arXiv subjects

K. G. Kompaniets

Publications and source records attributed to K. G. Kompaniets.

15 recordsLinked to original sources

arXiv2025

Energy spectrum and mass composition of the primary cosmic rays based on the intensity of muon bundles detected in the NEVOD-DECOR experiment

The results of the analysis of the NEVOD-DECOR data on the study of inclined muon bundles (with zenith angles from 40 to 85 degrees) of cosmic rays for the period from 2012 to 2023 are presented. An original method for studying the muon component of extensive air showers, local muon density spectra, was used. The data are compared with the calculations based on the simulation of air showers using the CORSIKA program for different models of hadronic interactions. The estimates of the energy spectrum and the behavior of the mass composition of primary cosmic rays in a wide energy range from 2 PeV to 3 EeV were obtained. They are compared with the data of other experiments.

astro-ph.HE↗

arXiv2024

Four years of wide-field search for nanosecond optical transients with the TAIGA-HiSCORE Cherenkov array

It has been previously demonstrated [Panov et al. Physics of Atomic Nuclei 84(2021)1037] that the TAIGA-HiSCORE Cherenkov array, originally built for cosmic ray physics and ultrahigh-energy gamma-ray astronomy studies using the extensive air shower method, can be used in conventional optical astronomy for wide-field searches for rare nanosecond optical transients of astrophysical origin. The FOV of the facility is on the scale of 1~ster, and it is capable of detecting very rare transients in the visible light range with fluxes greater than approximately 3000~quanta/m$^2$/10~ns (10~ns is the apparatus integration time) and pulse durations of 10\,ns. Among the potential sources of distant nanosecond optical transients are the evaporation of primary black holes, magnetic reconnection in the accretion disks of black holes, and signals from distant lasers of extraterrestrial civilizations. The paper describes the methods and results of the search for optical transients using the TAIGA-HiSCORE Cherenkov array from 2018 to 2022 (four winter seasons of data collection). No reliable astrophysical candidates for optical transients were found. We set an upper bound on the flux of the searched events as $\sim 1\times10^{-3}$\,events/ster/h.

astro-ph.IM↗

arXiv2023

Calibration of the NEVOD-EAS array for detection of extensive air showers

In this paper we discuss the calibration of the NEVOD-EAS array which is a part of the Experimental Complex NEVOD, as well as the results of studying the response features of its scintillation detectors. We present the results of the detectors energy calibration, performed by comparing their response to different types of particles obtained experimentally and simulated with the Geant4 software package, as well as of the measurements of their timing resolution. We also discuss the results of studies of the light collection non-uniformity of the NEVOD-EAS detectors and of the accuracy of air-shower arrival direction reconstruction, which have been performed using other facilities of the Experimental Complex NEVOD: the muon hodoscope URAGAN and the coordinate-tracking detector DECOR.

astro-ph.IM↗

arXiv2022

Cosmic ray anisotropy study by means of detection of muon bundles

In this work, we use muon bundles which are formed in extensive air showers and detected at the ground level as a tool for searching anisotropy of high energy cosmic rays. Such choice is explained by the penetrating ability of muons which allows them to retain the direction of primary particles with a good accuracy. In 2012-2022, we performed long-term muon bundle detection with the coordinate-tracking detector DECOR, which is a part of the Experimental complex NEVOD (MEPhI, Moscow). To search for the cosmic rays anisotropy, the muon bundles arriving at zenith angles in the range from 15 to 75 degrees in the local coordinate system are used. During the entire period of data taking, about 14 million of such events have been accumulated. In this paper, we describe some methods developed in the Experimental complex NEVOD and implemented in our research, including: the method for compensating the influence of meteorological conditions on the intensity of muon bundles at the Earth's surface, the method for accounting the design features of the detector and the inhomogeneity of the detection efficiency for different directions, as well as the method for estimating primary energies of cosmic rays. Here we present the results of the search for the dipole anisotropy of cosmic rays with energies in the PeV region and also compare them with the results obtained at the other scientific facilities.

astro-ph.HE↗

arXiv2022

Muon puzzle in inclined muon bundles detected by NEVOD-DECOR

The data of cosmic ray NEVOD-DECOR experiment on the investigation of inclined muon bundles for a long time period (May 2012 - March 2021) are presented. The analysis showed that the observed intensity of muon bundles at primary cosmic ray energies of about 1 EeV and higher can be compatible with the expectation in frame of widely used hadron interaction models only under the assumption of an extremely heavy mass composition. This conclusion is consistent with data of several experiments on investigations of muon content in air showers, but contradicts the available fluorescence data on Xmax which favor a light mass composition at these energies. In order to clarify the nature of the "muon puzzle", investigations of the muon bundle energy deposit in the detector material were carried out. For the first time, experimental estimates of the average energy of muons in the bundles of inclined air showers initiated by primary particles with energies from 10 to 1000 PeV have been obtained.

astro-ph.HE↗

arXiv2021

Search for Astrophysical Nanosecond Optical Transients with TAIGA-HiSCORE Array

A wide-angle Cerenkov array TAIGA-HiSCORE (FOV $\sim$0.6 sr), was originally created as a part of TAIGA installation for high-energy gamma-ray astronomy and cosmic ray physics. Array now consist on nearly 100 optical stations on the area of 1 km$^2$. Due to high accuracy and stability ($\sim$1 ns) of time synchronization of the optical stations the accuracy of EAS arrival direction reconstruction is reached 0.1$^\mathrm{o}$. It was proven that the array can also be used to search for nanosecond events of the optical range. The report discusses the method of searching for optical transients using the HiSCORE array and demonstrates its performance on a real example of detecting signals from an artificial Earth satellite. The search for this short flares in the HiSCORE data of the winter season 2018--2019 is carried out. One candidate for double repeater has been detected, but the estimated probability of random simulation of such a transient by background EAS events is not less than 10%, which does not allow us to say that the detected candidate corresponds to a real astrophysical transient. An upper bound on the frequency of optical spikes with flux density of more than $10^{-4} \mathrm{erg/s/cm}^2$ and a duration of more than 5\,ns is established as $\sim 2 \times 10^{-3}$ events/sr/hour.

astro-ph.IM↗

arXiv2021

The NEVOD-EAS air-shower array

The Experimental complex NEVOD includes several different setups for studying various components of extensive air showers (EAS) in the energy range from 10^10 to 10^18 eV. The NEVOD-EAS array for detection of the EAS electron-photon component began its data taking in 2018. It is a distributed system of scintillation detectors installed over an area of about 10^4 m^2. A distinctive feature of this array is its cluster organization with different-altitude layout of the detecting elements. The main goal of the NEVOD-EAS array is to obtain an estimation of the primary particle energy for events measured by various detectors of the Experimental complex NEVOD. This paper describes the design, operation principles and data processing of the NEVOD-EAS array. The criteria for the event selection and the accuracy of the EAS parameters reconstruction obtained on the simulated events are discussed. The results of the preliminary analysis of experimental data obtained during a half-year operation are presented.

astro-ph.IM↗

arXiv2017

The second knee observed in the local muon density spectra at various zenith angles

Local muon density spectra (LMDS) at various zenith angles have been reconstructed from the data of two detectors of the Experimental complex NEVOD. The inclined muon bundles at the ground level were detected with the coordinate detector DECOR, and for the near-vertical direction with the calibration telescope system (CTS) of the Cherenkov water detector. In comparison with the earlier DECOR results, the experimental statistics has been increased by 2-3 times for different ranges of zenith angle and muon bundle multiplicity and is now based on about 40,000 h of the setup operation. The live time of measurements with CTS is about 12,000 h. It is found with both setups that the slope of LMDS is increasing above the primary energy of about 1017 eV. The details of the experiment and data analysis are presented.

astro-ph.HE↗

arXiv2017

Energy spectrum of cascade showers generated by cosmic ray muons in water

The spatial distribution of Cherenkov radiation from cascade showers generated by muons in water has been measured with Cherenkov water calorimeter (CWC) NEVOD. This result allowed to improve the techniques of treating cascade showers with unknown axes by means of CWC response analysis. The techniques of selecting the events with high energy cascade showers and reconstructing their parameters are discussed. Preliminary results of measurements of the spectrum of cascade showers in the energy range 100 GeV - 20 TeV generated by cosmic ray muons at large zenith angles and their comparison with expectation are presented.

astro-ph.HE↗

arXiv2017

Results of measurements of the flux of albedo muons with NEVOD-DECOR experimental complex

Results of investigations of the near-horizontal muons in the range of zenith angles of 85-95 degrees are presented. In this range, so-called "albedo" muons (atmospheric muons scattered in the ground into the upper hemisphere) are detected. Albedo muons are one of the main sources of the background in neutrino experiments. Experimental data of two series of measurements conducted at the experimental complex NEVOD-DECOR with the duration of about 30 thousand hours "live" time are analyzed. The results of measurements of the muon flux intensity are compared with simulation results using Monte-Carlo on the basis of two multiple Coulomb scattering models: model of point-like nuclei and model taking into account finite size of nuclei.

astro-ph.HE↗

arXiv2016

Detection of extensive air showers with the NEVOD-EAS cluster type detector

A new cluster type shower array NEVOD-EAS is designed for estimating the size, axis position and arrival direction of extensive air showers registered by the Cherenkov water detector NEVOD and coordinate detector DECOR (Moscow, Russia). In 2015-2016, the central part of the array was deployed and started its operation. It includes 4 independent clusters of scintillation detector stations located around the NEVOD-DECOR experimental complex on the area of about $10^{4} m^{2}$. This article presents the results of studying amplitude and timing characteristics of the array clusters which are critical for EAS parameters reconstruction, as well as the examples of registered events.

astro-ph.IM↗

arXiv2016

Energy characteristics of multi-muon events in a wide range of zenith angles

Change of the energy characteristics of muon bundles with an increase of the primary cosmic ray particles energy can be a key to solving the problem of muon excess in the extensive air showers (EAS) observed in a number of experiments. In this work the data on the energy deposit of multi-muon events in a wide range of zenith angles (and as a consequence in a wide range of primary particles energies) obtained with NEVOD-DECOR setup over a long time period are presented. The experimental data are compared with the results of simulations of EAS muon component performed using CORSIKA code.

astro-ph.IM↗

arXiv2007

Ultra-high energy cosmic ray investigations by means of EAS muon density measurements

A new approach to investigations of ultra-high energy cosmic rays based on the ground-level measurements of the spectra of local density of EAS muons at various zenith angles is considered. Basic features of the local muon density phenomenology are illustrated using a simple semi-analytical model. It is shown that muon density spectra are sensitive to the spectrum slope, primary composition, and to the features of hadronic interaction. New experimental data on muon bundles at zenith angles from 30 degrees to horizon obtained with the coordinate detector DECOR are compared with CORSIKA-based simulations. It is found that measurements of muon density spectra in inclined EAS give possibility to study characteristics of primary cosmic ray flux in a very wide energy range from 10^15 to 10^19 eV.

astro-ph↗

arXiv2007

Study of Forbush effects by means of muon hodoscopes

Muon rate variations during Forbush effects registered by means of muon detectors DECOR, TEMP and URAGAN operated in the experimental complex NEVOD (MEPhI, Moscow) have been studied, and comparative analysis with neutron monitor data has been performed. The ratio of values of Forbush decreases in muon and in neutron fluxes is about one third, and preliminary rigidity dependence of Forbush decrease amplitude using muon data has been also obtained (for 2.4 GV cut-off rigidity). The detection of muon flux in the hodoscopic mode allows to study the dynamics of muon flux anisotropy related with magnetic field perturbations. Results of analysis of data from the new unique muon detector URAGAN indicate the change of muon flux asymmetry direction during the Forbush decrease. This phenomenon is related with the motion of solar plasma cloud and hodoscope acceptance cone relative to each other.

astro-ph↗

arXiv2006

Measurements of integral muon intensity at large zenith angles

High-statistics data on near-horizontal muons collected with Russian-Italian coordinate detector DECOR are analyzed. Precise measurements of muon angular distributions in zenith angle interval from 60 to 90 degrees have been performed. In total, more than 20 million muons are selected. Dependences of the absolute integral muon intensity on zenith angle for several threshold energies ranging from 1.7 GeV to 7.2 GeV are derived. Results for this region of zenith angles and threshold energies have been obtained for the first time. The dependence of integral intensity on zenith angle and threshold energy is well fitted by a simple analytical formula.

hep-ex↗