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Model simulations of test experiments on muon radiography for several configurations of voids in the ground and different muon detector positions are presented. The sensitivity of the method for the considered cases is estimated. This study lays the basis for quantitative analysis of data in muon radiography and can be used for planning future experiments.

Properties of the extragalactic magnetic field (EGMF) outside of clusters and filaments of the large-scale structure are essentially unknown. The EGMF could be probed with $\gamma$-ray observations of distant (redshift $z > 0.1$) blazars. TeV $\gamma$ rays from these sources are strongly absorbed on extragalactic background light photons; secondary electrons and positrons produce cascade $\gamma$ rays with the observable flux dependent on EGMF parameters. We put constraints on the EGMF strength using 145 months of Fermi-LAT observations of the blazars 1ES 1218+304, 1ES 1101-232, and 1ES 0347-121, and imaging atmospheric Cherenkov telescope observations of the same sources. We perform a series of full direct Monte Carlo simulations of intergalactic electromagnetic cascades with the ELMAG 3.01 code and construct a model of the observable spectra inside the point spread functions of the observing instruments for a range of EGMF strengths. We compare the observed spectra with the models for various values of the EGMF strength $B$ and calculate the exclusion statistical significance for every value of $B$. We find that the values of the EGMF strength $B \le 10^{-17}$ G are excluded at a high level of the statistical significance $Z > 4 \sigma$ for all the four options of the intrinsic spectral shape considered (power-law, power-law with exponential cutoff, log-parabola, log-parabola with exponential cutoff). The value of $B = 10^{-16}$ G is not excluded; it is still a viable option of the EGMF strength. These results were obtained for the case of steady sources., Comment: 10 pages, 6 figures, 2 tables. Published in MNRAS. This is the authors' version, not the final typeset. Minor main text changes w.r.t. v2, two appendices added. Supplementary material is available at https://doi.org/10.5281/zenodo.6483355

Current technical design of the SPHERE project’s new detector is presented. The SPHERE project is aimed at primary cosmic ray studies in the 1 - 1000 PeV energy range using reflected Cherenkov light. The concept of a drone-mounted detector with a photosensitive camera based on silicon photomultipliers is discussed. The combination of the reflected CL registration method with specific data analysis approaches is a unique feature of this project. The developed earlier event-by-event data analysis approach allows to carry out primary particle mass reconstruction and primary cosmic ray mass composition studies with high accuracy. This is achieved through careful analysis of each EAS Cherenkov light lateral distribution function without building any kind of intermediate distributions of any `typical' characteristics.

A phenomenon of abnormally weak absorption of very-high-energy cosmic-ray hadrons in lead is discussed. This phenomenon was first observed in Tien-Shan high-altitude experiments in hadronic cores of extensive air showers and has encouraged to introduce the hypothesis of a so-called long-flying or penetrating cosmic-ray component. A similar effect was detected later with deep uniform lead X-ray emulsion chambers (XREC) at the Pamirs. Experiments, which are sensitive to the production of charmed hadrons in the forward kinematic region (xLab ≳ 0.1), have been carried out at the Tien-Shan and Pamirs with exposing two-storey XRECs with large air gaps to prove explanation of the experimental results with high charm production cross section $${\sigma _{pp \to c\bar c}} \sim 8$$ at xLab ≳ 0.1 at ⟨ELab⟩ ∼ 75 TeV. This $${\sigma _{pp \to c\bar c}}$$ value makes it possible to reproduce the experimental hadron-absorption curve observed with XRECs, including curve’s bending at a depth of ∼70 c.u.

Cosmic ray muonography is a novel technique for imaging of the internal structures of large natural and industrial objects. It exploits the capability of high energy muons from cosmic rays to penetrate large thicknesses of large subjects to be studied, in order to obtain a density map. It uses muon flux attenuation and absorption in materials of investigated objects. Nuclear emulsions are tracking detectors well suited to be employed in muonography for investigations of inner structure of large objects up to kilometers size, since emulsions have firstly an excellent angular resolution, they are compact and robust, do not require power supply. The muonography methods are applied to study one of UNESCO world heritage objects, the unusual building in the Naryn-Kala citadel hidden underground. The use of nuclear emulsions as probing radiation detectors provides for a uniquely high resolution capacity of recording instrumentation combined with the potential of modern image analysis methods giving 3D reconstruction of the internal structures of the investigated object.

It has been shown experimentally that, in a complex field of ionizing particles generated by cosmic rays, the highest values of the specific absorbed energy and, therefore, the density of charge formed during the ionization correspond to the locations of ion stopping. The modeling shows that, in the same locations, the ratio of the energy absorption by the nuclear continuum to the ionizing particle energy absorption by the electronic continuum of the medium linearly depends on the mass of the projectile.

Storage properties (porosity) of productive strata at Stretenskoye field were determined using several methods of geophysical studies of wells. The filtration properties (permeability) are determined according to the interpretation of the hydrodynamic study materials under unsteady conditions. At the same time, the methods used in a number of cases showed different results. In order to avoid misinterpretation of the structure of void space and its properties, it is advisable to conduct studies to assess the reliability of all the methods. For this purpose, the paper used the tools of mathematical statistics such as correlation and multivariate regression analysis. As a result of the research, the authors gave the recommendations for the application of methods to determine the filtration and storage properties of reservoirs differentially for terrigenous and carbonate reservoirs of the studied field.

The paper considers probabilistic approach application to assess zonal oil and gas potential of the Visimskaya monocline area. The earlier studies have shown that the processes of generation, migration and accumulation of hydrocarbons (HC) shall be most effectually assessed from a probabilistic standpoint. Generation processes are best described by a complex probabilistic criterion – PcompG , migration and accumulation processes – by PcompMAC [1]. These criteria were used to develop a multivariate statistical model – Pcompzon , acting as an estimate of the system emergence regarding the zonal oil and gas potential. The values were ranked from maximum to minimum to assess the effect of PcompG and PcompMAC indicators on Pcompzon at different ranges of its values. We successively built and analysed 379 models. The analysis of these models has shown that at Pcompzon>0.5 there is a congruent effect of PcompG and PcompMAC on this indicator, the effect being different at Pcompzon A pattern of its variation over the area was built based on Pcompzon values, which allowed differentiating the area of the Visimskaya monocline into a high-potential western part and a lower-potential eastern part.

In this article, a factor analysis of well flow rate increase after hydraulic fracturing depending on facies conditions is carried out using the example of the Turne-Famenskoye reservoir of the Gagarinskoye field as an example. By constructing the equations of multiple regression, the influence of geological factors on the productivity coefficient and, consequently, on the additional oil production was determined. Based on the results of factor analysis and construction of statistical models, high significance of bottom hole and formation pressure values and their change depending on facial environment has been established. It is recommended to select candidate wells for hydraulic fracturing operations taking into account their facial affiliation, specific features of wells where hydraulic fracturing operations were carried out quite effectively, taking into account residual reserves density, water cut of well production, proximity to oil-bearing contour and to injection wells.

The article describes the possibility of usage of drawing method for production of pipes of fibered composite AL-B. The authors suggest using a construction of drawing mill, where the material volume reduction is carried out on the floating plug. With an aim of quality improvement technological shell is used. There were examined the mechanisms of joint deforming of compact blank part and solid shell.

Bentonite and kaolin were treated by high pressure (to 2200 MPa). Using the XRD parameters (full width at half maximum, integrated intensity, interplanar distance, diffraction angle 2θ of reflection maximum), a significant pressure effect on the crystallite size of main clay minerals (montmorillonite and kaolinite) was established. The crystallite size is closely related to the energy activity of the clay particles. The boundaries with a pressure of 125 and 750 MPa were identified, which divide the measurements into three classes. Each class has its own regularities for changing parameters. Mathematical models for predicting changes in energy activity of clay particles have been developed.

A method for estimation of the parameters of the primary particle of an extensive air shower (EAS) by a high-altitude detector complex is described. This method was developed as part of the Pamir-XXI project. The results may be useful for other high-altitude projects and the EAS method in general. The specific configurations of optical detectors for Cherenkov EAS radiation and charged-particle detectors, the methods for data processing, and the attainable accuracy of reconstruction of parameters of primary particles (energy, direction, mass/type) are presented. The results primarily cover optical detectors that are suitable for studying EASs from primary nuclei in the range of energies E0 = 100 TeV–100 PeV and showers from primary γ-quanta with energies of Eγ ≥ 30 TeV. Grids of charged-particle detectors designed to determine the EAS direction and energy in the E0 = 1 PeV–1 EeV range are also considered. The obtained accuracy estimates are the upper limits of the actual experimental accuracies.

SPHERE-2 is a Cherenkov telescope suspended under a tethered balloon and observing the optical Vavilov–Cherenkov radiation of extensive air showers (EAS) reflected from the snowy surface of Lake Baikal. Extended modeling of the SPHERE-2 detector’s response is done with a specially developed code. Resulting model events resemble EASes observed during observation runs at Lake Baikal. This work should facilitate event-by-event studies of cosmic ray mass composition in the 10–100 PeV range of energies.

Here is proposed, analyzed and substantiated a technique for selecting extensive air shower (EAS) from ultrahigh-energy gamma quanta against the background of protons by using angular Cherenkov telescopes. A concrete version of the configuration of optical detectors for recording EAS Cherenkov light (CL) and methods of processing their data and the achievable accuracy of separating gamma quanta against the background of protons are presented. The mechanism of operation of the criteria in the range of primary energies of 30–100 TeV is also described. The criterion separating the two classes of events is formed of the integrals of the measured angular distribution of EAS Cherenkov light over certain solid angles. The Cherenkov light spot seen by the telescope is related to the optical cascade curve of the EAS. This technique was developed within the framework of the “Pamir-XXI” project, but it can be useful both for other high-altitude projects, and for the EAS method in general.

The method of development of technological processes of production of items from composite materials is developed, based on application of the criterion system providing formation of strong connection of components and required level of mechanical properties in the material

A technique is developed to estimate the effect of the deformation parameters on the distribution of the mechanical properties of the products made of aluminum alloys. Regression dependences of the mechanical properties on the deformation intensity, the temperature, and the cooling rate are obtained. A software application to CAE systems is developed to predict the distribution of the mechanical properties of the products made of aluminum alloys over their volume.

The design for a balloon instrument to study the energy spectrum and mass composition of primary cosmic rays at energies exceeding 1018 eV is presented. It is planned to conduct the experiment during Antarctica’s polar night. The equipment allows the separate registration of fluorescent light (FL) and Cherenkov radiation (CR) in each event. The advantages of the experiment over existing ground-based installations and future orbiting stations are discussed. A way of separating FL from CR with light filters and optical silicon detectors is described.

This article presents experimental data of pressure influence on the energy potential of clay particle surface. The potential was estimated through the complex indicator Mk . In montmorillonite clay the energy potential reaches maximum values at the pressure up to 125 MPa. As the pressure rises to 2 200 MPa, the potential gets reduced. A different pattern has been found in kaolinite clay: when pressure increases, the energy potential of the particle surface increases as well. In kaolinite clay the influence of the fractional composition on Mk changes is rather insignificant whereas in montmorillonite clay it is significant. Based on the revealed relationships between the energy potential of clay particle surface and their content in the soil, the mathematical models have been developed that make it possible to predict Mk from the data of clay fractional composition.

A technique is developed to simulate the high-cycle rolling used to produce particle-reinforced materials, such as an aluminum–copper composite material. The technique is based on the results of real rolling and on a mathematical model, which is based on the results of calculation with criterion conditions. The application of a criterion approach allowed us to predict the possibilities of formation of high-strength bonding of the components of the aluminum–copper composite material at retained integrity in the first rolling cycle and to determine the conditions that ensure breaks in the integrity of the reinforcing component in the next cycles in order to produce a particle-reinforced material.

International audience; The Interhelioprobe mission aims to investigate the inner heliosphere and the Sun from close distances (up to 0.3 AU) and from out of the ecliptic plane (up to 30°). In this paper we present the relevance of the mission and its main scientific objectives, describe the scientific payload, ballistic scenario and orbits of the spacecraft. Possibilities of scientific cooperation with other solar and heliospheric space missions are also mentioned.

In Russia, the Lebedev Physical Institute of the Russian Academy of Sciences and the Skobeltsyn Institute of Nuclear Physics of Moscow State University are starting a series of pilot muon radiography exper-iments with nuclear emulsion detectors to study the interior structure of large-scale natural and industrial objects. As a result, the optimal conditions for experimental organization have been determined, algorithms of data processing have been worked out, and peculiarities of the method have been ultimately investigated. Here we present the experimental data, including field observations (in the mine of Geophysical department of Russian Academy of Sciences) confirming the availability of the method with track detectors on the base of nuclear emulsions with uniquely high spatial resolution, providing their high-tech automated processing.

The origin of an excess of hadrons observed in deep homogeneous lead X-ray emulsion chambers (XRECs) at depths of more than 70 radiation length units is analyzed. Preliminary experimental data on the absorption of cosmic-ray hadrons in a two-storied XREC with a large air gap, exposed in the Tien Shan mountains, are presented. The chamber was designed to test the hypothesis that the main source of the excess of dark spots detected on X-ray films deep inside the XREC was substantial growth of the charmed-particle production cross section at energy E lab ∼ 75 TeV. The experimental data obtained using a two-storied REC and in experiments with deep homogeneous XRECs are compared to the results from calculations using the FANSY 1.0 model. The comparison shows qualitative agreement between the experimental and the model data, assuming high values of the charmed-particle production cross section when E lab ∼ 75 TeV in the forward kinematic region with x F ≥ 0.1.

The Lebedev Physical Institute of the Russian Academy of Sciences and the Skobeltsyn Institute of Nuclear Physics of Moscow State University conduct experiments using nuclear photoemulsion to study the internal structure of large objects via muon radiography. Analysis of an experiment in a mine in Obninsk belonging to the Geophysical Service of the Russian Academy of Sciences is of particular interest. Calculated and experimental data are presented.

Appreciable hard X-ray (HXR) and gamma-ray emissions in the 0.04 to 150 MeV energy range associated with the 2003 October 29 solar flare (X10/3B) were observed at 20:38 to 20:58 UT by the SONG instrument onboard the CORONAS-F mission. To restore flare gamma-ray spectra we fitted the SONG energy loss spectra with a three-component model of the incident spectrum: (1) a power law in energy, assumed to be due to electron bremsstrahlung; (2) a broad continuum produced by prompt nuclear de-excitation gamma-lines; and (3) a broad gamma-line generated from pion decay. We also restored spectra from the RHESSI data, compared them with the SONG spectra and found a reasonable agreement between these spectra in the 0.1 to 10 MeV energy range. The pion-decay emission was observed from 20:44:20 UT and had its maximum at 20:48 to 20:51 UT. The power-law spectral index of accelerated protons estimated from the ratio between intensities of different components of gamma rays changed with time. The hardest spectrum with a power-law index S = - 3.5 to - 3.6 was observed at 20:48 to 20:51 UT. Time histories of the pion-decay emission and proton spectrum were compared with changes of the locations of flare energy release as shown by RHESSI hard X-ray images and remote H alpha brightening. An apparent temporal correlation between processes of particle acceleration and restructuring of flare magnetic field was found. In particular, the protons were accelerated to sub-relativistic energies after radical change of the character of footpoint motion from a converging motion to a separation motion., Comment: 28 pages, 8 figures, 2 tables, submitted to New Astronomy