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This paper presents the results of measurements of fission fragments using a time-of-flight system with a position-sensitive detector based on microchannel plates designed to measure the masses of nuclear reaction products at the MAVR facility. The advantage of such MCPs is their high positional sensitivity and high efficiency of registration of heavy charged particles with low energy. The paper presents a technical description of the fission fragments registration system and the results of measuring the parameters of a position-sensitive detector based on large-area microchannel plates (40 × 60 mm2) obtained by measuring 252Cf spontaneous fission fragments. The coordinate resolution along the X and Y axes was determined when fission fragments were registered in the 14N+192Au reaction at the MAVR installation. The time resolution of the PSD was obtained by registering the time of flight of alpha particles emitted by the radioactive source 226Ra. [ABSTRACT FROM AUTHOR]

In this study, we investigated the production of Au isotopes through neutron transfer reactions in the 48Ca + 197Au collision at a beam energy of 300 MeV. The reaction products of 197±xAu were captured and stopped within an assembly of Au targets after being irradiated with a 48Ca beam. The populated Au isotopes were identified through gamma decay spectroscopy and production cross-sections were determined. Furthermore, we performed model calculations based on the solution of the time-dependent Schrödinger equation for neutrons. These calculations aimed to estimate the formation probabilities and cross-sections of the measured Au isotopes and to elucidate the dynamics of the neutron transfer process. To describe the cross sections of neutron transfer channels and compare with the results of calculations within the framework of the model based on the time-dependent Schrödinger equation, calculations using the Grazing code were performed. [ABSTRACT FROM AUTHOR]

A technique for constructing force fields based on the use of genetic algorithms is proposed, which is aimed at parameterization of potentials intended for computer simulation of polyatomic nanosystems. To illustrate the proposed approach, a force field has been developed for modeling layered modifications of WS2, including multi-walled nanotubes, the dimensions of which are beyond the capabilities of ab initio methods. When determining the potential parameters, layered polytypes of bulk crystals, monolayers, bilayers, and nanotubes of small diameters were used as calibration systems. The parameterization found was successfully tested on double-walled nanotubes, the structure of which was determined using density functional calculations. The obtained force field was used for the first time to model the structure and stability of achiral multi-walled nanotubes based on WS2. The interwall distances obtained from the simulation are in good agreement with the results of recent measurements of these parameters for existing nanotubes. [ABSTRACT FROM AUTHOR]

The development of a warm phase in the climate since the middle of the last century and the improvement of conservation measures have led to the northward expansion of a large number of bird species originally distributed in the southern parts of the Palaearctic. The dispersal of the great egret in Europe is a vivid illustration of this process. Throughout the last century, only rare records of single birds in Russia's Northwest were known. At the beginning of this century, the breeding range of the species in the eastern Baltic States and Belarus came close to the borders of the region. Based both on original data and on analysis of scientific sources, the process of great egret invasion into Pskov, Leningrad, Novgorod, and Tver oblasts and the Republic of Karelia, the status change from a rare stray to a common vagrant , as well as the formation of the first great egret breeding colonies in Pskov and Leningrad oblasts are considered in detail. Features of the phenology of the species and the spatial distribution of its nesting settlements are given. An analysis of the climatic factors limiting the summer residence zone of the species is also presented. [ABSTRACT FROM AUTHOR]

The paper presents the results of the long-term agrochemical and ecotoxicological studies of reference sites of the gray forest soil farmlands in Vladimir oblast, which were carried out to establish a level of fertility based on the major agrochemical indicators and content of micronutrients and sulfur as well as ecotoxicological state based on content of the gross and mobile forms of heavy metals. The deterioration of soil fertility indicators was established, such as supply of organic matter, mobile forms of phosphorus and potassium, exchange bases of calcium and magnesium, and the exchangeable and hydrolytic acidity. Soil fertility was assessed by calculating the soil-ecological index. The study determined soil availability of boron, molybdenum, copper, and mobile sulfur. Concentrations of the gross and mobile forms of heavy metals in the surveyed soils did not exceed permissible limits. According to the content of the considered metals, the studied soils are slightly polluted and do not pose a hazard for cultivated plants and human health. The Pearson correlation coefficients served to establish a distinctive nature of the effect of the soil properties on concentrations of micronutrients, sulfur, and gross and mobile forms of metals. [ABSTRACT FROM AUTHOR]

The first principles calculations of single-wall and double-walled nanotubes have been performed. The nanotubes have been formed by rolling up binary MX and mixed (Janus) M2XY (M = Ga, In; X, Y= S, Te, X ≠ Y) monolayers. The structure and stability of nanotubes with two types of chirality and different diameters have been investigated. The modeling of double-walled nanotubes based on post-transition metal chalcogenides has been performed for the first time. The nanotubes stability has been analyzed with respect to the monolayers and with respect to the stable phases of bulk crystals. The role of binding energy to increase the stability of Janus double-walled nanotubes in comparison with that of binary double-walled nanotubes is discussed. [ABSTRACT FROM AUTHOR]

The energy spectra of alpha particles from reactions induced by 280-MeV Ca beams incident to Ta, Au, and U targets were measured at an angle of 0 by means of a high-resolution magnetic analyzer (MAVR setup). The sensitivity of the procedure used made it possible to measure alpha-particle yields that are five to six orders of magnitude less than the maximum yield. The cross section for the formation of alpha particles is shown to be dependent on their binding energy in the target nucleus. The experimental data obtained from these measurements were analyzed on the basis of the model of two- and three-body reaction channels and the model of moving sources. [ABSTRACT FROM AUTHOR]

The energy spectra of alpha particles emitted at an angle of 0 in the interaction of 400-MeV Fe ions with U, Ta, and Be targets were measured by means of a high-resolution magnetic analyzer (MAVR, which is the acronym of the Russian name of this setup). The energy spectra of charged particles ranging from Li to Ne were also measured. The experimental data obtained in this way indicate that the emission of alpha particles is a dominant process in the above reactions. Particles of high energy, up to those in the vicinity of the so-called kinematical limit for two-body reactions, were observed with a rather high yield. The sensitivity of the experimental procedure that employed the aforementioned magnetic analyzer made it possible to observe events characterized by cross-section values smaller by six to eight orders of magnitude than that at the maximum of the spectrum. The cross section for the production of light particles is shown to be dependent on their binding energy in the target. The experimental data obtained in this study were analyzed with aid of the moving-source model. [ABSTRACT FROM AUTHOR]

New semiconductor detectors based on CdZnTe and CeBr3 crystals are tested. A spectrometer facility consisting of CdZnTe, CeBr3, and Si (for α–γ measurements) detectors is assembled for verification tests. The main parameters of the detectors such as energy resolution FWHM/Eγ [keV] and detection efficiency (%) are investigated and measured. The possibilities of measuring photon radiation in a wide energy range are verified. γ–γ and α–γ coincidences are measured using the detectors. The results of the measurements show that the detectors can be used to study nuclear reactions and properties of reaction products. [ABSTRACT FROM AUTHOR]

Peptide drug Thymalin, isolated from the calve thymus, is successfully used for the treatment of various immunopathologies, including those in older age groups. The molecular mechanism of the Thymalin immunoprotective action is due to the effects of the short peptides KE, EW, EDP in its composition. These short peptides can specifically bind to double-stranded DNA and/or histone proteins and regulate gene expression, synthesis of immune system proteins, activity of gerontogenes, and stimulate stem cell differentiation. Regulation of immunogenesis is a key factor preventing the development of the "cytokine storm" that develops in severe COVID-19. The purpose of this work is to study the effectiveness of Thymalin in severe COVID-19 in older patients. Patients administered with Thymalin against the background of a standard therapy (n = 36) manifested a more rapid clinical improvement, higher proportions of recovery from lymphopenia, faster normalization of the concentration of C-reactive protein, D-dimer, the number of lymphocytes and NK-cells in the blood, compared to patients who received a standard therapy only (n = 44). Thymalin halved hospital mortality in older patients with severe COVID-19. The results obtained showed the effectiveness of Thymalin administration in the complex therapy of patients with severe COVID-19. [ABSTRACT FROM AUTHOR]

The results of an experiment carried out on the MAVR high-resolution magnetic spectrometer and devoted to studying neutron transfer in the Ta reaction at the projectile energy of 10 MeV per nucleon are presented. A theoretical analysis of the experimental cross sections is performed for the neutron transfer mechanism by means of a time-dependent approach based on solving the time-dependent Schrödinger equation. The dynamics of the neutron transfer process is described, and the probabilities for the population of unoccupied neutron levels in the O nucleus are determined. [ABSTRACT FROM AUTHOR]

Microcirculatory hemodynamic indexes (HI) were assessed in patients with moderate and severe COVID-19. In both groups, a significant increase in the absolute spectral indexes (HI1, HI2, and HI3) and the ratio of low-frequency to high-frequency component (HI1/HI3) was revealed. In the group of severe infection, only the "slow" index (low-frequency HI1) of microcirculatory hemodynamics was significantly lower. The oscillatory indices MAYER1-3 and RESP1-3 were reduced in patients of both groups. The aggravation of the disease course was accompanied by depression of the low-frequency index HI1. Regulatory shifts compensate for disturbances in microcirculatory processes in moderate COVID-19, but severe course was associated with their decompensation. [ABSTRACT FROM AUTHOR]

The differential cross sections for alpha-particle emission at an angle of 0 in the reactions induced by a 6-MeV/nucleon Fe beams incident to U and Ta targets were measured versus the alpha-particle energy by means of a high-resolution magnetic analyzer (MAVR setup). The resulting spectra were found to contain fast alpha particles of energy corresponding to the two- and three-body exit reaction channels, including alpha particles of energy close to the two-body kinematical limit. The data obtained in this experiment were analyzed on the basis of the moving-source model. The emission of nonequilibrium alpha particles in the forward direction from the heavier target nucleus upon the complete or incomplete fusion of nuclei was revealed within the time-dependent quantum approach. [ABSTRACT FROM AUTHOR]

The isomeric ratios in neutron capture reactions, induced by thermal, resonant and mixed thermal-resonant neutrons on 108Pd and 110Pd nuclei have been measured by the activation method. The data analysis and necessary corrections as the self-absorption and summing cascade effects were made in gamma rays radioactivity measurements to improve the precision of the isomeric ratio determination. The results were discussed and compared with those in the existing literature. The isomeric ratios in 108Pd(n, γ)109m,gPd and 110Pd(n, γ)111m,gPd reactions, induced by mixed thermal-resonant neutrons as well as in 110Pd(n, γ)111m,gPd reaction, induced by resonant neutron are first measurements. [ABSTRACT FROM AUTHOR]

The research is aimed at increasing the quality of a concast billet macrostructure by limiting static and dynamic longitudinal forces created in billets by electrical drives of withdrawal rolls during wear and bending of the withdrawal roll body and random and periodic slips of drives. The paper analyzes process requirements for electrical drives of withdrawal rolls: contains a procedure for calculating dynamic longitudinal forces created in billets by drives of withdrawal rolls, determines whether influence of operating modes of the said drives on changes in billet withdrawal force is relevant, contains developed techniques and algorithms of withdrawal roll drive automated control limiting static and dynamic longitudinal forces in billets, and includes the experimental analysis of efficiency of methods and technical solutions on operating drives. Research was carried out at the Russian large iron and steel works. When performing the research, the authors applied analytical and numerical methods of solving algebraic and differential equations and systems, methods for structural modeling. As a result of the research, the authors developed and experimentally confirmed methods for "soft" restoring of the contact between the withdrawal roll and the billet and adjusting phases of fluctuating changes in load currents of motor groups. The obtained results are transferred as technical specifications and taken for introduction, when revamping electrical equipment of existing continuous casting machines. Results of mathematical simulation and experimental research are used to design automated electrical drives of withdrawal rolls in the secondary cooling zone of the bow-type continuous casting machine. Impact dynamic loads were decreased by 3 times, resulting in an average increase of 8% in the quality of the billet center with regard to all types of defects. [ABSTRACT FROM AUTHOR]

The aim of this research is to help reduce the share of cast slabs with extensive macrostructural defects by changing the structure and the control system of the straightener drive. The article describes the results of a passive experiment. On the basis of these results, requirements have been formulated to the structure and the control system of the straightener drive, a control philosophy developed and a new functional block diagram proposed. The study has been carried out for the curve-type continuous caster operated by one of the major Russian steel producers. The experimental study involved a statistical analysis of the pinch roll drive load sharing data registered by the current monitoring system, as well as the data provided by the sample testing laboratory on the main internal defects found in slabs. The theoretical study included the application of analytical and numerical solutions to algebraic equations, as well as structural modelling. The results of this research were tested on a prototype electric drive for the continuous caster pinch rolls. The authors offer some recommendations on the design of the automatic drive for the pinch rolls installed in the horizontal section of the secondary cooling zone, which also include a technique for calculating the load torques on the straightener pinch rolls, a functional block diagram and a control algorithm for the pinch roll drive installed in the horizontal section of the secondary cooling zone. An average of 50% improvement has been seen in load sharing between the pinch roll drives of the secondary cooling zone. The maximum axial stresses in the slab have reduced four times. There has been an average of 16% improvement in the slab macrostructure for all types of defects and a 13% improvement in terms of axial defects. [ABSTRACT FROM AUTHOR]

Data on elastic and inelastic scattering, and the reactions of few-nucleon transfers in the interaction between the nuclei of deuteron and Be at energies of around 10 MeV/nucleon, are analyzed. A theoretical analysis is performed using the double-folding potential model with the wave function of the ground state of the Be nucleus, constructed in the three-cluster α + α + n-approximation. Calculations of the cross section of elastic scattering for the reaction d + Be using the calculated folding potential are preformed using the optical model. The resulting optical potential is used to analyze cross sections of transfer reactions and inelastic scattering in the context of the distorted waves method. A comparative analysis of the experimental data and theoretical calculations is performed. [ABSTRACT FROM AUTHOR]

Atomistic model has been proposed to describe the structure, phonon frequencies, and thermodynamic properties of multi-walled nanotubes based on molybdenum disulfide. [ABSTRACT FROM AUTHOR]

Atomistic model has been proposed to describe the structure, phonon frequencies, and thermodynamic properties of multi-walled nanotubes based on molybdenum disulfide. [ABSTRACT FROM AUTHOR]

Preliminary results of measurements of the total reaction cross sections σ for weakly-bound He and Li nuclei at energy range (25-45)/ A MeV on Al and Pb targets are presented. The secondary beams of He and Li were produced by bombardment of the B (33 A MeV) primary beam on Be (89 mg cm) target and separated by COMBAS fragment-separator. In dispersive focal plane a horizontal slit defined the momentum acceptance as 1% and a wedge degrader of 200 μm Al was installed. The B of the second section of the fragment-separator was adjusted for measurements in energy range (25-45)/ A MeV. The secondary products were detected by a telescope consisting of two Si Δ E detectors 300, 1000 μm and E-detector, which consisted of nine CsI/Tl granules. [ABSTRACT FROM AUTHOR]

This paper describes the development of the functional-neural-network (FN-network) formalism, which was worked out to create a range of information systems for the intelligent computer processing of heterogeneous data from various information sources and automated decision-making support systems. It considers the limitations of this formalism in solving the tasks when the time intervals at which a solution is searched for are given in the form of indefinite variables. A method is proposed for avoiding these limitations by entering knowledge about the internal structure of data (metaknowledge) on these intervals into the context of a solution and it is shown that the use of metaknowledge not only solves the problem, but also improves the efficiency of searching for a solution by attracting additional information from a knowledge base and the context of a task. [ABSTRACT FROM AUTHOR]

A study of inelastic scattering and multi-particle transfer reactions was performed by alpha and He beams on a Be target at energy about 50 MeV. Angular distributions of the differential cross sections for the Be(α,α′)Be*, Be(α,He)Be, Be(α,t)B, Be(He,Li)Li and Be(He,Be)He reactions were measured. Experimental angular distributions of the differential cross sections for the ground state and a few low-lying states were analyzed in the framework of the optical model, coupled channels and distorted-wave Born approximation. The information on the cluster structure of the reaction products are obtained. An analysis of the obtained spectroscopic factors was performed. [ABSTRACT FROM AUTHOR]

Most living cells maintain a continuous flow of electrons, which provides them with energy. Many compounds are present in a cell simultaneously in the oxidized and reduced states in the form of active redox couples. Some of the redox couples, such as NAD/NADH, NADP/NADPH, and oxidized/reduced glutathione (GSSG/GSH) are universal, as they are involved in the regulation of many cellular reactions. The ratio of the oxidized and reduced forms of these compounds is the important cellular redox parameter. Modern research approaches allow for revealing new functions of the main redox couples in complicated cellular processes. The review presents the information about the main cellular redox couples and their participation in various biological processes. [ABSTRACT FROM AUTHOR]

Redox processes play a key role in the cells of any organism. These processes imply directed flows of electrons transferred via the so-called redox pairs-compounds present in cells simultaneously in both oxidized and reduced states such as NAD/NADH, NADP/NADPH, GSSG/GSH. Up to now, investigation of redox processes in live cells has been hampered by the lack of suitable methods. Genetically encoded fluorescent biosensors represent a new tool for investigation of biological processes including redox ones. Biosensors allow real-time monitoring of messengers, metabolites, and enzyme activities in live systems of different levels of complexity from cultivated cells to transgenic animals. Major types of the known redox-biosensors and examples of their application are presented in this review. [ABSTRACT FROM AUTHOR]

Projectile fragmentation at Fermi energies is an important method to produce radioactive beams for the study of isospin asymmetric nuclear matter. Fragmentation is usually parametrized successfully by empirical phase space models. In this contribution we apply a microscopical method, semiclassical transport theory, to study in detail the reaction mechanism of the fragmentation process. We apply it to experimental data of O on Ta at E/ A = 35 MeV measured in Dubna. We calculate consistently the excitation energy of the primary fragments and take into account their decay by a statistical model. It is found that the dissipative part of the fragment spectra is well described by transport theory. However, there are in addition important direct and collective contributions. [ABSTRACT FROM AUTHOR]

An Erratum to this paper has been published: https://doi.org/10.1134/S1063778822330018 [ABSTRACT FROM AUTHOR]

Peripheral collisions of heavy ions at Fermi energies are a powerful tool for producing new isotopes far from stability line. The mechanism of these reactions has features between direct and dissipative reactions, as is seen from the velocity distributions of the projectile-like fragments, which are peaked near the beam velocity and have a long tail to the smaller velocities. In this report we treat these heavy ion collisions in a Boltzmannlike transport approach, which describes the evolution of the phase space distribution function under the influence of a mean field and a two-body collision term. It is used to calculate the primary fragments after the collision phase, which are, however, still highly excited. The de-excitation of the fragments is calculated in a statistical model. We calculate isotope distributions and velocity spectra for the reaction of Ar as a projectile on targets of Be and Ta at E/ A = 57 MeV and find reasonably good agreement with experimental data. [ABSTRACT FROM AUTHOR]

Properties of the COMBAS fragment separator are compared with respective properties of similar setups. Results of experiments aimed at obtaining products of one-proton-stripping reactions induced by a beam of Ar ions with an energy of 35 MeV/A and two-neutron-stripping reactions induced by a beam of Ne ions with an energy of 52 MeV/A are presented. A high resolution of the fragment separator in obtaining secondary neutron-rich Cl and neutron-deficient Ne ion beams is demonstrated. [ABSTRACT FROM AUTHOR]

The development of an experimental facility based on the high-luminosity COMBAS fragment separator and a fast ion catcher is discussed. The main characteristics of the COMBAS fragment separator and the ion catcher determining the advantages of the proposed combination are presented. The developed facility is expected to allow production of secondary radioactive beams with a quality higher than the quality of beams obtained using the in-flight separation technique. It is planned that the facility will be used in a tandem with a post-accelerator for producing single-isotope and monochromatic high-intensity secondary radioactive beams in a wide range of mass numbers A and atomic numbers Z. A list of perspective scientific problems requiring high-intensity and high-quality secondary beams of exotic nuclei is proposed. [ABSTRACT FROM AUTHOR]

The results of a joint analysis of experimental data (angular distributions for scattering and total reaction cross sections) are presented for the case of the interaction of Li ions with Si nuclei at energies between 7.5 and 32 MeV. The respective calculations were performed on the basis of a deformed potential of the optical model by using the SPI-GENOA code. The energy dependences of the parameters of the macroscopic optical model and the total cross section for the (Li+Si) reactions were obtained over the energy interval from 7.5 to 32 MeV. The calculated angular distributions and total reaction cross sections are in good agreement with experimental data. [ABSTRACT FROM AUTHOR]

Results of measurements of ion energy losses in the insufficiently known range βγ = 0.01-0.06 in thin (∼2 μg/cm) absorbers are presented. For this purpose, the energy losses and time-of-flight of ions have been measured simultaneously using low-pressure avalanche gas-filled detectors at P ≈ 1 Torr. These measurements have been complemented with ion residual energy measurements using a semiconductor detector. The energy of ions with βγ ≈ 0.01-0.03 has been reconstructed using the time-of-flight measurements. The Δ E( E) dependence for He, Be, C, and O ions is presented. [ABSTRACT FROM AUTHOR]

New data on the cross sections of reactions occurring during the interaction of He nuclei with Au at energies of He from 40 to 120 MeV are presented. The experiments were performed in the ACCULINNA secondary beam separator of the Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research. To identify the reaction products, the activation method for measuring the gamma activity of the target assembly of thin foils was used. The excitation functions for fusion reactions involving the evaporation of up to ten neutrons from the compound nucleus as well as reactions with the emission of charged particles and nucleon transfer in the investigated energy region are obtained. Data analysis was carried out using two codes: ALICE-MP and NRV. The cross sections for the (He, xn) reactions occurring through the compound nucleus are mostly in agreement with the results of model calculations based on the statistical approach. It is shown that, up to the energies of 114 MeV, the cross-section drop in the complete fusion reactions is negligible. The experimental excitation functions of reactions leading to the formation of isotopes of mercury and gold (transfer reaction) indicate that the main contribution to their formation is made by direct processes and that evaporation reactions (He, pxn) and (He, α xn) play a minor role, as is evidenced by a comparison of the measured cross sections with the calculation results. [ABSTRACT FROM AUTHOR]

New data on the cross sections of reactions that proceed during the interaction of He and Au nuclei in the He energy range of 40 to 120 MeV are reported. The experiments were performed using the secondary beam of the ACCULINNA separator at the Flerov Laboratory of Nuclear Reactions (FLNR), JINR. Reaction products are identified by means of activation method to measure the gamma activity of a thin-foil target assembly. Excitation functions for He fusion reactions with subsequent emission of up to 10 neutrons from the compound nucleus are measured. Cross sections for reactions with emission of charged particles and nucleon transfer were also measured. The experimental cross sections for the (He, xn) reactions that proceed via the formation of a compound nucleus agree in general with calculations using models that involve the statistical approach. It is shown that the complete fusion reaction cross section drops slightly up to an energy of 114 MeV. The experimental excitation functions for the reactions resulting in the formation of mercury and gold isotopes indicate that the main contribution to their formation comes from direct processes, while the evaporation reactions (He, p xn) and (He, α xn) are of minor importance. [ABSTRACT FROM AUTHOR]

Results are provided for industrial research on oil-refining pipeline corrosion, structural degradation of material with corrosion is demonstrated, and the life of a ELOU-AVT-3 installation is calculated. Areas most subject to active corrosion damage are revealed. [ABSTRACT FROM AUTHOR]

A setup for identifying low-energy (1-10 MeV) ions with charges Z ≥ 1 by simultaneously measuring the energy losses and the time of flight is described. The setup is composed of a multiwire proportional chamber and a strip silicon detector, which are used to measure the ion energy, and two low-pressure avalanche wireless detectors for measuring the energy losses and the time of flight. Results obtained in measuring α particles from Ra source and p, Be, C, and O ions produced on the ITs-100 cyclotron at the Flerov Laboratory of Nuclear Reactions are presented. [ABSTRACT FROM AUTHOR]

A high content of noncoding RNA in the total bacterial RNA significantly impedes analysis of their transcriptome using standard approaches, i.e., full-scale sequencing, analysis of gene expression profiles, and subtractive hybridization. A method of preparation of bacterial cDNA for transcriptome analysis is proposed that includes a depletion of the excess of rRNA and tRNA copies with the preservation of the relative abundance of transcripts. The method is based on the kinetics of DNA hybridization and the unique features of duplex-specific nuclease from the Kamchatka crab. The efficiency of the method was confirmed in a number of model experiments. [ABSTRACT FROM AUTHOR]

New results from a series of experiments dedicated to the study of the C exotic state (the so-called Hoyle state) are presented. In spite of the many investigations that have been carried out, the structure of this state (which lies above the threshold for breaking up into three alpha particles) is still unknown. The different models assume that the nucleus has an abnormally large size in this excited state. However, until recently, methods for measuring the radii of unbound states have not been suggested. The best way to solve this problem seems to be by measuring the angular distributions of elastic and inelastic scattering of C on different target nuclei, and the determination of the radii is based on the fact that, at small scattering angles, the cross sections for direct reactions at high enough energies behave like Frauenhofer diffraction on a black ball. Accordingly, an experiment was performed aimed at measuring the elastic and inelastic angular distributions of C with an energy of (121.5 ± 0.5) MeV on a C target. The elastic scattering was measured in the angular range from 18° to 50° in the c.m. system with uncertainty in the angle of measurement equal to Δθ = ± 0.6°. The inelastic cross section was measured for the C excited state 2 (4.44 MeV) and 0 (7.65 MeV). Estimates were made for the diffraction radii for the ground and excited states. An increase was observed in the radius of the state at 7.65 MeV compared to those of the ground and first excited states. [ABSTRACT FROM AUTHOR]

profilometer for diagnostics of secondary ion beams with Z ≥ 2 is described. Two methods of beam profile measurements are compared: a counting method, when pulses from each particle are registered, and a current method with channel-by-channel measurement of the integral current. The counting characteristics and the lifetimes of the profilometer for these methods of beam profile measurements are compared. [ABSTRACT FROM AUTHOR]

Experimental results from measuring the energy dependences of cross sections of fusion and transfer reactions for 6Li beams and Pt targets are presented. The experiments were performed using the MSP-144 magnetic analyzer; stacks of platinum foils were installed at the focal plane of this analyzer. In the energy range 22.5–42.5 MeV, the energy resolution of the beam hitting the target stack was not worse than 0.25 MeV and that of the transmitted beam was not worse than 0.40 MeV. The yields of products of neutron and deuteron transfer reaction on target nuclei were measured using the γ activity induced in the platinum targets. Thus, excitation functions for transfer reactions were obtained in a wide energy range, including near the Coulomb barrier. It was shown that the basic reaction channel is the deuteron capture from 6Li. In this case, the maximum of the excitation function for 6Li breakup and subsequent deuteron capture lies near the Coulomb barrier of the reaction. [ABSTRACT FROM AUTHOR]

Two methods for obtaining monochromatic beams of accelerated 6He ions with energies around the Coulomb barrier on the DRIB accelerator complex at the Joint Institute for Nuclear Research (JINR) is described. In the first method, the MSP-144 magnetic spectrometer is used as a monochromator of low-energy 6He beam after its passing through an energy absorber. The energy resolution of the 6He beam, which is 500 keV, is governed by the linear dimension of the target in the focal plane (18 mm). In the other method, a special probe is used to investigate nuclear reactions with accelerated 6He beams without loss of the beam intensity. With this probe, it is possible to perform experiments on the internal beam of the postaccelerator (U-400 cyclotron) of the DRIB complex. As a result, a 6He beam with a required energy and a beam resolution of 150 keV or better is produced at the target. [ABSTRACT FROM AUTHOR]

To investigate the structure of the halo of Borromean nuclei, we have studied quasi-free scattering of the proton by constituents of halo-nuclei 6He. The experimental study is performed using the 6He beam of the Flerov Laboratory of Nuclear Reactions (JINR) at an energy of about 10 MeV/ u and the technique of nuclear photoemulsions. Searching for events of quasi-free scattering and their processing is performed using the PAVICOM-setup at the Lebedev Physical Institute. [ABSTRACT FROM AUTHOR]

To estimate the probability of two-neutron configuration in halo nuclei, an experimental method for studying neutron-neutron correlations at the periphery of such nuclei by measuring the two-neutron transfer reaction is proposed. Experimental investigation of the 6He + A → 4He + B reaction was performed using a 60-MeV 6He radioactive beam at the Flerov Laboratory of Nuclear Reactions (Joint Institute for Nuclear Research, Dubna); the technique of nuclear photoemulsions was applied. Search for events of the two-nucleon transfer reaction was performed at the PAVIKOM setup (Lebedev Physical Institute, Russian Academy of Sciences). [ABSTRACT FROM AUTHOR]

The objective of our research is the interpretation of the results of the geomagnetic survey of the geologic structure in the Gorlo Strait of the White Sea. We used the maps of the anomalous magnetic field (AMF) available and processed them with original interpretation software. As a result of this processing, we compiled a structural-tectonic chart of this region. We distinguished the boundaries of the major first-order tectonic structures such as the underwater extension of the Leshukon graben and a number of minor structures related to the Proterozoic and Paleozoic stages of the magmatic activity in the region. Modeling was performed for the most important objects, which allowed us to refine the geological structure of these objects and their genesis. [ABSTRACT FROM AUTHOR]

Experimental data on the momentum distributions of 4He nuclei originating from 6He and 6Li breakup on various targets are presented over a wide beam energy range. The experiment with 6He was performed at the DRIBs accelerator complex for radioactive beams at the Joint Institute for Nuclear Research (JINR, Dubna). The intensity of the 6He beam used was 5 × 106 particles per second and its energy was 10 MeV per nucleon. The momentum distributions of breakup products were measured by means of the MSP-144 magnetic spectrometer. The distribution width was shown to be virtually independent of the target mass. A small value of this width, σ ∼ 28 MeV/ c, confirms the presence of a halo in 6He. The measurements performed with 6Li beams of energy 18 and 46 MeV per nucleon at the U-400M accelerator yielded a width value of σ ∼ 50 MeV/ c for the momentum distributions of 4He nuclei, which is intermediate between that for 6He and those for stable nuclei. A compilation of the widths of the momentum distributions of fragments originating from the breakup of various nuclei is presented versus the binding energy of one or two neutrons in these nuclei, the target mass and the projectile energy. [ABSTRACT FROM AUTHOR]

Excitation functions for evaporation residues in the reactions 197Au(6He, xn)203- xnTl, x = 2-7, and 206Pb(6He, 2n)210Po, as well as for neutron transfer reactions for the production of 196Au and 198Au in the interaction of 6He with 197Au were measured. The 6He beam was obtained from the accelerator complex for radioactive beams DRIBs (JINR). The maximum energy of the beam was about 10AMeV and the intensity reached 2×107pps. The stacked-foil activation technique was used directly in the beam extracted from the cyclotron or in the focal plane of the magnetic spectrometer MSP-144. The identification of the reaction products was done by their radioactive γ- or α-decay. The fusion reaction with the evaporation of two neutrons was characterized by an increase in the cross-section compared to statistical model calculations. The analysis of the data in the framework of the statistical model for the decay of excited nuclei, which took into account the sequential fusion of 6He has shown good agreement between the experimental and the calculated values of the cross-sections in the case of sub-Coulomb-barrier fusion in the 206Pb + 6He reaction. An unusually large cross-section was observed below the Coulomb barrier for the production of 198Au in the interaction of 6He with 197Au. Possible mechanisms of formation and decay of transfer reaction products are discussed. [ABSTRACT FROM AUTHOR]

Excitation functions were measured for fusion followed by the evaporation of neutrons in the reactions 206Pb(6He, 2 n )210Po and 197Au(6He, xn)203− xn T1, where x = 2−7, as well as for the transfer reactions on a 197Au target with the formation of the 196Au, 198Au, and 199Au isotopes. The experiment was carried out at the Dubna Radioactive Ion Beams (DRIBs) complex of FLNR, JINR. The 6He beam intensity was about 5 × 106 pps, the maximum energy being (60.3 ± 0.4) MeV. A significant increase in the cross section was observed below the Coulomb barrier for the fusion reaction with the evaporation of two neutrons compared to statistical model calculations. Unusual behavior for the production of 198Au is observed, whereas the cross section for the formation of 199Au is very low. The analysis of the data in the framework of the statistical model for the decay of excited nuclei, which took into account the sequential fusion of 6He, has shown good agreement between the experimental and calculated values of the cross sections for the case of sub-Coulomb-barrier fusion in the 206Pb + 6He reaction. [ABSTRACT FROM AUTHOR]