition and Structure of FCC-Structured High Entropy Alloys, Irradiated with Helium Ions
Authors: Uglov V. V. , Ivanov I. A. , Zlotski S. V. , Stepanjuk N. A. , Ryskulov A. E. , Kozlovski A. L. , Kurahmedov A. E. , Koloberdin M. V. , Sapar A. D. , Ungarbaev E. O. , Jin K.
Published: April 2024

In this study bulk samples of high-entropy alloys CoCrFeNi and CoCrFeMnNi, fabricated by arc melting (of pure metal powders up to 99.97%, argon atmosphere) followed by annealing (1150°C, 24 and 72 h) and cold rolling (85% decrease in thickness) were irradiated with He2+ ions (40 keV, fluence 2 × 1017 cm–2). Samples of CoCrFeNi and CoCrFeMnNi are substitutional solid solutions with a close to equiatomic composition and a uniform distribution of elements over the depth of the alloys. They have a coarse grain structure with a grain size of about 80 µm for CoCrFeNi and 100 µm for CoCrFeMnNi alloys. It was revealed that the surface microstructure, phase and elemental composition of high-entropy alloys are resistant to irradiation. No traces of radiation erosion and changes in the elemental and phase composition of the alloys were found. In alloys, the dislocation density increases, which leads to a decrease in the size of coherent scattering regions, and helium bubbles are also formed, leading to an increase in compressive macrostresses. It was found that tensile microstresses prevail in irradiated CoCrFeNi alloys, while compressive stresses prevail in CoCrFeMnNi alloys. It has been found that high-entropy CoCrFeMnNi alloys with a more complex composition are more resistant to radiation damage.
Geometry Design Optimization of High-Frequency Ion Thrusters and Ion Sources
Authors: Abgaryan V. K. , Melnikov A. V. , Kupreeva A. Yu. , Peisakhovich O. D.
Published: April 2024

The article presents the results of the computational determination of the optimal design geometry of a certain type of quasi-neutral plasma source. The scheme of an ion source with an inductive plasma discharge formed and maintained by a radio-frequency electromagnetic field in a MHz frequency range is considered. The surface profiles optimization of the main design units – namely, gas discharge chamber and ion extraction system – was carried out via computational modelling. Calculations were carried out using the previously developed engineering model of inductive discharge in plasma. The optimization criteria are the thrust and the value of the ion current extracted from the source, determined from the calculated distributions of electron density and electron temperature within the discharge chamber. Optimization calculations were carried out for an ion source with a discharge chamber diameter of 16 cm on a type of surfaces that are segments of a spherical surface. The results of the thrust calculations are presented in relative values in comparison with the values calculated for the basic configuration of the ion source scheme with a hemispherical discharge chamber and a flat ion extraction system. A significant increase in the value of the extracted ion current and thrust in the determined optimal configuration of the ion source was obtained in comparison with the same values calculated for the basic configuration of the ion source with a hemispherical discharge chamber and flat grids of the ion extraction system.
Protective Coatings of W–Re Thermocouples for Use in Aggressive Enviroments
Authors: Kirichuk G. V. , Kozlov A. A. , Prokopovich P. A. , Goikhman A. Yu. , Maksimova K. Yu.
Published: April 2024

A method for growing a hafnium oxide (HfO2) protective coating on the surface of a tungsten–rhenium (W–Re) thermocouple is described, the structural and morphological properties and chemical composition of the coating are studied, and temperature tests of thermocouples with a protective coating are carried out. The optimal conditions for the formation of coatings resistant to oxidation and high temperatures (above 2000°C) are found. The tests confirmed the ability of the HfO2 coating to slow down the processes of degradation and destruction of the thermocouple when operating in an aggressive oxidizing environment.
Influence of Modification of the Surface of a Metal Matrix on the Mechanical Properties of Layered Composites “Aluminum/Carbon Fiber” and Silumin/Carbon Fiber
Authors: Кlopotov А. А. , Ivanov Yu. F. , Ustinov А. М. , Teresov A. D. , Abzaev Yu. A. , Litvinova V. A.
Published: April 2024

The paper presents the results of a study of the effect of irradiation of the surface of a hypoeutectic silumin with a pulsed electron beam on the mechanical properties of the material. Silumin grade AK5M2 (Al–(4.0–6.0)Si–1.3Fe–0.5Mn–0.5Ni–0.2Ti–2.3Cu–0.8Mg–1.5Zn) was used as the research material. To carry out uniaxial tensile deformation, two-sided proportional samples with heads were made. The results of studying the evolution of deformation fields of layered composites silumin/CFRP for uniaxial tension based on irradiated silumin are also presented. The carbon fiber is made of a filler – carbon unidirectional fabric FibARM Tape-230 – and a binder – a two-component epoxy compound FibARM Resin 530. The fracture surface of the samples was studied using scanning electron microscopy techniques. The dependences of the maximum and minimum values of strains in the localizers on the sample surface on the averaged strains over the working area of the sample are plotted. An increase (relative to silumin in the initial state) in the strength and plastic properties of both samples of irradiated silumin and of the silumin/CFRP composite was determined. A sawtooth character of the deformation curve of uniaxial tension of the composite material silumin/carbon fiber with a pre-irradiated surface of the silumin plate is revealed.
Project of Scanning and Projection Microscopes for the Nanoscopy Station for Biological Research in the “Water Transparency Window”
Authors: Rakshun Ya. V. , Khomyakov Yu. V. , Chernov V. A. , Shchelokov I. A. , Malyshev I. V. , Pestov A. E. , Polkovnikov V. N. , Reunov D. G. , Toropov M. N. , Chkhalo N. I.
Published: April 2024

A brief description of the concept of a soft X-ray microscope for the Nanoscopy station is given, which is planned to be installed at the SKIF fourth-generation synchrotron. The microscope will be designed to study the structure of cells and dynamic processes in them with nanometer spatial resolution. It will use a unique absorption contrast of ~15 between carbon-containing structures and water in the spectral range of the “water transparency window”, λ = 2.3–4.3 nm, which eliminates the need for contrasting and the use of fluorophores and minimizes the doses of ionizing radiation absorbed in the samples to obtain high-quality 3D-images. The scanning and projection schemes of the microscope, their main technical characteristics, including the calculated spectra and parameters of the undulator source are presented, and an estimate of the absorbed doses depending on the resolution is obtained. The main advantage of the proposed concept lies in the use of an objective of high-aperture multilayer X-ray mirrors, which makes it possible to clearly visualize the focal section of the sample. Technically simple axial tomography will also be used to reconstruct the three-dimensional structure of frozen or dried samples. In the scanning scheme, due to the low dose of radiation, it will be possible to study living plant cells with a resolution of up to 10 nm, animals with a resolution of up to 80 nm, and cryofixed samples with a resolution of up to 5 nm. In the projection scheme, due to the simultaneous observation of the entire focal XY-section, the time for obtaining three-dimensional images is significantly reduced, but due to the large dose, it will be oriented mainly on the study of fixed samples.
Properties and Prospects for Application of Lithium Liquid Glass in Thermal Control Coatings of Spacecraft
Authors: Mikhailov M. M. , Lapin A. N. , Yuryev S. A. , Goronchko V. A.
Published: April 2024

A comparative study of the radiation resistance of the optical properties of binders for spacecraft thermostatic housings was carried out: widely sold liquid glass K2SiO3 and newly developed liquid glass Li2SiO3. At the analisis of diffuse reflection spectra (ρλ) in the wavelenght range 0.2–2.5 μm and the integral radiation absorption coefficient (аs) both before and after electron radiation, an incomparably higher radiation resistance of Li2SiO3 liquid glass compared to K2SiO3 glass was established. The values of the change in the absorption coefficient ∆аs of liquid glass Li2SiO3 comparing to one of K2SiO3 liquid glass are several times less: for electron radiation with an estimate of 30 keV at a fluence Ф = 2 × 1016 cm–2 – 35 times; at Ф = 4 × 1016 cm–2 – 25 times; at Ф = 6 × 1016 cm–2 – 7 times. Analysis of of the factors that determine the radiation resistance of these glasses was made. The advantage in the radiation resistance of Li2SiO3 liquid glass is making it prospective for use as connecting compounds in thermal control coatings of spacecraft, in paints, ceramics and other areas of technology and industry with the presence of ionizing traces.
Determination of the Kinetic Characteristics of Thermal Desorption and Heterogeneous Reaction of Dissociation of Morphine Molecules on the Surface of Oxidized Tungsten
Authors: Rakhmanov G. T. , Umirzakov B. Е. , Usmanov D. T.
Published: April 2024

Under the same experimental conditions the processes of adsorption, heterogenous reaction of dissociation on the surface and thermodesorption of C17H19NO3 morphine molecules with m/z 285 Da on the surface of oxidized tungsten was studied by the non-stationary such as voltage modulation and flux modulation methods. The experiments were carried out on a high-vacuum mass-spectrometer, in which a “black chamber” was used, all walls of which are cooled with liquid nitrogen. The kinetic characteristics of the processes of thermal desorption and the heterogeneous reaction of dissociation of molecules on the surface such as the rate constant of thermal desorption in the ionic and neutral states K+ and K0, the corresponding activation energies of thermal desorption E+ and E0, the pre-exponential factors C and D, as well as the rate constant of the heterogeneous dissociation reaction Kd and the activation energy of the heterogeneous reaction dissociations on the surface, exponential factors in the equation of continuity of the surface concentration for C9H7N+CH3 radicals with m/z 144 during the adsorption of morphine molecules on the surface of oxidized tungsten were determined.