A brief history and the main results of the study of cosmic rays and high-energy gamma radiation using the Cherenkov EAS installations located in the Tunka Valley 50 km from the southwestern tip of Lake Baikal are presented. Since 1993, the important results have been got about the energy spectrum and mass composition of cosmic rays in the energy range of 1 – 1000 PeV with the Tunka-4,...
Interest to study neutrons produced in Extensive Air Showers (EAS) is rising last years. Recent publications on this subject are overviewed and estimated. Advantages of the method to study hadronic component being the main EAS component, as well as perspectives of the method are shown.
Abstract-The origin of cosmic rays can be deciphered by accurately measuring the components and energy spectrum in the knee region. Extensive air shower (EAS) studies rely on information provided by secondary high energy hadrons, which generate evaporation neutrons when they interact with matter in the environment. In the early 21st century, the electron-neutron detector (EN-detector) was...
As part of the high-altitude LHAASO project, ENDA (Electron Neutron Detector Array) is being created in China. The concept of the ENDA consists in simultaneous registration of the electromagnetic and thermal neutron components (being a part of hadronic component) of the EAS. The report provides a brief overview of analytical and ML (Machine Learning) methods for shower and primary particle...
Currently, the deployment of the Baikal-GVD neutrino telescope is successfully underway in Lake Baikal. Baikal-GVD now comprises 96 strings with 3456 optical modules. We present the current status and plans for further deployment of the Baikal-GVD telescope and discuss issues related to the creation of a next-generation neutrino telescope in Lake Baikal.
Neutrino radio detectors are designed to target the first measurement of neutrinos beyond energies of ∼10 PeV. Several such radio detectors operate in Antarctica. They are scanning the ice sheet in search of Askaryan radio emission from neutrino induced showers. The Radio Neutrino Observatory in Greenland (RNO-G), designed to monitor ultra-high-energy neutrinos in the northern hemisphere, is...
We analyze neutrino fluxes near the surface of a protoneutron star in type II supernova explosions at core-collapse regime. For dynamoactive supernovae it is shown that effective neutrino collisions in a magnetized nucleon gas caused by the neutral current Gamow-Teller component lead to neutrino acceleration. Such an effect originates from spin-projection asymmetry in phase space volume of...
The TAIGA experiment in Tunka valley is expanding the present scintillation detector array with new TAIGA-Muon detector stations. A simulation model was developed for the new stations optimization and study of the identification performance of the array together with HiScore optical stations system. The extensive air showers (EASs) were simulated with the CORSIKA simulation tool, and the...
The High-Energy Ray Observatory (HERO) is a space experiment based on a heavy ionization calorimeter for direct study of cosmic rays. The effective geometric factor of the apparatus is not less than 12m2sr for protons and not less than 18m2sr for nuclei and electrons. During the exposure for ∼5-7 years this mission will make it possible to measure energy spectra of all abundant cosmic ray...
Paper contains the first results of our attempts in the development of a model of SPHERE-3 telescope for the primary cosmic ray studies in 1-1000 PeV energy range with reflected and direct Cherenkov light generated by extensive air showers (EAS).
The aim of the work is to develop an automated method for the design of SPHERE-3 telescope, which, on one hand, will enable it to obtain the best...
In recent decades, Cherenkov water (ice) telescopes such as IceCube, Baikal-GVD and KM3Net are being actively developed for research in the field of neutrino physics and astrophysics. Optical modules are the main detecting elements of such neutrino telescopes.
Calibration of optical modules of different neutrino telescopes under the same conditions is one of the important experimental...
The Experimental Complex NEVOD includes a number of large-scale facilities for detection of high energy cosmic rays, including the ProtoTREK and the NEVOD-EAS detectors. The coordinate detector ProtoTREK consists of 14 multiwire drift chambers with a total area of 13 $m^2$ and makes it possible to register and to reconstruct tracks of charged particles of extensive air showers (EAS). The...
The purpose of the work is to investigate energy characteristics of Forbush decreases using coupling functions according to muon hodoscope URAGAN data. A coupling function shows relative contribution of primary cosmic rays with different energies to a count rate observed by a particular detector, so it is a basic tool to study energy characteristics of various modulation phenomena, such as...
In a new capacity, Einstein's idea of the equivalence of mass and energy is confirmed. The equivalence manifests itself in similar functionality in the processes of pulsations (focusing and bounce) of "excess" energy in the generalized 2D Kepler problem and "excess" mass in the 3D Vysikaylo-Chandrasekhar problem of cumulation and dissipation of de Broglie waves in quantum stars (pulsating...
More than 80 years after the discovery of UHECRs, many questions remain about possible sources, mechanisms of acceleration, propagation, and so on. An important aspect of research is the analysis of their motion in the magnetic field of the Galaxy, which implies, first of all, model calculations. New works devoted to such an analysis appear with the accumulation of experimental observations of...
This paper studies the dynamics of proton flux in the South Atlantic Anomaly (SAA) region according to ARINA (was operated on the Resurs-DK1 satellite from 2006 to 2015) and VSPLESK (which was mounted on the ISS from 2008 to2013) satellite experiments. Both spectrometers have the same scheme.
The SAA drift is determined by the position of the maximum flux of high-energy protons with energies...
Since 2012 in the Experimental Complex NEVOD (MEPhI, Moscow), the PRISMA array for studying extensive air showers by detecting neutrons has been operated. In the array the en-detectors are used to detect neutrons. The detector consists of a thin (~ 30 mg/cm^2) inorganic scintillator ZnS(Ag)+6^LiF (the enrichment of Li with 6^Li isotope is 90%) and photomultiplier FEU-200, which are installed...
On the basis of the Experimental Complex NEVOD, the URAN setup has been deployed which serves to detect the electron-neutron component of extensive air showers (EAS). This setup includes 72 scintillation detectors and covers an area of ~10^3 m^2. Registration of the neutron component by detectors is possible due to the ZnS(Ag) + B2O3 scintillator, where the content of the 10B isotope is 18%....
The Forbush decreases (FDs) are known as sharp drops in cosmic ray intensity, registered by different scientific equipment on Earth and interplanetary space. These events correlate with solar activity, mainly with coronal mass ejections (CMEs). CMEs spreads into interplanetary space and swap out the cosmic ray particles from the modulation region. The main features of FDs are the intensity...
Antenna clusters located in the Tien Shan High Mountaine Scientific Station (TSHMSS) are designed for radio detection of Extensive Air Showers (EAS) of cosmic rays. The cluster consists of 4 radio antennas, which each of them consists of mutually perpendicular arcs distributed over an area of 1700 m2. The analog part of the measuring path consists of a SALLA type antenna. These high-frequency...
According to the long-term registration data from the small Cherenkov array of integral and Cherenkov differential detectors obtained the characteristics of air showers with energies above 3*10^15 eV, including of the maximum of the development of the Xmax. The dependence of Xmax on the shower energy found and the characteristics of air showers compared with the QGSjetII-04 model. From a...
In this paper a new effect have been taken into account which has ever been
used before in physics, this effect related to two different ?elds, Quantum physics and General Relativity. This effect takes name: Time Dilatation as an Effect of Approaching Planck Length, this effect is completely different from the gravitational time dilatation in general relativity and time dilatation due to...
At present, the method of muonography (by analogy with X-ray radiography) of the internal structure of various objects of natural or artificial origin using the natural flux of cosmic ray muons has become widespread.
To implement this method, a mobile muon hodoscope (MMH) is being developed at the NEVOD Scientific and Educational Center (MEPhI). The design of the MMH is a multichannel...
Sources of PeV cosmic rays (so called Pevatrons) can be identified by gamma and neutrino radiation with energy more than 100 TeV due to not destroyed trajectories by interstellar and galactic magnetic fields. In particular, one of such potential sources areas is considered to be the region of the double source PSR J2032+4127 in the Cocoon nebula in the constellation Cygnus. The ...
This work presents a comparative analysis of the time changes in the secondary cosmic ray fluxes recorded by the detector modules of the L.N. Gumilyov ENU scientific complex during the period of powerful geomagnetic disturbances on 04.11.2021 and 13-14.03.2022. Noticeable changes in the geomagnetic indices, solar wind plasma velocity and the potential gradient of the surface electric field...
The large-scale coordinate-tracking detector TREK is being constructed at the Experimental Complex NEVOD (MEPhI, Moscow). It is designed to detect high-density muon bundles of inclined extensive air showers. It will significantly expand the capabilities of the experimental complex and ensure the progress in solving the «muon puzzle».
The main elements of the coordinate-tracking detector TREK...
In the report we present the data on the development of a prototype of module for a solid-state detector of electron antineutrinos, which is based on a plastic scintillator for detecting positrons from the inverse beta decay (IBD) reaction. It is assumed that the complex of scintillation modules, supplemented with screens for detecting neutrons from IBD reaction using the ZnS(Ag)-6LiF (or...
To date, cosmic rays are the only tool that allows one to study nucleus-nucleus interactions at energies of hundreds of TeV in the center-of-mass system. Investigations of high-energy CR are carried out by detection of secondary particles of extensive air showers (EAS) formed in interactions of primary particles with the Earth's atmosphere.
Earlier studies of EAS revealed a number of unusual...
Methods for visualizing the structure of large, up to kilometer-sized objects based on recording the degree of absorption of atmospheric muons, which are called muonography, use the abundant natural flux of muons resulting from the interaction of cosmic rays in the atmosphere. In recent years, there has been an active development of muonography in various innovative interdisciplinary...
The LVD detector, located in the Gran Sasso Laboratory at a depth of 3600 m a.e., is designed for research in the field of neutrino physics, astrophysics, cosmic ray physics and the search for rare processes predicted by theory. The LVD experiment was built in 1991 to register neutrinos from collapses of stellar nuclei in our galaxy. The background of the detector is atmospheric muons,...
A new approach to the analysis of muon flux during atmospheric fronts passage is discussed. It is possible to select muons in specific planes providing different counting rate series that can reveal atmospheric waves that may accompany phenomena like the passage of atmospheric fronts. The plane includes muons from all zenith angles and some azimuth angles. This selection is made possible by...
The method of event reconstruction and obtaining of muonographs by a new hybrid muon hodoscope is considered. The design of the developed hodoscope is described. The first results of measurements, as well as the obtained estimates of the angular and coordinate accuracy of the detector are discussed.
The muonography method is based on the registration of the penetrating component of cosmic...
Cosmic rays,their role in atmospheric phenomena.
A new approach to determination of the cosmic ray composition
Acceleration of cosmic rays in astrophysical jets is investigated. Particles are
accelerated at the outer bow shock and by shear flows in the jet cocoon.
Applications for the origin and chemical composition of
ultra high energy cosmic rays are discussed.
The paper discusses an approach that made it possible to estimate the distance to the nearest pevatrons, which form a break in the spectrum of the cosmic ray nucleon component of about 4 PeV. It is based on the spectra of nucleons and electrons obtained by the authors in the framework of the superdiffusion model of nonclassical CR diffusion, which have a break, on the assumption that nucleons...
The commonly accepted CR transport theory is based on the diffusion equation, which in turn follows from the Boltzmann kinetic equation. The latter was derived for multiple collisions of particles with local formations (atoms, molecules) under the assumption of their statistical independence, more precisely, of the Poisson nature of the ISM ensemble. It is this property that is responsible for...
A set of eight scintillators with the reduced to (50-70)ns width of their output pulse signals is applied for determination of the arrival directions of extensive air showers which are effectively detected by the Tien Shan shower installation in the energy range between 1 and 100 PeV. Up to the present time, about ~$10^6$ shower events applicable for deducing their directional angles were...
The TUS experiment was the first detector to measure the fluorescence and Cherenkov radiation of extensive air showers (EAS) in the Earth's atmosphere from space orbit. The main goal of the TUS experiment was to search for and study ultra high-energy cosmic rays with energies E > 70 EeV. The TUS detector registered a number of unusual events, the origin of which is unclearwith an anomalously...
The Experimental Complex (EC) NEVOD (MEPhI, Moscow) includes the NEVOD-EAS array, detecting electron-photon component of extensive air showers (EAS), and the Cherenkov water calorimeter (CWC), measuring energy deposit of particles passing through its operating volume.
Reconstruction of main EAS parameters (axis position, arrival direction, age and size) is performed according to the data of...
We calculate cosmic ray intensity and anisotropy using the model of the Forbush decrease formation in a magnetic cloud by the electromagnetic mechanism for three events. The properties of the Forbush decrease are determined by solving the Boltzmann kinetic equation without particle scattering. Geometrical parameters of the magnetic cloud, such as velocity, velocity gradient, cross-section...
The work presents the results of calculations of the cosmic ray protons propagation through the Earth's atmosphere using the Monte Carlo method. We developed the model for this modeling with the GEANT4 software development toolkit. It uses the standard QGSP_BERT_HP class to describe the physics of the particle interactions with matter. The general results are a quantitative estimated secondary...
The special interest to the estimation of trapped proton intensities in low-altitude region of the near-terrestrial space environment concerns their effects on numerous robotic and manned missions. The main part of radiation exposure comes from the space region where the trajectory of mission orbit pass through the South Atlantic anomaly (SAA).
At present time, the nature of long-term...
For understanding cosmic ray propagation through the interstellar medium (ISM), an adequate model for the latter is needed. The ordinary diffusion approach, leading to the Brownian motion, assumes independence of ISM local inhomogeneities, such as molecular clouds and magnetic fluctuations. The long-range turbulent correlations created by magnetic force lines and gravitation forces require a...
Based on the data of 35-year (1987-2021) measurements of magnetospheric electron fluxes with energy >2 MeV in geostationary orbits, solar wind speed and geomagnetic activity, a catalog of electron flux enhancements was compiled in which the electron fluence exceeds $10^8$ $cm^{-2} sr^{–1} day^{–1}$. The epoch superposition method performed using the GOES-13 spacecraft data shows that large...
Using the helio-sphere as an example, we have investigated the hypothesis that stellar winds or cosmic rays originate in stars and accelerate in their star spheres in electric field shock waves. We have proved that a nonequilibrium inhomogeneous giant gas discharge occurs in the helio-sphere at large values of the parameter E/N, which determines the electron temperature. This quasi-stationary...
CMS measurementsm valuable for tuning CR generators are discussed.
Collisions of cosmic ray particles with ultra-high initial energies larger than 0.1–1 EeV with nuclei in the atmosphere lead to creation a strongly interacting matter under extreme conditions and open a wide room for appearing of the novel dynamical features for production of secondary particles. In particular, the estimations obtained for the space density of charged particles at freeze-out...
The excess of muons in ultra-high energy cosmic rays (UHECR) in comparison with the results of Monte-Carlo simulations that grows with the primary particle energy is known as the muon puzzle. Since the LHC data became available, many improvements have been done to the models of hadronic interactions used in extensive air showers (EAS) simulation tools. Yet the noticeable deviation from...
The report is devoted to the geometric and kinematic description of the azimuthal correlation of photon and hadron families, which was observed by the Pamir collaboration in emulsion experiments with cosmic rays. This effect is called «alignment», because quantitatively this feature demonstrates a deviation from the straight line of points on the emulsion film plane used for particles...
At National Research Nuclear University MEPhI, a large-scale coordinate-tracking detector TREK for the study of muon bundles at large zenith angles is under construction. The detector has an area of 250 $m^2$ and consists of two planes of multi-wire drift chambers.
In joint operation with the Cherenkov water detector of 2000 tons of distillated water, the TREK detector will provide on...
Recent experimental data from space-based instruments of the DAMPE and CALET collaborations have shown that the energy spectrum of protons has a new feature, a break in the $\sim 10$ TeV region. In this energy range, the spectrum index of the observed particles varies from $-2.6$ to $-2.9$.
The purpose of this work is to establish the location zone of the sources that determine this break,...
NEVOD-DECOR is the unique experiment where systematic studies of cosmic ray muon bundles in a wide range of zenith angles and, accordingly, the energies of primary cosmic rays are carried out. Impressive experimental material (more than 100 thousand events) has been accumulated over a long time period from May 2012 to December 2022. The earlier developed method of local muon density spectra...
The results of direct measurements of the muon density in extensive air showers (EAS) with zenith angles $\theta \leq 45^\circ$ and energies $Е_0\geq 10^{17}$ eV obtained in the Auger experiment and at the Yakutsk array are considered. In both cases muons were registered by underground scintillation detectors with the same threshold energy $Е_{\mu}\approx 1.0 \times \sec \theta$ GeV. The...
Systematic uncertainties in the energy estimation of EAS primaries are a source of headache for physicists and lead to elusive discrepancies in the energy spectra of cosmic rays measured with different arrays. We have found the zenith angle distribution of EAS event rate to be sensitive to these systematic uncertainties. It gives an opportunity to test different algorithms for the primary...
Since 1986, regular measurements of radio emission generated by air shower relativistic particles have been started at the Yakutsk array. As a result of studying the noise background on the array region, a frequency of 30-35 MHz was chosen with minimal radio noise. Showers with energies greater than 10 EeV were registered at the array. For the first time, radio emission in showers with...
The Carpet-2 collaboration reports on the observation and analysis of an event with a low muon content coincident with the gamma-ray burst GRB 221009A and the transient Swift J1913.1+1946. This bright transient was observed by numerous instruments in the optical, X-ray and gamma-ray energy ranges. The redshift of this GRB is z=0.1505 (measured from afterglow observations).
The Carpet-2 array...
According to the Moscow neutron monitor (NM MOSC) data, using harmonic analysis, the characteristics of the solar-diurnal anisotropy of cosmic rays (CR) on quiet days were obtained for a long period from 1965 to 2020. It has been established that the average daily CR variations at NM MOSC are almost completely described by two harmonics of the solar-diurnal anisotropy and does not contain...
Using data of ground level cosmic ray observations on neutron monitor world network, Yakutsk muon telescope complex and URAGAN muon hodoscope (Moscow), we carried out a research of magnetospheric and atmospheric cosmic ray variations over September 2017 by a modified spectrographic global survey method. We obtained time dependence of changes in the planetary system of rigidities of geomagnetic...
Cosmic ray variations observed with ground-based detectors include variations of extraterrestrial origin, atmospheric, magnetospheric, apparatus variations, and statistical fluctuations. The method of acceptance vectors allows us to determine cosmic ray anisotropy out of the magnetosphere for studying physics of solar-terrestrial relations. The basis of the technique are coupling function...
In order to develop methods for space weather forecasting, the dynamics of fluctuations (variations with periods from several minutes to 2-3 hours) of the intensity of galactic cosmic rays (CR) during the events of strong geomagnetic storms on February 26 and March 23, 2023, which are characterized by the values Dst < -100 nT. To do this, we use 1-minute pressure-corrected registration data...
The BECQUEREL experiment is aimed at solving topical problems in nuclear clustering physics [1]. The used method of nuclear track emulsion (NTE) makes it possible, due to its unique sensitivity and spatial resolution, to study in a unified approach multiple final states arising in dissociation of relativistic nuclei. The ideas about nuclear clustering obtained in high-energy physics are...
Search for gamma rays with energies ≥ 300 TeV was being performed at the Carpet-2 array at the INR RAS Baksan Neutrino Observatory from 2018 to 2022. We analyzed the spectra of gamma-like events from the Milky Way region and compared it with the rest of the sky. In addition, we studied several Galactic point sources, in particular those detected by LHAASO. The results of the searches will be...
